Safety analysis finds venetoclax monotherapy is well tolerated in patients with R/R CLL

A comprehensive safety analysis of venetoclax monotherapy was published in Clinical Cancer Research on 12 June 2018 by Matthew Davids, Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, and colleagues. The study evaluated patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) based on the 2008 iwCLL criteria.

Study Overview

• The analysis evaluated venetoclax monotherapy (400 mg daily) in n = 350 patients receiving treatment until disease progression, unacceptable toxicity or study discontinuation from June 2011 to November 2016
  • Median age was 66 years (range, 28–85)
  • 60% of patients had del(17p) CLL and 48% had TP53 mutation
  • The median prior lines of therapy was 3 (range, 0–15)
  • Median duration of exposure to venetoclax was 16 months (range, 0–56)
• Patients in the analysis were included from the phase-I M12-175 (NCT01328626), phase-II M13-982 (NCT01889168) or phase-II M14-032 (NCT02141282)

Key Findings

• The most frequent adverse events (AEs) of any grade included; diarrhea (41%) and nausea (39%)
• The most frequent AEs grade 3/4 included; neutropenia (37%), anemia (17%) and thrombocytopenia (14%)
• The most common AEs grade ≥3 that were possibly related to venetoclax, as assessed by the investigator, included; neutropenia (30%), thrombocytopenia (8%) and anemia (7%)
• 29 deaths were reported, 14 were due to disease progression
• 11 patients reported tumor lysis syndrome (TLS)
• 251 patients experienced infections, the most common was upper respiratory tract infection (25%), pneumonia (11%), nasopharyngitis (10%), and urinary tract infection (10%)

The authors found from this analysis that venetoclax monotherapy was well tolerated with patients with R/R CLL. They recommended that standardized ramp-up dosing and risk-adapted prophylaxis and monitoring can help prevent TLS risk.