A phase I study of enzastaurin combined with pemetrexed in advanced non-small cell lung cancer

Chiharu Tanai1, Nobuyuki Yamamoto, Yuichiro Ohe

  • 1National Cancer Center Hospital, Tokyo, Japan. tanai@east.ntt.co.jp

Abstract

Insights

This Phase I study found that enzastaurin plus pemetrexed is safe and effective for advanced non-small cell lung cancer. Both once-daily and twice-daily enzastaurin showed clinical activity in patients.

Area of Science:

  • Oncology
  • Pharmacology
  • Clinical Trials

Background:

  • Enzastaurin is an oral kinase inhibitor targeting PKC-beta and PI3K/AKT pathways.
  • Preclinical data suggested a synergistic effect between enzastaurin and pemetrexed.
  • This study investigated the combination in advanced non-small cell lung cancer (NSCLC).

Purpose of the Study:

  • Evaluate the safety and pharmacokinetics of enzastaurin combined with pemetrexed.
  • Assess the clinical activity of this combination in previously treated advanced NSCLC patients.

Main Methods:

  • Phase I clinical trial design.
  • Patients received oral enzastaurin (500 mg QD or BID) with pemetrexed (500 mg/m² on day 1) in 21-day cycles.
  • A 7-day enzastaurin lead-in was administered before pemetrexed in Cycle 1.

Main Results:

  • Twelve patients were treated (6 QD, 6 BID).
  • One dose-limiting toxicity (Grade 3 QTc prolongation) occurred in the QD cohort.
  • Partial responses were observed, and 5 patients had prolonged treatment (>10 cycles) without progression.
  • Enzastaurin exposure was higher with BID dosing but both regimens maintained target concentrations.

Conclusions:

  • Both enzastaurin dosing schedules (QD and BID) combined with pemetrexed were well-tolerated.
  • The combination demonstrated clinical activity in advanced non-small cell lung cancer patients.