Homology Medicines, Inc. announced the peer-reviewed publication of data showing that AAVHSC16, one of the capsids in its family of 15 naturally occurring AAVHSCs, demonstrated low levels of tropism to the liver while maintaining robust distribution to the central nervous system (CNS) and peripheral organs following a single I.V. administration in preclinical models. The Company believes that its unique properties, with high levels of tropism to the brain, heart and muscle, and no elevations in liver enzymes, could make AAVHSC16 an attractive capsid for new disease indications with Homology's genetic medicines platform. Homology's AAVHSC capsids differ from each other by one to four amino acids, resulting in differences in biodistribution and transduction efficiencies.

As described in the manuscript, AAVHSC16 has two unique amino acids, 501I and 706C, in addition to 505R that is shared across six AAVHSC serotypes. A series of experiments demonstrated that these amino acids contribute to AAVHSC16's unique properties, which include significantly reduced liver tropism compared to other AAVs, no liver enzyme elevations, and high tissue tropism to the CNS and other peripheral organs. Specifically, these data demonstrated: Naturally Occurring Variations in AAVHSC16 Alter Cellular Binding Affinity In Vitro; AAVHSC16 Has Significantly Reduced Liver Transduction in Vivoand In Vitro Models, with High Tropism to other Tissues Following a Single I.V. Administration; AAVHSC16 Did Not Lead to Elevations in Liver Function Tests.