BIOSENIC announced the completion of a post-hoc analysis of its phase 2 clinical trial of ATO, finding the best scheme for administration of an efficient treatment of cGvHD. The analysis will be used to decide on the best oral ATO?s posology for BioSenic?s forthcoming phase 3 clinical trial. BioSenic phase 2 clinical trial entitled ?Treatment of Chronic Graft Versus Host Disease with Arsenic Trioxide (GvHD-ATO)?

was conducted from 2016 to 2020 (ClinicalTrials.gov ID NCT02966301 - GMED16-001). The first results were originally published in 2022 in the peer-reviewed journal Transplantation and Cellular Therapy under the title ?High Response Rate and Corticosteroid (CS) Sparing with Arsenic Trioxide-Based First-Line Therapy in Chronic Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation?. These collated results demonstrated that the first-line use of ATO and corticosteroids is associated with a high clinical response rate and rapid CS sparing in moderate to severe cGvHD following allo-HSCT (current standard treatment for several types of leukaemias).

The primary endpoint of the phase 2 trial was preliminary efficacy based on the overall response rate (ORR; complete response [CR] or partial response [PR]) at 6 months, after 1 or 2 cycles of intravenous (IV) ATO treatment. At 6 months, the ORR was 75.0%, with a CR rate of 35% and PR of 40%. BioSenic?s new post-hoc analysis of the full set of clinical data gained during the phase 2 trial shows that among the group of patients who did not achieved complete remission after the first course, a significant one-fifth of these patients had a positive primary endpoint following a second cycle of treatment.

As a result, BioSenic will further use this 2-cycle treatment in its forthcoming trials. This will involve the administration of a double four-week course, separated by a rest period, resulting in a two-to-four times higher total dose of ATO. BioSenic expects thus to get closer to the optimal conditions for a curative treatment for cGvHD, for which there is currently no satisfactory therapy.

In the field of oncology, IV ATO is used as a first-line treatment for acute promyelocytic leukemia (APL) since 2003, with demonstrated safety and long-term remissions. Until now, in APL, ATO was administered daily by IV infusions for up to, or more than, a hundred accumulated doses. IV administration, because it requires hospitalization, is not practical for patients, results in lower quality of life, and is very expensive.

The introduction of an oral formulation of ATO during 2 short cycles, presently BioSenic?s optimal design of administration, will greatly improve patient quality of life and compliance, while reducing healthcare costs. This is a significant achievement in BioSenic?s aim to contribute improved and potentially curative treatment for an autoimmune disease, with no current satisfactory medical solutions.