SANTA FE, N.M.--(BUSINESS WIRE)-- Be Biopharma, Inc. (“Be Bio”), a company pioneering the development of engineered B Cell Medicines (BCMs), today announced an oral presentation and poster presentation at the Keystone Symposia on Emerging Cellular Therapies meeting, held from January 22 to 25, 2024 in Santa Fe, New Mexico. The data being presented support the utility of engineered B cell medicines (BCMs) across a broad range of applications. Together, the data demonstrate in vitro production and activity of several therapeutic proteins, as well as in vivo engraftment without preconditioning and activity in multiple model systems.

“Gene and cell therapies have transformative potential to treat previously intractable diseases, but have barriers to adoption such as lack of durability, inability to re-dose, and requirement of preconditioning for engraftment. Our BCM platform has the potential to address these barriers,” said Richard A. Morgan, Ph.D., Chief Scientific Officer, Be Bio. “The in vivo preclinical data presented today validates key attributes of our BCM platform – efficient protein production, editing and insertional efficiency, and durable protein production without preconditioning – while demonstrating its potential therapeutic benefits in genetic disease and cancer.”

Presentation Summary: Development of an Ex Vivo Precision Gene Engineered B Cell Medicine Platform that Produces Active and Sustained Levels of Therapeutic Proteins with Broad Utility

BCMs were produced via a precision genome engineering platform that achieves gene knockouts with greater than 90% efficiency and targeted HDR-mediated gene insertions at up to 60%. Modularity of the BCM platform was demonstrated across multiple models and proteins, including production of firefly luciferase, lysosomal storage disease enzyme acid sphingomyelinase, an anti-CD19/CD3 bispecific T cell engager, clotting factor IX, and fusion protein of tissue nonspecific alkaline phosphatase (ALP). These examples demonstrate that these BCMs can produce proteins with enzyme specific activity higher than recombinant proteins (ASM), show efficacy in tumor treatment (anti-CD19/CD3 scFv), and are stably expressed for at least 20 weeks in vivo (FIX). Engraftment in all models was achieved without preconditioning which broadens BCM clinical utility for patients for whom preconditioning toxicities are unacceptable or outweigh therapeutic benefit, and could facilitate additional rounds of treatment as needed. BCMs capable of expressing therapeutically relevant transgenes have the potential for broad and meaningful therapeutic utility in genetic diseases, cancer, and beyond.

Details for the oral presentation of this study are as follows:

Poster Summary: Development of an Ex Vivo Precision Gene Engineered B Cell Medicine Platform that Produces Active and Sustained Levels of Therapeutic Proteins with Broad Utility in Rare Diseases and Cancer

This study demonstrates production of BCMs via editing, expansion and differentiation of primary human B cells. Cells engineered to express firefly luciferase were engrafted into NOG-hIL6 mice and demonstrated in vivo persistence for 125 days. Data are also presented on BCMs engineered to produce FIX, which demonstrates activity via the chromogenic and aPTT assay. These BCMs were engrafted into NOG-hIL6 mice and demonstrate durable FIX secretion to 168 days. In addition to FIX, BCMs were engineered to produce an anti-CD19/CD3 bispecific T cell engager, which demonstrated potent activity in an in vivo PdX model of ALL, ALP, which corrected HPP-related bone mineralization deficits in vitro, and ASM, which demonstrated in vitro phenotypic correction in SMPD1 knockout cells. In addition, ex vivo-rhesus macaque plasma cells were generated and labeled with a radioactive tracer. These cells were administered without preconditioning and demonstrated homing to and engraftment in plasma cell niches in an autologous rhesus macaque.

Details for the poster presentation of this study are as follows:

About Engineered B Cell Medicines – A New Class of Cellular Medicines

The B cell is a powerful cell that produces thousands of proteins per cell per second at constant levels, over decades. Precision genome editing can now be used to engineer B Cells that produce therapeutic proteins of interest, driving a new class of cellular medicines – Engineered B Cell Medicines (BCMs) – with the potential to be durable, allogeneic, redosable and administered without pre-conditioning. The promise of BCMs could transform therapeutic biologics with broad application — across protein classes, patient populations and therapeutic areas.

About Be Biopharma

Be Biopharma (“Be Bio”) is pioneering Engineered B Cell Medicines (BCMs) to dramatically improve the lives of patients who are living with Hemophilia B and other genetic diseases, cancer, and other serious conditions. With eyes locked on the patient, our team of purpose-driven scientists, technologists, manufacturing experts and business builders collaborate to create a bold new class of cell therapies. Be Bio was founded in October 2020 by B cell engineering pioneers David Rawlings, M.D., and Richard James, Ph.D., from Seattle Children’s Research Institute. Be Bio is backed by ARCH Venture Partners, Atlas Venture, RA Capital Management, Alta Partners, Longwood Fund, Bristol Myers Squibb, Takeda Ventures, Seattle Children’s Research Institute and others. Since our founding, Be Bio’s investors have committed over $180 million to enable the Company to re-imagine medicine based on the power of B cell therapy. For more information, please visit us at Be.Bio and our LinkedIn page.

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