ESMO: Regeneron and Sanofi gun for Libtayo in first-line NSCLC with fresh survival stats

Libtayo bottle and box
If Libtayo is approved as a monotherapy for first-line non-small cell lung cancer, it will compete with a combination of chemotherapy and Merck's Keytruda. (Sanofi Genzyme/Regeneron)

Regeneron and Sanofi made a splash back in April with data from a first-line study in non-small cell lung cancer (NSCLC) showing that their PD-1 inhibitor Libtayo slashed the risk of death by 32% in patients with high levels of the biomarker PD-L1. Now, they're laying out more details from that study—data they hope will give Libtayo preferred status if it’s approved for previously untreated NSCLC patients.

In a trial with 710 NSCLC patients comparing Libtayo to platinum chemotherapy, the drug reduced the risk of death by 43% among those with PD-L1 levels of at least 50%, the companies said during the virtual meeting of the European Society of Medical Oncology (ESMO). In that subset, which included 563 patients, the risk of disease progression dropped 46%.

For the entire study population, the risk of death was 32% lower among those taking Libtayo than it was in the chemo group. The Regeneron/Sanofi drug reduced the risk of disease progression by 42%, and median survival was 22 months on Libtayo versus 14 months for chemo.

Regeneron and Sanofi stopped the trial back in April to allow patients in the control arm to cross over to Libtayo, and 74% of them made that switch after their disease progressed. The companies applied for first-line lung cancer approval in both the U.S. and EU; the drug is already approved to treat cutaneous squamous cell carcinoma.

“We think we have demonstrated that all our [NSCLC] data stacks up as well as anything else that’s out,” said Israel Lowy, Regeneron's senior vice president of translational and clinical science, oncology, in an interview.

RELATED: Sanofi, Regeneron take aim at Keytruda with Libtayo's first lung cancer win

But what’s out there in terms of competition could be daunting. Merck’s immuno-oncology blockbuster Keytruda owns the first-line NSCLC market as a combination treatment with chemotherapy, thanks to data showing the treatment can cut the risk of death by 51%.

And Merck has turned out its own impressive data in a phase 3 study of solo Keytruda, which is already FDA-approved for that use—and for all patients, not just those who are PD-L1-positive.

Then there’s Roche’s anti-PD-1 drug Tecentriq, which picked up an FDA approval as a monotherapy in first-line lung cancer in May. That approval was for NSCLC patients with PD-L1 levels of 50% or more—the same population that featured in Libtayo's new data—and it was based on stats showing the drug extended patients’ lives by seven months over chemotherapy.

Plus, Bristol Myers Squibb now offers a chemo-free combo option for NSCLC patients: its PD-1 inhibitor Opdivo combined with anti-CTLA-4 drug Yervoy. That combo won an FDA green light in May for previously untreated patients who've tested positive for PD-L1. In a phase 3 trial, BMS’ duo cut the risk of death by 21% in PD-L1-positive patients.

RELATED: Roche's Tecentriq nabs a solo OK in first-line lung cancer. But will it gain traction?

During ESMO, Regeneron and Sanofi also posted positive data on Libtayo in basal cell carcinoma. The companies are testing the drug in several other cancers, including colorectal cancer, melanoma and Hodgkin lymphoma.

Bernstein analysts predict Regeneron and Sanofi will see Libtayo sales eventually reach $2 billion. But that potential haul is far from certain, thanks to “advancement in standard of care coming from competitors,” Bernstein analyst Ronny Gal, Ph.D., wrote in an April investor note.

Roche, for example, is developing another chemotherapy alternative for NSCLC, tiragolumab, which targets TIGIT. At the virtual annual meeting of the American Society for Clinical Oncology in May, Roche released data from a phase 2 trial showing tiragolumab combined with Tecentriq shrank tumors in 31% of patients with metastatic NSCLC.  

Lowy said Regeneron and Sanofi are looking at a number of potential combo strategies in lung cancer for Libtayo. But, for now, they’re focusing on boosting the profile of Libtayo as a monotherapy—a challenge given the strong foothold Merck has for the Libtayo-chemo combo in NSCLC.

“There are some physicians that might say, ‘Well, we might as well give everyone chemo and not worry what the PD-L1 status is,’” Lowy said. “But there are a lot of patients who clearly will do much better on [Libtayo] monotherapy, and you can spare them the chemotherapy.”