Ascletis Pharma’s ASC22 Combo Therapy Shows Promise in HIV Functional Cure Clinical Trial

China-based Ascletis Pharma Inc., (HKG: 1672) has announced that the Shanghai Public Health Clinical Center presented clinical results of ASC22 (envafolimab) in combination with chidamide as a novel combination therapy aimed at achieving a functional cure for human immunodeficiency virus (HIV) infection. The findings were showcased at the 12th International AIDS Society (IAS) Conference on HIV Science in Brisbane, Australia, and virtually.

Phase II Trial Design and Efficacy Assessment
The investigator-initiated Phase II trial assessed the efficacy of ASC22 combined with chidamide on the viral reservoirs of latently infected cells in HIV-infected individuals. A total of 15 subjects living with HIV who had achieved virological suppression were enrolled in the study. Participants received a subcutaneous injection of ASC22 (1mg/kg) once every four weeks (Q4W) in combination with 10mg chidamide administered orally twice a week (BIW) during the 12-week treatment period while maintaining antiretroviral therapy (ART). The subjects were followed up for 24 weeks to measure changes in the levels of cell-associated (CA) HIV RNA, plasma HIV RNA, total and integrated HIV DNA, and HIV-specific CD8+ T cell function.

Well-Tolerated Combo Effectively Activates Latent HIV Reservoirs
The results demonstrated that the combination therapy was well tolerated and effectively activated latent HIV reservoirs. There was a significant increase in CA HIV RNA at week 8 and week 12 compared to the baseline, with an average rise of 4.27-fold and 3.41-fold, respectively (P=0.001, P=0.006) in the subjects. The HIV CA RNA to total DNA ratios also showed the same trend (P=0.038, P=0.017, respectively). Ascletis concludes that the findings indicate further investigations are warranted.

Background on Envafolimab and Chidamide
Envafolimab was originated by Alphamab Oncology (HKG: 9966), with 3D Medicines acting as co-development partner under a January 2019 deal. Ascletis gained rights to envafolimab for viral disease indications in another January 2019 deal, which was expanded to a global scale in November 2021 after initial trial successes against hepatitis B. Chipscreen’s chidamide, a first-in-class subtype-selective histone deacetylase inhibitor, has been on the market in China as a treatment for the rare disease peripheral T-cell lymphoma since December 2014. A second indication approval was awarded in November 2019 for use in combination with hormonal therapy in previously treated ER+/HER2- advanced breast cancer.-Fineline Info & Tech

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