ASCO: Idelalisib for Follicular Lymphoma

Closing out the review of ASCO with a look at a report of a phase II clinical trial for Idelalisib, the PI3Kδ inhibitor.

Idelalisib is also known as GS-1101 or CAL-101, and its job is to inhibit, or stop an enyzme that controls functions like cell growth, survival, and reproduction in cancer cells. Blocking that enzyme means stopping the cancer.


The clinical trial focused on Follicular Lymphoma patients who are heavily pre-treated, refractory to R+chemo (that is, Rituxan and chemotherapy have stopped working), specifically an alkylating agent, like what a patient would get in CHOP or Bendamustine. Basically, the trial looks at FL patients who have used up most of their options.

72 patients were involved in the trial. The results were great -- 57% of them saw their lymph nodes reduced in size by at least half.The Overall Response Rate was 56% (10 Complete Responses and 30 Partial Responses). The median response duration was 11 months overall, and 27 months for patients that had a Complete Response. Progression-free survival was 11 months, which doen't seem like a lot, but was "substantially longer" that the last treatment the patients had received (remember, this is a group that had pretty much run out of options).

So this is great news for us. A very specific arrow for a very specific quiver.  And, bigger picture -- it gives us an even better sense that kinase inhibitors, and other, newer targeted therapies, are working as well as we had hoped.

So, closing things out, ASCO wasn't about quantity for Follicular Lymphoma, but definitely about quality. I mentioned the study on Polatuzumab Vedotin in my post on Dr. Bruce Cheson's ASCO Preview, and the more I read about it, the more interesting it seems. And the R-Squared trials now underway look great, too.

Lots to keep an eye on for the future.