Sun Pharmaceutical Industries Limited (Reuters: SUN.BO, Bloomberg: SUNP IN, NSE: SUNPHARMA, BSE: 524715) announced that the US FDA has approved a revised label for UNLOXCYT™ (cosibelimab-ipdl). The therapy is indicated for adults with metastatic cutaneous squamous cell carcinoma (mCSCC) or locally advanced CSCC (laCSCC) who are not suitable candidates for curative surgery or curative radiation. The updated label now includes long-term findings from the pivotal CK-301-101 study, a multicentre, open-label trial involving 109 patients—31 with laCSCC and 78 with mCSCC—which demonstrated sustained and meaningful clinical responses with UNLOXCYT.
More than half of the patients in the study achieved the primary endpoint of objective response. Additionally, 14% of mCSCC patients and 32% of laCSCC patients achieved disease stability. At the time of the extended follow-up, the median duration of response had not been reached in either group. Many participants responded quickly, with median time to response at 1.9 months (range: 1.6–16.9) for mCSCC and 3.6 months (range: 1.7–10.1) for laCSCC. Common adverse reactions occurring in at least 10% of patients included fatigue, musculoskeletal pain, rash, diarrhea, hypothyroidism, constipation, nausea, headache, itching, swelling, localized infections, and urinary tract infections. Immune-mediated adverse reactions (imARs) were observed in 24% of patients, though high-grade events were rare. Only two patients (0.9%) experienced Grade 3 dermatologic imARs, and no treatment-related deaths were reported.
UNLOXCYT works by restoring adaptive immune activity, blocking PD-L1 from binding to PD-1 on T cells and B7.1 on antigen-presenting cells. It also activates the innate immune response through its Fc domain, which engages natural killer cells to trigger antibody-dependent cell-mediated cytotoxicity (ADCC). By sparing PD-L2, the therapy may help maintain immune tolerance in healthy tissues such as the liver and lungs, potentially reducing off-target immune reactions.
“The long-term results reinforce UNLOXCYT as a meaningful addition to the treatment landscape for advanced CSCC,” said Richard Ascroft, CEO, Sun Pharma North America. “These extended data show that more patients not only responded but maintained their responses longer than what was seen in the initial analysis. The updated label strengthens UNLOXCYT’s role as a next-generation checkpoint inhibitor.”
UNLOXCYT first received FDA approval in 2024. The updated label further highlights Sun Pharma’s commitment to data-driven innovation and to expanding its growing portfolio of differentiated immunotherapies in dermatologic oncology. Sun Pharma plans to introduce UNLOXCYT commercially in early 2026.
“Even with progress in aCSCC care, there is still a significant need for therapies that offer strong and long-lasting efficacy with manageable side effects—especially for older patients with multiple health conditions,” said Emily Ruiz, MD, MPH, Associate Professor of Dermatology at Harvard Medical School and primary author of the long-term data publication. “For many patients over 65 managing several comorbidities, UNLOXCYT offers an important option that balances effectiveness with tolerability.”
Sun Pharma is the world’s largest specialty generics company, with a portfolio spanning innovative medicines, generics, and consumer healthcare. It is India’s largest pharmaceutical manufacturer and a leading generics producer in the United States and key Emerging Markets. Its fast-growing global Innovative Medicines division covers dermatology, ophthalmology, and onco-dermatology, contributing around 20% of total revenue. With manufacturing sites across six continents and a workforce representing more than 50 nationalities, Sun Pharma supplies trusted therapies to patients in over 100 countries.
