PHASE I STUDY OF PKC412 (N-BENZOYL-STAUROSPORINE), A NOVEL ORAL PROTEIN KINASE C INHIBITOR, COMBINED WITH GEMCITABINE AND CISPLATIN IN PATIENTS WITH NON-SMALL-CELL LUNG CANCER.

ACKGROUND: PKC412 (N-benzoyl-staurosporine), an oral inhibitor of protein kinase C, is capable of cell cycle inhibition and is endowed with anti-angiogenic properties. This dose-finding phase I study was designed to establish the maximum tolerated dose (MTD) of PKC412 when combined with cisplatin-gemcitabine. PATIENTS AND METHODS: Escalating doses of PKC412 were given every day of a 4 week cycle with cisplatin 100 mg/m2 on day 2 and gemcitabine 1000 mg/m2 on days 1, 8 and 15 in patients with non-small-cell lung cancer. Dose escalation was based on a modified continuous reassessment method. RESULTS: Twenty-three patients, assigned to four cohorts receiving PKC412 at a dose ranging from 25 to 150 mg/day were evaluable. Grade 3 diarrhea occurring in 3/4 patients at cycle 1 led us to define 150 mg/day as the MTD. The MTD based on multiple cycles was redefined as 100 mg/day, since prolonged grade 2-3 nausea/vomiting leading to treatment discontinuation occurred in 3/7 patients after repeated cycles. The next lower dose tested of 50 mg/day was therefore considered as the recommended dose for phase II trials. Among 33 cycles in eight patients, toxicity consisted of grade 1-2 diarrhea (12.5%) and asthenia (50%) with only one patient experiencing grade 3 headache at this dose level. A partial response was observed in three patients. CONCLUSIONS: The results of the present study indicate that PKC412 at a dose of 50 mg/day can be safely added to cisplatin and gemcitabine in patients with advanced non-small-cell lung cancer.