ROP-ET: a prospective phase III trial investigating the efficacy and safety of ropeginterferon alfa-2b in essential thrombocythemia patients with limited treatment options

Interferon-based therapies, such as ropeginterferon alfa-2b have emerged as promising disease-modifying agents for myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET). Current ET treatments aim to normalize hematological parameters and reduce the thrombotic risk, but they do not modify the natural history of the disease and hence, have no impact on disease progression. Ropeginterferon alfa-2b (trade name BESREMi®), a novel, monopegylated interferon alfa-2b with an extended administration interval, has demonstrated a robust and sustained efficacy in polycythemia vera (PV) patients. Given the similarities in disease pathophysiology and treatment goals, ropeginterferon alfa-2b holds promise as a treatment option for ET. The ROP-ET trial is a prospective, multicenter, single-arm phase III study that includes patients with ET who are intolerant or resistant to, and/or are ineligible for current therapies, such as hydroxyurea (HU), anagrelide (ANA), busulfan (BUS) and pipobroman, leaving these patients with limited treatment options. The primary endpoint is a composite response of hematologic parameters and disease-related symptoms, according to modified European LeukemiaNet (ELN) criteria. Secondary endpoints include improvements in symptoms and quality of life, molecular response and the safety profile of ropeginterferon alfa-2b. Over a 3-year period the trial assesses longer term outcomes, particularly the effects on allele burden and clinical outcomes, such as disease-related symptoms, vascular events and disease progression. No prospective clinical trial data exist for ropeginterferon alfa-2b in the planned ET study population and this study will provide new findings that may contribute to advancing the treatment landscape for ET patients with limited alternatives. TRIAL REGISTRATION: EU Clinical Trials Register; EudraCT, 2023-505160-12-00; Registered on October 30, 2023.

Bosutinib (BOS) in newly diagnosed chronic myeloid leukemia (CML): Gastrointestinal (GI), liver, effusion, and renal safety characterization in the BFORE trial

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Background: Efficacy and safety of BOS vs imatinib (IMA) in patients (pts) with newly diagnosed chronic phase CML was assessed in the phase 3 BFORE trial. Here we characterize the safety profile of BOS after 5 yrs follow-up, with a focus on GI, liver, effusion and renal treatment-emergent adverse events (TEAEs). Methods: Pts who received ≥1 dose of BOS (n=268) or IMA (n=265) 400 mg/d in BFORE were included. Adverse events (AEs) of special interest were analyzed by selecting prespecified MedDRA terms to generate TEAE clusters. Final database lock: June 12, 2020. Results: Median duration of treatment (Tx) was 55 mo for pts receiving BOS or IMA; respective median (range) dose intensity was 393.6 (39–583) vs 400.0 (189–765) mg/d. Any grade TEAEs occurred in 98.9% and 98.9% of BOS- vs IMA-treated pts. Most common newly occurring TEAEs (any grade) after 12 mos were increased lipase (9.0%) with BOS, and diarrhea (8.3%) with IMA. In BOS- vs IMA-treated pts, 25.4% vs 14.3% had AEs leading to permanent Tx discontinuation; the majority discontinued in yr 1 (14.2% vs 10.6%). Most frequent AEs leading to discontinuation were increased ALT (overall, 4.9%; yr 1, 4.5%) with BOS vs thrombocytopenia (overall, 1.5%; yr 1, 1.5%) with IMA. GI, liver, effusion and renal TEAEs, respectively, occurred in 79.9%, 44.0%, 6.0% and 10.4% (maximum grade 3/4 [G3/4]: 9.0%, 26.9%, 1.1% and 2.2%) of BOS- vs 61.5%, 15.5%, 2.3% and 9.8% (G3/4: 1.1%, 4.2%, 0.4% and 0.8%) IMA-treated pts. One grade 5 renal TEAE occurred in the BOS arm and was not considered related to Tx. Cumulative rates per Tx yr are shown in the Table. Most common GI TEAEs were diarrhea (BOS vs IMA: 75.0% vs 40.4% [G3/4: 9.0% vs 1.1%]) with BOS, and nausea (37.3% vs 42.3% [G3/4: 0% vs 0%]) with IMA. In both arms, the most common liver, effusion and renal TEAEs, respectively, were increased ALT and/or AST (34.0% vs 8.3% [G3/4: 22.0% vs 2.3%]), pleural effusion (5.2% vs 1.9% [G3/4: 0.7% vs 0.4%]) and increased blood creatinine (6.7% vs 8.3% [G3/4: 0.4% vs 0.4%]). GI, liver, effusion and renal TEAEs infrequently led to Tx discontinuation (1.9%, 7.8%, 0.7% and 0.7% vs 1.1%, 0.8%, 0% and 0.4%). Conclusions: The safety profiles of BOS and IMA in BFORE were distinct, with no new safety signals identified after 5 yrs follow-up. Onset of TEAEs occurred primarily during yr 1 (eg, GI and liver), with an increased incidence of some TEAEs (eg, effusion and renal) in later yrs. Discontinuations due to AEs generally occurred early into Tx, with few due to GI, liver, effusion and renal AEs. These safety results support the use of first-line BOS as a standard of care in pts with CP CML. Clinical trial information: NCT02130557. [Table: see text]