Overview
Traws Pharma Plc (TRAW) saw shares fall 17% in premarket trading on Monday after the company disclosed a regulatory deferral affecting a mid-stage clinical program for its influenza treatment candidate.
Regulatory action and immediate impact
Late on Friday, Traws reported that the United Kingdom's Medicines and Healthcare Products Regulatory Agency (MHRA) issued a negative review of the company's proposed human challenge study for tivoxavir marboxil. The MHRA finding has resulted in the deferral of that planned mid-stage clinical trial, a development the company communicated to investors ahead of Monday's market open.
Company response
In its announcement, Traws said it is advancing backup drug candidates that it describes as retaining the long-acting pharmacologic profile and antiviral potency of tivoxavir marboxil but designed without any mutagenic potential. The statement indicates these alternative molecules are being pursued as contingency options while the current program remains on hold.
Regulatory history
The MHRA decision follows a prior regulatory action in the United States. In February, the U.S. Food and Drug Administration (FDA) placed a clinical hold on Traws' investigational new drug application for tivoxavir marboxil. That hold was issued because of concerns with the mutagenicity data package provided to U.S. regulators.
Clarifying mutagenicity
The company and regulators have focused on mutagenicity - the potential of a substance to cause genetic mutations - which can trigger safety questions in drug development programs. The mutagenicity concerns cited by regulators form the basis for both the FDA's clinical hold and the MHRA's negative review of the planned human challenge study.
What this means for markets and investors
The immediate market reaction was a steep premarket decline in Traws' share price. The regulatory deferral interrupts the planned mid-stage human challenge study for tivoxavir marboxil and has led the company to accelerate development of alternative candidates that avoid mutagenic characteristics.
Note: The article reflects the company's disclosures regarding regulator reviews, the FDA clinical hold, and the described attributes of backup candidates. No additional outcomes or timelines have been provided by the company in its announcement.