Nashville-based Revelyx Bio reported positive Phase II results for YY003, a recombinant botulinum toxin type A supplied as a ready-to-use liquid, supporting plans for an FDA End-of-Phase-II meeting and potential Phase III development. Currently approved US botulinum toxin type A products are supplied as lyophilized formulations requiring reconstitution, whereas YY003 would be the first recombinant, pre-mixed alternative if it reaches approval.
In the Phase II trial, 153 adults with moderate-to-severe glabellar lines were randomized across two parts. The double-blind Part B evaluated 30 U and 40 U doses against vehicle. The primary composite endpoint — requiring both investigator and participant to independently record a Facial Wrinkle Scale score of none or mild and at least a two-grade improvement from baseline — was met by 80.8% of participants in the 40 U group and 66.7% in the 30 U group at Week 4, versus 0% for vehicle (p<0.001 for each dose). By Week 1, 90.4% of participants receiving 40 U had already reached a score of none or mild, approaching the Week 4 rate of 92.3% on investigator assessment. No neutralizing antibodies were detected in any participant, and only one of 106 evaluable participants (0.9%) tested positive for anti-drug antibodies while maintaining clinical response. No treatment-related serious adverse events occurred, and there were no discontinuations due to adverse events.
YY003 is produced via recombinant expression in E. coli rather than purification from Clostridium botulinum cultures, yielding a neurotoxin Revelyx describes as structurally identical to the naturally derived protein. The ready-to-use liquid format removes the manual reconstitution step required for currently approved products.
Revelyx launched in August 2026 around an exclusive license from Chongqing Claruvis Pharmaceutical covering YY003 in all territories outside mainland China, Hong Kong, and Macau. Claruvis has already taken a related recombinant botulinum toxin product, the lyophilized YY001 (Retoxin), through regulatory approval in China, providing manufacturing and regulatory precedent for its recombinant BoNT/A platform. YY003 is a distinct asset differentiated by its ready-to-use liquid formulation.