With big Keytruda and Opdivo data coming at AACR, analyst hands Merck the early edge

With both Merck and Bristol-Myers Squibb rolling out closely watched data on their immuno-oncology contenders at a medical meeting this weekend, one thing’s for sure: Investors will be drawing comparisons.

And while those comparisons may not be totally fair, one analyst has already tapped Merck as the early winner.

On Monday at the American Association for Cancer Research annual meeting, Merck will unveil results from a Keytruda-chemo combo trial, Keynote-189, while Bristol will present data from Checkmate-227, which examines an Opdivo-Yervoy pairing.

"Invariably, these data sets will be compared side-by-side to better ascertain which regimen is likely to become the dominant choice of prescribers in the all-important, first-line, non-small lung cancer population,” Bernstein analyst Tim Anderson wrote in a Friday note to clients.

RELATED: With ASCO data tallied, Bristol-Myers loses ground to Merck in I-O field

Anderson is the first to point out that a comparison is “a bit apples-to-oranges” and will be limited by a couple of key factors, including BMS’ brand-new tumor mutation burden (TMB) biomarker. Merck’s trial relies on the “more common” PD-L1 biomarker, he pointed out. Additionally, Bristol won’t yet have mature overall survival data—considered more important than progression-free survival results—while Merck will have both.

Still, “our belief is that once both data sets are presented in full and side-by-side comparisons are done, MRK will appear to be the more victorious of the two companies at AACR,” Anderson wrote.

That’s not to say he doesn’t expect Bristol’s data to come up positive. The trial is “likely to show a robust hazard ratio"—which would demonstrate the combo's benefits—"but only for a more limited population”: Patients who register high TMB.

Merck has been leading the first-line lung cancer race ever since Opdivo flopped a monotherapy trial. From there, Keytruda went on to snag a solo approval in the front-line setting, and Merck followed up last year with its chemo combo OK, too.

Bristol’s approach, on the other hand, has yet to be validated. AstraZeneca, which is also trialling a member of the PD-1/PD-L1 class alongside a CTLA4 drug, hasn’t yet had good news to report.

RELATED: Warning to I-O drugmakers: If investors were hyperfocused on data this year, just wait till 2018

Meanwhile, Monday will be far from the first time investors use flawed comparisons to try to predict the eventual first-line lung cancer champion. After Roche came out with its first results from a trial pairing Tecentriq with Avastin and chemo, Anderson acknowledged that they wouldn’t be getting as much attention if the data investors really wanted to see—from a Tecentriq-chemo combo they could evaluate against Keytruda-chemo—were available.