BioAtla Hosting Virtual R&D Day To Highlight BA3071 CAB-CTLA-4 Phase 1 Data In Multiple Solid Tumor Types

Author: Benzinga Newsdesk | December 13, 2023 09:23am

Multiple confirmed responses and durable disease control observed

 

Emerging differentiated safety profile enables further exploration at higher doses

Ongoing Phase 2 clinical study of monotherapy and in combination with a PD-1 inhibitor

SAN DIEGO, Dec. 13, 2023 (GLOBE NEWSWIRE) -- BioAtla, Inc. (NASDAQ:BCAB), a global clinical-stage biotechnology company focused on the development of Conditionally Active Biologic (CAB) antibody therapeutics for the treatment of solid tumors, today is hosting a virtual R&D Day on its novel conditionally and reversibly active antibody targeting CTLA-4, BA3071. BA3071 is in Phase 2 development as a potential therapeutic for multiple solid tumor indications known to be responsive to CTLA-4 treatment as monotherapy, and in combination with a PD-1 blocking agent.

The event will feature Omid Hamid, MD, Chief, Translational Research and Immunotherapy, and Director, Melanoma Therapeutics at The Angeles Clinic and Research Institute, and highlights Phase 1 dose escalation trial results for BA3071.

"The initial results from our Phase 1 dose escalation clinical trial showcases the innovative tumor selective, CAB platform with our CAB-CTLA-4 antibody," said Jay M. Short, Ph.D., Chairman, Chief Executive Officer and co-founder of BioAtla, Inc. "We observed confirmed clinical responses and prolonged stable disease among 18 patients treated with BA3071 in combination with PD-1. In addition, the relatively low incidence of immune-related adverse events suggests our CAB antibody has the potential to address the current limitations of CTLA-4-targeted therapies."

"CTLA-4 therapies can prolong the survival of patients with metastatic melanoma and other cancers, but often cause severe immune related side effects," said Dr. Hamid. "Now having observed clinical benefit with acceptable tolerability among the first 18 patients treated with BA3071 in our dose escalation trial, I'm encouraged by the promise that this novel approach holds."

Key R&D Day Topics and Highlights

• Preclinical data review of targeted, pH-dependent binding of BA3071 in the tumor microenvironment demonstrated complete tumor regression following BA3071 treatment. Exposure levels of BA3071 were similar to that of ipilimumab analog, with significantly less GI toxicity when combined with nivolumab in a non-human primate model.
• A Phase 1 dose-escalation study evaluated BA3071 monotherapy followed by combination with nivolumab, conducted in 18 patients who had prior PD-1 failure and a median of at least three prior lines of treatment
  • Across the 6 cohorts (n = 16 evaluable patients), best overall response observed with two confirmed responses (one complete response [CR] and one partial response [PR]); nine stable disease (SD)
    • One uveal melanoma patient remains on treatment for more than 12 cycles
    • Two cutaneous melanoma patients remain on treatment for more than 14 and 17 cycles, respectively
    • One small-cell lung carcinoma (SCLC) patient continues on treatment more than one year (>22 cycles)
  • More specifically, in the 350 mg cohort in combination with 240 mg nivolumab (n = 5), meaningful clinical benefit was observed in three patients, including 1 CR, 1 PR, and 1 SD
    • The confirmed CR was observed in a heavily pre-treated patient with stage IV cervical cancer with three prior lines of therapy
    • The confirmed PR (54.3% tumor reduction) was observed in a heavily pre-treated patient with stage IV gastro-esophageal cancer with four prior lines of therapy
  • No grade 4 related treatment-emergent adverse events were observed among 18 treated patients
    • Two patients with immune-related adverse events (Grade 3) reported to date
    • Maximum tolerated dose was not reached
    • One DLT observed out of 3 patients who received 700 mg; further evaluation of 700 mg and potentially at 1000 mg is ongoing
• A Phase 2 clinical study of BA3071 monotherapy and in combination with PD-1 inhibitor is currently underway

A replay of the event will be available on BioAtla's "Events and Presentations" website after the event.

About BA3071

BA3071, is a CAB anti-CTLA-4 antibody that is being developed as an immuno-oncology agent with the goal of delivering efficacy at least comparable to the approved anti-CTLA-4 antibodies, but with lower toxicities due to the CAB's tumor microenvironment-restricted activity. This is expected to enable safer anti-CTLA-4 antibody combination therapies, such as with anti-PD-1 antibody checkpoint inhibitors, and potentially broaden the patient population tolerant to combination therapy and deliver greater efficacy. Like our other CAB candidates, this Phase 2 clinical asset is designed to be conditionally and reversibly active in the tumor microenvironment. BA3071 is being developed as a potential therapeutic for multiple solid tumor indications that are known to be responsive to CTLA-4 treatment in combination with a PD-1 blocking agent.

Posted In: BCAB