FLT3

Kanya Rajangam, MD, PhD, President, Head of R&D and Chief Medical Officer of Senti Bio discusses the positive data from lead program, SENTI-202, recently presented at the American Association for Cancer Research (AACR) Annual Meeting 2025 Watch the “What This Means” segment here SOUTH SAN FRANCISCO, Calif., May 01, 2025 (GLOBE NEWSWIRE) -- Senti Biosciences, Inc. (Nasdaq: SNTI) (“Senti Bio” or the “Company”), a clinical-stage biotechnology company developing next-generation cell and gene therapies using its proprietary Gene Circuit platform, today announced that Kanya Rajangam, MD, PhD, President, Head of R&D and Chief Medical Officer participated in a Virtual Investor “What This Means” segment. As part of the segment, Dr. Rajangam discussed the recently announced additional positive preliminary data from a Phase 1 clinical trial of SENTI-202, a potential first-in-class off-the-shelf Logic Gated selective CD33 OR FLT3 NOT EMCN chimeric antigen receptor natural killer (CAR-NK) investigational cell therapy, for the treatment of relapsed/refractory (R/R) hematologic malignancies including acute myeloid leukemia (“AML”). The Virtual Investor “What This Means” segment featuring Senti Bio is now available here. About SENTI-202 SENTI-202 is a First-in-Class Off-the-Shelf Logic Gated Selective CD33 OR FLT3 NOT EMCN CAR NK Cell Therapy product candidate designed to selectively target and eliminate CD33 and/or FLT3-expressing hematologic malignancies, such as AML and myelodysplastic syndrome (“MDS”), while sparing healthy bone marrow cells. SENTI-202 has three main components. First, SENTI-202 contains an OR GATE (providing a “kill” signal), which is an activating CAR that recognizes CD33 and/or FLT3. By targeting either or both of these antigens, SENTI-202 is designed to effectively kill both leukemic blasts and leukemia stem cells, which constitute a difficult-to-eradicate reservoir of AML disease. Second, SENTI-202 contains a NOT GATE (providing a “protect” signal), which is an inhibitory CAR that is designed to recognize healthy cells and protect those healthy cells from being killed, even if they were to express CD33 and/or FLT3, thus potentially widening the therapeutic window. Third, SENTI-202 contains calibrated-release IL-15 (providing an “enhance” signal), which is designed to significantly increase cell persistence, expansion and activity of both the CAR-NK cells and host immune cells. The NK cells used to manufacture SENTI-202 are sourced from selected healthy adult donors. Senti Bio is currently enrolling adult patients with R/R CD33 and/or FLT3-expressing heme malignancies in a Phase 1 clinical trial for SENTI-202, which can be a potential first-in-class allogeneic off-the-shelf treatment for AML/MDS patients. Senti Bio has published SENTI-202 preclinical data demonstrating the potential of Logic Gated CAR-NK cell therapy for the treatment of AML. About AML AML is a cancer of the blood and bone marrow and is the most common type of acute leukemia in adults. It is estimated there were 20,800 new cases of AML in the United States in 2024. The five-year survival rate for these patients is approximately 30%. AML is currently treated with chemotherapy, targeted therapies, and/or allogeneic or autologous stem cell transplant. For patients with R/R AML, there are few treatment options and median overall survival is typically approximately five months. About Senti Bio Senti Bio is a biotechnology company developing a new generation of cell and gene therapies for patients living with incurable diseases. To achieve this, Senti Bio is leveraging its synthetic biology platform to engineer Gene Circuits into new medicines with enhanced precision and control. These Gene Circuits are designed to precisely kill cancer cells, to spare healthy cells, to increase specificity to target tissues, and/or to be controllable even after administration. The Company’s wholly-owned pipeline is comprised of cell therapies engineered with Gene Circuits to target challenging liquid and solid tumor indications. Senti’s Gene Circuits have been shown preclinically to work in both NK and T cells. Senti Bio has also preclinically demonstrated the potential breadth of Gene Circuits in other modalities and diseases outside of oncology, and continues to advance these capabilities through partnerships. Forward-Looking Statements This press release and document contain certain statements that are not historical facts and are considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements generally are identified by the words “believe,” “could,” “predict,” “continue,” “ongoing,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” “forecast,” “seek,” “target” and similar expressions that predict or indicate future events or trends or that are not statements of historical matters. Forward-looking statements are predictions, projections, and other statements about future events that are based on current expectations of Senti Bio’s management and assumptions, whether or not identified in this document, and, as a result, are subject to risks and uncertainties. Forward-looking statements include, but are not limited to, expectations regarding Senti Bio’s growth, strategy, progress and timing of its clinical trials for SENTI-202;the timing of availability of data from the ongoing Phase 1 clinical trial of SENTI-202; the ability of any product candidate to perform in humans in a manner consistent with nonclinical, preclinical or previous clinical study data; expectations regarding the anticipated dosing of patients and availability of data from clinical trials, and the timing thereof. These forward-looking statements are provided for illustrative purposes only and are not intended to serve as and must not be relied on by any investor as, a guarantee, an assurance, a prediction, or a definitive statement of fact or probability. Actual events and circumstances are difficult or impossible to predict and will differ from assumptions. Many actual events and circumstances are beyond the control of Senti Bio. Many factors could cause actual future results to differ materially from the forward-looking statements in this document, including but not limited to: (i) changes in domestic and foreign business, market, financial, political and legal conditions, (ii) changes in the competitive and highly regulated industries in which Senti Bio operates, variations in operating performance across competitors, changes in laws and regulations affecting Senti Bio’s business, (iii) the ability to implement business plans, forecasts and other expectations, (iv) the risk of downturns and a changing regulatory landscape in Senti Bio’s highly competitive industry, (v) risks relating to the uncertainty of any projected financial information with respect to Senti Bio, (vi) risks related to uncertainty in the timing or results of Senti Bio’s clinical trial start up, clinical studies, patient enrollment, and GMP manufacturing startup activities, (vii) Senti Bio’s dependence on third parties in connection with clinical trial startup, clinical studies, and GMP manufacturing activities, (viii) risks related to delays and other impacts from macroeconomic and geopolitical events, increasing rates of inflation and rising interest rates on business operations, (ix) risks related to the timing and utilization of the grant from CIRM, and (x) the success of any future research and development efforts by Senti Bio. The foregoing list of factors is not exhaustive. You should carefully consider the foregoing factors and the other risks and uncertainties described in the “Risk Factors” section of Senti Bio’s most recent periodic report filed with the U.S. Securities and Exchange Commission (“SEC”), and other documents filed by Senti Bio from time to time with the SEC. These filings identify and address other important risks and uncertainties that could cause actual events and results to differ materially from those contained in the forward-looking statements in this document. There may be additional risks that Senti Bio does not presently know, or that Senti Bio currently believes are immaterial that could also cause actual results to differ from those contained in the forward-looking statements in this document. Forward-looking statements speak only as of the date they are made. Senti Bio anticipates that subsequent events and developments may cause Senti Bio’s assessments to change. Except as required by law, Senti Bio assumes no obligation to update publicly any forward-looking statements, whether as a result of new information, future events, or otherwise. Availability of Other Information About Senti Biosciences, Inc. For more information, please visit the Senti Bio website at www.sentibio.com or follow Senti Bio on X (@SentiBio) and LinkedIn (Senti Biosciences). Investors and others should note that we communicate with our investors and the public using our company website (www.sentibio.com), including, but not limited to, company disclosures, investor presentations and FAQs, Securities and Exchange Commission filings, press releases, public conference call transcripts and webcast transcripts, as well as on X and LinkedIn. The information that we post on our website or on X or LinkedIn could be deemed to be material information. As a result, we encourage investors, the media and others interested to review the information that we post there on a regular basis. The contents of our website or social media shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 SNTI@jtcir.com

ROCKVILLE, Md. and SUZHOU, China, April 28, 2025 (GLOBE NEWSWIRE) -- Ascentage Pharma (NASDAQ: AAPG; HKEX: 6855), a global biopharmaceutical company engaged in discovering, developing, and commercializing therapies to address global unmet medical needs primarily for hematological malignancies, today announced that it has presented results from five preclinical studies during poster presentations at the 2025 American Association for Cancer Research (AACR) Annual Meeting, taking place April 25-30, 2025, in Chicago, Illinois, USA. These poster presentations feature five of the company’s drug candidates: novel tyrosine kinase inhibitor (TKI) olverembatinib (HQP1351), Bcl-2 inhibitor lisaftoclax (APG-2575), FAK/ALK/ROS1 TKI APG-2449, embryonic ectoderm development (EED) inhibitor APG-5918, and IAP antagonist AS03157. Dr. Yifan Zhai, Chief Medical Officer of Ascentage Pharma, said, “The encouraging data from our investigational assets, presented at this year’s AACR Annual Meeting, are another testament to our strong and innovative pipeline. In particular, the combination of olverembatinib and lisaftoclax, two of our key drug candidates, has demonstrated strong synergistic effects in preclinical models of acute myeloid leukemia and T-cell acute lymphoblastic leukemia. These preclinical studies are expected to complement and further catalyze our clinical development. Moving forward, we will actively advance the clinical development of these programs in order to bring more treatment options to patients in need.” Detailed data presented at this year’s AACR Annual Meeting are as follows: Olverembatinib (HQP1351) in combination with lisaftoclax (APG-2575) overcomes venetoclax resistance in preclinical models of acute myeloid leukemia (AML) Abstract#: 5652Session: Novel Antitumor Agents 3 Introduction: Combining Bcl-2 inhibitor venetoclax with hypomethylating agents is the standard of care for patients with AML who are older or ineligible for intensive chemotherapy. However, resistance to venetoclax is a major clinical challenge, necessitating alternative therapeutic options. Olverembatinib, a multikinase inhibitor, targets kinases associated with leukemogenesis and venetoclax resistance in AML, including FLT3, cKIT, PDGFR, Src family kinases, PI3K, and FGFR. Lisaftoclax is an investigational, novel, selective Bcl-2 inhibitor currently being tested clinically for several hematologic malignancies, including relapsed/refractory AML. In this study, we evaluated the effects of olverembatinib combined with lisaftoclax in venetoclax-resistant (VEN-R) AML models. Summary: In VEN-R AML cell lines, the combination of olverembatinib and lisaftoclax synergistically inhibited cellular proliferation and induced cellular apoptosis. Olverembatinib in combination with lisaftoclax synergistically suppressed tumor growth in a MOLM-13-VEN-R AML xenograft model in vivo. Mechanistically, western blot analysis revealed that the combination synergistically downregulated several leukemogenic signaling pathways, including those associated with venetoclax resistance, such as FLT3, AKT, MCL-1, and activated apoptosis. In summary, olverembatinib in combination with lisaftoclax overcame venetoclax resistance in preclinical AML models, warranting further clinical investigation as a new therapeutic strategy for VEN-R AML. Effects of olverembatinib (HQP1351) in combination with Bcl-2 inhibitor lisaftoclax (APG-2575) in T-cell acute lymphoblastic leukemia (T-ALL) Abstract#: 5648Session: Novel Antitumor Agents 3 Introduction: T-ALL is a high-risk hematologic cancer arising from malignant transformation of T-cell progenitors, affecting approximately 15% of newly diagnosed pediatric and 25% of adult ALL cases. Survival in patients with relapsed or refractory disease is poor, with limited treatment options. Some T-ALL subtypes depend on pre-TCR/Src signaling and antiapoptotic Bcl-2 family proteins for growth and survival. Olverembatinib, a novel multikinase inhibitor, targets oncogenic Src-family kinases (Lck, Fyn, and YES1), which are essential for T-cell differentiation, survival, and activation. Lisaftoclax is a novel Bcl-2 inhibitor under investigation in late-stage clinical trials for multiple hematologic malignancies. We evaluated antitumor effects of olverembatinib combined with lisaftoclax in human T-ALL cell lines and xenograft models and explored potential mechanisms of action. Summary: Olverembatinib in combination with lisaftoclax synergistically inhibited proliferation and augmented apoptosis in T-ALL cells in vitro. The combination synergistically suppressed tumor growth in a MOLT4 xenograft model in vivo. Mechanistically, olverembatinib inhibited Lck phosphorylation, and when combined with lisaftoclax, synergistically reduced downstream NF-kB p65 and BCL-xL, which is typically upregulated in T-ALL. The combination also downregulated phosphorylation of AKT and GSK3b kinases, resulting in degradation of MCL-1 and c-MYC, an essential pro-oncogenic protein in T-ALL. In summary, our findings provide a scientific rationale for further clinical evaluation of this novel combination therapy in patients with T-ALL. Embryonic ectoderm development protein (EED) inhibitor APG-5918 exhibits potent antitumor activity and synergizes with androgen receptor (AR) inhibitor enzalutamide in preclinical prostate cancer (PCa) models Abstract#: 446Session: Experimental and Molecular Therapeutics Introduction: Castration-resistant prostate cancer (CRPC) remains incurable due to resistance to therapies including the new generation of androgen receptor pathway inhibitors (ARPIs) such as enzalutamide. Dysregulation of polycomb repressive complex 2 (PRC2) is common in PCa and is associated with poor prognosis and metastasis. The catalytic subunit of PRC2, enhancer of zeste homolog 2 (EZH2), promotes tumor suppressor gene silencing by methylating histone H3 on lysine 27 (H3K27me3) and directly activates AR gene expression. Another core PRC2 component, EED, is essential for the histone methyltransferase activity. Targeting EED has emerged as a promising strategy to inhibit PRC2 function. This study aims to evaluate the antitumor activity and molecular mechanisms of APG-5918, a potent and selective EED inhibitor, alone or in combination with enzalutamide, in preclinical PCa models. Summary: APG-5918 demonstrated superior inhibitory effects on PCa cell proliferation in vitro. APG-5918 in combination with enzalutamide synergistically suppressed cell proliferation. APG-5918 induced dose-dependent cell cycle arrest in LNCaP and C4-2B cells. Combining enzalutamide with APG-5918 deepened G0/G1 cell cycle arrest. APG-5918 showed significant antitumor activity in human LNCaP and enzalutamide-resistant 22Rv1 xenograft models in castrated nude mice. Mechanistically, APG-5918 downregulated key on-target PD markers (e.g., H3K27me3, EED, EZH2, SUZ12) and AR pathway proteins. APG-5918 also suppressed oncogenic driver ERG, DNA methylation factors (UHRF1, DNMT1), and antiapoptotic protein MCL-1, and reduced pRb, CDK4, cyclin B1 and cyclin D1—crucial mediators of cell cycle regulation. APG-5918 combined with enzalutamide further enhanced the downregulation of PRC2 components, AR pathway proteins, cell cycle regulators, oncogenic drivers, and DNA methylation factors. Our findings support EED inhibition, alone or in combination with enzalutamide, as a promising therapeutic strategy for the treatment of patients with prostate cancer, which is being further evaluated in the ongoing Phase 1 clinical trial. APG-2449, a novel focal adhesion kinase (FAK) inhibitor, enhances the antitumor activity of chemotherapy in preclinical models of small-cell lung cancer (SCLC) with activated FAK Abstract#: 1679Session: Drug Combination Strategies for Cancer Treatment Introduction: SCLC is a genetically heterogeneous disease with no standardized targeted therapy options. Despite the recent advancement of immune checkpoint inhibitors, improvements in overall survival have been modest, and platinum-based chemotherapy combined with topoisomerase inhibitors remains the standard of care in SCLC. FAK, a nonreceptor tyrosine kinase, has been reported to regulate cellular proliferation, migration, invasion, and DNA-damage repair. Previous studies have shown that FAK is amplified and overexpressed in approximately 69% of SCLC tumors. Although non-small-cell lung cancer cells harboring FAK (splicing isoform of FAK that increases phosphorylation of FAK [pFAK]) are more sensitive to FAK inhibition than wild-type FAK (FAKWT), the expression and implications of FAK expression in SCLC remain unclear. Given the role of FAK in cancer progression, we hypothesized that inhibition of FAK would augment the antitumor effects of chemotherapy in SCLC. The aim of this study was to evaluate the antitumor activity of investigational agent APG-2449, a novel FAK inhibitor, alone and in combination with chemotherapy in SCLC. Summary: Novel FAK inhibitor APG-2449 demonstrated synergistic antitumor effects when combined with first- and second-line chemotherapies in SCLC. APG-2449 combined with chemotherapy can enhance DNA damage and increase apoptosis in SCLC cells. These encouraging findings support further clinical development of APG-2449 for the treatment of patients with SCLC. Discovery of AS03157 as a highly potent and orally active antagonist of inhibitor of apoptosis proteins (IAPs) Abstract#: 5651Session: Novel Antitumor Agents 3 Introduction: Overexpression of antiapoptotic proteins, such as cellular inhibitor of apoptosis protein 1 (cIAP1) and 2 (cIAP2) and X-linked IAP (XIAP), occurs in various hematologic and solid cancers, and is associated with drug resistance and a poor prognosis. IAP inhibitors bind to IAP proteins, displace and activate caspases, and induce degradation of cIAP1/2 and XIAP, thereby inhibiting pro-survival signaling and promoting apoptosis in cancer cells. Several small molecules targeting IAPs are being investigated clinically as monotherapy or in combination therapy in hematologic malignancy and solid tumors. Investigational AS03157, a novel and structurally distinct IAP antagonist, was identified with enhanced specificity toward cIAP1 and XIAP. Here, we characterized the pharmacologic profiles of AS03157 in vitro and in vivo. Summary: AS03157 bound to cIAP1 and XIAP with high affinity and efficiently targeted cIAP1 for degradation, thereby generating potent antiproliferative activities (with IC50 values below 30 nM) in tested cancer cell lines. AS03157 demonstrated a favorable druggability profile. AS03157 showed promising in vivo activity in preclinical cancer models and displayed an acceptable safety profile. In summary, AS03157 appears to be a promising candidate for further clinical development. * Olverembatinib, lisaftoclax, APG-2449, APG-5918 and AS03157 are all investigational drugs and have not been approved by the U.S. FDA. About Ascentage PharmaAscentage Pharma is a global, integrated biopharmaceutical company engaged in discovering, developing and commercializing therapies to address global unmet medical needs primarily in hematological malignancies. Ascentage Pharma has been listed on the Main Board of the Stock Exchange of Hong Kong Limited with the stock code 6855.HK since October 2019 and has also been listed on the Nasdaq Global Market under the ticker symbol “AAPG” since January 2025. The company has built a rich pipeline of innovative drug candidates that includes inhibitors targeting key proteins in the apoptotic pathway, such as Bcl-2 and MDM2-p53; and next-generation TKIs that target kinase mutants emergent during cancer treatment. Ascentage Pharma is also the only company in the world with active clinical programs targeting all known key apoptosis regulators. Olverembatinib, one of the company’s lead assets, is already approved in China with all of its approved indications included into the China National Reimbursement Drug List (NRDL). Meanwhile, a New Drug Application (NDA) for another one of Ascentage Pharma’s key drug candidates, the novel Bcl-2 selective inhibitor lisaftoclax (APG-2575), has already been accepted and granted the Priority Review designation by the China CDE. To date, Ascentage Pharma has obtained a total of 16 ODDs from the US FDA and 1 Orphan Designation from the EMA of the EU for 4 of the company’s investigational drug candidates. Leveraging its robust R&D capabilities, Ascentage Pharma has built a portfolio of global intellectual property rights and entered into global partnerships and other relationships with numerous leading biotechnology and pharmaceutical companies such as Takeda, AstraZeneca, Merck, Pfizer and Innovent; and research and development relationships with leading research institutions such as Dana-Farber Cancer Institute, Mayo Clinic, National Cancer Institute and the University of Michigan. The company has built a talented team with a wealth of global experience in the discovery and development of innovative drugs and fully functional commercial manufacturing and Sales & Marketing teams. One pivotal aim of Ascentage Pharma is to continuously strengthen its R&D capabilities and accelerate its clinical development programs, in order to fulfil its mission of addressing unmet clinical needs in China and around the world for the benefit of more patients. Forward-Looking StatementsThis press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical facts, contained in this press release may be forward-looking statements, including statements that express Ascentage Pharma’s opinions, expectations, beliefs, plans, objectives, assumptions or projections regarding future events or future results of operations or financial condition. These forward-looking statements are subject to a number of risks and uncertainties as discussed in Ascentage Pharma’s filings with the SEC, including those set forth in the sections titled “Risk factors” and “Special note regarding forward-looking statements and industry data” in its Registration Statement on Form F-1, as amended, filed with the SEC on January 21, 2025 and the Form 20-F filed with the SEC on April 16, 2025, the sections headed “Forward-looking Statements” and “Risk Factors” in the prospectus of the Company for its Hong Kong initial public offering dated October 16, 2019, and other filings with the SEC and/or The Stock Exchange of Hong Kong Limited we made or make from time to time that may cause actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements contained in this presentation do not constitute profit forecast by the Company’s management. As a result of these factors, you should not rely on these forward-looking statements as predictions of future events. The forward-looking statements contained in this press release are based on Ascentage Pharma’s current expectations and beliefs concerning future developments and their potential effects and speak only as of the date of such statements. Ascentage Pharma does not undertake any obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Contact InformationInvestor Relations:Hogan Wan, Head of IR and StrategyAscentage PharmaHogan.Wan@ascentage.com+86 512 85557777 Stephanie CarringtonICR HealthcareStephanie.Carrington@icrhealthcare.com(646) 277-1282 Media Relations:Sean LeousICR HealthcareSean.Leous@icrhealthcare.com(646) 866-4012

Data presented at the American Association for Cancer Research (AACR) Annual Meeting 2025 Dose Finding completed with no dose limiting toxicities and preliminary recommended Phase 2 dose (RP2D) identified 5 of 7 best overall response evaluable patients achieved ORR (3 CR, 1 CRh and 1 morphologic leukemia-free state) across all dose cohorts, including 1 CR and 1 CRh in 3 patients in preliminary RP2D cohort 4 of 4 cCR patients were measurable residual disease (MRD) negative as assessed by local standard of care Early deep responses with SENTI-202 noted across dose levels with all cCRs ongoing as of the data cut and longest durability of 8+ months Company to host webcast to discuss the new Phase 1 SENTI-202 data today, April 28th at 8:30 AM ET; Register Here Announces certain preliminary first quarter 2025 financial results and provides pipeline update SOUTH SAN FRANCISCO, Calif., April 28, 2025 (GLOBE NEWSWIRE) -- Senti Biosciences, Inc. (Nasdaq: SNTI) (“Senti Bio” or the “Company”), a clinical-stage biotechnology company developing next-generation cell and gene therapies using its proprietary Gene Circuit platform, today reported additional positive preliminary data from a Phase 1 clinical trial of SENTI-202, a potential first-in-class off-the-shelf Logic Gated selective CD33 OR FLT3 NOT EMCN chimeric antigen receptor natural killer (CAR-NK) investigational cell therapy, for the treatment of relapsed/refractory (R/R) hematologic malignancies including acute myeloid leukemia (“AML”). As previously announced, the Company will host a conference call and webcast to discuss the presented data today, April 28, 2025, at 8:30 AM ET (details below). SENTI-202 CLINICAL DATA UPDATE The positive preliminary SENTI-202 clinical data was presented on April 27 in a Clinical Trials Oral Minisymposium at the American Association for Cancer Research (AACR) Annual Meeting 2025 in an abstract titled, “First-in-human, multicenter study of SENTI-202, a CD33/FLT3 selective off-the-shelf logic gated CAR NK cell therapy in hematologic malignancies including AML: Clinical data.” Timothy Lu, MD, PhD, Co-Founder and CEO of Senti Biosciences, commented, “Senti was founded on engineering Logic Gated cell therapies with the enhanced ability to selectively kill cancer cells and protect healthy cells for cancer indications not addressable by existing drugs. Building upon these exciting results, we are continuing to prioritize development of our Logic Gating programs, including SENTI-202 and additional discovery efforts for solid tumors.” SENTI-202 Clinical Results Summary As presented at AACR, 9 patients with relapsed or refractory AML have been treated with various doses of SENTI-202 in the dose finding part of the study and 7 were evaluable for overall response at the data cut-off. The Phase 1 study evaluated two dose levels (1 or 1.5 x 109 CAR NK cells/ dose) and two schedules (3 or 5 doses) of SENTI-202 administered every 28 days on Days 0,7,14 or Days 0,3,7,10,14, respectively, following lymphodepletion with fludarabine/Ara-C. SENTI-202 was well-tolerated with no dose limiting toxicities and a maximum tolerated dose was not reached. The preliminary recommended Phase 2 dose (RP2D) was identified based on the totality of clinical data, including efficacy, as 1.5 x 109 CAR NK cells administered on Days 0,7,14 in 28-day Cycles following lymphodepleting chemotherapy. Efficacy 2 of 3 patients in the preliminary RP2D cohort achieved a composite Complete Remission (cCR); 5 of the 7 best overall response evaluable patients achieved an ORR (cCR + morphologic leukemia-free state) outcome and 4 of the 7 achieved cCR (3 CR with full hematologic recovery, and 1 CRh (CR with partial hematologic recovery)). 4 of 4 cCR patients were MRD- (Measurable Residual Disease Negative) as assessed by local standard of care. All cCR patients continue in remission with the longest follow up being 8+ months, and 3 patients received a bone marrow transplant after treatment with SENTI-202. Pharmacokinetics (PK) SENTI-202 was detected in all treated patients, consistent with other allogeneic CAR NK cell therapy PK profiles, namely with modest expansion in the first 14 days in the periphery followed by clearance from peripheral blood. Bone marrow Cytometry by Time of Flight (CyTOF) analyses SENTI-202 treatment decreased AML blasts and leukemia stem cell (LSC) frequencies and maintained (or increased) healthy hematopoietic stem and progenitor cell (HSPC) frequencies in patients achieving cCR, consistent with the SENTI-202 Logic Gated gene circuit’s designed mechanism of action. Safety SENTI-202 is generally well tolerated with an adverse event profile that is consistent with other investigational NK cell therapies and patients with underlying AML receiving lymphodepleting chemotherapy. In terms of Grade 3 or higher events in >1 patient on trial, four patients each reported grade 3 or higher febrile neutropenia and decreased platelet count, and two patients each reported grade 3 anemia and abdominal pain, but these side effects were either deemed unrelated to SENTI-202 or resulting from the lymphodepleting chemotherapy in all patients except one. No grade 5 adverse events were observed. 2 of 3 patients in the preliminary RP2D cohort achieved a composite Complete Remission (cCR); 5 of the 7 best overall response evaluable patients achieved an ORR (cCR + morphologic leukemia-free state) outcome and 4 of the 7 achieved cCR (3 CR with full hematologic recovery, and 1 CRh (CR with partial hematologic recovery)). 4 of 4 cCR patients were MRD- (Measurable Residual Disease Negative) as assessed by local standard of care. All cCR patients continue in remission with the longest follow up being 8+ months, and 3 patients received a bone marrow transplant after treatment with SENTI-202. SENTI-202 was detected in all treated patients, consistent with other allogeneic CAR NK cell therapy PK profiles, namely with modest expansion in the first 14 days in the periphery followed by clearance from peripheral blood. SENTI-202 treatment decreased AML blasts and leukemia stem cell (LSC) frequencies and maintained (or increased) healthy hematopoietic stem and progenitor cell (HSPC) frequencies in patients achieving cCR, consistent with the SENTI-202 Logic Gated gene circuit’s designed mechanism of action. SENTI-202 is generally well tolerated with an adverse event profile that is consistent with other investigational NK cell therapies and patients with underlying AML receiving lymphodepleting chemotherapy. In terms of Grade 3 or higher events in >1 patient on trial, four patients each reported grade 3 or higher febrile neutropenia and decreased platelet count, and two patients each reported grade 3 anemia and abdominal pain, but these side effects were either deemed unrelated to SENTI-202 or resulting from the lymphodepleting chemotherapy in all patients except one. No grade 5 adverse events were observed. The Phase 1 study of SENTI-202 is continuing to enroll to confirm the preliminary RP2D followed by disease specific expansion cohorts. The trial is funded in part by a grant from the California Institute for Regenerative Medicine. Kanya Rajangam, MD, PhD, President, Head of R&D and Chief Medical Officer of Senti Bio, summarized, “Based on our clinical, correlative and preclinical data, we believe SENTI-202 has the potential to provide a safe and effective treatment option for AML. We remain focused on the successful execution of the study and look forward to further exploring SENTI-202’s potential.” Stephen A. Strickland, Jr., MD, MSCI, Director, Leukemia Research for Sarah Cannon Research Institute, and the lead author for the AACR abstract, added, “While preliminary, the results demonstrated by SENTI-202 to date continue to be encouraging. There remains a significant unmet medical need in AML for treatments that can overcome tumor heterogeneity and spare healthy cells. Early results are encouraging, not only for the deep durable complete remissions, but also for the excellent safety profile noted thus far. I look forward to seeing additional data and exploring the potential of SENTI-202 to provide a much-needed treatment option to people living with AML.” ADDITIONAL DATA TO BE PRESENTED In addition to the Oral Minisymposium, Senti will be presenting data on SENTI-202 in two additional posters during the AACR meeting. CONFERENCE CALL AND WEBCAST DETAILS Senti Bio management will host a conference call and webcast for investors, analysts and other interested parties to discuss the data presented at AACR today, April 28, 2025, at 8:30 AM ET. Interested participants may access the call by dialing (877) 524-8416 (Domestic) +1 (412) 902-1028 (International). The webcast will be accessible on the Events page under the Investors section of the Company’s website (www.sentibio.com), and will be archived for 90 days. FIRST QUARTER PRELIMINARY FINANCIAL HIGHLIGHTS Senti Bio also announced certain preliminary, unaudited financial results for the first quarter of 2025. These preliminary financial results are subject to change. Final unaudited financial results will be available upon the filing of the Company’s Quarterly Report on Form 10-Q with the Securities and Exchange Commission on or about May 6, 2025. Cash and Cash Equivalents: As of March 31, 2025, Senti Bio held cash and cash equivalents of approximately $33.8 million. R&D Expenses: Research and development expenses were $9.3 million and $8.8 million for the three months ended March 31, 2025 and 2024, respectively. The increase of $0.5 million was primarily due to an increase of $1.4 million in external services and supplies cost, offset by a decrease of $0.8 million in personnel-related expenses, including stock-based compensation and $0.2 million in facilities and other cost. G&A Expenses: General and administrative expenses were $7.1 million and $7.5 million for the three months ended March 31, 2025 and 2024, respectively. The decrease of $0.4 million was primarily due to a decrease of $0.9 million in personnel-related expenses offset by an increase of $0.5 million in external services and supplies cost. Net Loss: Net loss was $14.1 million, or $1.41 per basic and diluted share, for the quarter ended March 31, 2025. ADDITIONAL PIPELINE UPDATE SENTI-301A for HCC: As previously announced, Senti Bio has collaborated with Celest Therapeutics (Shanghai) Co. Ltd. (Celest) to evaluate SN301A in a single center Investigator Sponsored Trial in China. SN301A is a Celest product which incorporates Senti’s SENTI-301A gene circuit into Celest’s CAR-NK cells, which are made using Celest’s manufacturing platform in China, which is distinct from Senti Bio’s manufacturing process. Based on the observation of certain dose limiting toxicities in the SN301A Investigator Sponsored Trial, enrollment has been stopped. Senti is evaluating next steps with SENTI-301A/SN301A as part of ongoing pipeline prioritization. About SENTI-202 SENTI-202 is a First-in-Class Off-the-Shelf Logic Gated Selective CD33 OR FLT3 NOT EMCN CAR NK Cell Therapy product candidate designed to selectively target and eliminate CD33 and/or FLT3-expressing hematologic malignancies, such as AML and myelodysplastic syndrome (“MDS”), while sparing healthy bone marrow cells. SENTI-202 has three main components. First, SENTI-202 contains an OR GATE (providing a “kill” signal), which is an activating CAR that recognizes CD33 and/or FLT3. By targeting either or both of these antigens, SENTI-202 is designed to effectively kill both leukemic blasts and leukemia stem cells, which constitute a difficult-to-eradicate reservoir of AML disease. Second, SENTI-202 contains a NOT GATE (providing a “protect” signal), which is an inhibitory CAR that is designed to recognize healthy cells and protect those healthy cells from being killed, even if they were to express CD33 and/or FLT3, thus potentially widening the therapeutic window. Third, SENTI-202 contains calibrated-release IL-15 (providing an “enhance” signal), which is designed to significantly increase cell persistence, expansion and activity of both the CAR-NK cells and host immune cells. The NK cells used to manufacture SENTI-202 are sourced from selected healthy adult donors. Senti Bio is currently enrolling adult patients with R/R CD33 and/or FLT3-expressing heme malignancies in a Phase 1 clinical trial for SENTI-202, which can be a potential first-in-class allogeneic off-the-shelf treatment for AML/MDS patients. Senti Bio has published SENTI-202 preclinical data demonstrating the potential of Logic Gated CAR-NK cell therapy for the treatment of AML. About AML AML is a cancer of the blood and bone marrow and is the most common type of acute leukemia in adults. It is estimated there were 20,800 new cases of AML in the United States in 2024. The five-year survival rate for these patients is approximately 30%. AML is currently treated with chemotherapy, targeted therapies, and/or allogeneic or autologous stem cell transplant. For patients with R/R AML, there are few treatment options and median overall survival is typically approximately five months. About Senti Bio Senti Bio is a biotechnology company developing a new generation of cell and gene therapies for patients living with incurable diseases. To achieve this, Senti Bio is leveraging its synthetic biology platform to engineer Gene Circuits into new medicines with enhanced precision and control. These Gene Circuits are designed to precisely kill cancer cells, to spare healthy cells, to increase specificity to target tissues, and/or to be controllable even after administration. The Company’s wholly-owned pipeline is comprised of cell therapies engineered with Gene Circuits to target challenging liquid and solid tumor indications. Senti’s Gene Circuits have been shown preclinically to work in both NK and T cells. Senti Bio has also preclinically demonstrated the potential breadth of Gene Circuits in other modalities and diseases outside of oncology, and continues to advance these capabilities through partnerships. Forward-Looking Statements This press release and document contain certain statements that are not historical facts and are considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements generally are identified by the words “believe,” “could,” “predict,” “continue,” “ongoing,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” “forecast,” “seek,” “target” and similar expressions that predict or indicate future events or trends or that are not statements of historical matters. Forward-looking statements are predictions, projections, and other statements about future events that are based on current expectations of Senti Bio’s management and assumptions, whether or not identified in this document, and, as a result, are subject to risks and uncertainties. Forward-looking statements include, but are not limited to, expectations regarding Senti Bio’s growth, strategy, progress and timing of its clinical trials for SENTI-202; the timing of availability of data from the ongoing Phase 1 clinical trial of SENTI-202; the ability of any product candidate to perform in humans in a manner consistent with nonclinical, preclinical or previous clinical study data; expectations regarding the anticipated dosing of patients and availability of data from clinical trials, and the timing thereof. These forward-looking statements are provided for illustrative purposes only and are not intended to serve as and must not be relied on by any investor as, a guarantee, an assurance, a prediction, or a definitive statement of fact or probability. Actual events and circumstances are difficult or impossible to predict and will differ from assumptions. Many actual events and circumstances are beyond the control of Senti Bio. Many factors could cause actual future results to differ materially from the forward-looking statements in this document, including but not limited to: (i) changes in domestic and foreign business, market, financial, political and legal conditions, (ii) changes in the competitive and highly regulated industries in which Senti Bio operates, variations in operating performance across competitors, changes in laws and regulations affecting Senti Bio’s business, (iii) the ability to implement business plans, forecasts and other expectations, (iv) the risk of downturns and a changing regulatory landscape in Senti Bio’s highly competitive industry, (v) risks relating to the uncertainty of any projected financial information with respect to Senti Bio, (vi) risks related to uncertainty in the timing or results of Senti Bio’s clinical trial start up, clinical studies, patient enrollment, and GMP manufacturing startup activities, (vii) Senti Bio’s dependence on third parties in connection with clinical trial startup, clinical studies, and GMP manufacturing activities, (viii) risks related to delays and other impacts from macroeconomic and geopolitical events, increasing rates of inflation and rising interest rates on business operations, (ix) risks related to the timing and utilization of the grant from CIRM, and (x) the success of any future research and development efforts by Senti Bio. The foregoing list of factors is not exhaustive. You should carefully consider the foregoing factors and the other risks and uncertainties described in the “Risk Factors” section of Senti Bio’s most recent periodic report filed with the U.S. Securities and Exchange Commission (“SEC”), and other documents filed by Senti Bio from time to time with the SEC. These filings identify and address other important risks and uncertainties that could cause actual events and results to differ materially from those contained in the forward-looking statements in this document. There may be additional risks that Senti Bio does not presently know, or that Senti Bio currently believes are immaterial that could also cause actual results to differ from those contained in the forward-looking statements in this document. Forward-looking statements speak only as of the date they are made. Senti Bio anticipates that subsequent events and developments may cause Senti Bio’s assessments to change. Except as required by law, Senti Bio assumes no obligation to update publicly any forward-looking statements, whether as a result of new information, future events, or otherwise. Availability of Other Information About Senti Biosciences, Inc. For more information, please visit the Senti Bio website at www.sentibio.com or follow Senti Bio on X (@SentiBio) and LinkedIn (Senti Biosciences). Investors and others should note that we communicate with our investors and the public using our company website (www.sentibio.com), including, but not limited to, company disclosures, investor presentations and FAQs, Securities and Exchange Commission filings, press releases, public conference call transcripts and webcast transcripts, as well as on X and LinkedIn. The information that we post on our website or on X or LinkedIn could be deemed to be material information. As a result, we encourage investors, the media and others interested to review the information that we post there on a regular basis. The contents of our website or social media shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended. Investor Contact: JTC Team, LLC Jenene Thomas (908) 824-0775 SNTI@jtcir.com