Cemiplimab represents potential ‘practice-changing’ advance for cutaneous squamous cell carcinoma
Nearly half of patients with locally advanced and metastatic cutaneous squamous cell carcinoma responded to treatment with cemiplimab-rwlc, according to integrated data from phase 1 and phase 2 trials published in The New England Journal of Medicine.
Cemiplimab (Libtayo, Regeneron) is a fully human monoclonal antibody that targets PD-1.
The FDA approved the agent in September for IV treatment of patients with metastatic cutaneous squamous cell carcinoma or locally advanced cutaneous squamous cell carcinoma who are not candidates for curative surgery or curative radiation. The approval is the first of a drug specifically for advanced cutaneous squamous cell carcinoma, the second most common skin cancer in the United States.
Michael R. Migden, MD, professor in the departments of dermatology and head and neck surgery at The University of Texas MD Anderson Cancer Center, and colleagues suggested the mutational burden of cutaneous squamous cell carcinoma makes it an attractive target for immune therapy.
Their published paper reported on an open-label, multicenter phase 1 study of cemiplimab that included an expansion cohort of 26 patients (median age, 73 years; 81% men) with locally advanced or metastatic disease, as well as a nonrandomized, global phase 2 study of 59 patients (median age, 71 years; 92% men) with metastatic disease.
Clinicians administered the drug via IV at 3 mg/kg every 2 weeks for up to 48 weeks in the phase 1 study and up to 96 weeks in the phase 2 study.
Results of the phase 1 study showed a response rate of 50% (95% CI, 30-70), with seven of 13 responding patients remaining in response for longer than 6 months. The response rate in phase 2 was 47% (95% CI, 34-61), with 16 of 28 responding patients remaining in response for longer than 6 months.
The regimen appeared mostly well-tolerated.
HemOnc Today spoke with Migden about the rationale for this study, the implications of the results and the directions future research must take.
Question: How did this study come about?
Answer: Previously, available treatments for metastatic and locally advanced cutaneous squamous cell carcinoma had very limited efficacy with significant adverse reactions. There was no approved agent and no real standard of care for this patient population.
It is important to differentiate cutaneous squamous cell carcinoma from other head and neck squamous cell carcinoma. The vast majority of those patients are treatable with surgery, usually reaching a 90% or 95% cure rate. However, some patients develop advanced disease, making them no longer candidates for surgery or radiation. Epidermal growth factor receptor inhibitors have led to 15% to 25% response rates, but often with substantial adverse events.
When approaching companies about possible anti-PD-1 immunotherapy trials to treat squamous cell carcinoma of the skin, I was told, “Not that disease, not at this time.” I contacted Regeneron, where there was mutual interest in finding therapy for this patient population. The goal of the phase 2 registration study was to evaluate this therapy for patients with locally advanced and metastatic disease.
Q: Can you elaborate on the cohorts you included?
A: The phase 2 study included patients with locally advanced disease, as well as those with metastatic disease. Most clinicians understand the meaning of metastatic cutaneous squamous cell carcinoma. The idea of locally advanced cutaneous squamous cell carcinoma is a more nuanced, multifaceted concept. Because of this, initial enrollment of patients with metastatic disease exceeded that of patients with locally advanced disease. This is unfortunate, as most metastatic disease begins as locally advanced disease. If there were a better understanding of the concept of locally advanced disease, patients could be started on therapy or enrolled in a trial earlier, before their disease becomes even more difficult to treat. Many clinicians continue treating with additional surgery and/or radiation thinking that will take care of it. This often leads to additional morbidity and disfigurement for the patient but may not be curative. After all of this, it is difficult for people to grasp the idea that immunotherapy could work.
Q: As use of immune therapies becomes more common, will people be able to grasp this concept more readily?
A: Yes. Although immunotherapy is more well-known for treating melanoma, awareness should increase about its use in nonmelanoma skin cancers.
Q: Do you think these results are potentially practice-changing?
A: Yes. There have been no highly effective or standard-of-care therapies for these patients prior to immunotherapy. With a higher objective response rate and this therapy appearing associated with fewer adverse events, these patients now have better treatment options. Another measure to consider is durable disease control, reported to be up to 65% in the phase 1 trial and 61% in the phase 2 trial. Durable disease control means patients either responded or did not progress for a minimum of 105 days. Having the ability to hold patients from progression in an otherwise potentially fatal disease is practice-changing.
Q: What is the next step for research?
A: There are a lot of studies in development. These include a phase 2 study of cemiplimab for advanced basal cell carcinoma and other dosing interval regimens. Neoadjuvant and adjuvant use should be explored.
Q : Is there anything else you would like to mention?
A : I would like to emphasize the relationship between locally advanced and metastatic disease. As awareness of the locally advanced disease concept improves, we will hopefully see less repeat surgery and/or radiation and more consideration of immunotherapy approaches. – by Rob Volansky
For more information:
Michael R. Migden, MD, can be reached at Houston Medical Center Plaza, 6655 Travis St. #700, Houston, TX 77030; email: email@example.com.
Disclosure: Migden reports nonfinancial support (writing) from Prime during the conduct of the study, as well as personal fees from Eli Lilly, Regeneron and Sun Pharmaceuticals outside the submitted work.