10-K: Arcellx to Merge with Gilead, Anito-cel BLA Accepted

Arcellx announced its acquisition by Gilead Sciences for $115.00 per share plus a $5.00 CVR, following FDA acceptance of its BLA for anito-cel in relapsed or refractory multiple myeloma.

Summary

• Arcellx is a clinical-stage biotechnology company focused on developing innovative immunotherapies for cancer and other incurable diseases, leveraging its proprietary D-Domain synthetic binding scaffold.
• The lead product candidate, anito-cel (BCMA-targeting ddCAR), is being evaluated for relapsed or refractory multiple myeloma (rrMM).
• Interim data from the pivotal Phase 2 iMMagine-1 study (October 7, 2025 data cutoff) in 117 rrMM patients showed a 96% overall response rate (ORR), 74% complete response or stringent complete response (CR/sCR), and 88% very good partial response (VGPR) or higher, with median progression-free survival (PFS) and overall survival (OS) not yet reached at 15.9 months median follow-up.
• Phase 1 anito-cel trial data (October 3, 2024 data cutoff) in 38 rrMM patients demonstrated a 100% ORR, 79% CR/sCR, and 92% VGPR or higher, with a median PFS of 30.2 months and median OS not reached at 38.1 months median follow-up.
• The Biologics License Application (BLA) for anito-cel to treat fourth line or later rrMM was submitted to the FDA on December 23, 2025, and accepted on February 20, 2026, with an anticipated PDUFA action date of December 23, 2026.
• On February 22, 2026, Arcellx entered into a Merger Agreement with Gilead Sciences, Inc. for an acquisition price of $115.00 per share in cash, plus one contractual contingent value right (CVR) of $5.00 per CVR.
• The CVR payment is contingent on cumulative worldwide sales of the anito-cel product exceeding $6.0 billion on or prior to December 31, 2029.
• Kite Pharma, a Gilead company, initiated a global Phase 3 iMMagine-3 randomized controlled clinical trial for anito-cel in second through fourth line rrMM in 2024, with full enrollment expected by mid-2026.
• Arcellx is also evaluating anito-cel for non-oncology indications, including generalized Myasthenia Gravis (gMG), with a Phase 1 trial initiated in the second half of 2025.
• The company reported net losses of $228.9 million for 2025, $107.3 million for 2024, and $70.7 million for 2023, with an accumulated deficit of $725.8 million as of December 31, 2025.
• Cash, cash equivalents, and marketable securities totaled $520.1 million as of December 31, 2025, which is believed to be sufficient to fund operations into 2028.

Sentiment

Score: 9

Explanation: StockSavvy.ai views this as highly positive due to the definitive merger agreement with Gilead, providing immediate and potential future value to shareholders, coupled with the FDA's acceptance of the BLA for anito-cel, validating the company's lead asset and technology.

Positives

• The definitive merger agreement with Gilead Sciences, Inc. for $115.00 per share in cash plus a $5.00 CVR provides significant immediate value and potential upside for shareholders.
• The FDA accepted the Biologics License Application (BLA) for anito-cel for rrMM, assigning a PDUFA action date of December 23, 2026, indicating progress towards potential market approval.
• Anito-cel's pivotal Phase 2 iMMagine-1 trial demonstrated strong efficacy with a 96% ORR and 74% CR/sCR rate in heavily pre-treated rrMM patients, with median PFS and OS not yet reached at 15.9 months follow-up.
• The safety profile of anito-cel in clinical trials showed no delayed or non-ICANS neurotoxicities (e.g., Parkinsonism, Guillain-Barr syndrome, IEC-EC), which is a potential differentiator compared to other approved CAR-T therapies.
• The collaboration with Kite Pharma (a Gilead company) provides established global CAR-T infrastructure, manufacturing expertise, and shared development/commercialization costs for anito-cel.
• The D-Domain technology shows potential manufacturing advantages, including high transduction rates, high cell surface expression, and low tonic signaling.
• Expansion of anito-cel into autoimmune disorders, such as generalized Myasthenia Gravis (gMG), diversifies the pipeline and addresses unmet medical needs outside oncology.
• The company maintains a strong intellectual property portfolio with 51 issued U.S. and foreign patents and over 100 pending applications.
• Current cash, cash equivalents, and marketable securities of $520.1 million are believed to be adequate to fund operations into 2028.

Negatives

• The company has a limited operating history and has incurred significant and increasing net losses, reaching $228.9 million in 2025, and an accumulated deficit of $725.8 million as of December 31, 2025.
• No product sales revenue has been generated to date, and future profitability is contingent on successful development, regulatory approval, and commercialization of product candidates.
• The company is highly dependent on third parties for conducting clinical trials and manufacturing, which introduces risks of delays, quality control issues, and supply constraints.
• The proposed merger with Gilead is subject to customary closing conditions, and its failure could result in a $260.0 million termination fee payable to Gilead.
• The contingent value right (CVR) payment of $5.00 per share is not guaranteed and depends on anito-cel achieving cumulative worldwide sales exceeding $6.0 billion by December 31, 2029.
• The biotechnology industry is characterized by intense competition, with many competitors possessing greater financial resources and expertise.
• There is a risk of unforeseen safety issues or inadequate efficacy emerging in later-stage clinical trials, despite promising early results.
• Market opportunities for product candidates may be limited by factors such as patient availability, competition, reimbursement coverage, and system capacity.

Risks

• Uncertainties exist regarding the timing and completion of the tender offer and subsequent merger with Gilead, with no assurance that all required approvals will be obtained or conditions satisfied.
• If the merger agreement is terminated under specified circumstances, Arcellx will be required to pay Gilead a termination fee of $260.0 million.
• The announcement or pendency of the merger may disrupt business operations, divert management's attention, and negatively impact relationships with third parties and employees.
• Stockholder litigation in connection with the merger transactions may result in significant defense costs, indemnification, and liability.
• Arcellx has a limited operating history and has incurred significant losses since inception, with anticipated continued losses for the foreseeable future, making future viability difficult to assess.
• Substantial additional funding may be required if the merger does not close or if operations extend beyond current cash runway, and such funding may not be available on acceptable terms or at all.
• The ddCAR and ARC-SparX platforms represent novel and unproven approaches, making it difficult to predict the timing, results, and costs of product candidate development and regulatory approval.
• Clinical trials are lengthy, expensive, and uncertain, with a high risk of failure to demonstrate adequate safety and/or efficacy, which could prevent or delay regulatory approval.
• Product candidates may cause undesirable side effects or have other properties that could halt clinical development, prevent regulatory approval, or limit commercial potential.
• Interim, preliminary, or topline data from clinical trials may change as more patient data become available and are subject to audit and verification procedures.
• Manufacturing genetically engineered products is complex and subject to human and systemic risks, production difficulties, sourcing constraints, and variations in key components.
• The company relies heavily on third parties to conduct clinical trials and manufacture product supplies, and their failure to perform could delay or prevent regulatory approval and commercialization.
• If Arcellx is unable to obtain and maintain sufficient intellectual property protection, competitors could commercialize similar products, adversely affecting business.
• Third-party claims of intellectual property infringement may prevent or delay product discovery and development efforts, leading to substantial litigation expense or the need for costly licenses.
• The price of Arcellx's common stock has been, and may continue to be, highly volatile and subject to wide fluctuations, potentially leading to loss of investment.

Future Outlook

Arcellx expects to continue incurring significant losses and increasing operating expenses for the foreseeable future as product candidates advance through clinical development and regulatory approval processes. The company anticipates requiring substantial additional funding to support its operations, unless the acquisition by Gilead closes. Plans include establishing commercialization infrastructure, advancing anito-cel in earlier lines of therapy and non-oncology indications, and expanding the pipeline through internal efforts or collaborations. The proposed acquisition by Gilead is expected to close during the second quarter of 2026, and current cash, cash equivalents, and marketable securities are believed to fund operations into 2028.

Management Comments

• "We believe immunotherapies are one of the forward pillars of medicine, and our mission is to advance humanity by engineering immunotherapies that are safer, more effective and more broadly accessible."
• "We believe we can address these limitations by engineering a new class of D-Domain powered immunotherapies, including classical single infusion CAR-Ts called ddCARs and dosable and controllable universal CAR-Ts called ARC-SparX, to address hematologic cancers, solid tumors, and indications outside of oncology, such as autoimmune diseases."
• "We believe these results from our pivotal Phase 2 iMMagine-1 trial along with the Phase 1 trial of anito-cel, which together supported the filing of a BLA to the FDA in December 2025, demonstrate the potential for anito-cel to become a best-in-class treatment for patients suffering from rrMM, including those considered high risk."
• "We believe our preliminary clinical data for anito-cel have demonstrated that D-Domains can potentially provide meaningful clinical benefits."
• "We believe our D-Domain technology is a transformational platform that enables us to take the right approach for the right indication within CAR-T."
• "Based on our current operating plan, we believe that our existing cash, cash equivalents, and marketable securities will be sufficient to fund our planned operations for at least the next twelve months, but our assumptions could prove to be wrong, and we could consume capital significantly faster than we expect, requiring us to seek additional funding sources sooner than planned, through public or private financings or other sources, such as strategic collaborations."

Industry Context

StockSavvy.ai notes that the acquisition of Arcellx by Gilead Sciences, a major player in the CAR-T space through Kite Pharma, validates Arcellx's D-Domain technology and anito-cel's potential. This move reflects the ongoing consolidation and strategic investments in the high-growth immunotherapy sector, particularly for promising late-stage assets in multiple myeloma. The CAR-T market for hematologic cancers exceeded $5.9 billion in 2025, growing 30% year-over-year, indicating strong industry momentum. The focus on addressing limitations of existing CAR-T therapies, such as toxicity and accessibility, positions Arcellx's D-Domain platform as a potential innovator in a competitive landscape.

Comparison to Industry Standards

• Anito-cel (Arcellx) Phase 2 iMMagine-1 (rrMM, >=3 prior lines, median 15.9 months follow-up): Achieved 96% ORR, 74% CR/sCR, 88% VGPR or higher, with median PFS and OS not reached. Notably, no delayed neurotoxicities were observed.
• Carvykti (Legend/Johnson & Johnson) Phase 1b/2 CARTITUDE-1 (rrMM, >=3 prior lines): Reported 97.9% ORR, 82% CR/sCR, estimated mPFS of 34.9 months, and estimated mOS of 60.7 months. However, it carries a Black Box warning for Parkinsonism, Guillain-Barr syndrome, and IEC-EC.
• Abecma (2seventy bio/Bristol Myers Squibb) Phase 2 KarMMa (rrMM, >=3 prior lines): Demonstrated 73.4% ORR, 33% sCR/CR, and an estimated mPFS of 8.8 months.
• Tecvayli (Johnson & Johnson) (BCMA-targeting bispecific antibody, rrMM, >=4 prior lines): Showed 63% ORR, 46% CR/sCR, and mPFS of 11.4 months, but requires weekly/biweekly dosing and hospitalization for initial titration.
• Elrexfio (Pfizer) (BCMA-targeting bispecific antibody, rrMM, >=4 prior lines): Reported 61% ORR, 37% CR/sCR, and mPFS of 17.2 months, also requiring weekly/biweekly dosing and initial hospitalization.
• Lynozyfic (Regeneron) (BCMA-targeting bispecific antibody, rrMM, >=4 prior lines): Achieved 70% ORR and 45% CR/sCR, with weekly, biweekly, or monthly dosing and initial hospitalization.
• Blenrep (GSK) (BCMA-targeting ADC, rrMM, >=2 prior lines, in combination): Reported 81.5% ORR, 31.5% CR/sCR, and mPFS of 31.3 months, but requires ophthalmic exams due to side effects.
• Anito-cel's efficacy data (ORR, CR/sCR) is competitive with or superior to existing BCMA-targeting CAR-T therapies and significantly better than bispecific antibodies and ADCs. Its differentiated safety profile, particularly the absence of delayed neurotoxicities, positions it favorably against Carvykti.

Corporate Governance

Legal Proceedings

• As of December 31, 2025, Arcellx was not a party to any material litigation or legal proceedings.
• The company may be subject to stockholder lawsuits challenging the transactions contemplated by the Merger Agreement with Gilead, which could result in significant costs of defense, indemnification, and liability.

Related Party Transactions

• Gilead Sciences, Inc. held approximately 11.5% of Arcellx's outstanding common stock as of December 31, 2025.
• Arcellx entered into a Collaboration and License Agreement with Kite Pharma, Inc. (a Gilead company) in December 2022, and an amendment in December 2023, for co-development and co-commercialization of anito-cel and other CAR-T products.
• Received a $225.0 million upfront cash payment from Kite in January 2023.
• Received an $85.0 million upfront cash payment from Kite in December 2023.
• Received $68.3 million from Kite in 2024 for achieving a clinical milestone related to anito-cel enrollment in the iMMagine-1 trial.
• Gilead made equity investments of $100.0 million in January 2023 (3,478,261 shares at $28.75/share) and $200.0 million in December 2023 (3,242,542 shares at $61.68/share).
• Gilead has certain demand registration rights for the shares it acquired, subject to limitations in the Amended Standstill Agreement.

Stakeholder Impact

• Shareholders: Will receive $115.00 per share in cash plus a CVR of $5.00 per share, offering a premium and potential future upside. However, the CVR is contingent on sales milestones, and the merger is subject to closing conditions.
• Employees: May experience uncertainty about future roles but could benefit from integration into a larger pharmaceutical company. Subject to strict insider trading policies with disciplinary actions for violations.
• Patients: Potential for a new, highly effective, and potentially safer treatment option for relapsed or refractory multiple myeloma (anito-cel), and future treatments for other cancers and autoimmune diseases.
• Kite Pharma (Gilead subsidiary): Will integrate anito-cel into its portfolio, leveraging its manufacturing and commercialization infrastructure, and sharing development costs and profits/losses in the U.S.
• Regulatory Authorities: Continued engagement with the FDA for BLA review and potential post-approval requirements for anito-cel.

Next Steps

• Gilead's Purchaser will commence a tender offer to acquire all outstanding shares of Arcellx common stock.
• The merger of Purchaser with and into Arcellx will be effected under Section 251(h) of the Delaware General Corporation Law.
• The acquisition by Gilead is expected to close during the second quarter of 2026.
• The FDA is expected to make a decision on the anito-cel BLA by the anticipated PDUFA action date of December 23, 2026.
• Kite Pharma expects the global Phase 3 iMMagine-3 trial for anito-cel to be fully enrolled by mid-2026.
• Arcellx will continue evaluating anito-cel for non-oncology indications, including the ongoing Phase 1 trial in generalized Myasthenia Gravis.
• The company will continue to advance its ARC-SparX programs, including ACLX-001, ACLX-002, and ACLX-004.
• Kite Pharma plans to initiate clinical trials of anito-cel in earlier lines of therapy (e.g., frontline) and in additional key geographies such as Europe and Asia.
• Arcellx and Kite will continue to invest in process improvements to reduce overall manufacturing time and improve costs.

Key Dates

Recommendation

The definitive merger agreement with Gilead Sciences at a substantial cash price per share, coupled with a contingent value right, offers a clear and attractive exit for shareholders. The FDA's acceptance of the BLA for anito-cel further de-risks the lead asset and validates the underlying technology, making the acquisition highly strategic and beneficial.

Keywords

Arcellx, Gilead Sciences, Acquisition, CAR-T, Immunotherapy, Multiple Myeloma, anito-cel, FDA BLA, PDUFA, D-Domain, ARC-SparX, Clinical Trials, Biotechnology, Oncology, Autoimmune Disease, Merger Agreement, Contingent Value Right, ACLX