FDA medical oncologists discuss the September 28, 2018, approval of cemiplimab-rwlc for the treatment of select patients with cutaneous squamous cell carcinoma.
Dr. Sanjeeve Bala: Welcome back to the DISCO, the FDA’s Soundcast in Clinical Oncology from the Oncology Center of Excellence. We are coming to you from Silver Spring, MD and during our soundcasts, we discuss recent FDA approvals of cancer drugs and therapies. We hope this information will help you in better understanding these approvals and how new drugs and therapies are benefitting people fighting cancer. Today we’ll be discussing the recent approval of cemiplimab-rwlc for the treatment of select patients with cutaneous squamous cell carcinoma. This is the first approval for cemiplimab, marketed as Libtayo.
SB: I’m Dr. Sanjeeve Bala, a medical oncologist and clinical team leader at FDA, and I am joined by my colleague Dr. Abhi Nair, also a medical oncologist at the Oncology Center of Excellence here at the FDA. She’s going to start with some background on the disease.
Dr. Abhi Nair: Hi everyone. Thanks for joining us.
AN: Cutaneous squamous cell carcinoma is the second most common cancer in US, with about 700,000 new cases annually. Most of these are localized tumors that undergo curative local resection, but around 8% of these patients will have a local recurrence, and a quarter of these patients die from their disease. In addition, cutaneous squamous cell carcinoma causes significant functional deficits and cosmetic defects, since these tumors often arise on the face and can invade blood vessels, nerves, and the eye and ear. For patients with distant metastases, median survival is less than two years.
SB: So, for those patients who aren’t initially cured, the burden imposed by this disease is not only mortality, but disfigurement and loss of functional capacity. Abhi, what’s the previous standard of care for these patients?
AN: Sanjeeve, management of cutaneous squamous cell carcinoma begins with surgical resection with appropriate margins, and, in the presence of nodal involvement, regional lymph node dissection and adjuvant radiotherapy. Based on retrospective studies, radiation alone has a role for some presentations of locally advanced disease with compromised resectability or positive lymph nodes. Until now, there were no FDA-approved systemic treatment for patients with locally advanced and unresectable or metastatic cutaneous squamous cell carcinoma, though cisplatin, cisplatin plus 5-FU, and interferon alfa are commonly used agents, alone and in combination with EGFR inhibitors. But all of these have demonstrated modest response rates and no survival advantage.
SB: So, this approval does represent an important new option for patients with cutaneous squamous cell carcinoma.
AN: Yes, that’s true. Why don’t you tell us a bit about cemiplimab.
SB: PD-L1 is a ligand expressed on tumor cells that can interact with the PD-1 receptor on immune cells and block the activity of anti-tumor lymphocytes. Cemiplimab is an antibody that targets the PD-1 receptor and prevents its inhibition of those immune cells, allowing immune-mediated tumor killing. Of course, this is a bit of an oversimplification, but in general, this is the accepted mechanism of action.
AN: And the new indication?
SB: Cemiplimab is indicated for the 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 approved dose is 350 mg infused over 30 minutes every 3 weeks.
AN: Sanjeeve, let’s hear about the clinical trial that led to the approval.
SB: The approval of cemiplimab relied on the aggregation of data from two single-arm trials, which included data from 75 patients with metastatic cutaneous squamous cell carcinoma with at least six months of follow-up. Treatment with the cemiplimab resulted in an objective response rate of 47% by RECIST criteria, with four complete responses and 31 partial responses. As we’ve seen with immunotherapy in other settings, the duration of the responses was meaningful, with a median that was not reached on the study, and 60% of responding patients maintaining responses for at least six months.
AN: What about the patients without metastatic disease, but with locally advanced disease that was unresectable or not curable with radiotherapy?
SB: There were 33 patients with locally-advanced disease that were followed for at least nine months. Among these patients, there was a confirmed 49% response rate, and more than half of these patients had responses ongoing for at least six months.
AN: This application received regular approval, not accelerated approval, based on these results. Can you briefly explain how these findings resulted in regular approval?
SB: Durable objective responses in malignancies with primary skin responses may be sufficient to demonstrate direct clinical benefit, as has been seen before. In the case of cemiplimab, the application included photographic evidence of durable improvement in disfiguring cosmetic lesions, including cases of near-complete resolution that had been refractory to multiple prior interventions.
AN: So, the clinically meaningful shrinkage of disfiguring face, scalp, neck, or extremity lesions is also evidence of direct clinical benefit, leading to the regular approval. What were the overall safety findings?
SB: The most common toxicities that occurred in at least 20% of patients were fatigue, rash, and diarrhea. The most common immune-mediated adverse reactions occurring in at least 2% of patients were hypothyroidism, pneumonitis, and hepatitis. So, it looks like the adverse reaction profile of cemiplimab is similar to the other PD-1-directed immune-oncology agents, and the management of these immune-mediated adverse reactions is similar across the class, including steroids and hormone replacement therapy.
AN: Thanks, Sanjeeve. Why don’t you give us the three take-aways for this D.I.S.C.O.
SB: Sure, Abhi. 1) cemiplimab is a new anti-PD-1 antibody that has demonstrated clinical benefit for patients with metastatic or locally advanced cutaneous squamous cell carcinoma without local treatment options; 2) this intervention may reduce the impact of disfiguring skin lesions with durable responses; and 3) the safety profile of this PD-1 antagonist is similar to those for other PD-1-based immune-oncology approvals.
SB: For a transcript with links to an in-depth look at the FDA analysis, and the multidisciplinary team of FDA experts who conducted the review, visit the FDA Oncology Center of Excellence DISCO website at fda.gov/DISCO.
AN: Thank you Sanjeeve. Are there other FDA oncology drug approvals that you would like to hear about? Leave us your questions and comments on Twitter @FDAOncology, and as always, we welcome your feedback at our email address, FDAOncology@fda.hhs.gov. I’m Abhi Nair, thank you for tuning in to the DISCO today.
SB: And until next time at the DISCO, I’m Sanjeeve Bala.
This Drug Information Soundcast in Clinical Oncology was developed by Sanjeeve Bala, Abhilasha Nair, Denise Casey, Suzanne Demko, Kirsten B. Goldberg, and Richard Pazdur, of the Oncology Center of Excellence and the Office of Hematology and Oncology Products. Steven Jackson of the Division of Drug Information was the sound producer.
Members of the Multidisciplinary Review and Evaluation team for this New Drug Application were:
Regulatory Project Manager: Missiratch (Mimi) Biable
Nonclinical Reviewer: Emily Wearne
Nonclinical Team Leader: Whitney Helms
Office of Clinical Pharmacology Reviewers: Xiling Jiang, Yuan Xu
Office of Clinical Pharmacology Team Leaders: Hong Zhao, Jiang Liu
Clinical Reviewer: Denise Casey
Clinical Team Leader: Suzanne Demko
Statistical Reviewer: Mallorie Fiero
Statistical Team Leader: Pallavi Mishra-Kalyani
Cross-Disciplinary Team Leader: Suzanne Demko
Division Director (DHOT): John K. Leighton
Division Director (OCP): Nam Atiqur Rahman
Division Director (OB): Rajeshwari Sridhara
Division Director or designated signatory authority (OHOP): Steven Lemery
Office Director: Richard Pazdur