RAPT Therapeutics Announces Clinical Hold on Studies Evaluating Zelnecirnon
- RAPT Therapeutics is focused on developing oral small molecule therapies for inflammatory diseases and oncology.
- Approximately 350 patients have been enrolled in trials evaluating zelnecirnon.
- No evidence of liver toxicity in nonclinical studies or other trial participants.
- RAPT is conducting a thorough investigation into the serious adverse event of liver failure.
- Patient safety is the company's top priority according to the President and CEO, Brian Wong, M.D., Ph.D.
- A webcast conference call is scheduled for more information and to address questions from stakeholders.
- FDA has placed a clinical hold on RAPT's Phase 2b trial of zelnecirnon for atopic dermatitis and Phase 2a trial in asthma.
- Dosing of zelnecirnon has been halted in both trials, and enrollment of new participants has been stopped.
- The serious adverse event of liver failure in one patient has led to the clinical hold determination.
- The cause of the liver failure is currently unknown but potentially related to zelnecirnon.
- The clinical hold does not apply to RAPT's trial of tivumecirnon in oncology.
Insights
The clinical hold placed by the FDA on RAPT Therapeutics' trials for zelnecirnon due to a serious adverse event is a critical development, particularly for stakeholders and potential investors. The immediate cessation of dosing and enrollment signifies a significant setback in the drug's development timeline. Historically, clinical holds can lead to extensive delays, increased costs and may require additional studies to address safety concerns. The fact that this adverse event is potentially drug-related is concerning and could indicate issues with the drug's safety profile.
While no other liver toxicity has been reported, the singular event is enough to warrant caution. It is essential to consider the patient's complex medical history, which includes factors that could have contributed to the adverse event. The company's thorough investigation will need to address these confounding variables to determine causality. The outcome of this investigation will be pivotal for the future of zelnecirnon's clinical development and the company's valuation.
The news of the FDA's clinical hold on RAPT Therapeutics' trials is likely to have immediate repercussions on the company's stock price. Investors typically react negatively to such developments, as they introduce uncertainty and imply potential safety issues with the drug candidate. The direct financial implications include the costs associated with the hold, such as the investigation, potential trial redesigns and extended timelines. This could impact the company's burn rate and necessitate additional capital raising, diluting current shareholders.
In the long term, the company's market cap and future revenue projections could be affected, depending on the resolution of the clinical hold. If the investigation concludes favorably and trials resume, the impact may be mitigated. However, if the drug is deemed unsafe, the implications could be severe, potentially including the termination of the drug's development. Investors will need to monitor the situation closely and assess the risk versus the potential reward of the company's drug pipeline.
The occurrence of a serious adverse event such as liver failure in a clinical trial is a rare and significant concern in drug development. The role of pharmacovigilance is to ensure patient safety by monitoring and evaluating such events. The complexity of the patient's medical history, including the use of an herbal supplement associated with liver failure, adds layers to the investigation that must be meticulously analyzed to ascertain the relationship to zelnecirnon.
It is also important to note that the absence of liver toxicity in nonclinical studies and other trial participants suggests a non-systemic issue, which could potentially be an isolated incident. The pharmacovigilance team will be integral in dissecting the data from the trial, examining the patient's history and establishing a risk profile for the drug. The findings will have significant implications for the drug's safety assessment and the company's ability to proceed with development.
- RAPT to host a conference call today at 8:30 am ET -
SOUTH SAN FRANCISCO, Calif., Feb. 20, 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 that the U.S. Food and Drug Administration (FDA) has verbally notified the company that a clinical hold has been placed on the company’s Phase 2b trial of zelnecirnon (RPT193) in atopic dermatitis and its Phase 2a trial in asthma. The company expects to receive a formal clinical hold letter from the FDA. The clinical hold determination was based on a serious adverse event of liver failure in one patient in the atopic dermatitis trial, the cause of which is currently unknown but which has been characterized as potentially related to zelnecirnon. Dosing of zelnecirnon has been halted in both clinical trials, as has enrollment of new trial participants. The clinical hold does not apply to RAPT’s ongoing trial of tivumecirnon (FLX475) in oncology.
A total of approximately 350 patients have been enrolled across three trials evaluating zelnecirnon - the two Phase 2 trials and an earlier Phase 1a/1b study. No evidence of liver toxicity has been observed with any other trial participant. Additionally, no evidence of liver toxicity was observed in nonclinical studies.
RAPT is undertaking a thorough investigation of this case, which involved a patient with a complex medical history, including a history of drug allergy to dupilumab, autoimmune disease resulting in thyroid hormone replacement therapy and use of an herbal supplement known to be associated with liver failure, as well as a reported COVID-19 infection during the time of the event.
“This is an unfortunate and unexpected event, and we are working diligently to get more information on this case,” said Brian Wong, M.D., Ph.D., President and CEO of RAPT Therapeutics. “Patient safety is our top priority and we will work with the FDA to resolve this as quickly as possible.”
Webcast Conference Call Information
RAPT will host a webcast conference call today, February 20, 2024 at 8:30 a.m. ET. To join the conference call via phone and participate in the live Q&A session, please pre-register online here to receive a telephone number and unique passcode required to enter the call. The live webcast and audio archive of the presentation may be accessed on the RAPT Therapeutics website at https://investors.rapt.com/events-and-presentations.
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. RAPT has discovered and advanced two unique drug candidates, zelnecirnon (RPT193) and tivumecirnon (FLX475), each targeting C-C motif chemokine receptor 4 (CCR4), for the treatment of inflammation and cancer, respectively. The Company is also pursuing a range of targets that are in the discovery stage of development.
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 company’s expectations concerning the clinical hold, including its investigation of the incident and its ability to resolve issues to the FDA’s satisfaction. 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 September 30, 2023, 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
What is the reason for the FDA clinical hold on RAPT's Phase 2b trial of zelnecirnon?
How many patients have been enrolled in trials evaluating zelnecirnon?
Is there any evidence of liver toxicity in other trial participants?
What action has RAPT taken in response to the clinical hold?
Who is leading the investigation into the serious adverse event at RAPT?
