Multicenter Phase I Trial of Ivosidenib as Maintenance Treatment Following Allogeneic Hematopoietic Cell Transplantation for IDH1-Mutated Acute Myeloid Leukemia.

PURPOSE: Isocitrate dehydrogenase 1 (IDH1) mutations occur in 5% to 10% of patients with acute myeloid leukemia (AML). Ivosidenib is an IDH1 inhibitor, approved for use in patients with IDH1-mutated AML. PATIENTS AND METHODS: We conducted a multicenter, phase I trial of maintenance ivosidenib following allogeneic hematopoietic cell transplantation (HCT) in patients with IDH1-mutated AML. Ivosidenib was initiated between days 30 and 90 following HCT and continued for up to 12 28-day cycles. The first dose level was 500 mg daily, with level reduction to 250 mg daily, if needed, in a 3 × 3 de-escalation design. Ten additional patients would then receive the MTD or recommended phase 2 dose (RP2D). The primary endpoint was establishing the MTD or RP2D of ivosidenib. RESULTS: Eighteen patients were enrolled, of whom 16 initiated post-HCT ivosidenib. One dose-limiting toxicity, grade(g) 3 QTc prolongation, was observed. The RP2D was established at 500 mg daily. Attributable g≥3 adverse events were uncommon, with the most common being QTc prolongation in 2 patients. Eight patients discontinued maintenance, with only one due to adverse event. Six-month cumulative incidence (CI) of gII-IV aGVHD was 6.3%, and 2-year CI of all cGVHD was 63%. Two-year CI of relapse and nonrelapse mortality (NRM) were 19% and 0%, respectively. Two-year progression-free (PFS) was 81%, and 2-year overall survival (OS) was 88%. CONCLUSIONS: Ivosidenib is safe and well-tolerated as maintenance therapy following HCT. Cumulative incidence of relapse and NRM, as well as estimations of PFS and OS, were promising in this phase I study.

Enasidenib as maintenance following allogeneic hematopoietic cell transplantation for IDH2-mutated myeloid malignancies.

IDH2 (isocitrate dehydrogenase 2) mutations occur in approximately 15% of patients with acute myeloid leukemia (AML). The IDH2 inhibitor enasidenib was recently approved for IDH2-mutated relapsed or refractory AML. We conducted a multi-center, phase I trial of maintenance enasidenib following allogeneic hematopoietic cell transplantation (HCT) in patients with IDH2-mutated myeloid malignancies. Two dose levels, 50mg and 100mg daily were studied in a 3 × 3 dose-escalation design, with 10 additional patients treated at the recommended phase 2 dose (RP2D). Enasidenib was initiated between days 30 and 90 following HCT and continued for twelve 28-day cycles. Twenty-three patients were enrolled, of whom 19 initiated post-HCT maintenance. Two had myelodysplastic syndrome, and 17 had AML. All but 3 were in first complete remission. No dose limiting toxicities were observed, and the RP2D was established at 100mg daily. Attributable grade ≥3 toxicities were rare, with the most common being cytopenias. Eight patients stopped maintenance before completing 12 cycles, due to adverse events (n=3), pursuing treatment for graft-vs-host disease (GVHD) (n=2), clinician choice (n=1), relapse (n=1), and COVID infection (n=1). No cases of grade ≥3 acute GVHD were seen, and 12-month cumulative incidence of moderate/severe chronic GVHD was 42% (20-63%). Cumulative incidence of relapse was 16% (95% CI: 3.7-36%); 1 subject relapsed while receiving maintenance. Two-year progression-free and overall survival were 69% (95% CI: 39-86%) and 74% (95% CI, 44-90%), respectively. Enasidenib is safe, well-tolerated, with preliminary activity as maintenance therapy following HCT, and merits additional study. The study was registered at www.clinicaltrials.gov (#NCT03515512).

Efficacy and Safety of 1% Progesterone Gel to the Forehead for Ocular Chronic Graft-versus-Host Disease.

There is no Food and Drug Administration-approved treatments for ocular chronic graft-versus-host disease (oGVHD) to date, and current therapeutic options are limited. Forehead application of 1% progesterone gel provides corneal antinociception in preclinical models, suggesting it may be useful in alleviating ocular irritations. This study was conducted to evaluate the efficacy and safety of 1% progesterone gel in treating moderate to severe symptomatic oGVHD. Thirty-three patients with oGVHD following allogeneic stem cell transplantation were enrolled in this single-center, sponsor-initiated, prospective exploratory randomized double-masked placebo-controlled phase II clinical trial. The inclusion criteria included a National Institutes of Health consensus score of ≥2, moderate to severe ocular discomfort level, and receipt of a stable immunosuppression regimen. Twenty-one of the 22 patients in the progesterone arm and all 11 patients in the placebo arm completed the course of twice-daily forehead drug application for 10 weeks. The changes from baseline of self-reported ocular symptom scores and physician-recorded cornea fluorescein staining scores were analyzed using mixed-model repeated-measures regression model in an intention-to-treat population. The 33 patients included 12 women and 21 men, with a median age of 66 years (range, 24 to 75 years). At 10 weeks, there was a significant reduction in ocular symptoms from baseline in the progesterone group compared with the placebo group in symptom frequency (-30.7 versus -2.2; P < .001) and severity (-19.8 versus +1.6; P = .005). At 10 weeks, there was also greater reduction of cornea fluorescein staining centrally (-1.2 versus +.1; P = .001) and inferiorly (-1.4 versus -0.2; P = .005). No difference was noted in superior cornea staining. There were no severe adverse events in the progesterone group. Forehead application of 1% progesterone gel significantly improved ocular signs and symptoms within 10 weeks. It appears to be a safe and effective new therapy for oGVHD, and a novel mechanism for neuroaxis drug delivery. A multicenter phase III clinical trial is planned for further validation.