Based on Recent FDA Feedback RAPT Therapeutics Stops Zelnecirnon Program Following Clinical Hold Due to Single SAE of Severe Liver Injury

Rhea-AI Summary

RAPT Therapeutics (Nasdaq: RAPT) announced the termination of its zelnecirnon (RPT193) program following FDA clinical holds on two Phase 2 trials in asthma and atopic dermatitis. The holds were implemented in February 2024 due to a serious adverse event of liver injury requiring transplant in one patient. No other liver toxicity or treatment-related serious adverse events were reported in other participants. The company plans to advance next-generation CCR4 compounds with improved safety margins and expects to identify a new candidate in first half 2025, while pursuing in-licensing opportunities for clinical-stage assets.

Positive

• Company continues development of next-generation CCR4 compounds with improved safety profiles
• New drug candidate identification expected in H1 2025
• Actively pursuing in-licensing opportunities for clinical-stage assets

Negative

• Termination of zelnecirnon program following FDA clinical hold
• Serious adverse event of liver injury requiring transplant in Phase 2 trial
• Discontinuation of two Phase 2 clinical trials before completion
• Loss of potential market opportunity in asthma and atopic dermatitis treatments

Insights

Biotechnology Analyst

The termination of zelnecirnon represents a significant setback for RAPT Therapeutics, effectively eliminating their lead clinical program targeting inflammatory diseases. The severe liver injury SAE leading to transplant raises serious safety concerns that have proven insurmountable with regulators, despite occurring in only one patient. This development leaves RAPT without any near-term clinical-stage assets, significantly impacting their pipeline value.

The company's pivot to next-generation CCR4 compounds and in-licensing strategy suggests a lengthy timeline to return to clinical trials, with a new candidate not expected until H1 2025. With a market cap under $100 million, cash burn becomes a critical concern as the company must now essentially restart their clinical development efforts. The lack of clear near-term catalysts and the safety concerns around their lead program could challenge future fundraising efforts.

Continues to advance preclinical pipeline, including next generation CCR4 compounds, and pursue licensing opportunities

SOUTH SAN FRANCISCO, Calif., Nov. 11, 2024 (GLOBE NEWSWIRE) -- RAPT Therapeutics, Inc. (Nasdaq: RAPT), a clinical-stage, immunology-based biopharmaceutical company focused on discovering, developing and commercializing oral small molecule therapies for patients with significant unmet needs in inflammatory diseases and oncology, today announced it is terminating its zelnecirnon (RPT193) program. Zelnecirnon was being evaluated in two randomized, placebo-controlled Phase 2 clinical trials in asthma and atopic dermatitis (AD), and both trials were placed on clinical hold by the U.S. Food and Drug Administration (FDA) in February 2024 due to a serious adverse event (SAE) of liver injury requiring transplant in one patient in the AD trial. No liver toxicity nor other treatment-related SAEs were reported in any other trial participant. The company subsequently closed both studies before completing the planned enrollment. Following feedback recently received from the FDA, the company has stopped its zelnecirnon program.

“In light of the agency’s feedback, we do not see a viable path forward for zelnecirnon, although we continue to believe that CCR4 remains an exciting target with the potential to provide a safe, oral therapeutic option across a number of inflammatory diseases,” commented Brian Wong, M.D., Ph.D., President and CEO of RAPT. “We plan to continue advancing our next generation CCR4 compounds with improved safety margins for inflammatory disease and expect to identify a new candidate in the first half of 2025. Additionally, we continue to actively pursue in-licensing opportunities for clinical-stage assets.”

About RAPT Therapeutics, Inc.
RAPT Therapeutics is a clinical-stage, immunology-based therapeutics company focused on discovering, developing and commercializing oral small molecule therapies for patients with significant unmet needs in inflammatory diseases and oncology. Utilizing its proprietary discovery and development engine, the company is developing highly selective small molecules designed to modulate the critical immune drivers underlying these diseases.

Forward-Looking Statements
This press release contains 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 termination of the zelnecirnon program; the company’s business and clinical development plans, including future CCR4 molecules and pursuit of licensing opportunities for clinical-stage assets; and other statements that are not historical fact. Factors that may cause actual results to differ materially from the plans, intentions and expectations disclosed in these forward-looking statements include uncertainties inherent in the initiation, progress and completion of clinical trials and clinical development of RAPT’s product candidates; the risk that clinical trials may have unsatisfactory outcomes; risks associated with preclinical development of product candidates; risks that efforts to secure licensing and other business development opportunities may not be successful; and other important factors, detailed in RAPT’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2024, and subsequent filings made by RAPT with the Securities and Exchange Commission. These forward-looking statements speak only as of the date hereof. RAPT disclaims any obligation to update these forward-looking statements.

Investor Contact:
Sylvia Wheeler
swheeler@wheelhouselsa.com

Media Contact:
Aljanae Reynolds
areynolds@wheelhouselsa.com

FAQ

Why did RAPT Therapeutics terminate the zelnecirnon program in 2024?

RAPT Therapeutics terminated the zelnecirnon program following FDA clinical holds implemented in February 2024 due to a serious adverse event of liver injury requiring transplant in one patient during the atopic dermatitis trial.

What clinical trials were affected by the FDA hold on RAPT's zelnecirnon?

Two randomized, placebo-controlled Phase 2 clinical trials testing zelnecirnon in asthma and atopic dermatitis were placed on hold and subsequently terminated before completing planned enrollment.

What are RAPT Therapeutics' plans following the zelnecirnon program termination?

RAPT plans to advance next-generation CCR4 compounds with improved safety margins, expecting to identify a new candidate in first half 2025, while pursuing in-licensing opportunities for clinical-stage assets.