Phase I study of two different schedules of bortezomib and pemetrexed in advanced solid tumors with emphasis on non-small cell lung cancer

Bortezomib and pemetrexed are approved anticancer agents with non-overlapping mechanisms of action and toxicity. We examined the safety and tolerability of pemetrexed in combination with two different schedules of bortezomib in patients with advanced solid tumors.

Two separate dose-escalating arms (arm A and arm B) were conducted simultaneously. Patients received pemetrexed on day 1 (D1) (500-600 mg/m2 IV) every 21 days. In arm A, bortezomib was given twice weekly (0.7-1.3 mg/m2 on D1, 4, 8, and 11). In arm B, bortezomib was given weekly (1.0-1.6 mg/m2 on D1 and 8).

We treated 27 patients on four dose levels in arm A and three dose levels in arm B. Tumor types included lung (n = 16), adenoid cystic carcinoma (n = 2), prostate (n = 2), sarcoma (n = 2), breast (n = 1), thymus (n = 1), head and neck (n = 1), and gastrointestinal(n = 2). Dose-limiting toxicities were seen in arm A only; grade 3 asthenia (n = 2), grade 3 transaminitis and dehydration (n = 1). The most common grade 3/4 toxicity was neutropenia. Of 26 evaluable patients, 2 patients had partial response (1 in arm A and 1 in arm B), 13 had stable disease (7 in arm A and 6 in arm B), and 11 had progression (6 in arm A and 5 in arm B). Of the 16 patients with non-small cell lung cancer, 2 (12.5%) had partial response and 9 had stable disease, for a disease control rate of 68.8%. Recommended phase II dose for arm A is pemetrexed 500 mg/m2 and bortezomib 1.3 mg/m2 twice weekly. For arm B, the recommended dose is pemetrexed 500 mg/m2, bortezomib 1.6 mg/m2 weekly.

Pemetrexed with bortezomib is feasible and tolerable at recommended single-agent doses. Based on the observed efficacy, a phase II study in non-small cell lung cancer is warranted.