Keytruda Shows Promise for Certain Patients with Cutaneous Squamous Cell Carcinoma

Keytruda (pembrolizumab) demonstrated strong antitumor activity in patients with locally advanced or recurrent/metastatic cutaneous squamous cell carcinoma, according to a virtual presentation of trial findings at the American Association for Cancer Research Annual Meeting.

“(Cutaneous squamous cell carcinoma) is the second most common non-melanoma skin cancer in the world, representing approximately 20% of all non-melanoma skin cancers and 20% of all skin cancer-related mortality,” Dr. Brett G.M. Hughes, senior staff specialist/medical oncologist at Royal Brisbane and Women’s Hospital in Australia, said during a presentation of the data. “In the first interim analysis of this study, we demonstrated that (Keytruda) monotherapy had a clinically meaningful and durable antitumor activity with (a) manageable safety profile for recurrent and metastatic disease.”

At the meeting, Hughes reported initial efficacy and safety data from the locally advanced group of patients (54 patients) after a median follow-up of 13.4 months, and updated data from the recurrent/metastatic group (105 patients) after a median follow-up of 23.8 months. Patients had a median age of 74 years. All patients received 200 milligrams of Keytruda once every three weeks for up to 25 cycles, or approximately two years.

In this phase 2 study, objective response rate (the number of patients with a tumor size reduction in a certain period of time) for patients with locally advanced disease was 50% and 35.2% for those with recurrent/metastatic disease. For the total population, the objective response rate was 40.3%.

Disease control rate (stable disease for 12 weeks or more plus objective response rate) for those with locally advanced disease was 64.8% and 52.4% for those with recurrent/metastatic disease. This rate for the entire patient population was 56.6%.

Nine (16.7%) patients in the locally advanced group and 11 (10.5%) patients in the recurrent/metastatic group has a complete response. In addition, 18 (33.3%) patients with locally advanced disease and 26 (24.8%) patients with recurrent/metastatic disease had a partial response. Stable disease was observed in 13 (24.1%) patients in the locally advanced group and 30 (26.7%) of those in the recurrent/metastatic group. Eight (14.8%) patients with locally advanced disease and 18 (17.1%) patients with recurrent/metastatic disease had stable disease for 12 or more weeks. Progressive disease occurred in nine (16.7%) patients with locally advanced disease and 28 (26.7%) patients with recurrent/metastatic disease.

Progression-free survival (the length of time after treatment the patient lives with the disease but it does not worsen) at 12 months was 54% for patients with locally advanced cutaneous squamous cell carcinoma and 36.4% in those with recurrent/metastatic cutaneous squamous cell carcinoma. Median progression-free survival was not reached in the locally advanced group and was 5.7 months in the recurrent/metastatic group.

The overall survival rates (the percentage of patients who are still alive for a period of time after they were diagnosed or started treatment) at 12 months was 73.6% for patients with locally advanced cutaneous squamous cell carcinoma and 61% in those with recurrent/metastatic cutaneous squamous cell carcinoma. Median overall survival was not met in the locally advanced group and was 23.8 months in the recurrent/metastatic group.

Side effects from the treatment occurred in 69.2% of patients, including 11.9% with severe or life-threatening side effects. Most common side effects were itching, fatigue, lack of energy, rash, diarrhea, hyperthyroidism, joint pain and nausea.

“(Keytruda) has demonstrated robust durable anti-tumor activity and promising survival in both the locally advanced and recurrent metastatic cutaneous (squamous cell carcinoma) cohorts,” said Hughes. “This data establish (Keytruda) as a promising treatment option for those with locally advanced, recurrent/metastatic cutaneous (squamous cell carcinoma).”

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