One month after Regeneron and Sanofi posted impressive data from a phase 3 trial of their PD-1 inhibitor Libtayo in first-line non-small cell lung cancer (NSCLC), the FDA has shifted the drug into the fast lane—possibly offering the companies a chance to challenge the undisputed leader in that market, Merck’s Keytruda.
The FDA has granted priority review to Libtayo for the treatment of patients with locally advanced or metastatic NSCLC whose tumors have levels of biomarker PD-L1 of 50% or more. The agency is set to make its decision by Feb. 28, Regeneron announced.
The data supporting the FDA’s decision to speed up the review are impressive, to be sure. In a trial with 710 NSCLC patients, Libtayo slashed the risk of death by 43% among those with PD-L1 levels of 50% or more, when compared to platinum chemotherapy, Sanofi and Regeneron announced during the virtual meeting of the European Society of Medical Oncology (ESMO). In that subset of patients, the risk of disease progression fell 46%.
But a quick approval from the FDA won’t make the marketing challenge for Sanofi and Regeneron any easier. Merck owns the NSCLC market, thanks to an impressive string of data from ongoing clinical trials. The company demonstrated that combining Keytruda with chemo in previously untreated NSCLC patients can cut the risk of death by 51%, for example.
Merck has also been churning out data on Keytruda as a monotherapy in NSCLC. During ESMO, Merck presented long-term data showing that Keytruda doubled the five-year survival rate among NSCLC patients with high PD-L1 levels as compared to chemo. And Keytruda is FDA approved—both as a monotherapy and in combination with chemo—for the first-line treatment of metastatic NSCLC with low PD-L1 levels.
Keytruda “is deeply ingrained with docs, likely making it difficult for Libtayo to garner significant market share in the NSCLC setting,” Piper Sandler analysts said last month.
And Merck isn’t the only competitor facing Sanofi and Regeneron in the first-line NSCLC market. In May, the FDA approved Bristol Myers Squibb’s Opdivo-Yervoy combo, sans chemo, in previously untreated NSCLC.
Still, Libtayo could reach blockbuster territory if Regeneron and Sanofi can pull off their ambitious development plan for the drug, particularly in dermatology, analysts have said. Libtayo is already approved to treat cutaneous squamous cell carcinoma, and it’s in clinical trials for basal cell carcinoma. During ESMO, the companies released data showing that in a pivotal trial, 31% of basal cell carcinoma patients who stopped responding to hedgehog inhibitors did respond to Libtayo.
The drug is also being tested in colorectal cancer, melanoma, Hodgkin lymphoma and other cancers.
As for NSCLC, Regeneron executives remain confident about their chances in that market. “We think we have demonstrated that all our [NSCLC] data stacks up as well as anything else that’s out,” Israel Lowy, the company’s senior vice president of translational and clinical science, oncology, said in an interview during ESMO.