- Regeneron Pharmaceuticals on Friday secured an early approval from the Food and Drug Administration for a cancer immunotherapy that works in the same fashion as Merck & Co's Keytruda, adding yet another contender to the fast-growing immuno-oncology field.
- Regeneron's drug, called Libtayo, is a latecomer, arriving years behind Keytruda and Bristol-Myers Squibb's Opdivo, both of which target the same PD-1 protein. Three other approved immunotherapies block a related protein called PD-L1.
- Libtayo won't face any competition in its first indication for advanced cutaneous squamous cell carcinoma (CSCC), a disease for which none of the other five drugs are approved. Yet Regeneron's ambitions — and that of its development partner Sanofi — are broader, with plans to expand into more contested markets.
Regeneron certainly doesn't shy away from challenges.
Libtayo (cemiplimab) will enter an already crowded immuno-oncology arena that's dominated by Merck and Bristol-Myers, both of which have successfully developed their respective drugs for a dozen cancer types between them. Keytruda (pembrolizumab) and Opdivo (nivolumab) now each earn more than $1 billion in quarterly sales.
That success has made immuno-oncology one of the hottest fields of cancer research, with scores of other candidates targeting the same molecular pathway moving through testing. All of that activity has raised the question of whether there's room for more similar treatments.
But Regeneron sees itself as third to market, rather than sixth, pointing to Libtayo's blocking of the PD-1 receptor rather than the related PD-L1 ligand. While the evidence is still unsettled, Regeneron's theory is that PD-1 inhibition will end up proving more effective than targeting PD-L1.
CSCC is the second most common type of skin cancer in the U.S., accounting for 20% of all cases, Regeneron estimates. Most patients can be treated through surgery or radiation. In some, however, the cancer spreads to deeper layers of the skin or metastasizes further. Prior to Libtayo's approval, no treatments were available for these CSCC patients who were not candidates for surgery or radiation. An estimated 7,000 Americans die each year from advanced CSCC.
Combined results from the clinical studies supporting Libtayo's approval showed treatment with the drug led to a 47% response rate among the 108 patients tested. Serious adverse events were reported in more than a quarter of trial participants.
Libtayo will carry a list price of $9,100 per three-week treatment cycle. Sanofi and Regeneron will market the drug jointly in the U.S.
Though Regeneron and partner Sanofi aimed first at CSCC, the companies have also advanced Libtayo into Phase 3 testing for non-small cell lung cancer and cervical cancer.
There, the competitive challenge will be much steeper — particularly in lung cancer, where Merck has sewn up a formidable position in the first-line setting.
Like others, Regeneron and Sanofi are betting that combination therapy could improve upon the first wave of clinical progress for immuno-oncology. Winning approval of Libtayo is an important first step in that process, giving the companies a backbone treatment with which to pair other experimental drugs.
Roche, AstraZeneca and the team of Pfizer and Merck KGaA are also attempting to catch up to Merck and Bristol-Myers, with overlapping development strategies.
"With lung, we are not going to go in and take over the market," said Joanne Lager, head of development at Sanofi Oncology, in a March interview with BioPharma Dive. "But we think there is room for another option in that setting. The plan is to build on that with novel combinations to improve outcomes for those patients," she added.
Regeneron lists two such combos in its early-stage pipeline.
Libtayo is the biotech's seventh approved medicine, a fact that Regeneron leaders are quick to tout. Yet its three most recent biologic drugs to win a U.S. OK — Praluent (alirocumab), Dupixent (dupilumab) and Kevzara (sarilumab) — have all started slow, spurring some investor frustrations.
Libtayo is another calling card for Regeneron's drug development expertise. But turning it into a commercial blockbuster could be the biotech's toughest challenge yet.
Correction: Libtayo is Regeneron's seventh approved medicine, not its sixth.