News Release

Prometheus Biosciences to Host a Virtual R&D Day for Analysts and Investors on July 26, 2022

July 18, 2022

- The event will feature Prometheus management and key opinion leader presentations on PR600 target unveiling, scientific rationale, and corresponding therapeutic candidate, PRA052 -

- PRA052 is a novel, first-in-class monoclonal antibody addressing a target with one of the strongest genetic associations to IBD -

- PRA052 has a pleiotropic effect on both innate and adaptive immunity and targets a pathway that is distinct from TNF -

- IND planned for Q3 2022 with Phase 1 initiation planned for Q4 2022 -

SAN DIEGO, July 18, 2022 (GLOBE NEWSWIRE) -- Prometheus Biosciences, Inc. (Nasdaq: RXDX), a clinical-stage biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialization of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases, today announced it will host a virtual R&D Day for analysts and investors at 9:00 am ET on Tuesday, July 26, 2022. The presentations will showcase Prometheus’ second program, PR600 and its corresponding clinical candidate, PRA052, reveal the therapeutic target and provide detailed scientific rationale on the approach.

In addition to presentations by Prometheus’ senior management team, the R&D Day will feature key opinion leader, Marla Dubinsky, MD, Chief of the Division of Pediatric Gastroenterology and Director of the Inflammatory Bowel Disease Center at Mount Sinai Health System. Dr. Dubinsky was involved in the early development of Prometheus360TM while serving as the Director of the Pediatric IBD Center at Cedars Sinai.

The agenda for the Prometheus R&D Day is as follows:

Introduction from the Chairman & CEO

  • PR600/PRA052 Target Unveiling: Mark McKenna, Chairman & CEO of Prometheus Biosciences

Scientific Rationale

  • Discovery, Scientific Rationale, and Genetic Association: Olivier Laurent, PhD, Chief Scientific Officer of Prometheus Biosciences

Unmet Need: Precision in IBD

  • Unmet Need and Implication of Precision Approach in IBD: Marla Dubinsky, MD, Chief, Division of Pediatric Gastroenterology and Director, Inflammatory Bowel Disease Center Mount Sinai Health System

Webcasting Information

The R&D Day will be held on July 26th at 9:00 am ET. Registration for the event as well as a live and archived webcast of the R&D Day will be available in the Events & Webcasts section of the Prometheus Biosciences website.

About Prometheus Biosciences
Prometheus Biosciences, Inc. is a clinical-stage biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialization of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases. The company’s precision medicine platform, Prometheus360TM, combines proprietary machine learning-based analytical approaches with one of the world’s largest gastrointestinal bioinformatics databases to identify novel therapeutic targets and develop therapeutic candidates to engage those targets.

The Company is currently conducting three Phase 2 studies of its lead therapeutic candidate PRA023 targeting tumor necrosis factor (TNF)-like ligand 1A (TL1A): a Phase 2 trial in UC patients, ARTEMIS-UC, a Phase 2a trial in CD patients, APOLLO-CD, and a Phase 2 clinical trial in SSc-ILD, ATHENA-SSc, each utilizing a genetic-based companion diagnostic candidate designed to identify patients who are predisposed to increased expression of TL1A and therefore potentially more likely to respond to PRA023.

Forward Looking Statements
Prometheus cautions readers that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These statements are based on the company’s current beliefs and expectations. Such forward-looking statements include, but are not limited to statements regarding: the timing of filing the IND and initiating a Phase 1 clinical trial for PRA052; and the ability of Prometheus’ precision medicine platform to identify potential targets associated with immune-mediated diseases and particular patient subpopulations. The inclusion of forward-looking statements should not be regarded as a representation by Prometheus that any of our plans will be achieved. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in our business, including, without limitation: Prometheus’ approach to the discovery and development of precision medicines based on Prometheus360 TM is unproven; potential delays in the commencement, enrollment and completion of clinical trials and preclinical studies; Prometheus’ dependence on third parties in connection with product manufacturing, research and preclinical and clinical testing; Prometheus’ ability to develop companion diagnostics for our therapeutic product candidates; unexpected adverse side effects or inadequate efficacy of our product candidates that may limit their development, regulatory approval and/or commercialization, or may result in recalls or product liability claims; the results of preclinical studies and early clinical trials are not necessarily predictive of future results; Prometheus may not realize any benefits from our current and any future collaborations; regulatory developments in the United States and foreign countries; Prometheus’ ability to obtain and maintain intellectual property protection for our product candidates and maintain our rights under intellectual property licenses; Prometheus’ ability to maintain undisrupted business operations due to the COVID-19 pandemic, including delaying or otherwise disrupting its clinical trials, manufacturing and supply chain; and other risks described in the company’s prior press releases and filings with the Securities and Exchange Commission (SEC), including under the heading “Risk Factors” in our Form 10-K filed with the SEC on March 9, 2022 and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Contacts:
Noel Kurdi
VP Investor Relations and Communications
(646) 241-4400
nkurdi@prometheusbiosciences.com

Media contact:
Juniper Point
Amy Conrad
(858) 914-1962
media@prometheusbiosciences.com