We note that the central sulfur in the JMN3-003 chemical scaffold could potentially render the molecule vulnerable to rapid phase I oxidation and thus compromise both metabolic stability and bioavailability. For instance, it has been reported that flavincontaining monooxygenases [69] , dioxygenases [70] and cytochrome P-450 enzymes [71] catalyze oxidation of alkylaryl sulfides to sulfoxides (R 2 S = O). However, the high stability of JMN3-003 in the presence of human hepatocyte subcellular fractions and human plasma argues against an undesirable short in vivo half-life of the substance. This is corroborated by good metabolic stability of the structurally similar HIV reverse transcriptase inhibitor RDEA-806 [72, 73] , which shares the central 2-thio-acetamide connector with JMN3-003 and has achieved success in clinical trials: the compound was well tolerated in both Phase 1 and 2a studies after single or multiple oral doses and showed no drugrelated CNS toxicity [72, 73] , creating a clinical precedence for the applicability of the broader scaffold. Although RDEA-806 follows a different mechanism of action than JMN3-003 and lacks any anti-paramyxovirus activity, the structural similarities provide sufficient confidence for the overall developmental potential of the JMN3-003 class to recommend it as a promising candidate for advanced synthetic optimization towards preclinical validation and development.