We Are Likely To See Some More Of These Later Trial Discontinuations -- But They Remain... Immaterial, At Merck.

A clinical trial involving another anti-TIGIT antibody melanoma candidate in combination with Keytruda will be ended, due to the number of patients leaving the trial, citing immune response system off-target effects. [However, it is likely that most patients will keep taking pembrolizumab, without the second candidate.]

But to be clear, Merck's pembrolizumab remains firmly in control of this market (as the globe's highest revenue drug) -- with multiple melanoma approvals in its own right, and probably over $25 billion in sales coming in this full year 2024. In addition, it has a clear path to continued US market exclusivity through the mid-2030s. So this one event (or even a series of these later stage combo-trials ending) won't change that narrative arc in any material way. Here's Fierce on it all:

. . .Merck & Co. has bailed early on a phase 3 test of the anti-TIGIT antibody vibostolimab after a high rate of discontinuations rendered the trial's success unlikely.

The Big Pharma had been evaluating vibostolimab in combination with anti-PD-1 immunotherapy Keytruda in the KeyVibe-010 trial as an adjuvant treatment for patients with resected high-risk melanoma.

But a higher rate of discontinuations mainly due to “immune-mediated adverse experiences” among patients taking the combination regimen meant it was “highly unlikely that the trial could achieve a statistically significant improvement” in the primary endpoint of recurrence-free survival, the company said. . . .

So it goes -- and yet, the morning's sunshine. . . is amazing, here, just the same.

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