Tapencarium (RZL-012) for Flank Fat Reduction: A Proof-of-Concept Study

Abstract

Background RZL-012 is a novel cytolytic drug that has shown promise in reducing localized fat deposits in a single treatment session. Objectives To assess the safety and efficacy of injecting RZL-012 to the flanks. Methods A double-blind, placebo-controlled proof-of-concept study randomized 12 subjects to receive RZL-012 injections in 1 flank and placebo injections in the contralateral flank. After 12 weeks of follow-up, subjects could receive RZL-012 in the placebo-treated flank and be followed for 12 weeks in the open-label phase. Results At 12 weeks, Investigator Global Aesthetic Improvement Scale assessments showed improvement for 90.9% of RZL-012-treated flanks and 0% of placebo-treated flanks (p < 0.0001), 81.8% of subjects were satisfied with the RZL-012-treated flanks and 9.1% with the placebo-treated flanks (p = 0.0019), and volume reduction measured on 3-dimensional images was a mean 37.27 mL, which was significantly greater than placebo (p = 0.0052). The product was well tolerated, with no clinically significant trends in laboratory values, electrocardiograms, or vital signs. Pharmacokinetic analyses demonstrated that RZL-012 is quickly absorbed, reaches maximum concentration in approximately 1.67 hours, and has a half-life of 9.1 hours. The mean maximal concentration of RZL-012 found in the blood was <1 µg/mL. Conclusions RZL-012 is a promising option for injectable fat reduction of the flanks in a single treatment session. The drug was well tolerated in this small subject population, with no concerning safety signals, and it had indications of efficacy. Further research is needed in large phase 2 studies with robust efficacy measurements to confirm these early findings.