Prometheus Biosciences Announces FDA Acceptance of IND Application for PRA023 and Commences Dosing in Phase 1a Clinical Study


SAN DIEGO, Dec. 15, 2020 /PRNewswire/ --Prometheus Biosciences, Inc. ("Prometheus"), a biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialization of novel therapeutic and companion diagnostic products for the diagnosis and treatment of inflammatory bowel disease (IBD), today announced FDA acceptance of its Investigational New Drug Application (IND) for PRA023 and that dosing has commenced in a Phase 1a clinical study in normal healthy volunteers. PRA023, the company's lead product candidate, is a humanized IgG1 monoclonal antibody (mAb) that has been shown to block tumor necrosis factor (TNF)-like ligand 1A (TL1A). TL1A is a validated clinical target that is being developed for the treatment of the two most common forms of IBD, ulcerative colitis (UC) and Crohn's disease (CD). Prometheus recently completed a $130M financing to advance novel precision medicine approaches in IBD.

"PRA023 is a novel precision therapy approach for the treatment of IBD and we are pleased to initiate dosing in this clinical study," said Mark McKenna, President and CEO of Prometheus. "Importantly, TL1A is the only therapeutic target in development that targets both inflammation and fibrosis, which represents the biggest unmet medical need in IBD."

"Anti-TL1A therapy is a very promising mechanism for the treatment of IBD, and everyone has been waiting for companion diagnostic directed therapy that will allow us to treat the right patient with the right drug," remarked Dr. William Sandborn, MD, Chief of Gastroenterology and Director of the IBD Center at the University of California San Diego.

Study PR200-101 is a Phase 1a, single and multi-dose, randomized, double-blind, placebo-controlled study to determine the safety, tolerability, pharmacokinetics, and pharmacodynamics of PRA023 in healthy volunteers.

About PRA023, an Anti-TL1A mAb

PRA023 is an IgG1 humanized mAb that has been shown to block TL1A. Third-party antibody programs against TL1A have been shown to reduce both intestinal inflammation and fibrosis in preclinical studies, and this target has been clinically-validated in a third-party Phase 2a clinical trial in UC. PRA023 binds both soluble and membrane-associated human TL1A with high affinity and specificity and has the potential to substantially improve outcomes for moderate-to-severe IBD patients. Prometheus is developing PRA023 for the two most common forms of IBD, ulcerative colitis (UC) and Crohn's disease (CD).

About Inflammatory Bowel Disease (IBD)

IBD is a complex disease with many contributing factors, including genetic, environmental and immunologic, and is estimated to affect over 2,000,000 people in the United States and over 5,000,000 people globally. UC and CD are two of the most common forms of IBD. Both UC and CD are chronic, relapsing, remitting, inflammatory conditions of the GI tract that begin most commonly during adolescence and young adulthood. UC involves the innermost lining of the large intestine, and symptoms include abdominal pain and diarrhea, frequently with blood and mucus. CD can affect the entire thickness of the bowel wall and all parts of the GI tract from mouth to anus. CD symptoms include abdominal pain, diarrhea, and other more systemic symptoms such as weight loss, nutritional deficiencies, and fever.

The current standard of care for the treatment of patients with moderate-to-severe IBD is typically anti-inflammatory agents; however, none of these therapies address fibrosis, or scarring, in IBD. Since the approval of the first anti-TNF agent for the treatment of CD in 1998, the availability of JAK inhibitors and newer biological agents, including anti-integrin and anti-IL12/23, has improved the care of moderate-to-severe IBD (JAK inhibitors in UC only). However, these subsequently approved therapies have generally failed to demonstrate a clinical remission effect size of more than 15% relative to placebo. Moreover, among those patients who do respond to therapy, up to 45% will lose response over time. Current therapies used for the treatment of UC and CD apply a one-size-fits-all approach without regard to biologic variations amongst patients, and substantial unmet need remains.

About Prometheus Biosciences, Inc.

Prometheus Biosciences, Inc. is a privately held biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialization of novel therapeutic and companion diagnostic products for the treatment and diagnosis of IBD. The company's precision medicine platform, Prometheus360, combines proprietary bioinformatics discovery methods with one of the world's largest gastrointestinal bioinformatics databases to identify novel therapeutic targets and develop therapeutic candidates to engage those targets. Prometheus is guided by its board of directors, led by Chairman Tachi Yamada, M.D., and a scientific advisory board composed of key opinion leaders in IBD, including Stephan Targan, M.D., William Sandborn, M.D. and Dermot P. McGovern, M.D., Ph.D. In addition, Prometheus has entered into collaborations to develop targeted therapies for IBD.

Prometheus maintains its headquarters in San Diego, CA. For more information about Prometheus, please visit


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