Regeneron Pharmaceuticals Inc. and Sanofi's experimental cancer therapy cemiplimab reduced tumor size in about half of patients with an advanced form of skin cancer, the companies said in two studies published in The New England Journal of Medicine.
The drugmakers' cemiplimab — a checkpoint inhibitor that blocks the immune system's PD-1 protein from linking up with the PD-L1 arm of tumor cells — was studied in cutaneous squamous cell carcinoma, or CSCC, the second-most common skin cancer in the U.S. after melanoma.
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In the phase 2 trial, dubbed Empower-CSCC-1, 47.5% of patients with metastasized cancer responded to the drug, with four out of 59 patients showing no detectable sign of the disease, also known as a complete response, at a median follow-up time of eight months.
Of the patients who showed a response to the drug, 82% continued to respond and stayed on cemiplimab at the data cut-off date. The estimated probability of survival at the 12-month mark is 81%, the companies said.
Regeneron and Sanofi also shared data from an expanded phase 1 trial for metastasized or local advanced and inoperable cases of the disease in which half of 26 patients responded to the therapy.
In both studies, the median response time was two months.
Between 7,000 and 8,000 deaths occur each year from CSCC in the U.S., roughly equal to the annual number of melanoma deaths, according to Israel Lowy, Regeneron vice president of Clinical Sciences, head of Translational Science and Oncology. Yet CSCC is not always tracked as diligently since it can generally be removed surgically when caught early, he said.
"People didn't really have an appreciation for [patients with more severe stages of the disease] because the uncomplicated cancer is so common that it's not even followed in a regular database," Lowy said in an interview.
The companies have filed for U.S. and European approval for cemiplimab, with a U.S. decision expected in October and Europe's in 2019. If approved, it would be the third PD-1 targeting therapy available, after Merck & Co. Inc.'s Keytruda and Bristol-Myers Squibb Co.'s Opdivo.
Similarly, AstraZeneca PLC's Imfinzi and Roche Holding AG's Tecentriq target the PD-L1 arm of tumor cells that links up to healthy cells. All the drugmakers are sharing data for the therapies at the 2018 American Society of Clinical Oncology meeting.
Sanofi and Regeneron are also exploring cemiplimab's use in non-small cell lung cancer, cervical cancer and another skin cancer known as basal cell carcinoma, along with early stage research in head and neck cancer, melanoma, colorectal cancer, prostate cancer, multiple myeloma, Hodgkin lymphoma and non-Hodgkin lymphoma.
"In the field at large, there is only one approved agent so far in the first line setting from all the different agents that are out there, so we feel that we're a contender and we're going to step into the fray," Lowy said about the lung cancer market.
The 2018 American Society of Clinical Oncology meeting is expected to bring together more than 32,000 professionals from all over the world, with more than 2,500 study abstracts to be presented on-site and an additional 3,350 abstracts to be published online.

