Ambrx Biopharma Inc. announced it will lay off 15% of its workforce and suspend development of its lead candidate in a strategic realignment initiative.
California-based Ambrx Biopharma announced Tuesday it will lay off 15% of its workforce and suspend development of its lead candidate in a strategic realignment initiative.
According to Ambrx leadership, this move will allow the company to streamline its operations, extend its cash runway into 2025 and provide it with enough resources to invest in pipeline assets with the most potential to succeed in the crowded oncology space.
As part of the reprioritization, Ambrx is dropping the anti-HER2 antibody-drug conjugate (ADC) ARX788 as its lead asset, driven mainly by the increasingly tight competition in the HER2 therapeutic space. All clinical trials for the candidate will be suspended henceforth while Ambrx looks for out-licensing opportunities for ARX788.
“The HER2 space currently has over 175 ongoing clinical trials and represents a crowded space within the oncology landscape. Knowing that, we have chosen to deploy our novel technology in areas where we can be first-in-class and/or best-in-class,” Kate Hermans, Interim CEO at Ambrx told BioSpace Wednesday.
Instead, the company will focus its resources on ARX517, an ADC targeting the prostate-specific membrane antigen (PSMA). Ambrx dosed its first Phase Ia patient with PSMA-positive prostate cancer in August last year.
With some 1.4 million cases globally, the prostate cancer market is estimated to have a value of $9.9 billion.
Ambrx expects the initial safety readout from this study to come in late next year, allowing the company to settle on a dose for a subsequent Phase Ib/II study.
“As we reprioritize our development pipeline to position ARX517 as Amrbx’s lead clinical asset, we are confident in its potential to address the significant unmet medical need in prostate cancer,” Hermans said in an investor call Tuesday afternoon. “This highly stable asset has the potential to be the first ADC therapy that specifically targets PSMA to treat prostate cancer.”
Hermans told BioSpace the asset “has demonstrated a potent in vivo anti-tumor response in both enzalutamide-sensitive and enzalutamide-resistant prostate cancer models.”
The company is also keeping two earlier-stage pipeline programs. The first is ARX305, an ADC targeting the CD70 protein, which is typically enriched in many different cancers like acute myeloid leukemia and non-Hodgkin’s lymphoma. The second is ARX102, a preclinical smart PEG-IL2 cytokine.
Ambrx is expecting a Phase Ia trial for ARX305 in the latter half of next year and an investigational new drug submission for ARX102 in early 2024. Because of the strategic reprioritization, ARX305 and ARX102 will have funding available through these key milestones, said Hermans. ARX517 will also now have support through its Phase Ib/II study.
To reflect its new pipeline priorities, Ambrx is also undergoing corporate streamlining, which includes job cuts for approximately 15% of its employees. Roles critical to the development of ARX517 and other early-stage assets will remain.
All three assets that Ambrx were developed using its proprietary expanded genetic code technology, which allows the company to insert synthetic amino acids into specific sites in proteins. This creates a highly predictable attachment point for the conjugated payloads, leading to a very homogenous group of ADCs.
“Moving forward, we plan to focus on creating next-generation antibody-drug conjugates and other engineered therapies to modulate the immune system for a variety of oncology indications,” Hermans said on the investor call. “With a streamlined approach to development, we will be better positioned to progress future engineered precision biologics through development and into the clinic.”
