Asher Bio Announces Trial Collaboration for Etakafusp Alfa with T-cell Engager in Small Cell Lung Cancer

Asher Biotherapeutics, a biotech company located in South San Francisco, has entered into a new clinical trial collaboration and supply agreement with Amgen. This partnership focuses on evaluating etakafusp alfa, previously known as AB248, an innovative immunotherapy developed by Asher Bio. The therapy targets CD8+ T cells and utilizes interleukin-2 (IL-2) to enhance immune response against cancer. The trial will study the effects of this therapy combined with Amgen’s IMDELLTRA, a Bispecific T-cell Engager (BiTE) that targets DLL3, in treating patients diagnosed with extensive-stage small cell lung cancer (ES-SCLC).

Dr. Don O’Sullivan, the Chief Business Officer of Asher Bio, expressed optimism about this collaboration, highlighting the potential of etakafusp alfa to boost the effectiveness of T cell engagers (TCEs). By expanding the population of CD8+ T cells, the therapy aims to improve the immune system's ability to combat tumors, enhance cell function, and reverse desensitization induced by TCEs. The trial's goal is to determine whether this novel combination can lead to better outcomes for patients with ES-SCLC.

Under the terms of this collaboration, Amgen will lead and manage a global Phase 1b clinical trial to assess the safety and initial efficacy of combining etakafusp alfa with IMDELLTRA. Asher Bio will maintain complete ownership of etakafusp alfa and will supply it to Amgen without any cost.

Small cell lung cancer (SCLC) is a particularly aggressive form of solid tumor, characterized by a poor prognosis. The median survival time following initial treatment for extensive-stage SCLC is approximately 12 months, with a five-year relative survival rate of just 3%. Current second-line treatments offer limited benefits, with a median duration of response ranging from 3.3 to 5.3 months, and median overall survival between 5.8 to 9.3 months. Third-line treatments, primarily chemotherapy, fare worse, with a median duration of response of 2.6 months and overall survival of 4.4 to 5.3 months. SCLC accounts for roughly 15% of the more than 2.4 million lung cancer cases diagnosed globally each year.

Etakafusp alfa is a cutting-edge therapy specifically designed to activate CD8+ T cells, which play a central role in fighting tumors. It achieves this by fusing a modified IL-2 with an anti-CD8β antibody, thus selectively stimulating T cells without engaging natural killer (NK) cells or regulatory T (Treg) cells. This selectivity is crucial as NK cells can lead to increased toxicity, and Treg cells are known to suppress immune responses. Currently, etakafusp alfa is being investigated in a Phase 1a/1b clinical trial called AB248-101, which evaluates its safety, pharmacokinetics, pharmacodynamics, and anti-tumor activity both alone and in combination with pembrolizumab for patients with advanced solid tumors. Preliminary data from the trial has shown strong, selective CD8+ T cell activation with positive evidence of anti-tumor activity and a favorable safety profile.

Asher Bio is dedicated to developing immunotherapies that precisely target specific immune cells to combat cancer and chronic viral infections. Their proprietary platform enables the engineering of therapies that activate desired immune cells while minimizing activation of those that might cause toxicity or immune suppression. Besides etakafusp alfa, Asher Bio is also advancing other projects, including AB821, a CD8-targeted IL-21 immunotherapy, and early-stage programs targeting various immune cells.