8-K: Cullinan Therapeutics Delays Key Lupus Drug Data to H1 2026

Cullinan Therapeutics announced a delay in initial clinical data for its CLN-978 program in systemic lupus erythematosus to the first half of 2026, while other programs remain on track.

Summary

• Cullinan Therapeutics updated its corporate presentation, which is used in meetings with third parties and posted to its website.
• The anticipated timeline for announcing initial clinical data for the CLN-978 program in systemic lupus erythematosus (SLE) has been updated to the first half of 2026.
• The anticipated timeline for the announcement of clinical data for all other company programs remains unchanged.
• The company reported a cash position of $511 million as of June 30, 2025, providing a cash runway into 2028.
• Zipalertinib, an EGFR inhibitor for EGFR ex20ins NSCLC, met its primary endpoint (Objective Response Rate and Duration of Response) in the pivotal REZILIENT1 Phase 2b study.
• Taiho, a partner, is considering a potential New Drug Application (NDA) filing for Zipalertinib by year-end 2025 in relapsed EGFR ex20ins NSCLC.
• Velinotamig, a BCMAxCD3 bispecific T cell engager, demonstrated an 85.4% Overall Response Rate (ORR) in late-line relapsed/refractory multiple myeloma patients at the recommended Phase 2 dose.
• Genrix Bio plans to initiate a Phase 1 study of Velinotamig in China for autoimmune diseases later this year, which Cullinan expects to accelerate global development.
• CLN-049, an FLT3xCD3 bispecific T cell engager, is in Phase 1 for relapsed/refractory AML or MDS and for measurable minimal residual disease in AML, with clinical data expected in Q4 2025.
• CLN-978 is also being investigated in rheumatoid arthritis (RA) and Sjögren's disease (SjD), with initial data in RA expected in H1 2026.

Sentiment

Score: 6

Explanation: While the delay in CLN-978 SLE data is a negative, the company maintains a strong cash position into 2028, and its oncology program (Zipalertinib) shows promising pivotal data with a potential NDA filing by year-end 2025. The Velinotamig program also shows strong efficacy in multiple myeloma and is expanding into autoimmune diseases. The mixed news warrants a slightly positive sentiment as investors await further clinical readouts and regulatory progress across the diversified pipeline.

Positives

• The company maintains a strong cash position of $511 million as of June 30, 2025, providing a cash runway into 2028.
• Zipalertinib (EGFR inhibitor) met its primary endpoint of Objective Response Rate (ORR) and Duration of Response (DOR) in the pivotal REZILIENT1 Phase 2b study for EGFR ex20ins NSCLC.
• Zipalertinib demonstrated clinically meaningful efficacy, including a 24% ORR in patients previously treated with amivantamab, and a manageable safety profile.
• There is a potential New Drug Application (NDA) filing for Zipalertinib by Taiho by year-end 2025 in relapsed EGFR ex20ins NSCLC.
• Velinotamig (BCMAxCD3 bispecific T cell engager) showed a high Overall Response Rate (ORR) of 85.4% in late-line relapsed/refractory multiple myeloma patients.
• Velinotamig demonstrated a 79.2% ORR in patients with extramedullary disease (EMD), a particularly poor prognosis subset of multiple myeloma patients.
• Genrix Bio plans to initiate a Phase 1 study of Velinotamig in China for autoimmune diseases later this year, which is expected to accelerate global clinical development.
• Clinical data for CLN-049 (FLT3xCD3 bispecific T cell engager) in relapsed/refractory AML or MDS is expected in Q4 2025.
• Initial data for CLN-978 in Rheumatoid Arthritis (RA) is still expected in H1 2026, with other program timelines remaining unchanged.

Negatives

• The anticipated timeline for announcing initial clinical data for the CLN-978 program in systemic lupus erythematosus (SLE) has been delayed to the first half of 2026.

Risks

• Uncertainty regarding the timing and results of regulatory submissions.
• The risk that any INDs, NDAs, or other global regulatory submissions may not be cleared on expected timelines, or at all.
• The success of clinical trials and preclinical studies.
• Risks related to the company's ability to protect and maintain its intellectual property position.
• Risks related to manufacturing, supply, and distribution of product candidates.
• The risk that any one or more product candidates, including those that are co-developed, will not be successfully developed and commercialized.
• The risk that the results of preclinical studies or clinical studies will not be predictive of future results in connection with future studies.
• The success of any collaboration, partnership, license, or similar agreements.
• Other important risks and uncertainties discussed in the company's filings with the Securities and Exchange Commission, including under the caption Risk Factors in its most recent Annual Report on Form 10-K, Quarterly Report on Form 10-Q and other filings.

Future Outlook

Cullinan Therapeutics anticipates initial clinical data for its CLN-978 program in systemic lupus erythematosus in the first half of 2026, with initial data for CLN-978 in rheumatoid arthritis also expected in H1 2026. Genrix Bio plans to initiate a Phase 1 study of Velinotamig in autoimmune diseases in China later this year, which Cullinan expects to accelerate global development. Clinical data for CLN-049 in relapsed/refractory AML or MDS is expected in Q4 2025. Pending discussions with the U.S. FDA, Taiho may file an NDA for Zipalertinib in relapsed EGFR ex20ins NSCLC by year-end 2025. The REZILIENT3 frontline study for Zipalertinib is expected to complete enrollment in H1 2026, with further Zipalertinib data presentations scheduled for September and October 2025. The company is well-positioned to execute on strategic goals and advance to a commercial-stage organization, supported by a cash runway into 2028.

Management Comments

• Our Mission: Create new standards of care for patients.
• We use a unique R&D model of identifying high-impact targets and then applying the best modality to address each target.
• We are rigorously advancing only highly-differentiated molecules, yielding a robust portfolio of clinical-stage programs, including three T cell engagers, a core area of development expertise.
• Cullinan has a leadership position in the development of T cell engagers for autoimmune diseases with CLN-978 (CD19xCD3) and velinotamig (BCMAxCD3), utilizing a comprehensive potential disease modifying approach through both B cell and plasma cell depletion.
• We are simultaneously advancing a diversified pipeline of clinical-stage oncology programs, with multiple catalysts in 2025.
• We are well-positioned to execute on strategic goals and advance to a commercial-stage organization, with cash runway into 2028.

Industry Context

Cullinan Therapeutics operates in the highly competitive biopharmaceutical industry, focusing on both oncology and autoimmune diseases. The company's emphasis on T cell engagers for autoimmune conditions like SLE, RA, and SjD aligns with a growing industry trend to address the high unmet need for treatments that offer durable remissions beyond chronic immunosuppression. Its oncology pipeline, particularly Zipalertinib for EGFR ex20ins NSCLC and CLN-049 for AML, targets genetically defined patient populations with significant unmet needs, where current therapies often have limitations in efficacy or applicability. The development of bispecific T cell engagers represents a cutting-edge approach in both fields, aiming for more targeted and effective therapies.

Comparison to Industry Standards

• **CLN-978 (CD19xCD3 TCE for Autoimmune):** Positioned as potentially best-in-class, it aims for broader B cell lineage depletion due to very high affinity binding to CD19, offering a wider therapeutic index (10X higher potency for B cell depletion relative to cytokine induction) compared to other CD19 TCEs. Its half-life extended bispecific TCE format (65 kDa) and subcutaneous administration differentiate it from larger, IV-administered IgG-like molecules like Amgen's Blinatumomab (~55 kDa, IV) and other ~150 kDa IgG-like CD19 TCEs from Roche, Novartis, and Merck, as well as iTabMed's A-319 (~67 kDa, IV).
• **Velinotamig (BCMAxCD3 TCE for Multiple Myeloma/Autoimmune):** Demonstrated a higher Overall Response Rate (ORR) of 85.4% in relapsed/refractory multiple myeloma compared to approved BCMA TCEs such as Elranatamab (57.7%), Teclistamab (61.8%), and Linvoseltamab (70.9%). It also showed a higher ORR in patients with extramedullary disease (EMD) (79.2%) compared to Elranatamab (36.4%), Teclistamab (35.7%), and Linvoseltamab (52.6%), despite a larger proportion of EMD patients in its study. Its safety profile, while showing high rates of CRS and infection common to the class, reported no ICANS at the RP2D.
• **Zipalertinib (EGFR inhibitor for NSCLC):** Positioned as a selective EGFR inhibitor with best-in-class potential for EGFR ex20ins NSCLC. It demonstrated comparable efficacy (40% ORR) to Amivantamab (40% ORR) in patients treated with platinum-based chemotherapy. Zipalertinib offers an oral administration route (100mg twice daily) compared to Amivantamab's IV infusion, potentially improving patient convenience. While Amivantamab showed a longer median DOR (11.1 months vs. 8.8 months for Zipalertinib) and a slightly shorter median PFS (8.3 months vs. 9.5 months for Zipalertinib), Zipalertinib's safety profile showed lower rates of rash (30% vs. 84%) and infusion reactions (not reported vs. 64%) compared to Amivantamab, suggesting a potentially more manageable adverse event profile.

Stakeholder Impact

• **Shareholders:** The delay in CLN-978 SLE data may cause short-term concern, but strong cash runway into 2028 and positive pivotal data for Zipalertinib with potential NDA filing by year-end 2025 could provide long-term value.
• **Patients (Systemic Lupus Erythematosus):** Will experience a delay in the potential availability of CLN-978, a new treatment option.
• **Patients (EGFR ex20ins NSCLC):** May benefit from Zipalertinib as a new treatment option, especially for those who have progressed on platinum-based chemotherapy or prior amivantamab, given its promising efficacy and manageable safety profile.
• **Patients (Multiple Myeloma/Autoimmune Diseases):** Velinotamig's strong efficacy in multiple myeloma and planned expansion into autoimmune diseases could offer new therapeutic avenues.
• **Employees:** Continued progress across a diversified pipeline and strong financial position support ongoing research and development efforts.
• **Partners (Taiho Oncology, Genrix Bio):** Ongoing collaborations are progressing, with potential regulatory milestones and shared development/profit opportunities.

Next Steps

• Genrix Bio plans to conduct a Phase 1 study of Velinotamig in China in patients with autoimmune diseases beginning later this year (2025).
• Cullinan will conduct all further development of Velinotamig in autoimmune diseases following the completion of the Genrix Bio Phase 1 study.
• Clinical data for CLN-049 in relapsed/refractory AML or MDS is expected in Q4 2025.
• Initial results from REZILIENT2 Cohort C (zipalertinib monotherapy in patients with active brain metastases) to be shared at ESMO Congress 2025 in October 2025.
• Initial results from REZILIENT2 Cohort D (zipalertinib monotherapy in patients with uncommon EGFR mutations) to be shared at IASLC 2025 WCLC in September 2025.
• Updated efficacy and safety data for Zipalertinib in patients previously treated with amivantamab to be shared at the IASLC 2025 WCLC in September 2025.
• Pending discussions with the U.S. Food and Drug Administration, Taiho may file an NDA for Zipalertinib in relapsed EGFR ex20ins NSCLC by year-end 2025.
• The REZILIENT3 frontline study for Zipalertinib is expected to complete enrollment in H1 2026.
• Initial clinical data for CLN-978 in systemic lupus erythematosus is expected in H1 2026.
• Initial data for CLN-978 in rheumatoid arthritis is expected in H1 2026.
• Reviewing development of CLN-978 in additional autoimmune diseases.
• Opportunities to further mitigate Cytokine Release Syndrome (CRS) for Velinotamig are being implemented (alternative step-up dosing regimen, introduction of subcutaneous formulation).
• Augmented supportive care measures to reduce the risk of infection will be implemented in Velinotamig autoimmune studies.

Key Dates

Recommendation

The delay in CLN-978 SLE data introduces uncertainty for a key autoimmune program. However, the strong cash position and the promising pivotal data for Zipalertinib in NSCLC, with a potential NDA filing by year-end, provide significant upside. The Velinotamig program also shows strong efficacy in multiple myeloma and is expanding into autoimmune diseases. The mixed news warrants a 'hold' as investors await further clinical readouts and regulatory progress across the diversified pipeline.

Keywords

Cullinan Therapeutics, CLN-978, Systemic Lupus Erythematosus, SLE, Rheumatoid Arthritis, RA, Sjögren's Disease, SjD, Velinotamig, BCMAxCD3, Multiple Myeloma, Autoimmune Diseases, Zipalertinib, EGFRex20ins NSCLC, Non-Small Cell Lung Cancer, CLN-049, FLT3xCD3, AML, MDS, T cell engager, Bispecific antibody, Oncology, Drug development, Clinical trials, SEC filing, 8-K