Nearly Half of Patients in Trial Respond to Checkpoint Inhibitor Treatment for Common Skin Cancer

Cutaneous squamous cell carcinoma is the second most common skin cancer, with an estimated 1 million new cases diagnosed annually. However, there are currently no systemic therapies approved for the treatment of advanced cutaneous squamous-cell carcinoma in patients who show no progress with surgery or radiation.

According to recent clinical trials, an immune checkpoint inhibitor was found to shrink the tumors in nearly half of patients with the disease. The study, led by researchers at The University of Texas MD Anderson Cancer Center, was published in the New England Journal of Medicine.

In the trial, immunocompetent patients were treated with cemiplimab, an immune checkpoint inhibitor that works by blocking PD1, a surface receptor on T cells that shuts down the immune response to cancer.

According to the results, at median follow-up of 7.9 months, 28 of 59 patients with metastatic disease had an objective response to cemiplimab, defined as at least 30% tumor shrinkage observed via imaging. Four had complete responses, 24 had partial responses, and 82% of responders remain on the drug.

Additionally, the durable disease control rate of responders plus those with stable disease for at least 105 days was 61% and the response rate was 47%. Neither the median progression-free survival nor the median overall survival had been reached at the time of data cutoff, but the estimated probability of progression-free survival at 12 months was 53% and the estimated probability of overall survival at 12 months was 81%.

“Patient continue to do well, so median progression-free survival and overall survival have not been reached yet,” lead study author Michael Migden, MD, associate professor of Dermatology and of Head and Neck Surgery, said in a press release. According to Migden, response rates to chemotherapy regimens or targeted therapy against the epidermal growth factor receptor (EGFR) now used against advanced cutaneous squamous cell carcinoma range from 15% to 25%, with many debilitating adverse events.

Overall, 2 deaths occurred: 8 were due to disease progression and 3 were due to adverse events.

The phase 2 study for cemiplimab for locally advanced cutaneous squamous-cell carcinoma is ongoing.

The most common adverse events associated with cemiplimab were diarrhea, fatigue, nausea, constipation, and rash. Adverse events of grade 3 or higher that occurred in more than 1 patient were cellulitis, pneumonitis, hypercalcemia, pleural effusion, and death.

Migden noted that, although immunotherapies pose risks of inflammatory adverse effects that must be monitored, they otherwise have fewer day-to-day complications than chemotherapy and EGFR inhibitors.

“These results mark a potential paradigm shift in the treatment of patients with advanced cutaneous squamous cell carcinoma, who to date have had very limited results with chemotherapy and targeted therapies,” Dr Migden said in the press release.

The drug, which is being co-developed by Regeneron and Sanofi, has been granted breakthrough therapy status by the FDA.

Reference

1. Migden MR, Rischin D, Schmults CD, et al. PD-1 blockade with cemiplimab in advanced cutaneous squamous-cell carcinoma. NEJM. 2018. Doi: 10.1056/NEJMoa1805131.

2. Checkpoint inhibitor shrinks advanced squamous cell skin cancer [news release]. MD Anderson’s website. https://www.mdanderson.org/newsroom/2018/06/checkpoint-inhibitor-shrinks-advanced-squamous-cell-skin-cancer.html. Accessed June 7, 2018.