Rubius Therapeutics

Founded by Flagship Pioneering in 2014, Rubius Therapeutics (NASDAQ: RUBY) is a biopharmaceutical company pioneering a new era of cellular medicines. The company’s proprietary RED PLATFORM^® was designed to genetically engineer and culture Red Cell Therapeutics™ that are selective, potent, and ready-to-use cellular therapies for the potential treatment of several diseases across multiple therapeutic areas.

Rubius’ initial focus is to advance RCT™ product candidates for the treatment of rare diseases, cancer, and autoimmune diseases by leveraging three distinct therapeutic modalities — cellular shielding, potent cell-cell interaction, and tolerance induction.

During the second quarter of 2019, Rubius plans to begin treating patients in a Phase 1b trial, evaluating RTX-134 as a potential treatment of phenylketonuria (PKU). Rubius is planning to file additional investigational new drug applications (INDs) in rare diseases, cancer, and autoimmune diseases in 2019, 2020 and thereafter.

Versatile Platform Enabling Multiple Modalities

Rubius’ RED PLATFORM® and RCT™ product candidates potentially represent a transformative step in the evolution of cellular therapies and are designed to provide the following attributes:

A Broad and Diverse Pipeline

Rubius’ first product candidates were selected based on:

• Potential to address unmet medical needs
• Feasibility as determined by Rubius’ preclinical research and development efforts
• Potential to rapidly achieve proof-of-concept based on easy-to-measure validated regulatory endpoints
• Significant potential to help patients

Rare Diseases

RTX-134

In the second quarter of 2019, Rubius plans to begin treating patients in a Phase 1b trial, evaluating RTX-134 as a potential treatment of phenylketonuria (PKU), a rare inherited disease that causes build-up of the amino acid phenylalanine (Phe). Without the functional enzymes to process Phe, a buildup can occur, causing impaired cognitive function. RTX-134 is an RCT product candidate that expresses the enzyme phenylalanine ammonia lyase and coverts Phe to the metabolite transcinnamic acid, which is naturally cleared by the body. Initial clinical data is expected during the second half of 2019.

Cancer

RTX-240

Rubius is developing a pipeline of RCT product candidates that target T cells, natural killer (NK) cells, dendritic cells, and tumor cells. RTX-240 is an RCT product candidate that co-expresses 4-1BBL, a ligand that binds to and activates the co-stimulatory receptor 4-1BB, an important regulator of the immune system, and IL-15TP, a fusion of IL-15 and IL-15 receptor alpha, with the goal of improving anti-tumor activity and overcoming resistance to immunotherapy.

RTX-240 is Rubius’ first potential treatment for patients with solid tumor types. The company plans to file an IND application by early 2020.

Autoimmune Diseases

Rubius plans to select the company’ first clinical candidate designed to induce tolerance in an autoimmune disease in 2019.