Photys Therapeutics is a biotechnology company focused on developing innovative medicines by precisely controlling protein function within the body. They aim to address various diseases with limited treatment options through distinct biological mechanisms.
The Science of Targeted Protein Phosphorylation
Protein phosphorylation is a fundamental biological process that acts like a molecular switch, turning protein activity on or off. This modification involves the addition of a phosphate group to a protein, which can alter its shape, function, or interactions with other molecules in the cell. Kinases are enzymes responsible for adding these phosphate groups, while phosphatases remove them, maintaining a delicate balance in cellular signaling pathways.
Photys Therapeutics has developed a proprietary platform known as Phosphorylation-Inducing Chimeric Molecules (PHICS). These bifunctional molecules have two distinct parts linked together. One part binds to a specific kinase, and the other binds to a target protein implicated in a disease.
A PHICS molecule brings the kinase and the target protein into close proximity. This induced closeness allows the kinase to phosphorylate the target protein, even if it wouldn’t normally do so. By precisely controlling this phosphorylation, PHICS can alter the target protein’s function, activating, inactivating, or modifying its behavior to achieve a therapeutic effect.
Applications in Disease Treatment
The ability to precisely control protein activity through phosphorylation offers a promising strategy for treating various diseases. Photys Therapeutics primarily focuses on oncology, the field of cancer treatment. In cancer, uncontrolled protein activity often drives tumor growth and survival.
By modulating protein function through PHICS, the company aims to reactivate tumor suppressor proteins or alter the behavior of proteins that promote cancer development. For example, PHICS can induce phosphorylation events that inhibit oncogenic kinases, leading to cancer cell death. Beyond oncology, Photys is also applying its PHICS technology to develop medicines for autoimmune, inflammatory, and cardiometabolic diseases.
The Photys Corporate and Scientific Foundation
Photys Therapeutics was co-founded by leading scientific minds and established venture capital firms. The company originated from the research of Dr. Amit Choudhary, a chemical biologist from Brigham and Women’s Hospital and the Broad Institute of MIT and Harvard. Dr. Edward Holson is also a co-founder and the company’s chief scientific officer.
The company launched in September 2022 with a Series A financing round that raised $75 million. This funding was led by MPM Capital (now MPM BioImpact) and included participation from other prominent investors such as Omega Funds, Longwood Fund, 8VC, Arkin Bio, Mass General Brigham Ventures, MRL Ventures Fund, Merck & Co., Eli Lilly and Company, and Heritage Medical Systems. The scientific advisory board includes distinguished scientists like Eric Fischer from Dana-Farber Cancer Institute, Tony Hunter from the Salk Institute, Angela Koehler from MIT, and Dan Nomura from UC Berkeley.
Differentiating from Other Therapeutic Modalities
Photys Therapeutics’ PHICS molecules distinguish themselves from other therapeutic modalities, such as Proteolysis-Targeting Chimeras (PROTACs). Both PHICS and PROTACs are bifunctional molecules that leverage induced proximity, but their fundamental mechanisms and therapeutic goals differ. PROTACs function by recruiting an E3 ligase to a target protein, flagging it for degradation and complete removal from the cell via the ubiquitin-proteasome system. This process essentially eliminates the problematic protein.
In contrast, PHICS molecules operate by inducing a kinase to phosphorylate a target protein, modifying its function rather than destroying it. This modification can activate, inactivate, or alter the protein’s behavior in a precise manner. The ability to modify a protein’s function, rather than simply degrading it, offers potential advantages, such as fine-tuning cellular pathways or addressing diseases where complete protein removal is not desirable or possible. This approach may also target proteins not amenable to degradation by PROTACs, expanding the range of “undruggable” targets.