Regeneron Pharmaceuticals and ISA Pharmaceuticals B.V., a clinical-stage immunotherapy company, have announced a clinical collaboration to advance ISA101, an immunotherapy targeting human papillomavirus type 16 (HPV16)-induced cancer, in combination with cemiplimab (REGN2810), a PD-1 (programmed cell death protein 1) antibody. Regeneron and ISA will jointly fund and conduct clinical trials of the combination treatment in cervical cancer and head-and-neck cancer.

Expression of HPV oncoproteins contributes to the development of cervical and head-and-neck cancers, and approximately 55 per cent of cervical cancers and over 60 per cent of head-and-neck cancers are HPV16 positive.

Regeneron and ISA will share clinical trial costs and exchange product supply. In addition, Regeneron will provide an upfront payment and an equity investment in exchange for an option to an exclusive, global license for ISA101. If Regeneron exercises its option to commercialize ISA101, there is potential for various milestone payments and tiered royalty payments to ISA contingent on regulatory approvals, sales and additional indications. Further financial details were not disclosed.

"Regeneron continues to expand and advance our immuno-oncology program by studying multiple combination therapies in order to fully explore the scientific possibilities in this relatively new field," said Israel Lowy, M.D., Ph.D., vice president clinical sciences, head of Translational Science and Oncology at Regeneron. "Early clinical results with ISA101 in HPV16-positive indications have been promising, and we're eager to investigate the impact of adding cemiplimab with the goal of further enabling the body's immune system to attack the cancer."

"This collaboration with Regeneron is a strong validation of our proprietary SLP (Synthetic Long Peptides) platform and know-how," added Ronald Loggers, chief executive officer of ISA Pharmaceuticals. "We are proud to work with Regeneron, a science- and technology-driven biotechnology company, and aim to further strengthen our pioneering role in the development of innovative treatment options for oncology indications with a high unmet medical need."

Cemiplimab is being jointly developed by Regeneron and Sanofi under a global collaboration agreement for immuno-oncology therapeutics, and was developed using Regeneron's proprietary VelocImmune technology that yields optimized fully-human antibodies. Cemiplimab is currently being studied as a monotherapy in multiple cancers - including cutaneous squamous cell carcinoma (CSCC), basal cell carcinoma (BCC), non-small cell lung cancer (NSCLC) and cervical cancer - and in various therapeutic combinations. Cemiplimab is currently under clinical development, and its safety and efficacy have not been fully evaluated by any regulatory authority.

ISA101 is an SLP immunotherapy based on the delivery of oncogenic antigens in the form of synthetic long peptides and targets HPV-induced diseases. This innovative concept was discovered by emeritus professor Cornelis J. M. Melief and his team at the Leiden University Medical Center and has been the subject of multiple studies and peer-reviewed publications. It is ISA´s most advanced clinical-stage immunotherapeutic and is in clinical development in advanced and recurrent cervical cancer and incurable HPV16-positive solid tumors (such as squamous cell carcinoma of the head and neck). The first proof-of-concept data on ISA101 as a monotherapy treatment were published in the New England Journal of Medicine and initial results from the recently completed ISA101 combination trials in advanced cervical cancer and head-and-neck cancer were presented at ASCO-SITC and ESMO, respectively, in 2017.