PYTX-004

January 23, 2024 WEST CHESTER Pa — Papyrus Therapeutics Inc., a biotechnology platform company for the development of potent, multi-cancer, tumor suppressor precision therapies for solid cancers, is pleased to announce that the United States Patent and Trademark Office (USPTO) granted approval of all 20 claims in Papyrus’ submitted Patent. That the USPTO approved all 20 claims is distinguishing given the infrequency patent grants are awarded without prior art being cited against the claims. The nature of the expanded patent recognizes the groundbreaking novelty and potential of Papyrus’ platform’s science, knowledgebase, and AI enablement to streamline the discovery of naturally occurring tumor suppressor proteins like OPCML as therapeutics. Such proteins, when identified as silenced in human cancer, can be restored in those cancers by Papyrus’ recombinant-OPCML (r-OPCML) protein replacement therapy through intravenous delivery. Unlike chemotherapy and other oncogene-focused therapeutics, r-OPCML targets only cancer cells deficient in this protein without damaging healthy cells that normally express it. Further, the data-to-date points to the therapeutic being a well-tolerated and effective treatment. According to Papyrus’ co-founder / chief scientific officer, and renowned translational medical oncologist Hani Gabra, PhD FRCP, “Preclinical studies of Papyrus’ lead clinical asset PYTX-004, the r-OPCML-Fc fusion tumor suppressor analog, have demonstrated a high degree of tumor suppressor efficacy as a monotherapy and as a combination therapy in ovarian cancer with no adverse toxicities noted thus far. This, in concert with USPTO’s approval of all 20 claims reinforces the transformational potential of the Papyrus tumor suppressor discovery platform to enable a pipeline of novel, cancer-targeted protein-replacement tumor suppressor therapeutics.” Similar results for this suppressor replacement therapy have been observed for HER2+ breast cancer and are projected for other cancers, with loss of this tumor suppressor noted in at least half of all human solid cancers. OPCML, a member of the IgLON family of proteins, is a naturally occurring tumor suppressor protein. PYTX-004 is Papyrus’ r-OPCML-Fc lead tumor suppressor biotherapeutic in development that is outlined in the patent application. The Company expects to have continued success with upcoming patent filings based on unique synthetic alterations of OPCML and other related IgLON family members that will enable the development of a pipeline of pioneering unique synthetic tumor suppressor biotherapeutics with novel specificities for monotherapy and combination therapies in differing indications. About Papyrus Therapeutics Inc.: Papyrus Therapeutics, Inc. (https://papyrustherapeutics.com/) is a biotherapeutics platform company developing novel tumor suppressor-based therapies. Papyrus ́ lead therapeutic is a modified, recombinant analogue of Opioid Binding Protein/Cell Adhesion Molecule-like (r-OPCML-Fc), PYTX-004. PYTX-004 is a native engineered OPCML protein replacement therapy designed to suppress tumor growth. OPCML is a broadly acting tumor suppressor that is epigenetically silenced in many cancers, leading to tumor invasion and metastasis through deregulation of apoptosis, epithelial-to-mesenchymal transition (EMT) and cellular migration. Delivery of OPCML, which works at the cell surface, can overcome the challenge of RTK inhibitor resistance by reconstituting normal RTK signaling in the tumor. Contact Dr. Paul Blake pblake@pytxi.com