NKTX

Enrollment continues across all indications in Ntrust-1 and Ntrust-2 at the 4 billion cell dose level (12 billion cells in 3-dose cycle) Initial clinical data from Ntrust-1 and Ntrust-2 expected to be presented at a medical conference in 2026 Cash balance of $243.2 million on June 30, 2026, including cash, cash equivalents and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., Aug. 10, 2026 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biotechnology company developing engineered natural killer (NK) cell therapies to treat autoimmune diseases, today reported financial results for the second quarter ended June 30, 2026. "Expanding access to NKX019 in the communities where autoimmune patients already receive care is central to how we’re advancing this program," said Paul J. Hastings, Chief Executive Officer of Nkarta. "This quarter, we continued to enroll patients across all indications in Ntrust-1 and Ntrust-2 at the 4 billion cell dose level. Following our recent agreement with the FDA on outpatient dosing, we have begun administrating NKX019 through our expanding network of community-based sites, with re-dosing available, if needed, to patients in both trials. We look forward to presenting our initial clinical dataset from Ntrust-1 and Ntrust-2 at a medical conference in 2026." NKX019 Clinical Program Progress and Upcoming Milestones Enrollment continues across Ntrust-1 and Ntrust-2, our multi-center, open-label, dose-escalation clinical trials evaluating NKX019 in multiple autoimmune diseases. Outpatient dosing is underway within our network of community-based sites, broadening patient access beyond those who can travel to academic medical centers. Patients are being dosed at 4 billion cells per dose x 3 doses (12 billion cells total) across all indications in Ntrust-1 and Ntrust-2. Initial clinical data from Ntrust-1 and Ntrust-2 are planned for presentation at a medical conference in 2026. Second Quarter 2026 Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $243.2 million as of June 30, 2026. Research and development (R&D) expenses were $29.0 million for the second quarter of 2026. Non-cash stock-based compensation expense included in R&D expense was $0.7 million for the second quarter of 2026. General and administrative (G&A) expenses were $14.1 million for the second quarter of 2026. Non-cash stock-based compensation expense included in G&A expense was $1.1 million for the second quarter of 2026. Net loss was $40.4 million, or $0.54 per basic and diluted share, for the second quarter of 2026. This net loss includes non-cash charges of $11.8 million that consisted primarily of share-based compensation of $1.9 million, depreciation of $2.7 million, and impairment of right-of-use assets, leasehold improvements and other equipment of $8.0 million. Financial Guidance Nkarta expects its current cash and cash equivalents to fund its current operating plan into 2029. About the Ntrust℠ Clinical Trials in Autoimmune DiseaseNtrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials in patients with autoimmune disease receiving lymphodepletion followed by CD19-targeted CAR-NK cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its potential to achieve durable remission via a “reset” of the immune system through the elimination of pathogenic B cells. The Ntrust trials are enrolling up to 12 patients per dose level per disease indication across systemic sclerosis, idiopathic inflammatory myopathy, ANCA-associated vasculitis, rheumatoid arthritis, lupus nephritis, and primary membranous nephropathy. Additional participants may be enrolled if needed to refine patient populations for further study. In both studies, patients now receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepletion with fludarabine and cyclophosphamide or cyclophosphamide alone, if they have significant cytopenia at baseline. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in both trials may also receive additional cycles, if needed, to restore response or enable a deeper response. About NKX019NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About NkartaNkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for people living with autoimmune diseases. By harnessing the power of the innate immune system to eliminate pathogenic B cells driving the autoimmune response, Nkarta is advancing novel cell therapies engineered for deep therapeutic impact. The on-demand availability and outpatient dosing of our CAR-NK cells enables a broad population of patients with different autoimmune conditions to conveniently access NK cell therapy in community health settings. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as “anticipates,” “believes,” “expects,” “intends,” “plans,” “potential,” “projects,” “would” and “future” or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials); the therapeutic potential, accessibility and tolerability of NKX019 for the treatment of autoimmune diseases, including as a result of advancing Nkarta’s dose escalation and expansion of outpatient dosing in community-based settings; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, filed with the SEC on May 12, 2026, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact:Nadir MahmoodNkarta, [email protected]

Enrollment ongoing at 4 billion cell dose level (12 billion cells in 3-dose cycle) across all indications in Ntrust-1 and Ntrust-2 Regulatory agreement supports expansion into community-based settings with outpatient dosing to reduce patient burden Initial clinical data from Ntrust-1 and Ntrust-2 expected to be presented at a medical meeting in 2026 Cash balance of $266.7 million on March 31, 2026, including cash, cash equivalents and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., May 12, 2026 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biotechnology company developing engineered natural killer (NK) cell therapies to treat autoimmune diseases, today reported financial results for the first quarter ended March 31, 2026. “Putting patients first and providing access to care in a familiar setting close to home matters” said Paul J. Hastings, Chief Executive Officer of Nkarta. “In early April, we reached agreement with the FDA to amend our protocol to allow outpatient dosing in community settings as well as the option to re-dose patients if needed, the removal of overnight monitoring requirements, and the expansion of the Ntrust-2 study to include patients with rheumatoid arthritis. IRB approval of our protocol amendments has been secured across multiple sites, with additional approvals underway. These advancements will enable us to expand patient access beyond urban hubs and major academic centers by engaging community research centers and local rheumatology practices in the neighborhoods where most patients live. We look forward to providing our initial dataset in 2026.” NKX019 Clinical Program Progress and Upcoming Milestones Enrollment continues across Ntrust-1 and Ntrust-2, our multi-center, open-label, dose-escalation clinical trials evaluating NKX019 in multiple autoimmune diseases. IRB approval of our protocol amendments has been secured across multiple sites on outpatient dosing, re-dosing, ending overnight monitoring, and adding RA to Ntrust-2. Patients are being dosed at 4 billion cells per dose x 3 doses (12 billion cells total) across all indications in Ntrust-1 and Ntrust-2. Initial clinical data from Ntrust-1 and Ntrust-2 are planned for presentation at a medical conference in 2026. First Quarter 2026 Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $266.7 million as of March 31, 2026. Research and development (R&D) expenses were $25.0 million for the first quarter of 2026. Non-cash stock-based compensation expense included in R&D expense was $0.7 million for the first quarter of 2026. General and administrative (G&A) expenses were $5.9 million for the first quarter of 2026. Non-cash stock-based compensation expense included in G&A expense was $1.2 million for first quarter of 2026. Net loss was $27.8 million, or $0.37 per basic and diluted share, for the first quarter of 2026. This net loss includes non-cash charges of $3.4 million that consisted primarily of share-based compensation and depreciation expenses. Financial Guidance Nkarta expects its current cash and cash equivalents to fund its current operating plan into 2029. About the Ntrust℠ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials in patients with autoimmune disease receiving lymphodepletion followed by CD19-targeted CAR-NK cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its potential to achieve durable remission via a “reset” of the immune system through the elimination of pathogenic B cells. The Ntrust trials are enrolling up to 12 patients per dose level per disease indication across systemic sclerosis, idiopathic inflammatory myopathy, ANCA-associated vasculitis, rheumatoid arthritis, lupus nephritis, and primary membranous nephropathy. Additional participants may be enrolled if needed to refine patient populations for further study. In both studies, patients now receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepletion with fludarabine and cyclophosphamide or cyclophosphamide alone, if they have significant cytopenia at baseline. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles, if needed, to restore response or enable a deeper response. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for people living with autoimmune diseases. By harnessing the power of the innate immune system to eliminate pathogenic B cells driving the autoimmune response, Nkarta is advancing novel cell therapies engineered for deep therapeutic impact. The on-demand availability and outpatient dosing of our CAR-NK cells enables a broad population of patients with different autoimmune conditions to conveniently access NK cell therapy in community health settings. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as “anticipates,” “believes,” “expects,” “intends,” “plans,” “potential,” “projects,” “would” and “future” or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials); the therapeutic potential, accessibility and tolerability of NKX019 for the treatment of autoimmune diseases, including as a result of advancing Nkarta’s dose escalation; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 25, 2026, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]

Dose escalation for NKX019 advanced to 4 billion cells per dose on days 0, 3 and 7 for a total of 12 billion cells per cycle Initial clinical data from Ntrust-1 and Ntrust-2 targeted for presentation at a medical conference in 2026 Cash balance of $295.1 million on December 31, 2025, including cash, cash equivalents and investments, is expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., March 25, 2026 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biotechnology company developing engineered natural killer (NK) cell therapies to treat autoimmune diseases, today reported financial results for the fourth quarter and year ended December 31, 2025. “2025 was a year of strategic importance for Nkarta as we onboarded a clinical team with deep autoimmune experience, right-sized our workforce to be a responsible steward of investor capital, and continued to advance our CAR-NK cell therapy platform through dose escalation in the clinic,” said Paul J. Hastings, Chief Executive Officer of Nkarta. “Thoughtfully leveraging our safety data, we are now dosing patients at 4 billion cells in a three-dose cycle for a total of 12 billion cells as we look to maximize the depth and durability of B-cell depletion and clinical response, positioning us to unlock the full potential of NKX019 for people living with autoimmune disease.” “We look forward to sharing a comprehensive clinical update from Ntrust-1 and Ntrust-2 later this year with the aim of presenting a meaningful data set at a medical conference. With cash projected to fund operations into 2029, we remain focused on disciplined clinical execution as we continue enrollment in our Ntrust-1 and Ntrust-2 clinical programs.” NKX019 Clinical Program Progress and Upcoming Milestones Enrollment continued across Ntrust-1 and Ntrust-2, our multi-center, open-label, dose-escalation clinical trials evaluating NKX019 in multiple autoimmune diseases. Patients are now being dosed at 4 billion cells per dose as part of ongoing dose escalation. Enrollment remains open in both investigator-sponsored trials of NKX019 in generalized myasthenia gravis and systemic lupus erythematosus. Initial clinical data from Ntrust-1 and Ntrust-2 are planned for presentation at a medical conference later this year. Fourth Quarter and Full Year 2025 Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $295.1 million as of December 31, 2025. Research and development (R&D) expenses were $90.4 million for the full year 2025 and $25.3 million for the fourth quarter of 2025. Non-cash stock-based compensation expense included in R&D expense was $3.2 million for the full year 2025 and $0.7 million for the fourth quarter of 2025. General and administrative (G&A) expenses were $31.6 million for the full year 2025 and $5.7 million for the fourth quarter of 2025. Non-cash stock-based compensation expense included in G&A expense was $5.4 million for the full year 2025 and $1.2 million for the fourth quarter of 2025. Net loss was $104.1 million, or $1.41 per basic and diluted share, for the full year 2025. This net loss includes non-cash charges of $14.4 million that consisted primarily of share-based compensation, right-of-use asset impairment and depreciation expenses. Net loss was $27.4 million, or $0.37 per basic and diluted share, for the fourth quarter of 2025. This net loss includes non-cash charges of $3.3 million that consisted primarily of share-based compensation and depreciation expenses. Financial Guidance Nkarta expects its current cash and cash equivalents to fund its current operating plan into 2029. About the Ntrust℠ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials in patients with autoimmune disease receiving lymphodepletion followed by CD19-targeted CAR-NK cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its potential to achieve durable remission via a “reset” of the immune system through the elimination of pathogenic B cells. The Ntrust trials are enrolling up to 12 patients per dose level per disease indication across systemic sclerosis, idiopathic inflammatory myopathy, ANCA-associated vasculitis, lupus nephritis, and primary membranous nephropathy. In both studies, patients now receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepletion with fludarabine and cyclophosphamide or cyclophosphamide alone, if they have significant cytopenia at baseline. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles, if necessary, to restore response or enable a deeper response. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for autoimmune diseases. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies, Nkarta is building a pipeline of future cell therapies engineered for deep therapeutic activity and intended for broad access in the outpatient treatment setting. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as "anticipates," "believes," "expects," "intends," “plans,” “potential,” "projects,” “would” and "future" or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials); the therapeutic potential and tolerability of NKX019 for the treatment of autoimmune diseases, including as a result of advancing Nkarta’s dose escalation; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’sability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, filed with the SEC on November 10, 2025, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]

Enrollment now underway in second dose-escalation cohort Deep B-cell depletion observed in all patients treated to date who received NKX019 with lymphodepletion using fludarabine and cyclophosphamide versus partial B-cell depletion in patients receiving only cyclophosphamide Enrollment streamlined across Ntrust-1 and Ntrust-2 under a combined independent Data Safety Monitoring Board (iDSMB) to guide dose escalation Initial data for NKX019 in multiple autoimmune indications expected to be presented at a medical conference in 2026 Cash balance of $316.5 million on September 30, 2025, including cash, cash equivalents, and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biotechnology company developing engineered natural killer (NK) cell therapies to treat autoimmune diseases, today reported financial results for the third quarter ended September 30, 2025. “This quarter marks an important milestone for Nkarta as we advance the NKX019 clinical program to treat autoimmune diseases,” said Paul J. Hastings, Chief Executive Officer of Nkarta. “Following productive engagement with the FDA, we streamlined enrollment across our Ntrust-1 and Ntrust-2 clinical trials under a combined iDSMB, which has authorized initiation of the second dose-escalation cohort. This unified approach, combined with the ability to dose multiple patients simultaneously at each dose level and the removal of a patient-by-patient stagger, strengthens the efficiency of our trial enrollment and underscores the consistency of NKX019’s emerging safety profile. “With the modification of our lymphodepletion regimen to include both fludarabine and cyclophosphamide prior to treatment with NKX019, we are now seeing complete B-cell depletion in all patients treated to date, compared with partial B-cell depletion observed with patients receiving cyclophosphamide alone. Now that our study design modifications have been cleared by the FDA and institutional review boards, we’re enrolling patients with the new regimen at the higher dose. “We plan to present data with our investigators at a medical conference in 2026. In the interim, we remain focused on disciplined clinical execution. With a strong balance sheet projected to fund operations into 2029, we are now poised to meaningfully advance our clinical program in this challenging capital environment.” NKX019 Clinical Program Progress and Upcoming Milestones Following engagement with the U.S. Food and Drug Administration, the patient-by-patient stagger was eliminated, accelerating the ability to dose escalate. Protocol amendments now allow for simultaneous dosing of multiple participants in parallel within each dose cohort. Ntrust-1 and Ntrust-2 enrollment process was streamlined to permit data from both studies to be utilized by a combined, iDSMB to inform dose escalation decisions. After unanimous clearance from the combined iDSMB, enrollment has begun in the second dose-escalation cohort. NKX019 clinical programs in autoimmune diseases continue to enroll patients. This includes Ntrust-1, Ntrust-2, and two investigator-sponsored trials. Preliminary data from the Ntrust-1 and Ntrust-2 clinical trials are expected to be presented at a medical conference in 2026. Third Quarter 2025 and Recent Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $316.5 million as of September 30, 2025. Research and development (R&D) expenses were $20.2 million for the third quarter of 2025. Non-cash stock-based compensation expense included in R&D expense was $0.5 million for the third quarter of 2025. General and administrative (G&A) expenses were $7.1 million for the third quarter of 2025. Non-cash stock-based compensation expense included in G&A expense was $1.2 million for the third quarter of 2025. Net loss was $21.7 million, or $0.29 per basic and diluted share, for the third quarter of 2025. This net loss includes non-cash charges of $3.5 million that consisted primarily of share-based compensation, right-of-use asset impairment and depreciation expenses. Financial Guidance Nkarta expects its current cash and cash equivalents will be sufficient to fund its current operating plan into 2029. About the Ntrust℠ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials that build on academic studies of durable, drug-free remissions in patients with autoimmune disease after CD19-targeted cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its ability to enable durable remissions via a “reset” of the immune system through the elimination of pathogenic B cells. The Ntrust trials are enrolling up to 12 patients per dose level per disease indication across lupus nephritis, primary membranous nephropathy, systemic sclerosis, idiopathic inflammatory myopathy, and ANCA-associated vasculitis. In both studies, patients now receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepletion with fludarabine and cyclophosphamide or cyclophosphamide alone, if they have significant cytopenia at baseline. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles, if necessary, to restore response or enable a deeper response. About the Investigator-Sponsored Clinical Trial of NKX019 for Generalized Myasthenia Gravis The single-arm, open-label Phase 1 investigator-sponsored clinical trial is designed to enroll patients with generalized myasthenia gravis and will evaluate safety and clinical outcomes. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being co-led by Ali A. Habib, M.D., Clinical Professor of Neurology at the University of California, Irvine, and other investigators. About the Investigator-Sponsored Clinical Trial of NKX019 for Systemic Lupus Erythematosus The single-center, single-arm, open-label Phase 1 investigator-sponsored clinical trial (NCT06518668) is designed to enroll up to 6 patients with systemic lupus erythematosus, regardless of renal involvement, and will evaluate safety and clinical outcomes in a potentially different population than Ntrust-1. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being led by Anca D. Askanase, M.D., M.P.H., Director, Lupus Center at Columbia University Irving Medical Center and the Director of Rheumatology Clinical Trials. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for autoimmune diseases. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies, Nkarta is building a pipeline of future cell therapies engineered for deep therapeutic activity and intended for broad access in the outpatient treatment setting. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as "anticipates," "believes," "expects," "intends," “plans,” “potential,” "projects,” “would” and "future" or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the plans for Nkarta’s investigator-sponsored clinical trials, the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials, and the regulatory pathway for NKX019); the therapeutic potential, accessibility, tolerability, advantages, and safety profile of NK cell therapies, including NKX019 for the treatment of autoimmune diseases, such as lupus, primary membranous nephropathy, systemic lupus erythematosus, systemic sclerosis, myositis, vasculitis, and myasthenia gravis; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, filed with the SEC on August 12, 2025, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]

Initial update for NKX019 in multiple autoimmune indications expected in second half of 2025 Cash balance of $334.0 million on June 30, 2025, including cash, cash equivalents and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., Aug. 12, 2025 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biopharmaceutical company developing engineered natural killer (NK) cell therapies, today reported financial results for the second quarter and year ended June 30, 2025. “We remain focused on the execution of our clinical trials and continue to believe in the differentiated potential of NK cell therapy to address unmet needs in the treatment of autoimmune diseases,” said Paul J. Hastings, CEO of Nkarta. “Welcoming Dr. Rose and other key new members of our clinical team with rheumatology experience has provided us with world-class medical expertise to inform our ongoing enrollment of patients across our clinical studies and investigator-sponsored trials. Dr. Rose’s track record as a seasoned rheumatologist, immunologist and accomplished drug developer in the autoimmune space will be invaluable as we continue to advance our NKX019 clinical trial programs.” NKX019 Clinical Program Progress and Upcoming Milestones NKX019 clinical programs in autoimmune diseases continue to enroll patients. This includes Ntrust-1, Ntrust-2 and two investigator-sponsored trials. Preliminary data from the Ntrust-1 and Ntrust-2 clinical trials is planned for release in the second half of 2025. Other Corporate Updates Shawn Rose, M.D. Ph.D, was appointed Chief Medical Officer and Head of Research and Development in June 2025. In previous roles with Johnson & Johnson, BMS and emerging biopharma companies, Dr. Rose brought forward more than a dozen programs from discovery into clinical development, and he has developed multiple pioneering approved medicines for autoimmune conditions. Second Quarter 2025 and Recent Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $334.0 million as of June 30, 2025. Research and development (R&D) expenses were $20.8 million for the second quarter of 2025. Non-cash stock-based compensation expense included in R&D expense was $0.9 million for the second quarter of 2025. General and administrative (G&A) expenses were $6.4 million for the second quarter of 2025. Non-cash stock-based compensation expense included in G&A expense was $1.2 million for the second quarter of 2025. Net loss was $23.0 million, or $0.31 per basic and diluted share, for the second quarter of 2025. This net loss includes non-cash charges of $3.4 million that consisted primarily of share-based compensation and depreciation expenses. Financial Guidance Nkarta expects its current cash and cash equivalents will be sufficient to fund its current operating plan into 2029. About the Ntrust℠ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials that build on academic studies of durable, drug-free remissions in patients with autoimmune disease after CD19-targeted cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its ability to enable long-term remissions via a “reset” of the immune system through the elimination of pathogenic B cells. Ntrust-1 is initially enrolling up to 24 patients with lupus nephritis or primary membranous nephropathy. Ntrust-2 is initially enrolling up to 36 patients with systemic sclerosis, idiopathic inflammatory myopathy, or ANCA-associated vasculitis. In both studies, patients receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepleting conditioning with either fludarabine and cyclophosphamide or cyclophosphamide alone. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles, if necessary, to restore response. About the Investigator-Sponsored Clinical Trial of NKX019 for Generalized Myasthenia Gravis The single-arm, open-label Phase 1 investigator-sponsored clinical trial is designed to enroll patients with generalized myasthenia gravis and will evaluate safety and clinical outcomes. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being co-led by Ali A. Habib, M.D., Clinical Professor of Neurology at the University of California, Irvine, and other investigators. About the Investigator-Sponsored Clinical Trial of NKX019 for Systemic Lupus Erythematosus The single-center, single-arm, open-label Phase 1 investigator-sponsored clinical trial (NCT06518668) is designed to enroll up to 6 patients with systemic lupus erythematosus, regardless of renal involvement, and will evaluate safety and clinical outcomes in a potentially different population than Ntrust-1. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being led by Anca D. Askanase, M.D., M.P.H., Director, Lupus Center at Columbia University Irving Medical Center and the Director of Rheumatology Clinical Trials. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for autoimmune diseases. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies, Nkarta is building a pipeline of future cell therapies engineered for deep therapeutic activity and intended for broad access in the outpatient treatment setting. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as "anticipates," "believes," "expects," "intends," “plans,” “potential,” "projects,” “would” and "future" or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the plans for Nkarta’s investigator-sponsored clinical trials, the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials, and the regulatory pathway for NKX019); the therapeutic potential, accessibility, tolerability, advantages, and safety profile of NK cell therapies, including NKX019 for the treatment of autoimmune diseases, such as lupus, primary membranous nephropathy, systemic lupus erythematosus, systemic sclerosis, myositis, vasculitis, and myasthenia gravis; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed with the SEC on May 14, 2025, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]

Enrollment open in investigator-sponsored trial (IST) of NKX019 in myasthenia gravis; Ntrust-1, Ntrust-2, and IST of NKX019 in systemic lupus erythematosus remain open to enrollment Ntrust-1 expanded to include primary membranous nephropathy cohort Lymphodepletion regimen modified across platform to include fludarabine and cyclophosphamide with cyclophosphamide alone remaining available for eligible patients Initial data for NKX019 in multiple autoimmune indications expected in second half of 2025 Cash balance of $351.9 million on March 31, 2025, including cash, cash equivalents and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., May 14, 2025 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biopharmaceutical company developing engineered natural killer (NK) cell therapies, today reported financial results for the first quarter and year ended March 31, 2025. “Our recent restructuring and continued efforts at cost containment have positioned us well to achieve our clinical milestones while ensuring we have cash to support our critical operations into 2029,” said Paul J. Hastings, CEO of Nkarta. “In order to maximize success in our trials, we have incorporated a lymphodepletion regimen utilizing both cyclophosphamide and fludarabine. Similar trials have established this combination, and we believe there is value in producing a comparable dataset while still continuing our cyclophosphamide-only regimen for eligible patients. This approach has potential to provide data on both regimens, which best positions us to advance NKX019 in the clinic and deliver this potential new treatment to patients with B cell-mediated autoimmune diseases. We remain on track to provide our initial clinical update for the Ntrust-1 and Ntrust-2 studies in the second half of 2025.” Updates for NKX019 clinical programs in Autoimmune Diseases Ntrust-1, a clinical trial of NKX019 for the treatment of lupus nephritis (LN), expanded to include patients with primary membranous nephropathy (pMN) with an aim of addressing the unmet need for novel therapies in this disease. Ntrust-1 is currently open to enroll patients with pMN and remains open to enroll patients with LN. Ntrust-2, a clinical trial of NKX019 for the treatment of systemic sclerosis, idiopathic inflammatory myopathy and anti-neutrophil cytoplasmic antibody-associated vasculitis, continues to enroll patients. Ntrust-1 and Ntrust-2 protocols amended to modify lymphodepletion prior to administration of NKX019 to use of a combination of fludarabine and cyclophosphamide, with the option for eligible patients to continue to receive cyclophosphamide alone as modified lymphodepletion. The IST of NKX019 for the treatment of myasthenia gravis led by researchers at the University of California, Irvine opened to enrollment. The IST of NKX019 for the treatment of systemic lupus erythematosus led by researchers at the Columbia University Irving Medical Center, remains open for enrollment. Anticipated Ntrust clinical trial milestones for 2025 Preliminary clinical data from the Ntrust-1 and Ntrust-2 clinical trials is planned for the second half of 2025. The update is expected to include clinical response with available follow-up from a group of patients in the Ntrust-1 and Ntrust-2 studies. Other Corporate Updates Robert Ortmann, M.D., an accomplished rheumatologist with over 20 years of clinical and scientific experience to join Nkarta as Vice President, Clinical Development, effective May 15, 2025. Dr. Ortmann, who has extensive clinical development experience across a wide range of autoimmune diseases, will report to David Shook, M.D., Chief Medical Officer, Head of Research & Development. In March 2025, Nkarta announced a restructuring plan, including a reduction in force impacting 34% of its workforce, prioritizing investments in clinical execution, and freezing select future headcount to extend the cash runway by more than one year into 2029 to enable the achievement of key clinical milestones while maintaining sufficient funds to support ongoing operations beyond those milestones. First Quarter 2025 and Recent Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $351.9 million as of March 31, 2025. Research and development (R&D) expenses were $24.2 million for the first quarter of 2025. Non-cash stock-based compensation expense included in R&D expense was $1.1 million for the first quarter of 2025. General and administrative (G&A) expenses were $12.4 million for the first quarter of 2025, which included $5.1 million of restructuring expenses in March 2025. Non-cash stock-based compensation expense included in G&A expense was $1.7 million for the first quarter of 2025. Net loss was $32.0 million, or $0.43 per basic and diluted share, for the first quarter of 2025. This net loss includes non-cash charges of $4.3 million that consisted primarily of share-based compensation and depreciation expenses. Financial Guidance Nkarta expects its current cash and cash equivalents will be sufficient to fund its current operating plan into 2029. About the Ntrust™ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials that build on academic studies of durable, drug-free remissions in patients with autoimmune disease after CD19-targeted cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its ability to enable long-term remissions via a “reset” of the immune system through the elimination of pathogenic B cells. Ntrust-1 is initially enrolling up to 24 patients with lupus nephritis or primary membranous nephropathy. Ntrust-2 is initially enrolling up to 36 patients with systemic sclerosis, idiopathic inflammatory myopathy, or anti-neutrophil cytoplasmic antibody-associated vasculitis. In both studies, patients receive a three-dose cycle of NKX019 on Days 0, 3, and 7 following lymphodepleting conditioning with either fludarabine and cyclophosphamide or cyclophosphamide alone. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles to restore response. About the Investigator-Sponsored Clinical Trial of NKX019 for Generalized Myasthenia Gravis The single-arm, open-label Phase 1 investigator-sponsored clinical trial is designed to enroll patients with generalized myasthenia gravis and will evaluate safety and clinical outcomes. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being co-led by Ali A. Habib, M.D., Clinical Professor of Neurology at the University of California, Irvine, and other investigators. About the Investigator-Sponsored Clinical Trial of NKX019 for Systemic Lupus Erythematosus The single-center, single-arm, open-label Phase 1 investigator-sponsored clinical trial (NCT06518668) is designed to enroll up to 6 patients with systemic lupus erythematosus, regardless of renal involvement, and will evaluate safety and clinical outcomes in a potentially different population than Ntrust-1. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients receive 3 doses of NKX019 following lymphodepletion. The clinical trial is being led by Anca D. Askanase, M.D., M.P.H., Director, Lupus Center at Columbia University Irving Medical Center and the Director of Rheumatology Clinical Trials. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease and B cell-derived malignancies. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for autoimmune diseases. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies, Nkarta is building a pipeline of future cell therapies engineered for deep therapeutic activity and intended for broad access in the outpatient treatment setting. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as "anticipates," "believes," "expects," "intends," “plans,” “potential,” "projects,” “would” and "future" or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the potential impact of modified lymphodepleting conditioning on our clinical trials, the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials, and the regulatory pathway for NKX019); the therapeutic potential, accessibility, tolerability, advantages, and safety profile of NK cell therapies, including NKX019 for the treatment of autoimmune diseases, such as lupus, primary membranous nephropathy, systemic lupus erythematosus, systemic sclerosis, myositis, vasculitis, and myasthenia gravis; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling patients in or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Annual Report on Form 10-K for the quarter and year ended December 31, 2024, filed with the SEC on March 26, 2025, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]

Differentiated development program includes two Nkarta clinical trials and two investigator-sponsored trials of NKX019 in rheumatic and neurological diseases Initial data for NKX019 in multiple autoimmune indications expected in second half of 2025 Restructuring and workforce reduction of 34% (53 positions), including freezing of some future hires, to extend cash runway by more than one year to enable clinical milestones while having ample cash runway following the realization of those milestones Cash balance of $380.5 million on December 31, 2024, including cash, cash equivalents and investments, expected to fund operations into 2029 SOUTH SAN FRANCISCO, Calif., March 26, 2025 (GLOBE NEWSWIRE) -- Nkarta, Inc. (Nasdaq: NKTX), a clinical-stage biopharmaceutical company developing engineered natural killer (NK) cell therapies, today reported financial results for the fourth quarter and year ended December 31, 2024. “As the validation of cellular therapy in autoimmune disease expands to include CAR NK cells, we remain confident that the potential safety and accessibility advantages of NKX019 will allow it to occupy an important place in the future treatment of autoimmune disease,” said Paul J. Hastings, CEO of Nkarta. “The opportunity that novel B-cell targeting therapies like NKX019 have to become transformative is substantial, creating a highly competitive development landscape. The integration of cellular therapy into traditionally outpatient-based specialties has been challenging and has required time and investment. We plan to provide our initial clinical update from the Ntrust-1 and Ntrust-2 studies in the second half of 2025.” “To ensure that Nkarta is strongly positioned financially to achieve multiple value-generating milestones within our existing cash and to set the stage for an efficient regulatory pathway for NKX019, we have implemented a restructuring plan, including a significant reduction of our workforce. The restructuring prioritizes investment in clinical execution and impacts every level of the organization, including reducing the executive leadership team by over 50%.” “We believe that this decision is necessary in today’s challenging financial and competitive environment to fulfill Nkarta’s vision of bringing potentially life-saving cellular therapies to people with autoimmune disease. Saying goodbye to cherished and talented team members is very difficult, and we pay tribute to them and their families for their dedication to Nkarta.” NKX019 is an allogeneic, off-the-shelf, chimeric antigen receptor (CAR) NK-cell therapy candidate engineered to deplete CD19-positive cells in B-cell mediated autoimmune disease. The approach leverages the potential advantages of NK cell therapy, including deep and rapid B-cell killing, a lower risk of cytokine release syndrome and neurotoxicity, the opportunity for potential fludarabine-free lymphodepletion to reduce toxicity, the added utility of on-demand dosing allowing for better accessibility, and the opportunity for repeated dosing as needed. Clinical Program Progress and Upcoming Milestones Dosing of the first patient in Ntrust-1, a clinical trial of NKX019 for the treatment of lupus nephritis, reported in November 2024. Opening of enrollment for Ntrust-2, a clinical trial of NKX019 for the treatment of systemic sclerosis (SSc), idiopathic inflammatory myopathy (IIM, myositis) and ANCA-associated vasculitis (AAV), reported in December 2024. Dosing of the first patient in the investigator-sponsored trial (IST) of NKX019 for the treatment of systemic lupus erythematosus (SLE) led by researchers at the Columbia University Irving Medical Center, reported in November 2024. Clearance of the IND for the IST of NKX019 for the treatment of myasthenia gravis (MG) led by researchers at the University of California, Irvine and the University of Kansas Medical Center, reported in December 2024. The dosing schedule of NKX019 was harmonized across all four clinical trials in the fourth quarter of 2024. Patients receive NKX019 on Days 0, 3 and 7 following single-agent lymphodepletion with cyclophosphamide. Preliminary clinical data from the Ntrust-1 and Ntrust-2 clinical trials is planned for the second half of 2025. The update is expected to include clinical response with available follow-up from a group of patients in the Ntrust-1 and Ntrust-2 studies. Fourth Quarter and Full Year 2024 Financial Highlights Nkarta had cash, cash equivalents, restricted cash, and investments in marketable securities of $380.5 million as of December 31, 2024. Research and development (R&D) expenses were $96.7 million for the full year 2024 and $23.1 million for the fourth quarter of 2024. Non-cash stock-based compensation expense included in R&D expense was $8.0 million for the full year 2024 and $1.8 million for the fourth quarter of 2024. General and administrative (G&A) expenses were $31.5 million for the full year 2024 and $7.8 million for the fourth quarter of 2024. Non-cash stock-based compensation expense included in G&A expense was $8.8 million for the full year 2024 and $2.1 million for the fourth quarter of 2024. Net loss was $108.8 million, or $1.60 per basic and diluted share, for the full year 2024. This net loss includes non-cash charges of $22.9 million that consisted primarily of share-based compensation and depreciation expenses. Net loss was $25.9 million, or $0.35 per basic and diluted share, for the fourth quarter of 2024. This net loss includes non-cash charges of $4.9 million that consisted primarily of share-based compensation and depreciation expenses. Restructuring Expenses and Financial Guidance Cash payments resulting from the restructuring are estimated to be $5.5 to $6.5 million. Nkarta anticipates its cash and cash equivalents to be sufficient to fund its current operating plan into 2029, an extension of its cash runway by more than one year based on cost reductions to be realized from the restructuring. About NKX019 NKX019 is an allogeneic, cryopreserved, off-the-shelf immunotherapy candidate that uses natural killer (NK) cells derived from the peripheral blood of healthy adult donors. It is engineered with a humanized CD19-directed chimeric antigen receptor (CAR) for enhanced cell targeting and a proprietary, membrane-bound form of interleukin-15 (IL-15) for greater persistence and activity without exogenous cytokine support. CD19 is a biomarker for normal B cells as well as those implicated in autoimmune disease and B cell-derived malignancies. Nkarta is evaluating NKX019 in multiple autoimmune conditions. About the Ntrust™ Clinical Trials in Autoimmune Disease Ntrust-1 (NCT06557265) and Ntrust-2 (NCT06733935) are multi-center, open label, dose escalation clinical trials that build on academic studies of durable, drug-free remissions in patients with autoimmune disease after CD19-targeted cell therapy. Both trials will assess the safety of NKX019 in people living with autoimmune diseases as well as its ability to enable long-term remissions via a “reset” of the immune system through the elimination of pathogenic B cells. Ntrust-1 is enrolling patients with lupus nephritis. Ntrust-2 is enrolling patients with systemic sclerosis (scleroderma), idiopathic inflammatory myopathy (myositis), or ANCA-associated vasculitis (AAV). In both studies, patients receive a three-dose cycle of NKX019 on Days 0, 3 and 7 following single-agent lymphodepletion with cyclophosphamide, an agent with an established safety profile across autoimmune diseases. Leveraging the engineering of NKX019, no patients in either trial will receive supplemental cytokines or antibody-based therapeutics. This approach is designed to evaluate the single-agent activity of NKX019 and facilitate a more rapid path to regulatory approval. Patients in Ntrust-1 may also receive additional cycles to restore response. Each trial is designed to initially enroll up to 12 patients. About the Investigator-Sponsored Clinical Trial of NKX019 for Systemic Lupus Erythematosus The single-center, single-arm, open-label Phase 1 investigator-sponsored clinical trial (NCT06518668) is designed to enroll up to 6 patients with systemic lupus erythematosus, regardless of renal involvement, and will evaluate safety and clinical outcomes in a potentially different population than Ntrust-1. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are also planned. Patients receive NKX019 following single-agent lymphodepletion with cyclophosphamide. The clinical trial is being led by Anca D. Askanase, M.D., M.P.H., Director, Lupus Center at Columbia University Irving Medical Center and the Director of Rheumatology Clinical Trials. About the Investigator-Sponsored Clinical Trial of NKX019 for Generalized Myasthenia Gravis The single-arm, open-label Phase 1 investigator-sponsored clinical trial is designed to enroll patients with generalized myasthenia gravis, and will evaluate safety and clinical outcomes. Translational and biomarker studies, including autoantibodies, cytokine profiles and pharmacokinetics are planned. Patients will receive NKX019 following single-agent lymphodepletion with cyclophosphamide. The clinical trial is being co-led by Ali A. Habib, M.D., Clinical Professor of Neurology at the University of California, Irvine, and other investigators. About Nkarta Nkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies for autoimmune diseases. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies, Nkarta is building a pipeline of future cell therapies engineered for deep therapeutic activity and intended for broad access in the outpatient treatment setting. For more information, please visit the company’s website at www.nkartatx.com. Cautionary Note on Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as "anticipates," "believes," "expects," "intends," “plans,” “potential,” "projects,” “would” and "future" or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include, but are not limited to, statements concerning Nkarta’s expectations regarding any or all of the following: Nkarta’s position, plans, strategies, and timelines for the continued and future clinical development and commercial potential of NKX019 (including the plans for Nkarta’s investigator-sponsored clinical trials, the future availability and disclosure of clinical data and other updates from Nkarta’s clinical trials, and the regulatory pathway for NKX019); the therapeutic potential, accessibility, tolerability, advantages, and safety profile of NK cell therapies, including NKX019 for the treatment of autoimmune diseases, such as lupus, systemic sclerosis, myositis, vasculitis, and myasthenia gravis; the expected cost associated with and impact of the restructuring; and Nkarta’s expected cash runway. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Nkarta’s limited operating history and historical losses; Nkarta’s lack of any products approved for sale and its ability to achieve profitability; the risk that the results of preclinical studies and early-stage clinical trials may not be predictive of future results; Nkarta’s ability to raise additional funding to complete the development and any commercialization of its product candidates; Nkarta’s dependence on the clinical success of NKX019; that Nkarta may be delayed in initiating, enrolling or completing its clinical trials; competition from third parties that are developing products for similar uses; Nkarta’s ability to obtain, maintain and protect its intellectual property; Nkarta’s dependence on third parties in connection with manufacturing, clinical trials and pre-clinical studies; the complexity of the manufacturing process for CAR NK cell therapies; and the success of Nkarta’s recent (and any future) cost containment measures. These and other risks and uncertainties are described more fully in Nkarta’s filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of Nkarta’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2024, filed with the SEC on November 7, 2024, and Nkarta’s other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Nkarta undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. Nkarta Media/Investor Contact: Nadir Mahmood Nkarta, Inc. [email protected]