A phase I pharmacological and biological study of PI-88 and docetaxel in patients with advanced malignancies.

PURPOSE: This study evaluated the safety, toxicity, pharmacological properties and biological activity of PI-88, a heparanase endoglycosidase enzyme inhibitor, with fixed weekly docetaxel in patients with advanced solid malignancies. EXPERIMENTAL DESIGN: This was a phase I study to determine the maximal-tolerated dose of escalating doses of PI-88 administered subcutaneously for 4 days per week, along with docetaxel 30 mg/m(2) given on days 1, 8, 15 of a 28-day schedule. RESULTS: Sixteen patients received a total of 42 courses of therapy. No dose-limiting toxicities were observed despite escalation to the highest planned dose level of PI-88 (250 mg/day). Frequent minor toxicities included fatigue (38%), dysgeusia (28.5%), thrombocytopenia (12%), diarrhea (14%), nausea (12%), and emesis (10%) in the 42 courses. No significant bleeding complications were observed. One patient developed a positive anti-heparin antibody test/serotonin releasing assay with positive anti-platelet factor 4/PI-88 antibodies and grade 1 thrombocytopenia in cycle 5, and was withdrawn from the study without any sequelae. PI-88 plasma concentrations (mirrored by APTT) and urinary elimination were linear and dose-proportional. Docetaxel did not alter the pharmacokinetic (PK) profile of PI-88, nor did PI-88 affect docetaxel PK. No significant relationship was determined between plasma or urine FGF-2, or plasma VEGF levels and PI-88 dose/response. Although no objective responses were observed; 9 of the 15 evaluable patients had stable disease for greater than two cycles of therapy. CONCLUSION: PI-88 administered at 250 mg/day for 4 days each week for 3 weeks with docetaxel 30 mg/m(2) on days 1, 8 and 15, every 28 days, was determined to be the recommended dose level for phase II evaluation. This combination was well tolerated without severe toxicities or PK interactions.

A phase I safety, pharmacological, and biological study of the farnesyl protein transferase inhibitor, lonafarnib (SCH 663366), in combination with cisplatin and gemcitabine in patients with advanced solid tumors.

PURPOSE: This phase I study was conducted to evaluate the safety, tolerability, pharmacological properties and biological activity of the combination of the lonafarnib, a farnesylproteintransferase (FTPase) inhibitor, with gemcitabine and cisplatin in patients with advanced solid malignancies. EXPERIMENTAL DESIGN: This was a single institution study to determine the maximal tolerated dose (MTD) of escalating lonafarnib (75-125 mg po BID) with gemcitabine (750-1,000 mg/m(2) on days 1, 8, 15) and fixed cisplatin (75 mg/m(2) day 1) every 28 days. Due to dose-limiting toxicities (DLTs) of neutropenia and thrombocytopenia in initial patients, these patients were considered "heavily pre-treated" and the protocol was amended to limit prior therapy and re-escalate lonafarnib in "less heavily pre-treated patients" on 28-day and 21-day schedules. Cycle 1 and 2 pharmacokinetics (PK), and farnesylation of the HDJ2 chaperone protein and FPTase activity were analyzed. RESULTS: Twenty-two patients received 53 courses of therapy. Nausea, vomiting, and fatigue were frequent in all patients. Severe toxicities were observed in 91% of patients: neutropenia (41%), nausea (36%), thrombocytopenia (32%), anemia (23%) and vomiting (23%). Nine patients withdrew from the study due to toxicity. DLTs of neutropenia, febrile neutropenia, thrombocytopenia, and fatigue limited dose-escalation on the 28-day schedule. The MTD was established as lonafarnib 75 mg BID, gemcitabine 750 mg/m(2) days 1, 8, 15, and cisplatin 75 mg/m(2) in heavily pre-treated patients. The MTD in the less heavily pre-treated patients could not be established on the 28-day schedule as DLTs were observed at the lowest dose level, and dose escalation was not completed on the 21-day schedule due to early study termination by the Sponsor. No PK interactions were observed. FTPase inhibition was not observed at the MTD, however HDJ-2 gel shift was observed in one patient at the 100 mg BID lonafarnib dose. Anti-cancer activity was observed: four patients had stable disease lasting >2 cycles, one subject had a complete response, and another had a partial response, both with metastatic breast cancer. CONCLUSION: Lonafarnib 75 mg BID, gemcitabine 750 mg/m(2) days 1, 8, 15, and cisplatin 75 mg/m(2) day 1 on a 28-day schedule was established as the MTD. Lonafarnib did not demonstrate FTPase inhibition at these doses. Despite the observed efficacy, substantial toxicity and questionable contribution of anti-tumor activity of lonafarnib to gemcitabine and cisplatin limits further exploration of this combination.