Xilio Therapeutics is focused on advancing highly potent, tumor-selective immunotherapies designed to improve patient outcomes

Our Focus

Immunotherapies have shown great promise for attacking tumors. But currently only a fraction of cancer patients can benefit – often because the therapies have potent effects throughout the body, leading to severe side effects.

Our vision at Xilio is to transform the lives of cancer patients, by developing next-generation immunotherapies that unleash the power of the immune system selectively at the site of the tumor.

Our Science

Xilio Therapeutics is developing its proprietary technology to create a new class of ultra-potent IO therapies that are activated selectively within the tumor. These tumor-selective therapies are designed to overcome the significant toxicities associated with validated IO therapies, which have historically limited the number of patients that can be treated and prevented patients from completing full courses of treatment.

Our lead programs have demonstrated potent, tumor-selective activity in preclinical models. XTX201 (IL-2) induces immune activity in tumors without the toxicity seen with non-selective IL-2s, and XTX101 (aCTLA4 mAb) demonstrates improved antitumor activity compared to ipilimumab. These data suggest tumor selectivity significantly widens the potential therapeutic index for these therapies.

Our Pipeline

Xilio has developed an exciting pipeline of tumor-selective immunotherapies, with our first two Investigational New Drug (IND) filings projected for 2021.

About Xilio

“Xilio” (pronounced “ex-il-ee-oh”) is derived from the Latin term Ex Nihilo, meaning creation or big-bang, and embodies the company’s vision to create transformative treatments for individuals living with cancer by unleashing the full power of highly potent immune therapies selectively in tumors.

Xilio Therapeutics is a biotechnology company advancing next-generation cancer immunotherapies designed to improve patient outcomes by unleashing the power of the immune system selectively at the site of the tumor. The company’s tumor-selective immunotherapies are based on its proprietary technology, which maximizes the potency of proven immuno-oncology therapies and restricts their activity to the tumor to minimize peripheral side effects. The broad applicability of these therapies across cancer types means that all patients could benefit from these potentially curative medicines.

Xilio was founded in 2016 and is headquartered in Waltham, MA.

Our Team

We are a team of passionate leaders and investors with deep experience in growing successful companies and delivering breakthrough medicines to cancer patients.

Our Leadership

Executive Officer
Operating Officer
Medical Officer
SVP Research
& Trans. Sci.

Our Board and Investors

Our Board includes the following industry leaders and representatives from our investors:

  • Dan Lynch — Chair of Board
  • Paul Clancy — Independent Director
  • Peter Dudek — MRL Ventures Fund
  • David Grayzel — Atlas Venture
  • Nancy Hong — Rivervest Venture Partners
  • Rachel Humphrey — Independent Director
  • Jayson Punwani — Takeda Ventures
  • Mike Ross — SV Health Investors
  • Robert Weisskoff — F-Prime


Our Scientific Advisory Board

We are advised by world-leading scientists with deep expertise in cytokine biology, cancer immunology, protein engineering, protease biology, and oncology drug development.

Dr. Deborah Charych has held scientific leadership positions in both academia and biotech. At Nektar Therapeutics, she led the strategic development of the Immuno-Oncology pipeline and designed NKTR-214, an IL-2 receptor agonist, currently in Phase 3. Alternative engineering of the IL-2 pathway led to clinical development of NKTR-358 for autoimmune disease. Follow-on cytokine and small molecule immune modulators include an IL-15 receptor agonist and a TLR 7/8 agonist. At FivePrime Therapeutics, Dr. Charych led a team that contributed to the clinical development of FP-1039, a pan-FGF inhibitor for oncology. While at Chiron Corporation she initiated and led a large proteomics effort to guide oncology target discovery. At Lawrence Berkeley National Laboratory, she assumed an academic leadership role as tenured Principal Investigator, focusing on new materials. Dr. Charych’s formal education is in Chemistry, earning a Ph.D. from University of California at Berkeley and a B.S. in Chemistry from Carnegie-Mellon University, Pittsburgh, PA.

Michael Gladstone is a Board Member at Xilio and Parter at Atlas Venture. Michael was a member of the founding teams of several Atlas Venture-originated companies, including Padlock Therapeutics (acquired by BMS), Surface Oncology (NASDAQ: SURF), and IFM Therapeutics Inc. (acquired by BMS). He serves as a board member of Obsidian Therapeutics and as a board observer for IFM Therapeutics LLC, Kyn Therapeutics, Replimune (NASDAQ: REPL), and AvroBio (NASDAQ: AVRO); he was previously a board observer for Delinia (acquired by Celgene). He has also been closely involved with Atlas’s immuno-oncology investments CoStim Pharmaceuticals (acquired by Novartis) and Unum Therapeutics (NADSAQ: UMRX). Prior to joining Atlas in 2012, Michael was a senior associate consultant in the life sciences practice at L.E.K. Consulting, where he focused on business development and corporate strategy for biopharma clients. Prior to that, Michael was a Massachusetts Life Sciences Center Fellow at Eutropics, a Dana Farber Cancer Institute spin out, where he helped develop BH3 domain focused therapeutics and companion diagnostics for multiple myeloma and other malignancies. Previously, Michael worked in the Viral Pathogenesis department of Beth Israel Deaconess Medical Center where he led research on cellular HIV vaccines with Harvard Medical School Professor Norman Letvin. His research focused on elucidating the role of interleukin-21 in CD8+ T cell memory response to viral antigens. Michael received an AB in biochemical sciences with highest honors from Harvard College, where he graduated magna cum laude and was awarded the Harvard College Scholarship. While at Harvard, he received a Herchel Smith Undergraduate Fellowship, among other grants, for his undergraduate immunology research. Michael is on the Corporate Advisory Committee for National Tay-Sachs and Allied Diseases, a national organization focused on funding research, promoting awareness, and supporting families affected by Tay-Sachs and related genetic diseases.

Dr. Christopher A. Hunter is currently the Mindy Halikman Heyer President's Distinguished Chair in the Department of Pathobiology at the University of Pennsylvania and a leading expert in cytokines and immunology. Over three decades, Dr. Hunter’s research has focused on key aspects of host-pathogen interactions, specifically on understanding the role of the cytokine networks in responding to immune insults and regulating protective and pathological immune responses. Dr. Hunter earned a B.Sc. and a Ph.D. in Zoology from the University of Glasgow, with a post-doctoral fellowship at Stanford University.

Margaret was previously Senior Vice President of Preclinical Development at Xilio Therapeutics. Prior to Xilio, she was an Executive Director at Amgen for 10 years where she held multiple roles in drug development. These included Executive Director in the Biosimilars Business Unit as the lead for Biosimilars Process Development, and as an Executive Director in Discovery Research leading the Biologics Optimization organization, Protein Sciences at the Thousand Oaks campus, and the site head for the Burnaby, Canada research site where XenoMouse antibody development is based. Prior to Amgen, Margaret was a Vice President at Regeneron Pharmaceuticals, where in a 10 year tenure she was closely involved with the development of the Traps technology in addition to driving numerous target identification and discovery initiatives. She was also the co-lead for the development of the VelocImmune mouse platform for the production of human antibodies. Margaret completed her post-doctoral work at Temple Medical School and her Ph.D. at the the University of Utah. She holds a BA in MCD Biology from the University of Colorado.

Dr. Andrew Luster currently serves as Chief for the Division of Rheumatology, Allergy and Immunology at Massachusetts General Hospital. He is also a Professor of Medicine at Harvard Medical School. Dr. Luster’s laboratory research focuses on understanding the role of chemokines and lipid chemoattractants and their receptors in controlling the migratory behavior, cellular interactions, and trafficking of leukocytes in vivo. Dr. Luster earned a Ph.D. from Rockefeller University and an M.D. from Cornell University.

Dr. Anthony J. O’Donoghue is an assistant professor at Skaggs School of Pharmacy and Pharmaceutical Sciences at University of California San Diego. He has nearly two decades of experience studying proteases and focused his academic research on understanding the functional role of these enzymes in cancer and infectious disease. He received the Bioanalysis Young Investigator Award in 2013 for development of a global and unbiased protease substrate profiling method and has utilized this technology to develop diagnostic assays for pancreatic cancer and peptide inhibitors that target pathogen proteases. Dr. O’Donoghue earned a Ph.D. in Biochemistry and Fungal Biotechnology from the National University of Ireland and a B.S. in Biochemistry and Microbiology from the National University of Ireland.

Dr. John C. Williams is a professor in the Department of Molecular Medicine at City of Hope, a world-renowned independent research and treatment center for cancer, diabetes and other life-threatening diseases, and a scientific co-founder of Xilio Therapeutics. Dr. Williams’ areas of scientific research and expertise include structural biology, with a focus on x-ray crystallography and NMR, biophysics and protein engineering. Xilio’s proprietary technology is licensed from City of Hope and Thomas Jefferson University. Additionally, he is a member of the Cancer Immunotherapeutics Program and co-director of the Drug Discovery and Structural Biology Core at City of Hope, a National Cancer Institute-designated Comprehensive Cancer Center. Dr. Williams earned a Ph.D. in Chemistry from Columbia University and a B.S. in Chemistry from the University of California Santa Cruz.


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