Aptevo, Alligator Bioscience report interim data of ALG.APV-527 Phase 1 trial

Alligator Bioscience and Aptevo Therapeutics announced interim data from the dose escalation phase of their Phase 1 trial evaluating ALG.APV-527 for the treatment of solid tumors likely to express the tumor antigen 5T4. The multi-center, dose escalation trial is now more than 50% enrolled, and preliminary results include: Treatment was overall well-tolerated, and a maximum tolerated dose has not yet been determined, dose-escalation in higher-dose cohorts is ongoing; ALG.APV-527 could be measured in all patients with plasma concentration of ALG.APV-527 consistent with the administered dose; Biomarker analyses indicate the expression of the targets in tumor biopsies and confirm biological activity of ALG.APV-527. Of particular interest, signs of clinical activity were observed for both enrolled patients with heavily pre-treated breast cancer. These patients demonstrated measurable level of drug in circulation and reproducible elevation of serum pharmacodynamic markers with dosing, suggesting the drug is biologically active. One patient remained on study for seven months and a second remains on study beyond nine months. Both patients achieved best overall response of stable disease. “I am pleased to share that we are now dosing cohort four, heading into higher dose ranges where we believe there is potential for increased signs of clinical activity based on preclinical models. We have treated patients with multiple tumor types including breast, pancreatic, non-small cell lung cancer and colorectal cancer. It is our belief that continued analysis of this cross section of tumor types will offer important insights about ALG.APV-527 that can be used to increase our success in later stage development,” said Dirk Huebner, MD, Chief Medical Officer at Aptevo. “Additionally, as the trial has progressed, we have seen growing enthusiasm among our clinical sites, evidenced by a long and growing waiting list of patients who would like to participate in the study. We look forward to announcing additional data later in the year.”