DEM BioPharma Launches with $70 Million Financing
Company will pursue untapped opportunities in the field of innate immune system
checkpoints to eliminate cancer
Proprietary platform leverages CRISPR screening and macrophage biology tosystematically discover and drug “don’t eat me” (DEM) and “eat me” (EM) signals
June 23, 2022, 06:00 AM Eastern Daylight TimeCAMBRIDGE, Mass., June 23, 2022-- DEM BioPharma, Inc. (DEM Bio), an immuno-oncology company
developing therapies that target novel innate immune system checkpoints to eliminate cancer, todayannounced its initial $70 million financing led by founding investor Longwood Fund and Alta Partners,
with additional participation from Insight Partners, Pfizer Ventures, Astellas Venture Management,
Emerson Collective, UTokyo Innovation Platform and Alexandria Venture Investments.
DEM Bio is pioneering the next generation of immunotherapeutics designed to unleash macrophages
and other myeloid effector cells to eliminate tumors by targeting novel ‘don’t eat me’ (DEM) and ‘eatme’ (EM) signals on cancer cells and macrophages. The company’s approach builds on thegroundbreaking research from its scientific co-founders:•••

Jonathan Weissman, Ph.D. - Whitehead Institute, National Academy of Sciences member, HHMI,
world leader in genome-wide CRISPR screens;
Michael Bassik, Ph.D. - Stanford University, a distinguished biologist in cancer, phagocytes, andCRISPR screening; andKipp Weiskopf, M.D., Ph.D. – Whitehead Fellow and physician at Dana-Farber Cancer Institute,
one of the world’s leaders in macrophage and cancer biology.

DEM Bio is focused on accessing the largely untapped opportunity around macrophage biology andinnate immune system pathways to discover potent DEM and EM signals on cancers and expand thetherapeutic potential of the field beyond the relatively small number of signals targeted by current
investigational therapies. The company’s proprietary CHoMP™ platform (Co-culture with Human
Myeloid Phagocytes) will be used to identify unexplored DEM and EM signals in a systematic andunbiased manner via inter-cellular CRISPR screening using tumor cells, primary macrophages, and otherinnate immune effector cells.
DEM Bio also announced the appointment of Jan Skvarka, former CEO of Trillium Therapeutics (acquiredby Pfizer for $2.22 billion in November 2021), as Executive Chairman. As part of the financing, ChristophWestphal, M.D., Ph.D., Founding CEO, DEM Bio, and Founding Partner Longwood Fund; Dan Janney,Managing Partner, Alta Partners; Dylan Morris, Managing Director, Insight Partners; Marie-Claire
Peakman, Ph.D., Principal, Pfizer Ventures; and Hiro Kimura, Ph.D., Investment Director, Astellas
Venture Management have joined DEM Bio’s Board of Directors.

“Currently known DEM signals have been described in an ad hoc manner. DEM Bio’s foundersdiscovered a scalable approach to systematically unlock the potential of innate immune system
checkpoints,” noted Dr. Westphal.
“This financing from an exceptional group of investors positions us to execute on our ambitious plans todevelop the next generation of macrophage checkpoint inhibitors that may revolutionize how we treat
cancer,” said Mr. Skvarka.
DEM Bio has assembled a world-class Scientific Advisory Board consisting of leaders in the field ofCRISPR high-throughput screening, immune phagocytes, cancer biology, and therapeutic development,
including co-founders Drs. Weissman, Bassik and Weiskopf, Roarke Kamber, Ph.D., Postdoctoral fellow,Genetics, Stanford School of Medicine, Dian Yang, Ph.D., Postdoctoral fellow, Whitehead Institute for
Biomedical Research, as well as Kai Wucherpfennig, M.D., Ph.D., Professor and Chair, Dana-Farber
Cancer Institute; Dane Wittrup, Ph.D., Professor of Chemical Engineering & Bioengineering, MIT; andBob Uger, Ph.D., former CSO, Trillium Therapeutics.
“The currently known DEM and EM pathways were discovered serendipitously,” said Dr. Bassik. “Similarto 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.”“By leveraging cutting-edge functional genomics and macrophage biology, we created the CHoMP
platform to discover new DEM/EM signals in a fully unbiased and systematic way,” said Dr. Weiskopf.
“CHoMP is a highly differentiated platform built on unique, proprietary CRISPR screening capabilities inprimary human cells, enabling DEM Bio to methodically evaluate unexplored DEM/EM signals,” said Dr.
Weissman.
The CHoMP platform has identified a number of promising new DEM/EM signals, including the novel
DEM pathway APMAP. In preclinical work, targeting APMAP enhanced tumor cell phagocytosis in
multiple cancer cell types and animal cancer models, and demonstrated synergistic effects with a broad
range of tumor-binding antibodies.
David Donabedian, Co-founder and start-up CEO of DEM Bio, and Operating Partner, Longwood Fund
added, “APMAP is just one of the promising programs identified using the CHoMP platform, and theencouraging initial data on this pathway has helped validate our differentiated approach to identifying
novel, potent DEM/EM signals. The company plans to use proceeds from this financing to further
develop our platform and to advance our portfolio of novel targets towards therapeutic development inoncology.”

About DEM BioPharma Inc.
DEM Bio is pioneering the next generation of immunotherapeutics that unleash the innate immune
system to eliminate tumors by targeting ‘don’t eat me’ (DEM) and ‘eat me’ (EM) signals on cancer cells,
macrophages and other myeloid effector cells. Founded by Longwood Fund, the company’s approachbuilds on the groundbreaking functional genomics research and discoveries in macrophage biology fromits scientific co-founders: Drs. Jonathan Weissman and Kipp Weiskopf of the Whitehead Institute and Dr.
Michael Bassik of Stanford University. The proprietary CHoMP™ platform (Co-culture with Human

Myeloid Phagocytes) utilizes CRISPR-based functional genomic screens in human cancer cells and/or
primary macrophages to discover and validate new DEM and EM signals that could profoundly induceand enhance cancer cell elimination through increased phagocytosis.

Contacts
Kari Watson or Nicholas Changkwatson@macdougall.bio or nchang@macdougall.bio(781) 235-3060