I haven’t written much about ARRY-520, this year’s rising myeloma star at ASH.
ARRAY Biopharma is developing ARRY-520, a potent, selective KSP inhibitor; its mechanism of action is distinct from other drugs used to treat multiple myeloma. I have written about it before and featured ARRY-520 a number of times on MyelomaNews.com.
I attended an oral presentation at ASH, involving a two cohort Phase II study of this novel KSP inhibitor. My notes remind me that patients were very, very heavily pretreated. Cohort One included the normal range of relapsed, refractory patients. Patients in cohort Two averaged 10 previous therapies and were 100% refractory to Velcade and Revlimid.
Toxicity levels were very, very good.
Cohort One OS was 16% (no dex) with PR or better. Average response of 8.6 months. Cohort Two involved more heavily pre-treated patients. Also, dexamethasone was added to dosing regimen. Cohort Two had a 22% PR rate, with a 5.4 months median response rate.
Sounds like another promising complimentary, combo drug. Like tabalumab,
ARRY-520 adds little toxicity to the mix, and seems to do much more. My take on ARRY-520 is this drug may be approved some day. I rate it a step below impressive.
Next, well known myeloma specialist, Sundar Jagannath, presented a Phase II pomalidomide with low dose dex study. The next generation IMiD, pomalidomide (Actimid) is the drug that marathoner Don Wright has been on for four years.
Patients in the study all had experienced at least two cycles of both Revlimid and Velcade, and they needed to be refractory to their last therapy. Two thirds of the patients had used Thalomid and/or undergone at least one SCT.
An impressive number of 80% of the patients responded. Response was fast but didn’t seem to be very durable. Dr. Jagannath found that adding dex late didn’t help much. Better to use it up front.
Safety data was just OK. Neutropenia was common. Peripheral neuropathy (PN) was not. 13% experienced grade one or two PN. Aspirin helped prevent clots.
Pomalidomide has enough single agent action to garner fast approval by the FDA. But like most other myeloma drugs, pom’s numbers soar when used in combination.
Tomorrow I’m going to go out on a very, very long limb to try to interpret how what I learned at ASH might actually help us live longer.
Feel good and keep smiling! Pat