8-K: Adicet Bio's ADI-001 Shows Positive Phase 1 Data in Lupus

Adicet Bio announced positive preliminary Phase 1 data for ADI-001 in lupus nephritis and systemic lupus erythematosus, demonstrating high response rates and a favorable safety profile.

Summary

• Seven patients (five Lupus Nephritis (LN) and two Systemic Lupus Erythematosus (SLE)) were evaluated with follow-up ranging from two to nine months.
• 100% of patients in the LN cohort achieved renal response, including three complete responses and two partial responses, with all responses ongoing.
• 100% of all patients saw rapid and sustained reductions in Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) and Physicians Global Assessment (PGA) scores.
• All patients discontinued immunosuppressants and either discontinued or tapered corticosteroids to physiological levels.
• ADI-001 demonstrated hallmarks of an immune reset, including elimination of dominant B cell clones and subsequent emergence of naive B cells and new B cell repertoire following single dose treatment.
• As of the August 31, 2025 cut-off date, ADI-001 was generally well tolerated with a favorable safety profile, showing no serious adverse events, no Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS), two Grade 1 cytokine release syndrome (CRS) cases, and one Grade 1 infection.

Sentiment

Score: 9

Explanation: The preliminary data is exceptionally strong, showing 100% response rates in a challenging disease, a favorable safety profile, and clear evidence of immune reset, positioning ADI-001 as a potential paradigm shift. The company also has a clear development path and sufficient cash.

Positives

• 100% of LN patients achieved renal response, including three complete renal responses and two partial renal responses, with all responses ongoing.
• 100% of all patients experienced rapid and sustained reductions in SLEDAI-2K and PGA scores, indicating a durable effect on a broad range of lupus symptoms.
• All patients discontinued immunosuppressants and either discontinued or tapered corticosteroids to physiological levels, suggesting a potential for treatment-free remission.
• Clear evidence of immune reset was observed, with elimination of dominant B cell clones and emergence of naive B cells and a new B cell repertoire after a single dose.
• ADI-001 demonstrated a favorable safety profile, with no serious adverse events, no ICANS, and only two Grade 1 CRS cases and one Grade 1 infection, supporting potential for outpatient administration.
• The company plans to request an FDA meeting in Q1 2026 to inform Phase 2 pivotal trial design, with study anticipated to commence in Q2 2026.
• The Phase 1 program is expanding to include enrollment for patients with systemic sclerosis (SSc), idiopathic inflammatory myopathy, stiff person syndrome, anti-neutrophil cytoplasmic autoantibody associated vasculitis, and rheumatoid arthritis (RA).
• More than 25 clinical sites globally are now open for enrollment for the Phase 1 study of ADI-001 in autoimmune indications.

Risks

• Global economic conditions and public health crises could disrupt preclinical and clinical studies, business operations, employee hiring and retention, and ability to raise additional capital.
• Ability to execute strategy, including obtaining requisite regulatory approvals, may not occur on the expected timeline, if at all.
• Positive results, including interim results, from a preclinical or clinical study may not necessarily be predictive of the results of future or ongoing studies.
• Clinical studies may fail to demonstrate adequate safety and efficacy of product candidates, which would prevent, delay, or limit the scope of regulatory approval and commercialization.
• Regulatory approval processes of the U.S. Food and Drug Administration and comparable foreign regulatory authorities are lengthy, time-consuming, and inherently unpredictable.
• Ability to meet production and product release expectations may be challenged.

Future Outlook

Adicet plans to request an FDA meeting in Q1 2026 to inform the Phase 2 pivotal trial design for ADI-001 in LN/SLE, with study initiation anticipated in Q2 2026. Enrollment for ADI-001 Phase 1 will continue for LN/SLE and has expanded to other autoimmune indications including systemic sclerosis, idiopathic inflammatory myopathy, stiff person syndrome, anti-neutrophil cytoplasmic autoantibody associated vasculitis, and rheumatoid arthritis. For ADI-212, a regulatory filing for metastatic castration-resistant prostate cancer is planned for Q1 2026, with enrollment initiation in Q2 2026 and initial clinical data in H2 2026.

Management Comments

• "We are extremely encouraged to share preliminary results highlighting disease remissions or a halting of disease progression in the first seven patients treated in our Phase 1 trial. After a single dose of ADI-001, all patients discontinued immunosuppressant medications and all either discontinued or tapered corticosteroids to below physiological levels." Julie Maltzman, M.D., Chief Medical Officer.
• "ADI-001 has also demonstrated a favorable safety and tolerability profile with no ICANS, and only two patients experiencing Grade 1 CRS, which is promising and has the potential to support outpatient administration of ADI-001. In addition, ADI-001's potential availability as an off-the-shelf therapy may allow for far broader accessibility to many more patients and treating physicians." Julie Maltzman, M.D., Chief Medical Officer.
• "We believe ADI-001 represents a potential paradigm shift in the treatment of autoimmune diseases that traditionally has required chronic therapy to treat unpredictable and dangerous flares, potentially resulting in end-organ damage." Julie Maltzman, M.D., Chief Medical Officer.
• "These preliminary results reinforce our belief that ADI-001 has the potential to transform the treatment landscape for autoimmune diseases." Chen Schor, President and Chief Executive Officer.
• "We observed clear evidence of immune reset with subsequent emergence of nave B cell repertoire following a single treatment of ADI-001. ADI-001's potential to reset the immune system with a one-time, off-the-shelf therapy and a generally favorable safety profile could be practice-changing for patients and providers alike." Chen Schor, President and Chief Executive Officer.

Industry Context

The announcement positions ADI-001 as a potentially transformational, off-the-shelf, one-time therapy for autoimmune diseases, aiming to address the limitations of chronic therapies and the high unmet needs in conditions like LN and SLE. The favorable safety profile and immune reset mechanism suggest a competitive advantage in the emerging CAR-T landscape for autoimmune conditions, potentially offering a more accessible and safer alternative to existing autologous CAR-T therapies.

Comparison to Industry Standards

• ADI-001 (Adicet Bio): 7 SLE/LN patients, 28% any Grade CRS, no Grade 3 CRS, no ICANS, 14% any Grade infection.
• BMS-986353 (BMS): 11 SLE/LN patients, 55% any Grade CRS, no Grade 3 CRS, 9% any Grade ICANS, 20% any Grade infection (across 15 AID patients).
• Rapcabtagene-autoleucel (Novartis): 21 SLE/LN patients, 57% any Grade CRS, no Grade 3 CRS, 5% any Grade ICANS, 71% any Grade infection (5% Grade 3).
• Obecabtagene autoleucel (Autolus): 6 LN patients, 50% any Grade CRS, no Grade 3 CRS, no ICANS, 100% any Grade infection (33% Grade 3).
• Resecabtagene autoleucel (Cabaletta Bio): 8 SLE/LN patients, 25% any Grade CRS, no Grade 3 CRS, 13% any Grade ICANS (13% Grade 3), serious infections only reported.
• ADI-001's safety profile appears favorable compared to autologous CAR-T therapies, particularly regarding lower rates of CRS (28% vs. 25-100%) and infections (14% vs. 20-100%), and the absence of ICANS (0% vs. 0-13%).
• ADI-001 achieved 100% renal response in LN patients, including three complete and two partial responses, with all responses ongoing, and rapid/sustained reductions in SLEDAI-2K and PGA scores across all patients. This efficacy trend is comparable to or potentially better than that observed in other industry-sponsored autologous CD19 CAR-T trials for similar indications, which also show sustained reductions in SLEDAI.

Stakeholder Impact

• Shareholders: Highly positive clinical data and a clear development pathway could significantly increase share value and investor confidence.
• Patients: Potential for a one-time, off-the-shelf therapy with a favorable safety profile could offer a transformative treatment option for severe autoimmune diseases, reducing reliance on chronic immunosuppressants and corticosteroids.
• Healthcare Providers: The potential for outpatient administration could simplify treatment logistics and increase accessibility for patients.
• Employees: Positive clinical progress strengthens the company's position, enhances morale, and supports future growth and stability.

Next Steps

• Continue SLE and LN patient enrollment to the ongoing Phase 1 study until the Phase 2 pivotal study is open for enrollment.
• Enroll patients with systemic sclerosis (SSc), idiopathic inflammatory myopathy, stiff person syndrome, anti-neutrophil cytoplasmic autoantibody associated vasculitis, and rheumatoid arthritis (RA) into the Phase 1 program.
• Request a meeting with the U.S. Food and Drug Administration (FDA) in Q1 2026 to inform Phase 2 pivotal trial design for ADI-001.
• Initiate Phase 2 pivotal study for ADI-001 in LN or LN/SLE in Q2 2026.
• Provide SLE and LN clinical updates in H1 2026 and H2 2026.
• Align with FDA on pivotal study design in LN or LN/SLE in H1 2026.
• Provide SSc clinical updates in H1 2026 and H2 2026.
• Provide potential clinical updates in other autoimmune indications in H1 2026 and H2 2026.
• Provide clinical update in RA with cyclophosphamide/fludarabine vs cyclophosphamide only conditioning in H2 2026.
• Submit a regulatory filing for ADI-212 for the treatment of metastatic castration-resistant prostate cancer in Q1 2026.
• Initiate enrollment for ADI-212 in Q2 2026.
• Provide initial clinical data for ADI-212 in H2 2026.

Key Dates

Recommendation

The preliminary Phase 1 data for ADI-001 in lupus nephritis and systemic lupus erythematosus is exceptionally strong, demonstrating 100% renal response in LN patients and significant disease activity reductions across all patients, coupled with a highly favorable safety profile compared to other CAR-T therapies. The clear evidence of immune reset and the potential for a one-time, off-the-shelf, outpatient-administered therapy represent a significant advancement in autoimmune disease treatment. The company has a well-defined regulatory and clinical development pathway for ADI-001 and ADI-212, supported by a solid cash position. These results suggest a high probability of success in future trials and a potentially transformative impact on patient care, making the stock a compelling 'strong buy' for long-term investors.

Keywords

Adicet Bio, ADI-001, Lupus Nephritis, Systemic Lupus Erythematosus, Autoimmune Disease, CAR-T Therapy, Gamma Delta T Cell, Phase 1 Clinical Trial, Biotechnology, Clinical Data, FDA, Immunosuppressants, Corticosteroids, Immune Reset, SLEDAI-2K, PGA, Renal Response, Off-the-shelf, Oncology, ADI-212, Prostate Cancer