A phase I trial of pan-Bcl-2 antagonist obatoclax administered as a 3-h or a 24-h infusion in combination with carboplatin and etoposide in patients with extensive-stage small cell lung cancer

Br J Cancer. 2012 Feb 28;106(5):839-45. doi: 10.1038/bjc.2012.21. Epub 2012 Feb 14.

Abstract

Background: Bcl-2 family genes are frequently amplified in small cell lung cancer (SCLC). A phase I trial was conducted to evaluate the safety of obatoclax, a Bcl-2 family inhibitor, given in combination with standard chemotherapy.

Methods: Eligible patients (3-6 per cohort) had extensive-stage SCLC, measurable disease, ≤ 1 before therapy, Eastern Cooperative Oncology Group performance status 0 or 1, and adequate organ function. Patients were treated with escalating doses of obatoclax, either as a 3- or 24-h infusion, on days 1-3 of a 21-day cycle, in combination with carboplatin (area under the curve 5, day 1 only) and etoposide (100 mg m(-2), days 1-3). The primary endpoint was to determine the maximum tolerated dose of obatoclax.

Results: Twenty-five patients (56% male; median age 66 years) were enrolled in three dose cohorts for each schedule. Maximum tolerated dose was established with the 3-h infusion at 30 mg per day and was not reached with the 24-h infusion. Compared with the 24-h cohorts, the 3-h cohorts had higher incidence of central nervous system (CNS) adverse events (AEs); dose-limiting toxicities were somnolence, euphoria, and disorientation. These CNS AEs were transient, resolving shortly after the end of infusion, and without sequelae. The response rate was 81% in the 3-h and 44% in the 24-h infusion cohorts.

Conclusion: Although associated with a higher incidence of transient CNS AEs than the 24-h infusion, 3-h obatoclax infusion combined with carboplatin-etoposide was generally well tolerated at doses of 30 mg per day. Though patient numbers were small, there was a suggestion of improved efficacy in the 3-h infusion group. Obatoclax 30 mg infused intravenously over 3 h on 3 consecutive days will be utilised in future SCLC studies.

Publication types

  • Clinical Trial, Phase I
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / adverse effects
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Carboplatin / administration & dosage*
  • Carboplatin / adverse effects
  • Central Nervous System / drug effects
  • Drug Administration Schedule
  • Etoposide / administration & dosage*
  • Etoposide / adverse effects
  • Female
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / pathology
  • Male
  • Maximum Tolerated Dose
  • Middle Aged
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors
  • Pyrroles / administration & dosage*
  • Pyrroles / adverse effects
  • Small Cell Lung Carcinoma / drug therapy*
  • Small Cell Lung Carcinoma / pathology

Substances

  • Proto-Oncogene Proteins c-bcl-2
  • Pyrroles
  • Etoposide
  • Carboplatin
  • obatoclax