The U.S. Food and Drug Administration (FDA) has granted priority review to an application seeking the approval of Libtayo (cemiplimab) as a first-line therapy for advanced non-small cell lung cancer (NSCLC) and high PD-L1 levels, according to a press release.
This priority status is expected to shorten Libtayo’s regulatory review to six months from the standard 10 months, and a decision is expected by Feb. 28, 2021. A similar application is also being reviewed by the European Medicines Agency, with a decision expected between April and June 2021.
Libtayo is an engineered fully human antibody developed by Regeneron Pharmaceuticals, in collaboration with Sanofi. As an immune checkpoint inhibitor, it works by blocking mechanisms often used by cancer cells to evade immune attacks.
Specifically, Libtayo suppresses the activity of a protein receptor found on the surface of immune T-cells, called PD-1, preventing its binding to the PD-L1 protein on the surface of cancer cells. By preventing their interaction, the therapy is expected to boost the ability of immune cells to recognize and eliminate malignant cells.
Libtayo is approved in the U.S. and Europe for the treatment of adults with metastatic or locally advanced cutaneous squamous cell carcinoma, a common form of skin cancer, who were not good candidates for surgery or radiation therapy.
The supplemental biologics license application, expected to extend Libtayo’s indication, was based on positive data from the EMPOWER-Lung 1 Phase 3 clinical trial (NCT03088540).
The open-label, multicenter study is evaluating the safety and effectiveness of Libtayo, compared with standard platinum-based chemotherapy, in 710 adults with previously untreated metastatic or locally advanced NSCLC whose tumors contain PD-L1.
Participants were randomly assigned to receive either 350 mg of intravenous (into-the-vein) Libtayo every three weeks for up to 27 months (356 patients), or four to six cycles of the investigators’ choice of chemo (354 patients). Those receiving chemotherapy were allowed to switch over to Libtayo after showing signs of disease worsening.
The trial’s main goals were to assess whether Libtayo was superior to standard chemo at extending overall survival, as well as prolonging the time patients lived without signs of disease progression. Secondary goals included response rates, response duration, and quality of life.
Libtayo was found to prolong patients’ lives from a median of 14.3 to 22.1 months, reflecting a 32% lower risk of death, according to the latest trial data, presented at the European Society for Medical Oncology Virtual Congress 2020.
The immunotherapy also significantly lowered patients’ risk of disease progression or death by 41%, compared with chemotherapy.
A greater proportion of patients responded to Libtayo (37%), compared with those on chemotherapy (21%), and the duration of Libtayo-induced responses was more than three-times longer than those with chemo (21.0 months vs 6.0 months).
Notably, Libtayo’s survival benefits over placebo were even more pronounced in a subgroup of 563 patients whose tumors had at least 50% of PD-L1-positive cells. In these patients, Libtayo dropped the risk of death by 43% and the risk of disease progression or death by 46%, compared with chemo.
These benefits were observed despite 73.9% of patients in the chemotherapy group crossing over to Libtayo.
Findings also indicated that in Libtayo-treated patients, higher response rates were associated with higher PD-L1 levels. Patients whose tumors had at least 90% of PD-L1-positive cells showed a response rate of 46%, with their target tumors shrinking by more than 40% after a mean of six months of treatment.
No new Libtayo’s safety concerns were identified, and the immunotherapy was associated with a lower frequency of severe, life-threatening, or fatal adverse events, compared with chemotherapy (37% vs. 49%). However, the percentage of patients discontinuing treatment due to side effects was slightly higher in the Libtayo group (6% vs. 4% in the chemo group).
Libtayo is also being evaluated, either alone or in combination with other therapies, in other types of solid and blood cancers, including basal cell carcinoma, cervical cancer, colorectal cancer, melanoma, and Hodgkin’s lymphoma.
