A multicenter phase II study of gemcitabine, paclitaxel, and cisplatin in chemonaïve advanced ovarian cancer

Role of gemcitabine in the treatment of ovarian cancer

The US FDA has recently approved the combination of carboplatin and gemcitabine as a second-line therapy for recurrent platinum-sensitive ovarian cancer. This article briefly reviews the pharmacokinetics and mechanism of action of gemcitabine and its synergistic effect with platinum. An overview of the literature on the role of gemcitabine in the treatment of epithelial ovarian cancer is also presented.

Phase III trial of carboplatin plus paclitaxel with or without gemcitabine in first-line treatment of epithelial ovarian cancer

PURPOSE

One attempt to improve long-term survival in patients with advanced ovarian cancer was thought to be the addition of more non-cross-resistant drugs to platinum-paclitaxel combination regimens. Gemcitabine was among the candidates for a third drug.

PATIENTS AND METHODS

We performed a prospective, randomized, phase III, intergroup trial to compare carboplatin plus paclitaxel (TC; area under the curve [AUC] 5 and 175 mg/m(2), respectively) with the same combination and additional gemcitabine 800 mg/m(2) on days 1 and 8 (TCG) in previously untreated patients with advanced epithelial ovarian cancer. TC was administered intravenously (IV) on day 1 every 21 days for a planned minimum of six courses. Gemcitabine was administered by IV on days 1 and 8 of each cycle in the TCG arm.

RESULTS

Between 2002 and 2004, 1,742 patients were randomly assigned; 882 and 860 patients received TC and TCG, respectively. Grades 3 to 4 hematologic toxicity and fatigue occurred more frequently in the TCG arm. Accordingly, quality-of-life analysis during chemotherapy showed a disadvantage in the TCG arm. Although objective response was slightly higher in the TCG arm, this did not translate into improved progression-free survival (PFS) or overall survival (OS). Median PFS was 17.8 months for the TCG arm and 19.3 months for the TC arm (hazard ratio [HR], 1.18; 95% CI, 1.06 to 1.32; P = .0044). Median OS was 49.5 for the TCG arm and 51.5 months for the TC arm (HR, 1.05; 95% CI, 0.91 to 1.20; P = .5106).

CONCLUSION

The addition of gemcitabine to carboplatin plus paclitaxel increased treatment burden, reduced PFS time, and did not improve OS in patients with advanced epithelial ovarian cancer. Therefore, we recommend no additional clinical use of TCG in this population.

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.

The role of gemcitabine in first-line treatment of advanced ovarian carcinoma

The combination of paclitaxel and carboplatin is now established as the standard first-line chemotherapy regimen for advanced ovarian cancer. Ways in which this standard therapy can be further improved are being investigated, and several approaches have been taken. One approach is to integrate a different cytotoxic agent into the standard combination. Gemcitabine is one such cytotoxic agent that is of particular interest because it has activity in disease resistant to treatment with paclitaxel plus carboplatin, and also has a different mechanism of action to that of the two agents in the standard combination. Gemcitabine plus cisplatin has shown activity in phase II trials and results are awaited from a phase III trial comparing paclitaxel plus carboplatin with gemcitabine plus carboplatin doublets. Using agents sequentially has been shown to be as effective as using them in combination; therefore, using a gemcitabine plus platinum doublet sequentially with paclitaxel plus carboplatin has also been studied. A phase III trial has closed and results are expected shortly. Triplet combinations have also been shown to be effective in early stage trials, although dose-limiting myelosuppression occurs with gemcitabine plus paclitaxel plus carboplatin. Two phase III trials of this triplet have finished and are awaiting data maturation. Lastly, a sequential triplet of gemcitabine plus paclitaxel plus carboplatin has been investigated, but high pulmonary toxicity led to the study being halted. The role of gemcitabine in first-line advanced ovarian cancer will become much clearer once the results from the various phase III trials are published.