USA – Pfizer has deepened its collaboration with PostEra, a start-up specializing in artificial intelligence for medicinal chemistry, with an agreement that could see the pharmaceutical giant paying up to US $350 million.
The expanded partnership includes designing new small molecules and exploring antibody-drug conjugates (ADCs), a first for their collaboration.
ADCs represent a new dimension in the relationship between the two companies, which began in late 2020.
At that time, Pfizer enlisted the then one-year-old PostEra to apply machine learning to the design of small molecules for an undisclosed sum.
A year later, their partnership expanded to include antivirals and cancer drugs, with Pfizer making an initial payment of US $13 million and pledging up to US $248 million in milestone rewards.
Under the latest agreement, Pfizer will pay US $12 million upfront and further broaden its targets to include ADCs.
PostEra’s proprietary machine-learning platform, Proton, plays a central role in this collaboration.
Proton integrates medicinal chemistry design hypotheses with synthesis-aware technologies to design, create, and test novel molecules.
Initially, Pfizer partnered with PostEra to accelerate small molecule drug discovery by developing a generative chemistry platform.
This led to the establishment of an AI Lab in 2021, where the two companies combined Pfizer’s biological data with PostEra’s machine-learning expertise to develop cancer therapies and COVID-19 antivirals.
The expanded agreement allows the companies to add additional small molecule targets to their work and introduces ADC discovery into the mix.
ADCs, which combine an antibody, a small-molecule payload, and a linker, require intricate optimization—particularly of their payloads. PostEra will utilize Proton to refine these payloads under the new partnership.
Alpha Lee, PostEra’s co-founder and chief scientific officer, emphasized the tangible impact of AI-driven drug discovery, noting that the collaboration with Pfizer has already demonstrated faster-than-expected preclinical milestones in peer-reviewed publications.
Similarly, Aaron Morris, PostEra’s co-founder and CEO, highlighted the importance of designing machine learning models with chemical synthesizability in mind, a principle that also applies to ADC development.
PostEra has already achieved remarkable results, including a compound that prevents SARS-CoV-2 replication in mice by targeting the virus’s papain-like protease (PLpro), a different mechanism from the one used by Pfizer’s Paxlovid.
This compound progressed from concept to in vivo proof within eight months, a timeline significantly faster than traditional drug discovery processes. Beyond its work with Pfizer, PostEra has other notable collaborations.
These include agreements with Amgen to develop up to five small molecules and with the U.S. National Institutes of Health (NIH) as part of an Antiviral Drug Discovery (AViDD) Center for Pathogens of Pandemic Concern.
The AViDD program, which focuses on antivirals for coronaviruses, flaviviruses, and picornaviruses, faces funding expiration in the coming months. PostEra is actively seeking financial support to continue this critical work.
Outside these partnerships, PostEra has four wholly owned preclinical programs focused on women’s health and fertility, as highlighted on its website.
According to Morris, the company’s three key collaborations—with Pfizer, Amgen, and the NIH—form the foundation of its mission to benefit patients beyond its internal p
