CAEL-101 is a fibril-reactive monoclonal antibody (mAb) that has completed a Phase 1a/1b study for the treatment of patients with amyloid light chain (“AL”) amyloidosis ( Identifier: NCT02245867).

Final data presented by Suzanne Lentzsch, MD, at ASH’s 59th Annual Meeting in December 2017, demonstrated CAEL-101’s (mAb 11-1F4) ability to bind to light-chain amyloid fibrils and achieve early and clinically efficacious organ responses in patients with relapsed and refractory AL amyloidosis.

Twenty-seven patients were treated with CAEL-101 in this open-label, dose-escalation trial. In the Phase 1a trial, CAEL-101 was administered to eight patients via a single IV infusion at week one. In the Phase 1b trial, CAEL-101 was administered to 19 patients via one weekly IV infusion for four weeks. Trial investigators at Columbia determined the study achieved its primary objective of establishing maximum tolerated dose of up to 500mg/m2 of CAEL-101.

Trial investigators presented organ response rates in the Phase 1a and the Phase 1b, with 63 percent (14 of 24) overall organ response rate, 67 percent (8 of 12) overall cardiac response rate and 50 percent (5 of 10) overall renal response rate.[1] Early organ response was demonstrated in a high-mortality population (21 days median time to cardiac response in Phase 1b; 28 days median time to renal response in Phase 1b[2]).

Trial investigators found that CAEL-101 achieved and demonstrated organ response at multiple points in time throughout the duration of treatment; all patients either showed an organ response or were stable, and no patients showed organ progression. Organ response independent of a chemotherapy-free light chain response was demonstrated. No drug-related grade 4 or 5 adverse events or dose-limiting toxicities were seen in the trial. There was no mortality during the study. The investigators followed patients beyond the study and reported an overall survival rate of 93 percent (median follow-up period of 18.6 months).

Caelum Biosciences holds two Orphan Drug Designations for CAEL-101, one for use as a therapeutic agent for patients with AL amyloidosis and another for use as a radio imaging agent in amyloidosis.

[1] Response rates are based on the number of evaluable patients.

[2] First renal response evaluation point was 28 days for all but one patient, who was evaluated at 21 days.