Phase I dose-escalating study of PM02734 in a 24-hour infusion schedule every 21 days in advanced solid tumors

Abstract

2511 Background: PM02734 is a chemically synthesized depsipeptide with a broad spectrum of activity against solid tumors in vitro (breast, colon, lung, neuroblastoma, prostate, sarcoma and thyroid) and in vivo (breast, prostate, melanoma); as well as an acceptable non-clinical toxicology profile. Methods: Patients (pts) with metastatic or advanced solid tumors were enrolled in a phase I, open-label, dose-escalating study to assess safety, tolerability, pharmacokinetics (PK), and to identify the dose limiting toxicity (DLT) and recommended dose (RD) of PM02734 infused over 24 hours every 21 days (d). The starting dose was 0.48 mg/m2. Cohorts of 1–6 pts were treated at different dose levels. Results: Thirty seven pts were treated in this study. The median age was 55 years (40–75), sex: males/females 20/19. The median PS was 1 (range 0–2). The most frequent cancer types were colon/ gastric/ sarcoma (n=8/5/5). Most patients were heavily pretreated, with a median of prior therapy lines of 4 (1–12). Patients were treated at 8 dose levels (0.48, 0.72, 1.0, 1.6, 2.4, 3.6, 5.4, and 6.8 mg/m2), the MTD was 6.8 mg/m2 and the RD was 5.4 mg/m2 (10 mg flat dose).Common toxicities grade ≤ 2 included asthenia, nausea/emesis, lymphopenia, injection site reactions and asymptomatic elevated transaminases (TAs). DLT were grade 3 asymptomatic, reversible TA elevations at 6.8 mg/m2. Preliminary PK data is characterized by long half life (>100 h), a wide distribution and high inter-patient variability. Clearance was not correlated with dose or body surface area (BSA), therefore, flat dose was implemented and the RD was explored with this schedule. Efficacy data showed one complete response (CR) of +28 months observed in a pt with metastatic large cell esophageal carcinoma, and five more showed stable disease (SD) for more than 3 months in different histologies. Conclusions: PM02734 shows to be safe, well tolerated and with evidence of activity (1 CR and 5 SD > 3 months) in pts with advanced solid tumors. The DLT was grade 3 asymptomatic and reversible TA elevations, and the RD for further phase II studies is 10 mg. [Table: see text]