Phase 1 dose escalation study of the MDM2 inhibitor milademetan as monotherapy and in combination with azacitidine in patients with myeloid malignancies.

BACKGROUND: Mouse double minute-2 homolog (MDM2) plays a key role in downregulating p53 activity in hematologic malignancies, and its overexpression is associated with poor outcomes. METHODS: This phase 1 study assessed the safety and efficacy of different dosing regimens of the MDM2 inhibitor milademetan as monotherapy and in combination with azacitidine (AZA) in patients with relapsed or refractory acute myeloid leukemia or high-risk myelodysplastic syndromes. RESULTS: Seventy-four patients (monotherapy, n = 57; milademetan-AZA combination, n = 17) were treated. The maximum tolerated dose of milademetan was 160 mg once daily given for the first 14-21 days of 28-day cycles as monotherapy and on Days 5-14 in combination with AZA. Dose-limiting toxicities were gastrointestinal, fatigue, or renal/electrolyte abnormalities. Treatment-emergent adverse events related to milademetan occurred in 82.5% and 64.7% of participants in the monotherapy and AZA combination arms, respectively. Two participants (4.2%) in the monotherapy arm achieved complete remission (CR), and 1 (2.1%) achieved CR with incomplete blood count recovery (CRi). Two participants (13.3%) achieved CRi in the combination arm. New TP53 mutations, detected only during milademetan monotherapy, were found pre-existing below standard detection frequency by droplet digital polymerase chain reaction. INTERPRETATION: Milademetan was relatively well tolerated in this population; however, despite signals of activity, clinical efficacy was minimal.

Late morbidity and mortality after autologous blood or marrow transplantation for lymphoma in children, adolescents and young adults-a BMTSS report.

We determined the risk of late morbidity and mortality after autologous blood or marrow transplantation (BMT) for lymphoma performed before age 40. The cohort included autologous BMT recipients who had survived ≥2 years after transplantation (N = 583 [HL = 59.9%; NHL = 40.1%]) and a comparison cohort (N = 1070). Participants self-reported sociodemographics and chronic health conditions. A severity score (grade 3 [severe], 4 [life threatening] or 5 [fatal]) was assigned to the conditions using CTCAE v5.0. Logistic regression estimated the odds of grade 3-4 conditions in survivors vs. comparison subjects. Proportional subdistribution hazards models identified predictors of grade 3-5 conditions among BMT recipients. Median age at BMT was 30.0 years (range: 2.0-40.0) and median follow-up was 9.8 years (2.0-32.1). Survivors were at a 3-fold higher adjusted odds for grade 3-4 conditions (95% CI = 2.3-4.1) vs. comparison subjects. Factors associated with grade 3-5 conditions among BMT recipients included age at BMT (>30 years: adjusted hazard ratio [aHR] = 2.31; 95% CI = 1.27-4.19; reference: ≤21 years), pre-BMT radiation (aHR = 1.52; 95% CI = 1.13-2.03; reference: non-irradiated), and year of BMT (≥2000: aHR = 0.54; 95% CI = 0.34-0.85; reference: <1990). The 25 years cumulative incidence of relapse-related and non-relapse-related mortality was 18.2% and 25.9%, respectively. The high risk for late morbidity and mortality after autologous BMT for lymphoma performed at age <40 calls for long-term anticipatory risk-based follow-up.