Merck claims a brace of head and neck cancer approvals

Merck & Co/MSD has done the double in head and neck cancer with a pair of FDA approvals for Keytruda in newly diagnosed patients on the same day.

PD-1 inhibitor Keytruda (pembrolizumab) has been approved as a second-line therapy for head and neck squamous cell carcinoma (HNSCC) since 2016 in the US, but can now be prescribed first-line to patients with advanced, unresectable tumours.

One approval is as a monotherapy in PD-L1-positive HNSCC patients, while the second is as a combination with chemotherapy (platinum drugs plus fluorouracil) in HNSCC patients regardless of their PD-L1 status. The FDA also approved a new companion diagnostic that can be used to identify patients suitable for Keytruda alone.

The green light comes after a priority review from the FDA and is another score to Merck in its ongoing rivalry with Bristol-Myers Squibb, whose PD-1 inhibitor Opdivo (nivolumab) was also approved as a post-chemotherapy option for HNSCC in 2016.

It opens up a market of around 65,000 patients who are diagnosed with HNSCC each year in the US, according to Merck, and makes Keytruda the first and so far only PD-1/PD-L1 inhibitor drug to include first-line HNSCC on its label.

Claiming the dominant position in first-line non-small cell lung cancer (NSCLC) – the largest market for immuno-oncology drugs – has been a key driver for Keytruda as it has chased down and overtaken Opdivo in sales terms in the last couple of years.

Securing first-line use in any cancer indication tends to be an advantage because patients will likely stay on the same drug if they relapse and need further lines of combination therapy. Merck is also muscling into the first-line kidney cancer category, one of Opdivo’s strongholds, with an FDA approval for a combination regimen with Pfizer’s targeted drug Inlyta (axitinib) in April.

The approvals were based on the KEYNOTE-048 study, which showed that Keytruda both alone and with chemo was able to achieve a significant improvement in overall survival compared to the current EXTREME regimen of Eli Lilly’s Erbitux (cetuximab) with carboplatin or cisplatin plus fluorouracil.

Bristol-Myers Squibb is running a phase 3 trial comparing the combination of Opdivo and its CTLA4 inhibitor Yervoy (ipilimumab) to EXTREME in first-line HNSCC – called CheckMate-651 – which started in 2016 and according to the clinicaltrials.gov database is due to complete next year.