Nkarta Presents NKX019 Clinical Data at the European Hematology Association 2023 Congress and 17th International Conference on Malignant Lymphoma

7 of 10 r/r NHL patients achieved complete response (70% CR rate) following treatment with NKX019 monotherapy at 1 billion and 1.5 billion CAR NK cells per dose in the Phase 1 dose escalation studyData demonstrate potential for redosing of allogeneic CD19 CAR NK to deepen response or restore response post-relapse Majority of patients achieved CR after a single cycle of NKX019 Early safety data support potential of allogeneic CD19 CAR NK to be administered on outpatient basis No neurotoxicity / ICANS, graft versus host disease (GvHD), or > Gr3 cytokine release syndrome (CRS)40% of eligible patients received NKX019 in the outpatient setting after first cycle SOUTH SAN FRANCISCO, Calif., June 10, 2023 (GLOBE NEWSWIRE) — Nkarta, Inc. (Nasdaq: NKTX), a biopharmaceutical company developing engineered natural killer (NK) cell therapies, today announced presentations highlighting preliminary data based on a November 2022 data cut-off from its Phase 1 dose escalation clinical trial of NKX019 at two scientific conferences: the European Hematology Association (EHA) 2023 Hybrid Congress and the 17th International Conference on Malignant Lymphoma (17-ICML). NKX019 is an allogeneic, off-the-shelf NK cell therapy candidate derived from healthy donors and engineered to target CD19. Seven of ten patients with relapsed/ refractory non-Hodgkin lymphoma (NHL) treated at the higher dose levels showed a complete response (70% CR), including two patients with aggressive large B cell lymphoma (LBCL) as well as other difficult histologies, including mantle cell lymphoma (MCL), high-risk follicular lymphoma (FL) and marginal zone lymphoma (MZL). No dose limiting toxicity, neurotoxicity / ICANS, graft versus host disease (GvHD), or >Grade 3 cytokine release syndrome (CRS) were observed in the study. “Autologous CAR-T cell therapies set a standard for responses in patients with relapsed/ refractory B-cell malignancies. However, potential for toxicity and logistic challenges have limited access to these therapies, and many patients could still benefit from a safe, on-demand treatment,” said Michael Dickinson, M.D., Lead, Aggressive Lymphoma disease group, Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, and investigator in the NKX019 trial. “In this early evaluation of an allogeneic CAR-NK cell therapy candidate, NKX019 had a manageable safety profile with encouraging anti-tumor activity as well as the option for retreatment after relapse. Based on these early data, NKX019 merits further study as a potential outpatient cell therapy approach.” “These data highlight the encouraging safety profile and clinical activity across different histologies in the dose escalation portion of the NKX019 study,” said David R. Shook, M.D., Nkarta’s Chief Medical Officer. “We continue to explore the potential of allogeneic CAR NK cells, leveraging their biology to create a differentiated cellular therapy, and we look forward to the next update on the NKX019 program later this year.” Nkarta’s presentation materials from EHA and ICML will be available for download on the Nkarta website (https://www.nkartatx.com/publications/). The presentations will ensure that the broader clinical and academic community has the opportunity to assess the NKX019 clinical data in a peer-reviewed format. All data were previously disclosed at a company event in December 2022. Nkarta plans to provide an update from the NKX019 program, including data from dose expansion cohorts, in 2023. About NKX019NKX019 is an allogeneic, cryopreserved, off-the-shelf cancer 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 CAR for enhanced tumor 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 and malignant B cells, and it is a validated target for B cell cancer therapies. To learn more about the NKX019 clinical trial in adults with advanced B cell malignancies, please visit ClinicalTrials.gov. About NkartaNkarta is a clinical-stage biotechnology company advancing the development of allogeneic, off-the-shelf natural killer (NK) cell therapies. By combining its cell expansion and cryopreservation platform with proprietary cell engineering technologies and CRISPR-based genome engineering capabilities, Nkarta is building a pipeline of future cell therapies engineered for deep anti-tumor 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: the timing of release of additional NKX019 clinical trial data and the nature of the data to be released; the anti-tumor activity and safety profile of NKX019; the potential for NKX019 to be a differentiated, outpatient cellular therapy; and the ability of redosing with NKX019 to restore responses post-relapse. Clinical data referenced in this press release are as of the November 28, 2022 data cut-off date and are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more data on existing patients become available.  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 its two lead product candidates, NKX101 and NKX019; that Nkarta may be delayed in initiating, enrolling or completing any 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; the availability of components and supplies necessary for the conduct of our clinical trials; and risks relating to the impact on our business of the COVID-19 pandemic or similar public health crises.  Interim data from clinical trials are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more data on existing patients become available. The clinical trial program is ongoing, and the final results may be materially different from those reflected in any interim data we report. Further, others, including regulatory agencies, may not accept or agree with Nkarta’s assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and the value of the company in general. In addition, the information Nkarta chooses to publicly disclose regarding a particular study or clinical trial is typically a summary of extensive information, and you or others may not agree with what Nkarta determines is the material or otherwise appropriate information to include in Nkarta’s disclosure, and any information Nkarta determines not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular product, product candidate or business.  These and other risks 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, 2023, filed with the SEC on May 11, 2023, 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:Greg MannNkarta, [email protected]