CHoMP: Westphal's Dem gobbles up $70M in Pfizer-backed round to fund macrophage cancer R&D

Christoph Westphal is back with another biotech, joining with scientists including Jonathan Weissman, Ph.D., to work on signals that dictate whether macrophages gobble up cancer cells. The startup, Dem BioPharma, is beginning life with $70 million and former Trillium Therapeutics CEO Jan Skvarka in a leading role.

Dem is part of a band of biotechs working on the signaling between cancer cells and macrophages. To date, CD47, known as the “don’t eat me signal,” has attracted the most attention, with Gilead and Pfizer buying their way into the space in multibillion-dollar deals. Yet, if Dem is right, CD47 may just be scratching the surface of what is possible. The biotech wants to target a range of eat me and don’t eat me signals.

The pursuit of that opportunity has brought together some notable names. Weissman, of the Whitehead Institute, sits with Stanford University’s Michael Bassik, Ph.D., and Dana-Farber Cancer Institute’s Kipp Weiskopf, M.D., Ph.D., on the list of scientific co-founders, giving Dem a grounding in CRISPR screens and cancer biology.

Westphal, who previously helped set up biotechs including Alnylam and Momenta Pharmaceuticals, is another co-founder and served as Dem’s founding CEO. Skvarka, fresh from leading CD47 biotech Trillium to a $2.3 billion takeover by Pfizer, is in the executive chairman role. David Donabedian is co-founder and start-up CEO.

The team has secured $70 million to get Dem off the ground. Longwood Fund, where Westphal serves as a general partner, and Alta Partners came together to lead the round. Insight Partners, Pfizer Ventures, Astellas Venture Management, Emerson Collective, UTokyo Innovation Platform and Alexandria Venture Investments provided assists.

Dem will use the money to try to systematically identify innate immune system checkpoints that can turn macrophages against cancer. To support the work, Dem has built the co-culture with its human myeloid phagocytes platform, known as CHoMP. The inter-cellular CRISPR screening platform equips Dem to use tumor cells, primary macrophages and other innate immune effector cells to identify signals. 

“The currently known [don’t eat me] and [eat me] pathways were discovered serendipitously,” Bassik said in a statement. “Similar to other areas of immunotherapy, there are likely other signals that are more potent and offer better therapeutic targets, but no one has yet taken a systematic approach to identifying those pathways.”

So far, Dem has disclosed the identification of the APMAP don’t eat me pathway. Bassik and Weissman were among the co-authors of a 2021 Nature paper about the discovery of the pathway, which described the use of CRISPR knockout and overexpression screens to reveal that the loss of APMAP synergizes with anti-CD47 and tumor-antigen targeting antibodies to increase immune ingestion of cancer cells.