– 96% Overall Response Rate, 74% Stringent Complete Response/Complete Response, and 95% Minimal Residual Disease Negativity Observed at a Median 15.9-months of Follow-up, with Responses Continuing to Deepen Over Time –

– Observed Safety Profile is Predictable and Manageable to Date; No Delayed Neurotoxicities or Immune Effector Cell-Associated Enterocolitis across Phase 1 and 2 (iMMagine-1) Studies –

– Data from Investigational Agent Anito-cel Support Planned 2026 Launch in the U.S. –

Kite, a Gilead Company (Nasdaq: GILD), and its partner Arcellx, today announced new positive data from its pivotal iMMagine-1 Phase 2 study of anitocabtagene autoleucel (anito-cel), an investigational agent, which continues to show clinically meaningful deep and durable efficacy with predictable and manageable safety observed to date in relapsed or refractory multiple myeloma (RRMM) patients who had received at least three prior lines of therapy. These new findings from the ongoing study will be shared in an oral presentation (Abstract #256) today at 2:45 PM ET during the 67th American Society of Hematology (ASH) Annual Meeting and Exposition.

“These data are compelling and are an important advancement for patients living with multiple myeloma,” said Dr. Krina Patel, lead investigator, Associate Professor, Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center. “I am encouraged by the depth of responses in the iMMagine-1 study. For clinicians, we rely on therapies that deliver continued meaningful efficacy, a predictable safety profile, and reliable manufacturing. Anito-cel demonstrates that it could become a significant new treatment option in our efforts to improve outcomes for patients with multiple myeloma.”

Data from an October 7, 2025 cutoff date, including 117 patients treated with anito-cel, who were followed for a median of 15.9 months, showed an independent review committee (IRC)-assessed overall response rate (ORR) of 96%, with 74% achieving a stringent complete response or complete response (sCR or CR) per International Myeloma Working Group (IMWG) criteria. 102 of 117 patients (87%) were triple refractory, 48 of 117 patients (41%) were penta refractory, 21 of 117 patients (18%) had extramedullary disease, and 47 of 117 patients (40%) had high risk cytogenetics. For many in this heavily pre-treated population, responses began quickly, often within one month. Median time to best response was 4.8 months and median time to sCR or CR was 3.2 months. Of the 96 patients evaluable for minimal residual disease (MRD) testing, 91 (95%) achieved MRD negativity at a median time of 1 month, meaning no cancer cells could be detected even with highly sensitive tests (≤10^-5 sensitivity).

The progression-free survival (PFS) rates were 82.1% at 12 months, 67.4% at 18 months and 61.7% at 24 months, meaning many patients were still alive and free from cancer progression at those timepoints. The overall survival (OS) rates showed that a significant majority of patients remained alive, with 94% at 12 months, 88% at 18 months and 83% at 24 months. The median PFS and OS have not yet been reached, suggesting sustained and ongoing benefit for a majority of patients.

Importantly, no delayed (non-ICANS) neurotoxicities, including no Parkinsonism, no cranial nerve palsies, no Guillain-Barré syndrome, and no immune effector cell-associated enterocolitis, have been observed to date, with all patients dosed at least 12 months prior to the cutoff. In an exploratory study sponsored by Kite (Abstract #503), characterization of CD4+ CAR T cell subtypes provide further mechanistic hypotheses supporting the neurologic tolerability profile of anito-cel.

“For multiple myeloma patients in advanced treatment stages, effective options are critical as resistance to treatment grows,” said Cindy Perettie, Executive Vice President, Kite. “The deep, durable responses seen with iMMagine-1, combined with a predictable and manageable safety profile and rapid and reliable manufacturing, highlight anito-cel’s potential to redefine care. Together with Arcellx, our goal is to deliver a differentiated, one-time treatment option in 2026 that may reduce patient burden and improve access, including in outpatient and community oncology settings.”

Observed side effects were generally consistent with past readouts. Cytokine release syndrome (CRS) was observed in 86% of patients but was generally mild and manageable. In fact, 83% of patients in the study experienced no CRS or Grade 1 CRS (fever only). Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 8% of patients, with only one Grade 3 case and all other cases Grade 2 or lower. The most common hematologic adverse events noted during treatment were low white blood cell counts (neutropenia) in 71% of patients, low red blood cells (anemia) in 28%, and low platelets (thrombocytopenia) in 26%. Grade 3 or higher infections occurred in 9% of patients.

Additional research presented at ASH provided further insights into CAR T-cell therapies, detailing anito-cel's mechanism and factors influencing treatment outcomes.

Preclinical research (Abstract #7644) shows that anito-cel's D-Domain binder interacts with BCMA by binding and releasing quickly. Relative to a comparator CAR T-cell therapy in preclinical models, this transient interaction with cancer cells may be associated with decreased inflammation while maintaining the ability to effectively kill cancer cells. Additionally, the abstract shows anito-cel retains its ability to target cancer cells with altered BCMA expression after previous treatments, demonstrating the potential for anito-cel to maintain efficacy in patients previously exposed to BCMA-targeting therapies. Further research, including crystallography and epitope mapping, is ongoing to provide more detail on this mechanism.

About anitocabtagene autoleucel (anito-cel)

Anitocabtagene autoleucel (anito-cel, previously ddBCMA) is the first BCMA-directed CAR T-cell therapy to be investigated in multiple myeloma that utilizes Arcellx’s novel and compact binder known as the D-Domain. The small, stable D-Domain binder enables high CAR expression without tonic signaling and is designed to quickly release from the BCMA target. This combination may allow for the effective elimination of multiple myeloma cells without severe immunotoxicity. Anito-cel has been granted Fast Track, Orphan Drug, and Regenerative Medicine Advanced Therapy Designations by the U.S. Food and Drug Administration.

About Multiple Myeloma

Multiple myeloma (MM) is a type of hematological cancer in which diseased plasma cells proliferate and accumulate in the bone marrow, crowding out healthy blood cells and causing bone lesions, loss of bone density, and bone fractures. These abnormal plasma cells also produce excessive quantities of an abnormal immunoglobulin fragment, called a myeloma protein (M protein), causing kidney damage and impairing the patient’s immune function. MM is the third most common hematological malignancy in the United States and Europe, representing approximately 10% of all hematological cancer cases and 20% of deaths due to hematological malignancies. The median age of patients at diagnosis is 69 years with one-third of patients diagnosed at an age of at least 75 years. Because MM tends to afflict patients at an advanced stage of life, patients often have multiple comorbidities and toxicities that can quickly escalate and become life-endangering.

About iMMagine-1

iMMagine-1 is a Phase 2 registrational, pivotal open-label study of anito-cel in patients with relapsed or refractory multiple myeloma (RRMM) who have received at least three prior regimens of systemic therapy including proteasome inhibitor, immunomodulatory drugs (IMiD) and anti-CD38 antibody and are refractory to the last line of therapy.

The trial assessed both safety and efficacy in 117 patients receiving a single infusion of anito-cel (target dose of 115×10⁶ CAR+ viable T cells). Efficacy was assessed monthly for the first 6 months, then quarterly up to 2 years, or upon patient relapse. Long-term safety data will be collected under a separate long-term follow-up study for up to 15 years.

The primary endpoint is overall response rate (ORR) per International Myeloma Working Group (IMWG) criteria, as assessed by an independent review committee. Secondary endpoints include complete response rate (CR/sCR), progression-free survival, overall survival, duration of response, minimal residual disease negativity and safety.

About Gilead and Kite Oncology

Gilead and Kite Oncology are working to transform how cancer is treated. We are innovating with next-generation therapies, combinations and technologies to deliver improved outcomes for people with cancer. We are purposefully building our oncology portfolio and pipeline to address the greatest gaps in care. From antibody-drug conjugate technologies and small molecules to cell therapy-based approaches, we are creating new possibilities for people with cancer.

About Arcellx and Kite Collaboration

Arcellx and Kite, a Gilead Company, formed a global strategic collaboration to co-develop and co-commercialize anito-cel for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). Anito-cel is currently being developed in a Phase 2 registrational study and a Phase 3 pivotal study for RRMM, iMMagine-3. Kite and Arcellx will jointly commercialize the anito-cel asset in the United States, and Kite will commercialize the product outside the United States.

Forward-Looking Statements

This press release includes forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including the ability of Gilead and Kite to initiate, progress or complete clinical trials within currently anticipated timelines or at all, and the possibility of unfavorable results from ongoing or additional clinical studies, including those involving anito-cel (such as iMMagine-1); uncertainties relating to regulatory applications and related filing and approval timelines, including pending or potential applications for indications currently under evaluation, and the risk that any regulatory approvals, if granted, may be subject to significant limitations on use or subject to withdrawal or other adverse actions by the applicable regulatory authority; the possibility that Gilead and Kite may make a strategic decision to discontinue development of these programs and, as a result, these programs may never be successfully commercialized for the indications currently under evaluation; and any assumptions underlying any of the foregoing. These and other risks are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, as filed with the U.S. Securities and Exchange Commission. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The reader is cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties and is cautioned not to place undue reliance on these forward-looking statements. All forward-looking statements are based on information currently available to Gilead and Kite, and Gilead and Kite assume no obligation and disclaim any intent to update any such forward-looking statements.

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