MBRX

Positive interim MIRACLE data showed complete remission rates three times higher than control in relapsed/refractory AML MIRACLE trial advancing toward planned 90-patient enrollment milestone in September 2026 with the unblinded efficacy readout in December 2026 to February 2027 timeframe MIRACLE trial Part B initiation expected in the first half of 2027 following optimal dose selection Cash position, including $9.3 million raised after quarter-end, expected to fund operations into the first quarter of 2027 Absence of cardiotoxicity continues in the MIRACLE trial HOUSTON, Aug. 14, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today reported financial results for the second quarter ended June 30, 2026, and highlighted continued progress in its pivotal Phase 2/3 MIRACLE trial evaluating Annamycin in relapsed or refractory acute myeloid leukemia (AML). Moleculin continues to advance the pivotal Phase 2/3 MIRACLE trial following positive preliminary unblinded efficacy results from the first 45 patients enrolled in Part A, which showed complete remission rates at least three times greater than the control arm. Enrollment remains on track to reach the 90-patient milestone in September with the data readout in the December 2026 to February 2027 timeframe. These data are expected to support selection of the optimal Annamycin dose and the planned initiation of Part B in the first half of 2027. Walter Klemp, Chairman and Chief Executive Officer of Moleculin, commented, “In addition to the positive interim MIRACLE results, we are just as excited by the feedback we are receiving from investigators about Annamycin and their enthusiasm for participating in the study. Their response reflects both the significant unmet need in relapsed or refractory AML and growing recognition of Annamycin’s potential, with its encouraging data generated to date and differentiated cardiac safety profile, to play an important role in the treatment landscape. As we advance toward the 90-patient milestone and next unblinded efficacy readout, this strong investigator engagement adds to our confidence in the program and the potential for Annamycin to meaningfully improve outcomes for patients.” Recent Highlights Reported positive interim results from the Phase 2/3 MIRACLE trial, with both Annamycin treatment arms demonstrating complete remission (CR) rates at least three times higher than the control arm in patients with relapsed or refractory AML. The interim analysis demonstrated a clear efficacy advantage for both Annamycin treatment arms, 190 mg/m² plus cytarabine and 230 mg/m² plus cytarabine, over the cytarabine control arm. CR reached 43% and 36% in the respective Annamycin cohorts, compared with 12% for control, while composite complete remission (CRc) reached 50% and 57%, respectively, versus 29% for the control arm. The n=45 population contained 75.6% over 60 years of age, 55.6% 7+3 and 31.1% venetoclax regimens for first line (1L) therapies. Announced independent market research indicating strong physician intent to prescribe Annamycin based on its potential efficacy, transplant-bridging potential and favorable cardiac safety profile. Presented data at the 2026 ASCO Annual Meeting demonstrating no detectable cardiotoxicity with Annamycin despite cumulative exposure levels exceeding conventional anthracycline limits, further supporting its differentiated safety profile. Chairman and Chief Executive Officer Walter Klemp discussed the positive preliminary MIRACLE interim results during a Virtual Investor "What This Means" segment, providing additional context on the Company's clinical progress and anticipated next milestones. Enrollment continued in Part A of the MIRACLE trial, with more than 80% of the planned 90 patients enrolled as of the interim analysis. Cash on hand and cash equivalents as of June 30, 2026, together with $9.3 million in financing proceeds raised subsequent to the quarter, expected to support planned operations into the first quarter of 2027. Clinical Development Update Annamycin - MIRACLE TrialMoleculin continues to advance the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial, a pivotal adaptive-design Phase 2/3 study evaluating Annamycin in combination with cytarabine (AnnAraC) for the treatment of adults with relapsed or refractory acute myeloid leukemia. During the second quarter, the Company reported positive preliminary unblinded efficacy results from the first 45 patients enrolled in Part A of the trial. Both Annamycin treatment arms demonstrated substantially higher complete remission rates than the control arm, while maintaining the encouraging safety profile previously observed in clinical studies. Activity in the MIRACLE trial continues to demonstrate no evidence of cardiotoxicity. The Company continues to enroll patients in Part A and expects to use these data to select the optimal dose for advancement into Part B. Expected Milestones for the Annamycin Development Program September 2026: Completion of enrollment in Part A of MIRACLE December 2026 to February 2027 timeframe: MIRACLE – data unblinding for Part A 90 subjects completed 2H 2026: Atlantic Health pancreatic cancer clinical trial begins 1H 2027: MIRACLE – Start of Part B 2027: Begin 3rd line R/R AML subject trial 2027: Begin pediatric AML clinical study 2028: End recruitment of Part B 2028: Primary efficacy data for MIRACLE 2nd line subjects 2028: Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE 2029: NDA submission complete Additional Pipeline Programs Moleculin continues to support development activities for WP1066 through investigator-sponsored and externally funded studies, while maintaining its focus on advancing Annamycin as the Company's lead clinical program. Second Quarter 2026 Financial Results Research and development expenses were $5.5 million and $3.6 million for the three months ended June 30, 2026 and 2025, respectively. The increase of $1.9 million is mainly related to the MIRACLE clinical trial of $1.1 million, additional nonclinical studies of $0.4 million, and $0.4 million in other research costs during the current quarter as compared to the prior year quarter. General and administrative expenses for the quarter ended June 30, 2026 were approximately $2.1 million, compared with approximately $2.1 million for the same period in 2025. As of June 30, 2026, the Company had cash and cash equivalents of approximately $7.3 million. Management believes that its cash on hand and cash equivalents as of June 30, 2026, together with $9.3 million in financing proceeds raised subsequent to the quarter, will support planned operations into the first quarter of 2027. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical-stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation, highly efficacious and well-tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive-design Phase 2/3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA and the EMA, the Company believes it has substantially de-risked the development pathway toward a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, statements regarding the progress and outcome of clinical trials, including the continued recruitment, treatment, and receipt of the unblinded data for the 90 subjects in Part A of the MIRACLE clinical trial as described, the interpretation of preliminary blinded data and subgroup analyses, the potential for regulatory approval for Annamycin, the timing of future milestones, the Company’s expectations regarding its cash runway and the sufficiency of its capital resources to fund planned operations into the first quarter of 2027, and the Company’s ability to secure necessary financing. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact:JTC Team, LLCJenene Thomas(908) [email protected]

Access the segment here HOUSTON, July 06, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today announced that Walter Klemp, Chairman and Chief Executive Officer of Moleculin, participated in a Virtual Investor “What This Means” segment. For the segment, Chairman and CEO Wally Klemp discusses the positive preliminary unblinded efficacy results from the first 45 patients enrolled in Part A of the pivotal Phase 2/3 MIRACLE trial evaluating Annamycin in relapsed or refractory acute myeloid leukemia (R/R AML). During the conversation, Mr. Klemp provides his perspective on the significance of the early efficacy trends observed across both Annamycin treatment arms, summarizes the key data, and discusses the commercial opportunity, including insights from the Company's recent market research assessing the potential addressable market for Annamycin if approved. The segment is now available for on-demand viewing here. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin (also known as naxtarubicin), is a highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design, multi-center, randomized, double-blind, placebo-controlled Phase 2/3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”) for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the potential efficacy and safety of Annamycin and AnnAraC in R/R AML and the expectation that interim efficacy trends observed in a limited patient population will be confirmed in the full study population (the interim results presented are based on a small sample size (n=45), have not achieved statistical significance, and may not be predictive of results from the completed trial). Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. The Company relies on the reports of its expert with regard to the absence of cardiotoxicity. The dataset referenced in this press release is subject to the review of the data from future subjects in its current and future clinical trials and long-term follow-up with subjects in its current trials. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact:JTC Team, LLCJenene Thomas(908) [email protected]

Moleculin Biotech, Inc. Both Annamycin dose arms outperformed control on the primary endpoint of complete remission (CR): 43% and 36% versus 12% — reported on a full intent-to-treat (ITT) basis with no patient exclusions Composite complete remission (CRc) reached 50% and 57% in the respective Annamycin arms versus 29% for control Enrollment in the MIRACLE trial continues with more than two-thirds (67 of 90 subjects) of Part A target as Company advances toward optimal dose selection HOUSTON, June 30, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today announced positive preliminary unblinded efficacy results from the first 45 patients enrolled in Part A of the Company's pivotal Phase 2/3 MIRACLE trial, analyzed on a full intent-to-treat basis with no patient exclusions. Both Annamycin treatment arms demonstrated favorable efficacy trends compared with the control arm in patients with relapsed or refractory acute myeloid leukemia (R/R AML). The interim analysis demonstrated a clear efficacy advantage for both Annamycin treatment arms, 190 mg/m² plus HiDAC and 230 mg/m² plus HiDAC, over the HiDAC control arm. CR reached 43% and 36% in the respective Annamycin cohorts, compared with 12% for control, while CRc reached 50% and 57%, respectively, versus 29% for the control arm. The n=45 population contained 75.6% over 60 years of age, 55.6% 7+3 and 31.1% venetoclax regimens for first line (1L) therapies. Importantly, the remission rates for all three arms, including the control arm, reflect outcomes measured after only a single cycle of therapy, as specified by the MIRACLE protocol. The most commonly cited historical benchmarks in this setting, including the MIRROS and CLASSIC I studies, as well as Moleculin’s own MB-106 study, permitted multiple cycles of treatment. The Company therefore expected absolute remission rates for both the control and Annamycin arms in this single-cycle interim analysis to be lower than those reported in such multi-cycle datasets and believes the most meaningful comparison is the performance of the Annamycin arms relative to the concurrent, randomized control arm evaluated on the same single-cycle basis. "These interim Phase 2/3 results on such a challenging subject population represent a defining moment for Moleculin and, we believe, the strongest clinical validation of Annamycin we have seen to date," said Walter Klemp, Chairman and Chief Executive Officer of Moleculin. "To see both Annamycin dose arms meaningfully outperform the control arm across both the primary endpoint of complete remission as well as composite complete remission in patients with relapsed or refractory AML is an exceptional outcome. Importantly, these responses were achieved after only a single treatment cycle, providing what we believe is compelling evidence of Annamycin's anti-leukemic activity. We believe these results further validate Annamycin's differentiated profile and strengthen our confidence as we advance the MIRACLE trial toward completion." "From a clinical perspective, these interim results are highly encouraging," Mr. Klemp continued. "Historically, achieving meaningful remission rates in relapsed or refractory AML has been exceptionally difficult, especially with subjects pretreated with venetoclax, which is why seeing both Annamycin treatment arms outperform the control arm across both efficacy endpoints is so noteworthy. The remission rates observed to date are particularly compelling when viewed in the context of outcomes historically reported for currently available therapies in this setting, especially given that patients in MIRACLE were evaluated after only a single treatment cycle. While cross-trial comparisons should be made with caution, these findings suggest the potential for a level of clinical activity that could meaningfully advance the treatment landscape for patients with relapsed or refractory AML. If these results continue to be observed as the trial progresses, Annamycin could represent an important new option for patients facing a disease with substantial unmet medical need." The interim review was conducted by the trial's Independent Data Monitoring Committee (iDMC). The committee unanimously concluded that for the primary efficacy endpoint of CR rates, although there was no statistical significance, there was a strong numeric trend suggesting that the experimental treatment arms (L-Annamycin at one of two doses plus high dose cytarabine) were superior to the placebo plus high dose cytarabine control arm. To that end, there was sufficient evidence of efficacy to support continuing the trial. The committee also concluded that the data did not support dropping either of the two experimental treatment arms since the efficacy data were too similar between these two treatment arms. The Company decided to accept the recommendation of the iDMC and continue with the MIRACLE trial as planned. The absence of formal statistical significance at this first interim analysis reflects the trial’s prespecified statistical design, not the strength of the data. As in most group-sequential studies, MIRACLE distributes its statistical “budget” across three planned analyses using a conservative O’Brien-Fleming spending function, which by design sets a very high bar for significance at an early interim look and reserves essentially the entire budget for the final analysis in the full population of approximately 282 subjects. Statistical significance was therefore neither expected nor required at this stage; the relevant question at an interim look is the direction and strength of the efficacy trend, which the iDMC found clearly favored both Annamycin arms over control. The trial remains fully powered, at 80%, to establish statistical significance at its planned final analysis (calculated to detect 20% vs. 35% CR for control vs. test, respectively). The MIRACLE trial is a pivotal Phase 2/3, multi-center, randomized, double-blind, placebo-controlled, adaptive design study of L-Annamycin for injection in combination with Cytarabine injection versus placebo in combination with Cytarabine injection as second line therapy for remission induction in adult subjects with R/R AML. Part A of the study is designed to identify the optimal Annamycin dose before advancing into the pivotal portion of the trial. Moleculin reported that 67 of the targeted 90 patients for Part A have been enrolled, representing approximately 74% of the planned enrollment. Following completion of Part A, the selected dose arm is expected to advance into Part B, where efficacy data from Part A will be carried forward into the pivotal analysis. Acute myeloid leukemia remains an area of significant unmet medical need, particularly among patients who relapse after frontline therapy. Moleculin believes the preliminary MIRACLE results further support Annamycin's potential to improve remission outcomes in this patient population and strengthen the rationale for the program's continued advancement toward registration. The interim results related to efficacy are final and other data remain subject to Part A final database review and readout. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin (also known as naxtarubicin), is a highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design, multi-center, randomized, double-blind, placebo-controlled Phase 2/3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”) for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the potential efficacy and safety of Annamycin and AnnAraC in R/R AML and the expectation that interim efficacy trends observed in a limited patient population will be confirmed in the full study population (the interim results presented are based on a small sample size (n=45), have not achieved statistical significance, and may not be predictive of results from the completed trial). Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. The Company relies on the reports of its expert with regard to the absence of cardiotoxicity. The dataset referenced in this press release is subject to the review of the data from future subjects in its current and future clinical trials and long-term follow-up with subjects in its current trials. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact:JTC Team, LLCJenene Thomas(908) [email protected] Attachment Moleculin Biotech, Inc.

Early blinded results show 40% composite complete remission rate across difficult-to-treat AML patient population in MIRACLE Trial First interim unblinding expected in June 2026 following 45 subject enrollment milestone achieved in MIRACLE trial Enrollment in MIRACLE trial continues to advance on pace with 90th subject expected in Q3 2026 HOUSTON, May 15, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today reported financial results for the first quarter ended March 31, 2026 and provided a corporate update. “With enrollment now surpassing the first interim analysis threshold in the MIRACLE trial, we are just weeks away from beginning what we believe will be the most transformative period in the Company’s history. The impressive preliminary blinded remission data trend we reported earlier this year continues with the 45 subject blinded data. This trend supports our belief in Annamycin’s potential to meaningfully improve outcomes for patients with relapsed or refractory AML,” said Walter Klemp, Chairman and Chief Executive Officer of Moleculin. “We also believe Annamycin has the potential to redefine the anthracycline class by addressing one of the most significant limitations of these foundational therapies, cardiotoxicity, while potentially expanding access to treatment options for patients who otherwise may not be eligible for standard anthracycline-based therapy due to current life-time dose limits,” Mr. Klemp added. Recent Highlights Achieved enrollment of the first 45 subjects in the pivotal MIRACLE Phase 2B/3 trial evaluating Annamycin in combination with cytarabine (“AnnAraC”) for the treatment of relapsed/refractory acute myeloid leukemia (AML) Continued to observe encouraging blinded efficacy trends in the MIRACLE trial, including a previously reported preliminary blinded composite complete remission (CRc) rate of 40% at the first 30 subjects treated mark and also at the 45th subject mark Completed financing transactions during the first quarter of 2026 resulting in approximately $8.3 million in gross proceeds, strengthening the Company’s near-term operating runway Continued expansion of clinical trial operations across the United States and Europe to support accelerated enrollment and future development activities Bolstered global intellectual property strategy for Annamycin, now covering four continents Clinical Development Update Annamycin – MIRACLE Trial Moleculin continues to advance the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) trial, a pivotal adaptive-design Phase 3 study evaluating AnnAraC in adult patients with relapsed or refractory AML. Expected Milestones for Annamycin Development Program Q2 2026: MIRACLE – Unblinding of data for 45 subjects Q3 2026: MIRACLE – Part A 90 subjects recruited and unblinding thereafter 2H 2026: MIRACLE – Start of Part B 2H 2026: Atlantic Health pancreatic cancer clinical trial begins 2027: Begin recruitment of 3rd line AML subjects 2027: Begin pediatric AML clinical study 2028: End recruitment of Part B 2028: Primary efficacy data for MIRACLE 2nd line subjects 2028: Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE Additional Pipeline Programs Moleculin continues to support externally funded and investigator-sponsored studies involving WP1066 and other pipeline candidates targeting difficult-to-treat cancers and viral diseases. First Quarter 2026 Financial Results Research and development expenses for the three months ended March 31, 2026 and 2025 were $5.4 million and $3.4 million, respectively. The increase of $2.0 million is mainly related to the MIRACLE clinical trials in Europe of $1.4 million, additional nonclinical studies of $0.3 million and other research costs during the current quarter as compared to the prior year quarter. General and administrative expenses for the quarter ended March 31, 2026 were approximately $2.5 million, compared with $2.5 million for the same period in 2025. As of March 31, 2026, the Company had cash and cash equivalents of approximately $10.3 million. Management believes current cash resources, together with recent financing proceeds, will support planned operations into the third quarter of 2026. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin (also known as naxtarubicin), is a highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”), for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the expected timing and results of the 45-subject interim data unblinding in the MIRACLE trial, the anticipated clinical milestones set forth above, the potential efficacy and safety of Annamycin and AnnAraC in R/R AML and other indications, the expected commencement and results of the pancreatic cancer and other investigator-initiated studies, the Company's ability to secure sufficient financing to fund planned operations, and the Company's expectations regarding the sufficiency of its cash resources into the third quarter of 2026. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. The Company relies on the reports of its expert with regard to the absence of cardiotoxicity. The dataset referenced in this press release is subject to the review of the data from future subjects in its current and future clinical trials and long-term follow-up with subjects in its current trials. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected] Moleculin Biotech, Inc. Unaudited Condensed Consolidated Balance Sheets Unaudited Condensed Consolidated Statements of Operations

Miracle Trial Preliminary Blinded CRc Rate of 40% in First 30 Patients Suggests Encouraging Early Results in Relapsed/Refractory AML HOUSTON, March 19, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today reported financial results for the year ended December 31, 2025 and provided a clinical update highlighting rapid progress toward a major upcoming milestone in its pivotal MIRACLE trial of Annamycin in combination with cytarabine for the treatment of adult patients with acute myeloid leukemia (AML) who are refractory to or relapsed (R/R) after induction therapy (R/R AML). “With the MIRACLE trial rapidly progressing and the first MIRACLE interim readout now clearly within reach, we believe 2026 will be a defining year for Moleculin,” said Walter Klemp, Chairman and CEO of Moleculin. “The encouraging blinded efficacy data seen so far, particularly in a pretreated population that includes venetoclax failures, reinforces our belief that Annamycin has the potential to represent a significant advancement in AML therapy.” Recent Highlights Reported (n=30) MIRACLE Trial delivered 40% preliminary blinded CRc rate; Received a new independent assessment for the absence of cardiotoxicity in subjects treated with Annamycin, bringing the total number of Annamycin treated subjects reviewed by its independent expert to 90; Entered a new Annamycin research collaboration focused on glioblastoma multiforme (GBM) with CIC biomaGUNE to evaluate intra‑arterial delivery of Annamycin in preclinical models; Announced positive results from a Phase 1 clinical trial of WP1066 in pediatric recurrent malignant brain tumors, showing safety and signs of antitumor immune responses and supporting potential progression to Phase 2; Announced a grant-funded preclinical research agreement with the University of North Carolina at Chapel Hill to evaluate Annamycin for pancreatic cancer treatment; and Announced a targeted new investigator-initiated Phase 1B/2 study of Annamycin in third-line pancreatic cancer with Atlantic Health, based on preclinical data suggesting activity in advanced pancreatic tumors. Clinical Development Update Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) The Company is currently evaluating Annamycin in combination with cytarabine (Ara-C), collectively referred to as AnnAraC, in its pivotal Phase 3 “MIRACLE” trial for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (R/R AML) following induction therapy. The MIRACLE trial is a global, adaptive Phase 2B/3 clinical study being conducted across the United States, Europe, and other international sites. The study’s adaptive design will integrate data from the ongoing Phase 2B portion (i.e., Part A) with the eventual Phase 3 portion (i.e., Part B). In Part A, approximately 75 to 90 subjects are randomized in a 1:1:1 ratio to receive high-dose cytarabine (HiDAC) combined with either placebo, 190 mg/m² Annamycin, or 230 mg/m² Annamycin. These Annamycin doses were selected based on recommendations from the FDA during the Company’s End-of-Phase 2 meeting. The protocol allows for early unblinding of data at 45 subjects, enabling an initial readout of approximately 30 subjects treated with Annamycin plus cytarabine and 15 subjects in the control arm receiving cytarabine plus placebo. This initial unblinding is expected in mid-2026, following completion of treatment for the first 45 patients. In February 2026, Moleculin reported a blinded preliminary composite complete remission (CRc) rate of 40% in the MIRACLE trial’s first 30 subjects treated and with blinded, preliminary efficacy data. This CRc rate is comprised of a complete remission (CR) rate of 30% and complete remission with partial hematological recovery (CRh) of 10%. MIRACLE is randomizing 1:1:1 of the three different arms described above. This includes the control arm of cytarabine plus placebo. Even with the control arm included, these preliminary, blinded results substantially outperform historical outcomes for CR with cytarabine alone in the treatment of R/R AML. Of particular note is that roughly 35% of the subjects treated to date are relapsed or refractory (R/R) from a venetoclax regimen, a subject population that is generally considered among the most challenging to address with 2nd line therapies. The subjects treated to date presented with a high degree of genetic markers that are considered predictive of poor treatment response. These efficacy rates were observed across six different countries. For Part B of the trial, 222 additional subjects will be randomized to receive either HiDAC plus placebo or HiDAC plus the optimum dose of Annamycin (randomized 1:1). The selection of the optimum dose will be based on the overall balance of safety, pharmacokinetics and efficacy, consistent with the FDA’s new Project Optimus initiative. Data from the control arm and the optimum dose of Annamycin chosen in the Phase 2B portion of the trial will be combined with the data for the Phase 3 portion of the trial in determining efficacy and safety for the trial. For additional information, the MIRACLE trial is registered on ClinicalTrials.gov under identifier NCT06788756. Expected Milestones for Annamycin AML Development Program Q1 2026: MIRACLE - 45th subject treated with unblinding of data for 45 subjects expected in mid-2026 Q3 2026: MIRACLE - 90 subjects treated and unblinding thereafter 2H 2026: MIRACLE - Start of Part B 2H 2026: Atlantic Health pancreatic cancer clinical trial begins 2027: Begin recruitment of 3rd line AML subjects 2027: Begin pediatric AML clinical study 2028: End recruitment of Part B 2028: Primary efficacy data for MIRACLE 2nd line subjects 2028: Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE Soft Tissue Sarcoma (STS Lung Metastases) Program Moleculin’s Phase 1B/2 trial of Annamycin for soft tissue sarcoma lung metastases demonstrated: Median overall survival of 13.5 months Achieved in a median seventh-line therapy population These results compare favorably with historical outcomes in earlier-line therapies. Pancreatic Cancer Program An investigator-initiated Phase 1B/2 study evaluating Annamycin for third-line pancreatic cancer is expected to begin in 2026. Preclinical research suggests Annamycin may have particular activity in pancreatic tumors due to its ability to concentrate in pancreatic tissue. WP1066 Program The Company’s STAT3-inhibiting immunomodulator WP1066 continues to advance through investigator-initiated clinical studies targeting glioblastoma and pediatric brain tumors. Moleculin expects several important milestones in the coming months. Summary of Financial Results for the Full Year 2025 Research and development (R&D) expense was $15.9 million and $17.7 million for the years ended December 31, 2025 and 2024, respectively. The decrease in R&D of $1.8 million is primarily attributable to a reduction in sponsored research activities during the current year compared to the prior year. General and administrative (G&A) expenses and depreciation and amortization expenses were $9.2 million and $8.9 million for the years ended December 31, 2025 and 2024, respectively. The increase in G&A of $0.3 million was primarily attributable to higher regulatory and legal services, as well as increased consulting and investor relations expenses. As of December 31, 2025, the Company had cash and cash equivalents of $8.9 million and prepaid expenses and other current assets of $0.8 million. The Company also had $3.5 million of accounts payable and $3.3 million of accrued expenses and other current liabilities. A significant portion of the accounts payable and accrued expenses were due to work performed in relation to our preclinical activities and our clinical trials. Management believes that cash resources as of December 31, 2025, along with $8.3 million in gross proceeds received via financing activities in the first quarter of 2026 will be sufficient to fund the Company’s planned operations into the third quarter of 2026. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin (also known as naxtarubicin), is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”) and, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the expected timing and results of the 45-subject interim data unblinding in the MIRACLE trial, the anticipated clinical milestones set forth above, the potential efficacy and safety of Annamycin and AnnAraC in R/R AML and other indications, the expected commencement and results of the pancreatic cancer and other investigator-initiated studies, the Company's ability to secure sufficient financing to fund planned operations, and the Company's expectations regarding the sufficiency of its cash resources into the third quarter of 2026. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. The Company relies on the reports of its expert with regard to the absence of cardiotoxicity. The dataset referenced in this press release is subject to the review of the data from future subjects in its current and future clinical trials and long-term follow-up with subjects in its current trials. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected]

Emory University physician-sponsored clinical trial conducted at the Aflac Cancer and Blood Disorders Center at Children’s Healthcare of Atlanta Results demonstrated WP1066 induces anti-tumor immune responses and were recently published in the Journal of Clinical Investigation Insight WP1066 found to be safe and effective, warranting a Phase 2 trial HOUSTON, Dec. 17, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today announced positive results from the Emory University physician-sponsored Phase 1 clinical trial conducted at the Aflac Cancer and Blood Disorders Center at Children’s Healthcare of Atlanta led by pediatric oncologist, Tobey MacDonald, MD, who discovered STAT3 is critical to certain childhood brain tumors and currently serves as Professor of Pediatrics and Director of the Pediatric Neuro-Oncology Program. WP1066 is Moleculin’s flagship Immune/Transcription Modulator designed to stimulate the immune response to tumors by inhibiting the errant activity of regulatory T cells while also inhibiting key oncogenic transcription factors, including p-STAT3 (phosphorylated signal transducer and activator of transcription 3), c-Myc (oncogene driving many aggressive cancers) and HIF-1α (hypoxia-inducible factor 1α). These transcription factors are widely sought targets because of their role in cancer cell survival and proliferation, angiogenesis (coopting vasculature for blood supply), invasion, metastasis, and inflammation associated with tumors. “The results of this first-in-child trial show some encouraging signals of activity in a highly aggressive chemotherapy resistant brain cancer, such as partial tumor response in a diffuse intrinsic pontine glioma (DIPG) patient and clear anti-tumor immune changes,” said Dr. MacDonald. For the Phase 1 trial, 10 children were treated with WP1066 twice daily for 14 days to determine the maximum feasible dose. Compassionate use treatment in three children with high-grade glioma was also evaluated. Results showed there was no significant toxicity, and a maximum feasible dose was determined. Importantly, WP1066 suppressed the expression of STAT3, inhibiting its activity and demonstrating anti-tumor immune responses. While the preclinical efficacy of WP1066 had been previously demonstrated, and its effectiveness had been studied among adults, this trial was the first to test it in children. Dr. MacDonald and his team recruited pediatric patients with high-grade glioma, which include diffuse midline glioma (DMG) and DIPG, and account for most pediatric brain tumor-related deaths. Both DMG and DIPG have an average survival rate of nine to 11 months following diagnosis. Additionally, patients with relapsed medulloblastoma and ependymoma who have no accepted standard therapy following a relapse were also included in the study. Thus, Dr. MacDonald’s research helps fill a critical need to identify new treatment options for patients with these incurable tumors. Mr. Walter Klemp, Chairman and CEO of Moleculin, “We are very encouraged by the positive results from our Phase 1 clinical trial evaluating WP1066 in children with recurrent malignant brain tumors. These early data show that WP1066 has the ability to activate meaningful anti-tumor immune responses, an important proof of mechanism in a patient population with extremely limited treatment options. While still early, these findings reinforce the potential of WP1066 as a novel immunomodulatory approach for some of the most difficult-to-treat pediatric brain cancers. We are deeply grateful to Dr. MacDonald and his team, and the patients and families who participated in this study. We look forward to the continued advancement of WP1066 as a potential therapy that can make a real difference for children facing these devastating diseases.” Results from the study were recently published in the Journal of Clinical Investigation Insight. For more information about the WP1066 Phase 1 clinical trial, visit clinicaltrials.gov and reference identifier NCT04334863. The results of this study are the foundation of the Phase 2 concept Dr. MacDonald’s team would like to pursue in a follow-up trial. The current study was funded by Peach Bowl LegACy Fund and CURE Childhood Cancer. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”) and, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, statements regarding the continued recruitment, treatment, and receipt of the unblinded data for the first 45 subjects of the MIRACLE clinical trial and the timing to complete Part A of the MIRACLE trial with up to 90 patients, each as described above. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected]

- Continues recruitment and opens US and EU sites for the Phase 2B/3 MIRACLE trial - 20+ additional clinical sites in Europe and the US expected to begin recruitment by the end of Q3 - Anticipated data readout of MIRACLE Part A targeted before end of 2025 HOUSTON, Aug. 13, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), a late-stage pharmaceutical company with a broad portfolio of drug candidates targeting hard-to-treat cancers and viruses, today reported its financial results for the second quarter ended June 30, 2025. “The second quarter of 2025 marked a period of momentum for Moleculin. We continued to make meaningful progress in our MIRACLE trial, including a significant expansion into a number of countries, positioning ourselves to achieve our enrollment targets and, importantly, reach an expected pivotal data readout before the end of this year. In addition to progress in our AML program, we reported compelling topline data in our Phase 1B/2 soft tissue sarcoma lung metastases (STS lung mets) trial and continue to build a growing body of preclinical and clinical data showcasing the depth and breadth of the potential Annamycin has to treat a range of cancer indications,” commented Walter Klemp, Chairman and Chief Executive Officer of Moleculin. “I am proud of the dedication our team continues to show, and we look forward to building on this progress in the second half of the year and beyond.” Recent Highlights Annamycin for the Treatment of AML Expanded its Phase 2B/3 MIRACLE trial with secured approval from the Regulation Agency for Medical and Pharmaceutical Activities (RAMPA) in Georgia; Four active MIRACLE sites now screening subjects in Ukraine, Georgia, Spain and the US; Expect to add more than 20 additional sites in the European Union (EU) and the US by the end of Q3 2025; and Received positive FDA feedback on pediatric study plan for Annamycin in children with R/R AML, setting the start of that trial in 2027. Other Annamycin Announced the presentation of encouraging preclinical data for Annamycin, which demonstrated significant efficacy against various primary and metastatic liver cancers; Bolstered Annamycin intellectual property portfolio with notice of intent to grant a new European patent; Engaged industry veteran Adriano Treve to explore Annamycin related strategic partnerships; and Reported positive topline efficacy results from U.S. Phase 1B/2 clinical trial evaluating Annamycin for the treatment of STS lung metastases (MB-107). Clinical Development Update Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) The Company is currently evaluating Annamycin in combination with Cytarabine (also known as “Ara-C” and for which the combination of Annamycin and Ara-C is referred to as “AnnAraC”) in a Phase 3 pivotal trial for the treatment of AML patients who are refractory to or relapsed after induction therapy (R/R AML). This Phase 3 “MIRACLE” trial (derived from Moleculin R/R AML AnnAraC Clinical Evaluation) will be global, including sites in the US, Europe and the Middle East. The MIRACLE study is a Phase 2B/3 clinical trial whereby data from the Phase 2B portion will be combined with the Phase 3 portion for purposes of measuring its primary efficacy endpoint. MIRACLE is subject to appropriate future filings with and potential additional feedback from the FDA and their foreign equivalents, and utilizes an adaptive design whereby the first 75 to 90 subjects will be randomized (1:1:1) in Part A of the trial to receive high dose cytarabine (HiDAC) combined with either placebo, 190 mg/m2 of Annamycin, or 230 mg/m2 of Annamycin, which Annamycin doses were specifically recommended by the FDA in the Company’s end of Phase 1B/2 meeting. The protocol for the MIRACLE trial allows for the unblinding of preliminary primary efficacy data (Complete Remission or CR) and safety/tolerability of the three arms at 45 subjects, in addition to the conclusion of Part A (at 75 to 90 subjects). The first early unblinding will yield 30 subjects treated with Annamycin (190mg/m2 and 230 mg/m2) in combination with HiDAC and 15 subjects treated with just HiDAC plus placebo. The Company expects to reach the first unblinding (45 subjects) before the end of 2025, in addition to the second unblinding, which is expected in the first half of 2026. This accelerated estimated timeline is due in part to the positive response the Company received in meetings during December with potential investigators regarding recruitment for the trial. As previously announced regarding the EU, the clinical trial approval with EMA was granted under the condition that the Company present results of appropriate nonclinical GLP studies before initiating the Phase 3 portion (Part B) of the study. Results will be submitted as a substantial modification to the existing approved CTA. For Part B of the trial, approximately 220 additional subjects will be randomized to receive either HiDAC plus placebo or HiDAC plus the optimum dose of Annamycin (randomized 1:1). The selection of the optimum dose will be based on the overall balance of safety, pharmacokinetics and efficacy, consistent with the FDA’s new Project Optimus initiative. Patient dosing has commenced, and the initial data readout is on track for the second half of 2025. For more information about the MIRACLE trial, visit clinicaltrials.gov and reference identifier NCT06788756. Additionally, the clinical trial in the EU is on euclinicaltrials.eu and the reference identifier there is 2024-518359-47-00. Expected Milestones for Annamycin AML Development Program Q3 2025 – Site and recruitment updates for MIRACLE trial Q3 2025 - First patients treated in the US and the EU Q4 2025 – Announcement of 45th subject being recruited and data readout (n=45) unblinded efficacy/safety review Q1 2026 – Impact of data readout (n=45) on regulatory pathway; Recruitment update 1H 2026 – Interim efficacy and safety data (n=~75-90) unblinded and Optimum Dose set for MIRACLE trial 2027 – Begin enrollment of 3rd line subjects in MIRACLE2 2027 – Enrollment ends in 2nd line subjects 2027 - Prepare for the launch of an AML pediatric trial 2028 – Primary efficacy data for 2nd line subjects in MIRACLE 2028 – Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE 2028 – Primary efficacy data for 2nd line subjects Soft Tissue Sarcoma (STS) Lung Metastases As previously announced, the Company reported positive topline efficacy results from its completed U.S. Phase 1B/2 clinical trial evaluating Annamycin for the treatment of STS lung mets (MB-107). The final topline results of MB-107 demonstrated median overall survival (OS) of 13.5 months for subjects as median 7th line therapy (n=36). This compares to OS of 8-12 months for standard of care treatments and 13.4 months for experimental treatments for advanced STS as 2nd line.1 For more information about the MB-107 trial visit clinicaltrials.gov and reference identifier NCT04887298. Expected Milestones for Annamycin STS Lung Mets Development Program Q4 2025 – Identify next phase of development / pivotal IIT (investigator-initiated-trial) program Annamycin, also known by its non-proprietary name of naxtarubicin, currently has Fast Track Status and Orphan Drug Designation from the FDA for the treatment of relapsed or refractory acute myeloid leukemia, in addition to Orphan Drug Designation for the treatment of soft tissue sarcoma. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the EMA. WP1066 & Brain Tumors With regard to the Company’s WP1066 oral formula, the Company has an externally funded Phase 1B/2 in combination with radiation treating glioblastoma (GBM), a form of brain cancer, at Northwestern University (Northwestern) that is actively recruiting. This is an investigator-initiated trial where Moleculin’s main cost is supplying drug product. To date Northwestern has recruited 7 subjects, of which 5 have completed treatment and are undergoing follow-up while 2 continue with treatment. No data has been released. Also, the Company has signed an agreement with Emory University enabling Emory to study various WP1066 IV formulations in preclinical studies with the goal of selecting the best molecule to move into a clinical setting towards, most likely, brain cancers such as GBM. Study drug was delivered in April 2025 to Emory with results from such studies expected in the second half of 2025. Summary of Financial Results for the Second Quarter 2025 Research and development (R&D) expense was $3.6 million and $4.1 million for the three months ended June 30, 2025 and 2024, respectively. The decrease of $0.5 million is mainly related to a reduction in the clinical trials activity. General and administrative expense was $2.1 million each for the three months ended June 30, 2025 and 2024. As of June 30, 2025, the Company had cash and cash equivalents of $7.6 million and believes that the cash on hand is sufficient to fund planned operations into the fourth quarter of 2025. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin is also engaged in the development of a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, statements regarding the clinical trial timelines, potential regulatory approvals, and anticipated milestones. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected] 1 Comandone A, et al; “Salvage Therapy in Advanced Adult Soft Tissue Sarcoma: A Systematic Review and Meta-Analysis of Randomized Trials”; The Oncologist 2017;22:1518–1527

Annamycin delivering better performance 7th line than would be expected even in 2nd line for monotherapy Responders (Stable Disease or Partial Response) after 2 cycles of Annamycin showed improvement in OS and Progression Free Survival (“PFS”) Clinical Benefit Rate (“CBR”) was 59.4% (n=32), comprised of 18 subjects with stable disease and 1 subject with a partial response Potential to address 13,500 new incidents of STS each year and market opportunity expected to grow to $2.6B by 20301 On-demand video webcast with members of the Moleculin management team and internationally renowned Key Opinion Leaders available Thursday, June 5th HOUSTON, June 04, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), a late-stage pharmaceutical company with a broad portfolio of drug candidates targeting hard-to-treat cancers and viruses, today reported positive topline efficacy results from its completed U.S. Phase 1B/2 clinical trial evaluating Annamycin for the treatment of soft tissue sarcoma lung metastases (“STS lung mets”) (MB-107). The MB-107 trial was a multi-center, open-label, single-arm monotherapy study that in Phase 1B determined the Maximum Tolerable Dose and Recommended Phase 2 Dose (“MTD”, “RP2D” respectively) and safety of Annamycin and in Phase 2 explored the efficacy of Annamycin as a single agent for the treatment of subjects with STS lung mets for which chemotherapy was considered appropriate. For more information about the MB-107 trial visit clinicaltrials.gov and reference identifier NCT04887298. “These positive topline results from MB-107 are incredibly encouraging. The impact Annamycin demonstrated on median overall survival, particularly with patients who received multiple prior chemotherapy regimens, exceeded expectations. Additionally, the improvement seen with PFS after two doses represents a real potential for Annamycin to provide a meaningful treatment option for the treatment of STS lung mets,” commented Walter Klemp, Chairman and Chief Executive Officer of Moleculin. “Looking ahead, we believe these results strongly support further evaluations of Annamycin for the treatment of STS lung mets and we look forward to exploring opportunities to potentially bring this important treatment option to patients.” Topline Efficacy Results Summary Clinical Benefit Rate (“CBR”) was 59.4% (n=32), comprised of 18 subjects with stable disease and 1 subject with a partial response (no subjects achieved Complete Response or CR) Progression Free Survival (“PFS”) & Overall Survival (“OS”): Dose and regimen optimized subjects demonstrated PFS of ~4 months and OS of ~20 months Overall (N=36) Median PFS was 63 days, with a 95% Confidence Interval (“CI”) between 43 and 105 days Median OS was 411 days, with a 95% CI between 241 and 583 days In Phase 2 (N=17) at 330 mg/m2: Median PFS was 105 days and OS for all-comers (median 6 prior therapies) of 13.5 months exceeded typical results for 2nd line monotherapies (8-12 months)1 OS/PFS was higher (19.9 months/127 days) for subjects with fewer prior therapies (≤2) (n=7) and receiving doses of Annamycin ≤ 330 mg/m2 (the RP2D) Results suggest overall disease control was better at 330 mg/m2, but once combined with Phase 1B data OS and PFS was the same as overall Subjects achieving a Partial Response (“PR”) or Stable Disease (“SD”) with ≥2 cycles also experienced higher OS/PFS (19.7 months/122 days), demonstrating that achieving CBR from Annamycin resulted in better outcomes No cardiotoxicity demonstrated in all subject data as noted by an independent Expert Annamycin currently has Fast Track Status and Orphan Drug Designation from the FDA for the treatment of relapsed or refractory acute myeloid leukemia, in addition to Orphan Drug Designation for the treatment of soft tissue sarcoma. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the EMA. On-Demand Webcast Details An on-demand Virtual STS Lung Mets KOL Webcast to discuss the MB-107 data will be available for investors, analysts, and other interested parties on Thursday, June 5, 2025 beginning at 8:30 AM ET. For the event, Walter Klemp, Chairman and Chief Executive Officer, and Dr. Paul Waymack, Senior Chief Medical Officer of Moleculin will be joined by Key Opinion Leaders: Mohamad Cherry, MD, Medical Director of Hematology at Atlantic Health System; Prof. Bernd Kasper, Sarcoma Unit of the Mannheim Cancer Center (MCC) at the Mannheim University Medical Center, University of Heidelberg; and Sant P. Chawla, MD, Director, Sarcoma Oncology Center, Director, Cancer Center of Southern California. Interested participants and investors may access the on-demand video webcast on the Events page of the Investors section of the Moleculin website, moleculin.com. The webcast will be accessible for 90 days. About STS Lung Mets Soft tissue sarcoma is a type of cancer that originates in the soft tissues of the body, including muscles, tendons, fat, blood vessels and nerves. Lung metastases are a common occurrence in STS, and can impact overall survival. According to The American Cancer Society approximately 13,500 individuals, both adults and children, will be diagnosed with soft tissue sarcoma in 20252. Soft tissue sarcomas account for 1% of all adult cancers, 7% of cancers in children up to age 15, and 3% of cancers in children under the age of 14. The Soft Tissue Sarcoma Market was valued at USD 1.58 Billion in 2024, and is expected to reach USD 2.57 Billion by 2030, rising at a CAGR of 8.43%. OS for standard of care for metastatic STS has been estimated at 8-12 months and certain experimental targeted and cytotoxic therapies (as monotherapies or some in combination) have yielded OS of 13.4 months as second line therapy.3 MB-107 Study Design In Phase 2, Annamycin was administered as an intravenous (IV) infusion over 2 hours on Day 1, followed by 20 days off (1 cycle = 21 days). Subjects visit the study site every 21 days (±3 days) at which time safety monitoring – including for adverse events (AEs), as well as a physical examination, laboratory evaluations (clinical chemistry, complete blood count), vital signs, weight measurements, Eastern Cooperative Oncology Group (ECOG) performance status, and electrocardiograms (ECGs) – is performed, followed by an IV infusion of study drug. Cardiac function is followed by echocardiogram (ECHO) scans at screening, at the end of the first two cycles and then following every other cycle thereafter, at the End of Treatment visit, and if feasible, during follow up at 6 months (±1 month) and 1 year (±1 month) after study drug discontinuation. As long as the Investigator considers that the benefits of treatment with Annamycin continue to outweigh the risks, treatment will continue every 21 days until tumor progression is observed or unacceptable toxicity occurs. Tumor response is monitored every 6 weeks (±1 week) from Cycle 1 Day 1 during treatment, at the End of Treatment visit, and then every 3 months (±1 month) until disease progression using RECIST 1.1 criteria. Those subjects who leave the study after a maximum response is achieved and who do not start another therapy will be followed every 3 months (±1 month) for progression-free survival (PFS). If a subject receives further therapy after discontinuing from the study, they will be followed only for overall survival (OS) and if feasible, follow-up ECHO scans at 6 months (±1 month) and 1 year (±1 month) were conducted after study drug discontinuation. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin is also engaged in the development of a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the timing of the release of the initial data on the first 45 subjects in the trial and the Company’s ability to reconcile the US and EU protocols with the FDA and EMA, respectively. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected] 1 https://www.researchandmarkets.com/reports/5893492/soft-tissue-sarcoma-market-global-industry 2 American Cancer Society. Cancer Facts & Figures 2025. Atlanta: American Cancer Society; 2025. Available at https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/2025-cancer-facts-figures.html 3 Comandone A, et al; “Salvage Therapy in Advanced Adult Soft Tissue Sarcoma: A Systematic Review and Meta-Analysis of Randomized Trials”; The Oncologist 2017;22:1518–1527

Release Date: May 14, 2025 For the complete transcript of the earnings call, please refer to the full earnings call transcript. Moleculin Biotech Inc (NASDAQ:MBRX) has officially started the Phase 3 Miracle trial for Anamycin, with the first patient already treated and 38 sites selected worldwide. The European Medicines Agency has given complete sign-off for the trial in all nine EU countries, marking a significant milestone. The World Health Organization has recognized a new generic drug name for Anamycin, Naxorubicin, aiding in its future market positioning. Additional patent protection for Anamycin has been secured, extending its composition of matter protection into at least 2040. The company is progressing with WP 1,066, a lead statory inhibitor, which is showing promise in treating brain tumors and is in a new clinical trial at Northwestern University. Moleculin Biotech Inc (NASDAQ:MBRX) ended the quarter with $8 million in cash, which will only sustain operations into the third quarter of the year, necessitating a $15 million raise. The company faces potential delays in EU approval due to additional GLP preclinical data requested by the EMA. There are minor differences between the US and EU protocols for the Phase 3 trial, which could complicate the harmonization process. The company acknowledges that the development of an IV delivery for WP 1,066 could encounter speed bumps, potentially delaying progress. The durability of complete remission in the MB 106 trial is still developing, with some patients relapsing after significant periods. Warning! GuruFocus has detected 1 Warning Sign with MBRX. Q: Does the requirement for additional GLP preclinical data by the EMA affect the timeline for EU approval compared to the US? A: Walter Klimt, CEO: We don't believe it will negatively impact the timeline. The EMA requested additional GLP preclinical data, which we can produce. While this could theoretically delay the EU's progression to Part B, we plan to continue recruiting in the US and non-EU sites during this period. Thus, the trial should not slow down, and we expect to meet EU patient requirements without affecting the approval timeline. Q: How close is Emory University to developing an optimal formulation for WP 1,066? A: Walter Klimt, CEO: We are beyond the discovery phase and are now implementing a strategy for a new formulation suitable for IV delivery. We aim to have progress by the end of the year, although there could be unforeseen delays. We expect to provide updates before the year ends. Q: Is the $3.5 million a fair run rate for R&D for the rest of the year, or will it increase? A: Jonathan Foster, CFO: The R&D expenses will increase, especially as we move into 2026 and incur GLP and manufacturing expenses. Currently, we have enough drugs for Part A, but we will need to start manufacturing for Part B. Q: Do you need durability data for potential approval, or is the 35-day CR rate sufficient? A: Walter Klimt, CEO: Durability is not a primary endpoint for approval; it's a secondary objective. The FDA has indicated that the CR rate is the primary endpoint. While durability is interesting, our approval doesn't depend on it. We are confident in our CR rate, which is expected to be significantly higher than the control arm. Q: Could underlying factors like age and genetic mutations impact the results? A: Walter Klimt, CEO: We will stratify by age and genetic mutations, but our primary endpoint isn't dependent on these factors. Our phase two data shows we are agnostic to genetic mutations and prior therapies, including Vanita lacks failures. We welcome all patient types, including elderly and those with mutational abnormalities. For the complete transcript of the earnings call, please refer to the full earnings call transcript. This article first appeared on GuruFocus.

Enrollment and dosing underway in Phase 3 clinical trial (the “MIRACLE” trial) evaluating Annamycin (naxtarubicin) for the treatment of R/R AML Regulatory and site selection progress to date supports interim data readout expected in the second half of 2025 Recently received European Medicines Agency (EMA) approval adds nine additional countries to the Company’s ongoing MIRACLE trial; Authorization granted in all EU countries requested Company to host conference call and webcast today, May 14th at 8:30 AM ET HOUSTON, May 14, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), a late-stage pharmaceutical company with a broad portfolio of drug candidates targeting hard-to-treat cancers and viral infections, today reported its financial results for the first quarter 2025 ended March 31, 2025. As previously announced, the Company will host a conference call and live audio webcast to discuss the operational and financial results today, May 14, 2025 at 8:30 AM ET. “We are pleased with the continued progress of our pivotal, adaptive Phase 3 MIRACLE trial and remain encouraged by the Annamycin data demonstrated to date. In particular, with the sites opening in the US, the recent approval from the EMA, and the individual country committee and/or ethics approvals we have received for Belgium, Czechia, France, Germany, Italy, Lithuania, Poland, Romania, and Spain positions us to continue building momentum and remain on track with our expected enrollment and data milestones,” commented Walter Klemp, Chairman and Chief Executive Officer of Moleculin. Mr. Klemp continued, “In addition to the progress with our AML program, we are seeing advancements across our pipeline. We continue to be encouraged by the MB-107 trial data demonstrated by Annamycin for the treatment of STS lung mets and expect to report final data readouts from that trial before the end of June. Additionally, investigator-initiated clinical and preclinical work continues on WP1066, our STAT3 inhibitor.” Recent Highlights Received European Medicines Agency (EMA) approval for its Clinical Trial Application (CTA) to conduct Phase 3 MIRACLE clinical trial in all nine countries submitted in the European Union (EU); Announced the International Nonproprietary Names (INN) Expert Committee of the World Health Organization approved “naxtarubicin” for the non-proprietary names of the Company’s next-generation anthracycline in development, Annamycin; Bolstered Annamycin intellectual property portfolio with granting of two new U.S. patents: U.S. patent number 12,257,261 titled, “Preparation of Preliposomal Annamycin Lyophilizate“ and U.S. patent 12,257,262 titled “Method of Reconstituting Liposomal Annamycin“; Presented new pre-clinical data for Annamycin demonstrating market expansion potential including treatment for pancreatic cancer at the American Association for Cancer Research (AACR) Annual Meeting 2025; and Commenced patient dosing in its ongoing pivotal, adaptive design Phase 3 MIRACLE trial. Clinical Development Update Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) The Company is currently evaluating Annamycin (naxtarubicin) in combination with Cytarabine (also known as “Ara-C” and for which the combination of Annamycin and Ara-C is referred to as “AnnAraC”) in a Phase 3 pivotal trial for the treatment of AML patients who are refractory to or relapsed after induction therapy (R/R AML). This Phase 3 “MIRACLE” trial (derived from Moleculin R/R AML AnnAraC Clinical Evaluation) will be global, including sites in the US, Europe and the Middle East. As of the end of April 2025, 38 sites have been selected in all of the regions targeted, with 5 sites in the US. The MIRACLE study is a Phase 2B/3 clinical trial whereby data from the 2B portion will be combined with the Phase 3 portion for purposes of measuring its primary efficacy endpoint. MIRACLE is subject to appropriate future filings with and potential additional feedback from the FDA and their foreign equivalents, utilizes an adaptive design whereby the first 75 to 90 subjects will be randomized (1:1:1) in Part A of the trial to receive high dose cytarabine (HiDAC) combined with either placebo, 190 mg/m2 of Annamycin, or 230 mg/m2 of Annamycin, which Annamycin doses were specifically recommended by the FDA in the Company’s end of Phase 1B/2 meeting. The protocol for the MIRACLE trial allows for the unblinding of preliminary primary efficacy data (Complete Remission or CR) and safety/tolerability of the three arms at 45 subjects, in addition to the conclusion of Part A (at 75 to 90 subjects). The first early unblinding will yield 30 subjects treated with Annamycin (190mg/m2 and 230 mg/m2) and HiDAC and 15 subjects treated with just HiDAC plus placebo. The Company expects to reach the first unblinding (45 subjects) in the second half of 2025, in addition to the second unblinding, which is expected in the first half of 2026. This accelerated estimated timeline is due in part to the positive response the Company received in meetings during December with potential investigators regarding recruitment for the trial. The clinical trial approval with EMA was granted under the condition that the Company present results of appropriate nonclinical GLP studies before initiating the Phase 3 portion (Part B) of the study. Results will be submitted as a substantial modification to the existing approved protocol. For Part B of the trial, approximately 220 additional subjects will be randomized to receive either HiDAC plus placebo or HiDAC plus the optimum dose of Annamycin (randomized 1:1). The selection of the optimum dose will be based on the overall balance of safety, pharmacokinetics and efficacy, consistent with the FDA’s new Project Optimus initiative. Patient dosing has commenced, and the initial data readout is on track for the second half of 2025. For more information about the MIRACLE trial, visit clinicaltrials.gov and reference identifier NCT06788756. Additionally, the clinical trial in the EU is on clinicaltrials.eu, and the reference identifier there is 2024-518359-47-00. Expected Milestones for Annamycin AML Development Program 1Q – 3Q 2025 – Update on MIRACLE trial site selection/approvals by countries 2025 – Recruitment update for MIRACLE trial 2H 2025 – Data readout (n=45) unblinded efficacy/safety review 2H 2025 – 2026 – Impact of data readout (n=45) on regulatory pathway; Recruitment update 1H 2026 – Interim efficacy and safety data (n=~75-90) unblinded and Optimum Dose set for MIRACLE trial 2027 – Begin enrollment of 3rd line subjects in MIRACLE2 2027 – Enrollment ends in 2nd line subjects 2027 – Begin enrollment in pediatric AML trial 2028 – Primary efficacy data for 2nd line subjects in MIRACLE 2028 – Begin submission of a Rolling New Drug Application (NDA) for the treatment of R/R AML for accelerated approval on primary endpoint of CR from MIRACLE 2028 – Primary efficacy data for 2nd line subjects 2028 – Rolling NDA submission begins Soft Tissue Sarcoma (STS) Lung Metastases As previously announced, the Company completed enrollment in the Phase 2 portion of its U.S. Phase 1B/2 clinical trial evaluating Annamycin as monotherapy for the treatment of soft tissue sarcoma lung metastases. Subjects who had stable disease at the time of study discontinuation were followed for progression free response and overall survival. The clinical study report is finalized but has not yet been filed. The Company remains positive about the data and is expected to release the data by the end of June. Expected Milestones for Annamycin STS Lung Mets Development Program 1H 2025 – Final MB-107 data readout 2025 – Identify next phase of development / pivotal IIT (investigator-initiated-trial) program Annamycin (naxtarubicin) currently has Fast Track Status and Orphan Drug Designation from the FDA for the treatment of relapsed or refractory acute myeloid leukemia, in addition to Orphan Drug Designation for the treatment of soft tissue sarcoma. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the European Medicines Agency (EMA). WP1066 & Brain Tumors With regard to the Company’s WP1066 oral formula, the Company has an externally funded phase 1B/2 in combination with radiation treating glioblastoma (GBM), a form of brain cancer, at Northwestern University (Northwestern) that is actively recruiting. This is an investigator-initiated trial where Moleculin’s main cost is supplying drug product. To date Northwestern has recruited 7 subjects. No data has been released. Also, the Company has signed an agreement with Emory University enabling Emory to study various WP1066 IV formulations in preclinical studies with the goal of selecting the best molecule to move into a clinical setting towards, most likely, brain cancers such as GBM. Study drug was delivered in April 2025 to Emory with results from such studies expected in the second half of 2025. Summary of Financial Results for the First Quarter 2025 Research and development (R&D) expense was $3.4 million and $4.3 million for the three months ended March 31, 2025 and 2024, respectively. The decrease of $0.9 million is mainly related to the clinical trials activity levels. General and administrative expense was $2.5 million and $2.4 million for the three months ended March 31, 2025 and 2024, respectively. The increase of $0.1 million is mainly related to a slight overall increase in regulatory and legal fees. As of March 31, 2025, the Company had cash and cash equivalents of $7.7 million and believes that the cash on hand is sufficient to fund planned operations into the third quarter of 2025. Conference Call and Webcast Moleculin management will host a conference call and live audio webcast to discuss the operational and financial results today, Wednesday, May 14, 2025 at 8:30 AM ET. Interested participants and investors may access the conference call by dialing (877) 407-0832 (domestic) or (201) 689-8433 (international) and referencing the Moleculin Biotech Conference Call. The live audio webcast will be accessible on the Events page of the Investors section of the Moleculin website, moleculin.com, and will be archived for 90 days. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin (naxtarubicin), is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to eliminate the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. In March of this year, the Company initiated recruitment of patients into its MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study is subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin is also engaged in the development of a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the timing of the initial data readout in the MIRACLE trial. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected]

HOUSTON, May 07, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), a late-stage pharmaceutical company with a broad portfolio of drug candidates targeting hard-to-treat cancers and viruses, today announced that it will report its financial results for the first quarter ended March 31, 2025 on Tuesday afternoon, May 13, 2025. Moleculin management will host a conference call and live audio webcast to discuss the operational and financial results on Wednesday morning, May 14, 2025 at 8:30 AM ET. Interested participants and investors may access the conference call by dialing (877) 407-0832 (domestic) or (201) 689-8433 (international) and referencing the Moleculin Biotech Conference Call. The live audio webcast will be accessible on the Events page of the Investors section of the Moleculin website, moleculin.com, and will be archived for 90 days. About Moleculin Biotech, Inc. Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to eliminate the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases. In March of this year, the Company initiated recruitment of patients into its MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study is subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents. Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin is also engaged in the development of a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications. For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook. Forward-Looking Statements Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, the timing of the initial data readout in the MIRACLE trial. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 [email protected]