In one way or another, very few of us are left untouched by this disease. As many of you know, it’s been almost a year since I lost my Dad to cancer (along with several friends, I might add) so I was interested to read in Chemical & Engineering News (C&EN Vol. 95 No. 11 July 3rd, 2017) that a new drug has been approved that treats cancers in any tissue –provided that the patient has a specific genetic profile. The FDA approval of Keytruda® (Merck & Co.) illuminates a paradigm shift in the approach to cancer research.
Historically, cancer was defined according to which tissue it started to grow in. (e.g. lung, pancreas, colon, etc.) as well as what the biopsy cells looked like under a microscope (e.g. small cell, non-small cell) This meant that cancer treatment was also focused upon the organ in which it first appeared. Historically, the FDA has required that cancer drug treatments needed a separate clinical trial for each organ to be treated. However, researchers in industry, government, and academia are now realizing that with gene sequencing, they are able to match the genetic makeup of the patient to more targeted treatments.
This useful personalized medicine approach is yet another example that supports the use of A New DNA Preservation Technology, featured in my blog post last year. Redefining cancer in terms of which mutation is detected vs. which organ it grows in is a sure step forward – but evidently not quite yet a “silver bullet”. Some metabolic pathways can be subtly different in cells located in one organ or another. For instance, researchers found that the drug Vermurafenib (from Roche) was usually effective against skin melanoma, but was found to be ineffective against similar cancers (i.e. those with similar mutations) in the colon. That is, unless it is accompanied by a second mutation-blocking drug, in which case the tumor responds.
In a clinical trial of 50 adults and children, Larotrectinib (from Loxo Oncology) was able to shrink the various types of tumors in 76% of patients who shared a common gene mutation. This extra-ordinary leap was made possible by a license agreement and development partnership with Array Biopharma. Tissue agnostic treatment trials with a handful of other drug candidates intended to block specific mutations are showing promise in small scale clinical trials of multiple tumor types.
While still a work in progress, genetically tailored medicine research continues to evolve. FDA new drug applications for several additional new tissue agnostic treatments for cancers will be requested in 2018 by more than one company.