Monday, November 2, 2015

Keytruda® Gets New FDA Breakthrough Designation In Relatively Narrow Set Of Colorectal Cancers -- Smallish Good News

This is clearly welcome news -- for Kenilworth -- but it covers only about a fifth (give or take), of all current colorectal oncology cases. And the underlying study, called "Keynote-164", is still in Phase II.

But we note it -- as more step by step evidence that Merck has an important new oncology product/candidate franchise here. [As ever, BMS is out ahead -- but there will be multiple billions in annual revenue available to Merck, even as the "second place" overall finisher.] Here's a bit of the morning's press release:

. . . .Testing tumors for microsatellite instability can identify patients with defective DNA mismatch repair (MMR) systems. DNA MMR is a process that permits cells to recognize and repair genetic mismatches generated during DNA replication. A defective MMR system allows mismatch mutations to persist. The average tumor has dozens of mutations; however tumors with DNA MMR deficiency may harbor thousands, especially in regions of repetitive DNA known as microsatellites. Tumors that are found to have mutations in select microsatellite sequences, called microsatellite instability (MSI), are considered DNA MMR-deficient. These tumors are referred to as being “MSI high.” Overall, DNA MMR-deficiency is present in approximately 15-20 percent in Stage II disease, 10 percent in Stage III disease and approximately 5 percent or less in Stage IV disease. In colorectal cancers, MMR-deficiency is seen in approximately 15-20 percent of non-hereditary colorectal cancers and in most hereditary colorectal cancers associated with Lynch Syndrome.

Merck is conducting a Phase 2 registration study (KEYNOTE-164) to evaluate the efficacy and safety of KEYTRUDA based on microsatellite instability status in patients with previously treated advanced colorectal cancers, and is also planning a Phase 3 study (KEYNOTE-177) in a treatment naïve patient population. . . .

Now you know -- and we will keep an eye on Keynotes-164 and -177. 'Tis a perfectly sunny fall day here. . . so I am grinning, ear to ear!

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