SOUTH SAN FRANCISCO, Calif., Sept. 29, 2025 (GLOBE NEWSWIRE) -- RAPT Therapeutics, Inc. (Nasdaq: RAPT), a clinical-stage immunology-based biopharmaceutical company focused on discovering, developing and commercializing novel therapies for patients living with inflammatory and immunological diseases, today announced that the U.S. Food and Drug Administration (FDA) has cleared RAPT’s Investigational New Drug (IND) Application to proceed to a Phase 2b clinical trial of RPT904 for the treatment of patients with food allergy. The planned Phase 2b trial in food allergy is a randomized double-blind placebo-controlled study designed to evaluate the safety and efficacy of RPT904 dosed every 8 weeks (Q8W) and every 12 weeks (Q12W).

“Clearance of our IND application, which included data from our Chinese partner Jeyou, is an important and meaningful step for the program,” said Brian Wong, M.D., Ph.D., President and CEO of RAPT. “We are excited to advance clinical development of RPT904, our next-generation, half-life extended anti-IgE molecule with a differentiated product profile. We are on track to initiate our Phase 2b clinical trial by the end of the year, taking us closer to our objective of delivering a best-in-class therapeutic option to patients in the large and underserved food allergy community. Furthermore, we look forward to data from Jeyou’s Phase 2 trials in chronic spontaneous urticaria and asthma, which we also expect by the end of the year.”

About the RPT904-01 (prestIgE) Phase 2b Trial
The Phase 2b trial, named “prestIgE”, is designed to assess the efficacy and safety of RPT904 monotherapy in participants with IgE-mediated food allergy. The two-part, multi-center, randomized, double-blind, placebo-controlled study will compare two dosing regimens of RPT904 (administered subcutaneously every 8 weeks or every 12 weeks, including a loading dose at Week 2) to placebo in a 2:2:1 ratio. In Part 1, approximately 100 participants with at least one food allergy (peanut, milk, egg, walnut or cashew) will be treated for 24 weeks. The primary endpoint for the trial is the proportion of participants who achieve a prespecified target threshold at a double-blind, placebo-controlled, oral food challenge (DBPCFC) at Week 24. In Part 2, the participants in the RPT904 treatment arms will continue treatment for another 24 weeks, while participants on placebo will be re-randomized 1:1 to receive RPT904 either every 8 weeks or every 12 weeks (with a loading dose at Week 26) through Week 48 and all participants will undergo a DBPCFC at Week 48. Participants will also be followed for an additional 16 weeks in a safety follow-up period.

About RPT904
RPT904 is a novel, half-life extended anti-IgE bio-better monoclonal antibody (mAb) targeting the same epitope as omalizumab for the treatment of patients with food allergies, chronic spontaneous urticaria and other allergic inflammatory diseases. RPT904 is designed to inhibit free and cell-bound human immunoglobulin E (IgE), a key driver of allergic diseases, and in early clinical studies has demonstrated extended pharmacokinetics and pharmacodynamic properties compared to omalizumab, a first generation anti-IgE mAb.

About RAPT Therapeutics, Inc.
RAPT is a clinical-stage immunology-based biopharmaceutical company focused on discovering, developing and commercializing novel therapies for patients living with inflammatory and immunological diseases. Utilizing our deep and proprietary expertise in immunology, we develop novel therapies that are designed to modulate the critical immune responses underlying these diseases.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as “anticipate,” “estimates,” “expects,” “look forward,” “on track,” “planned,” “potential” “will” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These statements relate to future events and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future performances or achievements expressed or implied by the forward-looking statements. Each of these statements is based only on current information, assumptions and expectations that are inherently subject to change and involve a number of risks and uncertainties. Forward-looking statements include, but are not limited to, statements about the development of RPT904, regulatory interactions, the therapeutic and commercial potential of RPT904, the design and timing of clinical trials and the availability of data therefrom, and other statements that are not historical fact. Many factors may cause differences between current expectations and actual results, including unexpected or unfavorable safety or efficacy data observed during clinical studies, preliminary data and trends that may not be predictive of future data or results or that may not demonstrate safety or efficacy or lead to regulatory approval, our reliance on our partners and other third parties, clinical trial site activation or enrollment rates that are lower than expected, unanticipated or greater than anticipated impacts or delays due to macroeconomic and geopolitical conditions (including the long-term impacts of ongoing overseas conflicts, tariffs and trade tensions, fluctuations in inflation and interest rates and other economic uncertainty), changes in expected or existing competition, changes in the regulatory environment, the uncertainties and timing of the regulatory approval process and the sufficiency of RAPT’s cash resources. Detailed information regarding risk factors that may cause actual results to differ materially from the results expressed or implied by statements in this press release may be found in RAPT’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, filed with the Securities and Exchange Commission (SEC) on August 7, 2025, and subsequent filings made by RAPT with the SEC. These forward-looking statements speak only as of the date hereof. RAPT disclaims any obligation to update these forward-looking statements, except as required by law.

RAPT Investor Contact:
Sylvia Wheeler
[email protected]

RAPT Media Contact:
Aljanae Reynolds
[email protected]