Data from Pharmawand - Curated by EPG Health - Date added 06 November 2019
Regeneron Pharmaceuticals, Inc. provided an update on the ongoing Phase III development program evaluating Libtayo (cemiplimab), a PD-1 inhibitor, as monotherapy and combination therapy in first-line patients with advanced non-small cell lung cancer (NSCLC).
Regeneron is currently recruiting patients in two Phase III trials in first-line NSCLC. The first trial , an open-label randomized trial that compares Libtayo monotherapy to standard-of-care platinum-based chemotherapy in patients with high PD-L1 expression (tumor proportion score [TPS] >50%): The trial has enrolled 90% of the 700 planned patients and is expected to be fully enrolled by year's end. The independent data monitoring committee recently conducted an interim analysis for overall survival (OS) based on approximately 34% of anticipated events and recommended the trial should continue as planned. The next event-driven interim analysis for OS is anticipated in 2020. In the first 361 randomized patients (minimum 6 months of follow-up), the confirmed objective response rate (ORR), as determined by investigators, is currently 42% for Libtayo patients and 22% for patients treated with chemotherapy.
The second trial , which consists of two parts, evaluates Libtayo in combination with platinum-based chemotherapy: Part 1 is fully enrolled (n=323), and evaluates patients with PD-L1 expression of <50% in three treatment groups: chemotherapy, chemotherapy with Libtayo, and chemotherapy in combination with Libtayo and ipilimumab. Part 2, a randomized, double-blind, placebo-controlled Phase III trial (n=450), has enrolled approximately 20% of patients, and is expected to complete enrollment in the second half of 2020. The trial evaluates patients with all PD-L1 expression levels in two treatment groups: chemotherapy alone or chemotherapy in combination with Libtayo.
Libtayo is being jointly developed by Regeneron and Sanofi under a global collaboration agreement. Libtayo is a PD-1 inhibitor that was invented by Regeneron using the company's proprietary VelocImmune technology, which uses a genetically-humanized mouse to produce optimized fully-human antibodies.
About the Phase III Libtayo NSCLC Trials : The primary endpoints of the randomized, open-label Phase III monotherapy trial are OS and progression-free survival (PFS). Patients receive either Libtayo 350 mg every 3 weeks or investigator's choice of a standard-of-care platinum-based doublet chemotherapy regimen (with or without maintenance therapy). Patients in the trial have stage IIIB, IIIC or stage IV squamous or non-squamous NSCLC, are not candidates for definitive chemotherapy and radiation, have not received prior systemic treatment for their advanced disease, and have high PD-L1 expression. As part of a separate internal research effort assessing the effect of baseline patient variables, an unintended aggregation of open-label ORR data by treatment group occurred for the first 361 enrolled patients. In NSCLC, regulatory authorities do not consider ORR a validated surrogate endpoint. In the Phase III combination trial, the Part 1 primary endpoint is ORR and the Part 2 primary endpoints are OS and PFS. Patients in the Libtayo treatment groups receive 350 mg every 3 weeks. Trial patients have either stage IIIB or IIIC squamous or non-squamous NSCLC and are not candidates for treatment with definitive concurrent chemoradiation, or have stage IV disease and have not received prior systemic treatment for recurrent or metastatic NSCLC.
Comment:Among the first 361 randomized patients with a minimum of 6 months of follow-up, 42% experienced decreases in tumor size following treatment with Libtayo, versus 22% for those given chemotherapy. This result is similar to the 45% overall response rate Keytruda posted in its initial Keynote-024 study, suggesting similar efficacy could be a goal for Regeneron.50>