Sun Pharma's UNLOXCYT Shows Durable 50% Response in Advanced Skin Cancer Study

The study represents the second largest prospective study conducted in patients with locally advanced cutaneous squamous cell carcinoma treated with PD-(L)1 monotherapy.

The investigator-reviewed data showed that 64 patients with laCSCC received at least one dose of UNLOXCYT. The median age of patients was 77 years and 66 per cent of participants were male. Patients received a median of 29 doses over a median treatment duration of 60 weeks.

Sun Pharma reported that the objective response rate in the study was 50 per cent, including 17 patients or nearly 27 per cent achieving complete response and 15 patients or 23 per cent achieving partial response. Over a median follow-up period of 31 months, responses remained durable and the median duration of response had not yet been reached.

The company stated that only one patient experienced a Grade 3 or higher immune-related adverse event, which was dermatologic in nature and considered treatment-related.

Medical Oncologist Dr Rahul Ladwa, who is also the presenting study co-author at ASCO, said the findings demonstrated clinically meaningful efficacy and durable responses in patients with laCSCC along with a manageable safety profile.

According to the safety analysis, the most common adverse events observed in the study were anemia and diarrhea, each reported in 27 per cent of patients. Immune-related adverse reactions occurred in 34 per cent of patients, while Grade 3 or higher treatment-emergent adverse events were reported in 41 per cent of patients. None of the treatment-emergent adverse events were fatal.

Dr Emily Ruiz, Associate Professor of Dermatology at Harvard Medical School and study co-author, stated that cosibelimab appears to work differently from other checkpoint inhibitors by restoring adaptive immune response while engaging the innate immune system and preserving the PD-1/PD-L2 pathway.

Sun Pharma informed that the poster presentation titled “Efficacy and safety of cosibelimab 800 mg every 2 weeks for locally advanced cutaneous squamous cell carcinoma: Updated follow-up from a pivotal study” will be presented during the Melanoma/Skin Cancers poster session at ASCO on May 31, 2026 between 9 am and 12 pm CDT.

Ahmad Naim, Senior Vice President and North America Chief Medical Officer at Sun Pharma, said the data reinforce the company’s commitment to the skin cancer community and highlight durable clinical responses observed with UNLOXCYT after more than two and a half years of follow-up.

UNLOXCYT is indicated for treatment of adults with metastatic cutaneous squamous cell carcinoma or locally advanced CSCC who are not candidates for curative surgery or radiation therapy. The recommended dosage is 1,200 mg administered intravenously over 60 minutes every three weeks.

The company noted that the approved dosing schedule was based on pharmacokinetic and pharmacodynamic modelling demonstrating similar exposure and PD-L1 receptor coverage compared to the clinical trial regimen of 800 mg every two weeks.

According to the release, cutaneous squamous cell carcinoma is among the most common skin cancers globally. Around 40,000 patients in the United States progress to advanced disease annually, leading to nearly 15,000 deaths each year.

Sun Pharma highlighted that it has been expanding its presence in cutaneous oncology for more than two decades and continues to focus on specialty medicines and advanced skin cancer therapies globally.

The company also detailed important safety information for UNLOXCYT, including risks of immune-mediated adverse reactions, infusion-related reactions, transplant-related complications and embryo-fetal toxicity. Common adverse reactions include fatigue, musculoskeletal pain, rash, diarrhea, hypothyroidism, constipation, nausea, headache, pruritus, edema and infections.