Weekly Carboplatin and Taxotere in Platinum Sensitive Relapsed Ovarian or Tubal or Primary Peritoneal Cancers

Ovarian cancer is the sixth most common malignancy in women, with estimated 2500 cases diagnosed in 2001, and 1500 deaths. Despite maximal cytoreductive therapy, followed normally by a taxane and carboplatin (or cisplatin) chemotherapy, most patients will relapse, and require chemotherapy in a palliative setting. The goal of this second line therapy is to prolong survival and to improve quality of life. This disease has been characterized as chronic, as many patients may eventually go on to respond to additional lines of therapy.

Response to second line therapy has been correlated to length of time since the end of the first line treatment (treatment free interval, TFI). Patients relapsing or progressing while on therapy are defined as platinum-refractory. In North America the norm is to label patients with a TFI of 6 months or less as platinum-resistant. A TFI of greater than 6 months would make a patient platinum-sensitive.

These platinum-sensitive patients are generally treated with single agent carboplatin or carboplatin and taxol by 3-weekly administration. The ICON-4 trial published in June 2003 compared single agent platinum to combination of platinum-taxol. Patients could have received one or both of these agents in the adjuvant setting. At a median follow-up of 42 months the absolute difference in 2-year survival was 7% [P=0.0004} in favor of the combination arm. Thus combination platinum-taxol is the present standard of care in platinum-sensitive relapsed ovarian cancer. Use of taxol is limited by persistent neuropathy in 20%.

Presently there is growing evidence in support of giving chemotherapy at shorter intervals at low-doses. Hypothetically, this allows less advancement of cancer cells through the cell cycle. Moreover weekly taxanes are associated with an anti-angiogenic effect- more so with taxotere than taxol in cell-lines.

Several randomized trials in breast cancer have shown the improved efficacy of weekly taxol over 3-weekly taxol. The neoadjuvant study showed an increase in pCR [complete response on pathologic evaluation] of 10%with weekly taxol. The adjuvant study with 2-weekly chemotherapy showed a 7% improvement in time-to-progression over 3-weekly chemotherapy.

In ovarian cancer- a Phase II study of weekly carboplatin (AUC-2) with taxol (80mg/m2/week) given on day 1,8,15 of 28 day cycles has shown a response rate of 100% [80% CR, 20% PR] in 21 platinum-sensitive patients- with either measurable or evaluable disease. Median duration of response was 11.7 months (95% CI- 8.0-18.5 months). 46% reported Grade I neuropathy, 1 patient had febrile neutropenia, and 32% had Grade 3 neutropenia.

Weekly administration of taxotere with carboplatin has been studied in a Phase I study. Maximum tolerated dose was Taxotere 35mg/m2 with carboplatin AUC-2. At this dose no Grade 3 or 4 cytopenias were seen. Nor were there significant neuropathies.

Our study plans to evaluate Taxotere 35mg/m2 with Carboplatin at AUC-2 given weekly. 3 weekly treatments will constitute one cycle. We expect to see equivalent response rates and equivalent or higher duration of responses with better toxicity profile.