Diagnostics, Pharma

Merck, Foundation Medicine to build companion diagnostics for Keytruda

Companies to create tests for tissue-agnostic MSI-H and dMMR cancers using Foundation's next-generation sequencing platform.

 

Drugs that target genetic abnormalities in cancer patients regardless of what specific tumor they have are an emerging trend in oncology drug development. But one challenge is identifying those patients, whose genetic anomalies may be exceedingly rare.

With that in mind, drugmaker Merck & Co. and diagnostics maker Foundation Medicine announced Thursday a collaboration to develop companion diagnostics for Merck’s drug Keytruda in patients with microsatellite instability-high (MSI-H) and mismatch repair deficiency (dMMR).

Keytruda received accelerated approval from the Food and Drug Administration last May for MSI-H and dMMR patients with solid tumors, making it the first time a drug won a “tissue-agnostic” label.

The companion diagnostic will use Foundation’s FoundationOne CDx next-generation sequencing system, with the companies developing a pan-cancer diagnostic to measure MSI. FoundationOne CDx assesses genomic alterations in 324 genes known to provide cancer growth in order to provide information for guiding treatment options. MSI-H and dMMR occur at frequencies that vary by tumor type, ranging from 22-33 percent of endometrial cancer to rates in skin and breast cancers as low as 2 or even zero percent, according to a 2016 study.

Other tissue-agnostic drugs in development include Loxo Oncology’s LOXO-101 and LOXO-195, which target NTRK fusions, and LOXO-292, which targets RET mutations and fusions. Ignyta, now owned by Roche, is also targeting NTRK fusions with RXDX-101, while Blueprint Medicines is targeting RET with BLU-667.

A report issued Tuesday by Trinity Partners identified 37 clinical trials of drugs in tissue-agnostic “basket” studies. These included two drugs in registrational trials, namely LOXO-101 and RXDX-101. Nine more were in potentially registrational studies, and the remainder were in exploratory studies.

Loxo announced in March that it had completed its rolling submission of data for an accelerated approval of LOXO-101, whose generic name is larotretinib. A presentation of data from its LOXO-292 clinical program is anticipated at the upcoming American Society of Clinical Oncology meeting next month. An abstract on the data last week caused a 20 percent increase in the company’s stock.

Photo: farakos, Getty Images

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