Pinpointing Best Dose of Immunotherapy (AMG 420) in Resistant Myeloma
Posted: Thursday, August 15, 2019
In updated results, researchers reported a 70% response rate with a dose of 400-µg/day of AMG 420 in 10 patients with relapsed and/or refractory multiple myeloma. Their first-in-human phase I dose-escalation study examined the safety and activity of this bispecific T-cell engager immunotherapy. Five of the seven responders achieved a stringent complete response, and one each had a very good partial response and a partial response. Now, 400-µg/day is the dose recommended for further investigation, according to Max S. Topp, MD, of University Hospital Würzburg, Germany, and colleagues.
The median age, multiple myeloma duration, and number of prior therapies were 65 years, 5.2 years, and four, respectively, in the original cohort of 42 patients, the team noted at the 2019 American Society for Clinical Oncology (ASCO) Annual Meeting (Abstract 8007); these findings were also published in the Journal of Clinical Oncology. The doses tested, given in 6-week cycles, ranged from 0.2 µg/day to 800 µg/day. The 800-µg/day dose was deemed not tolerable, with two of three patients developing dose-limiting toxicities that required hospitalization; toxicity ultimately resolved in both patients. Of the 42 patients taking any dose of AMG 420, 13 responded (6 stringent complete responses, 3 complete responses, 2 very good partial responses, and 2 partial responses).
As of data cutoff in December 2018, responses in the 400-µg/day group had lasted for 5.6 months to 10.4 months, with four patients continuing treatment, noted Dr. Topp and co-investigators. As of February 2019, some responses had lasted more than 1 year.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.