Eprenetapopt Plus Azacitidine in TP53-Mutated Myelodysplastic Syndromes and Acute Myeloid Leukemia: A Phase II Study by the Groupe Francophone des Myélodysplasies (GFM).

PURPOSE: TP53-mutated (TP53m) myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) have very poor outcome irrespective of the treatment received, including 40% responses (20% complete remission [CR]) with azacitidine (AZA) alone, short response duration, and a median overall survival (OS) of approximately 6 months. Eprenetapopt (APR-246), a novel first-in-class drug, leads to p53 protein reconformation and reactivates its proapoptotic and cell-cycle arrest functions. PATIENTS AND METHODS: This phase II study assessed the safety and efficacy of eprenetapopt in combination with AZA in untreated high or very high International Prognostic Scoring System-R TP53m MDS and AML patients. RESULTS: Fifty-two TP53m patients (34 MDS, 18 AML [including seven with more than 30% blasts]) were enrolled. In MDS, we observed an overall response rate (ORR) of 62%, including 47% CR, with a median duration of response at 10.4 months. In AML, the ORR was 33% including 17% CR (27% and 0% CR in AML with less than and more than 30% marrow blasts, respectively). Seventy-three percent of responders achieved TP53 next-generation sequencing negativity (ie, variant allele frequency < 5%). The main treatment-related adverse events were febrile neutropenia (36%) and neurologic adverse events (40%), the latter correlating with a lower glomerular filtration rate at treatment onset (P < .01) and higher age (P = .05), and resolving with temporary drug interruption without recurrence after adequate eprenetapopt dose reduction. With a median follow-up of 9.7 months, median OS was 12.1 months in MDS, and 13.9 and 3.0 months in AML with less than and more than 30% marrow blasts, respectively. CONCLUSION: In this very high-risk population of TP53m MDS and AML patients, eprenetapopt combined with AZA was safe and showed potentially higher ORR and CR rate, and longer OS than reported with AZA alone.

Incidence of ATRX mutations in myelodysplastic syndromes, the value of microcytosis.

Acquired α-thalassemia myelodysplastic syndrome (MDS) (ATMDS) is an acquired syndrome characterized by a somatic point mutation or splicing defect in the ATRX gene in patients with myeloid disorders, primarily MDS. In a large MDS patient series, the incidence of ATMDS was below 0.5%. But no large series has yet assessed the incidence of ATMDS in microcytic MDS. In this study, we focused on patients with MDS and unexplained microcytosis, which was defined as absence of iron deficiency, inflammatory disease, or history of inherited hemoglobinopathy. Our data confirm the low frequency of ATRX mutations in MDS: 0% in an unselected clinical trial cohort of 80 low risk MDS, 0.2-0.8% in a multicenter registry of 2,980 MDS and 43% of MDS with unexplained microcytosis in this same registry. In addition, we reported four novel mutations of the ATRX gene in ATMDS. This study further determines the frequency of ATRX mutations and highlights the importance of microcytosis to detect ATRX mutations within MDS patients.

Azacitidine in untreated acute myeloid leukemia: a report on 149 patients.

Limited data are available on azacitidine (AZA) treatment and its prognostic factors in acute myeloid leukemia (AML). One hundred and forty-nine previously untreated AML patients considered ineligible for intensive chemotherapy received AZA in a compassionate patient-named program. AML diagnosis was de novo, post-myelodysplastic syndromes (MDS), post-MPN, and therapy-related AML in 51, 55, 13, and 30 patients, respectively. Median age was 74 years, median white blood cell count (WBC) was 3.2 × 109 /L and 58% of the patients had ≥ 30% marrow blasts. Cytogenetics was adverse in 60 patients. Patients received AZA for a median of five cycles (range 1-31). Response rate (including complete remission/CR with incomplete recovery/partial remission) was 27.5% after a median of three cycles (initial response), and 33% at any time (best response). Only adverse cytogenetics predicted poorer response. Median overall survival (OS) was 9.4 months. Two-year OS was 51% in responders and 10% in non-responders (P<0.0001). Adverse cytogenetics, WBC >15 × 109 /L and ECOG-PS ≥ 2 predicted poorer OS, while age and marrow blast percentage had no impact. Using MDS IWG 2006 response criteria, among patients with stable disease, those with hematological improvement had no significant survival benefit in a 7 months landmark analysis. Outcomes observed in this high-risk AML population treated with AZA deserve comparison with those of patients treated intensively in prospective studies.