DHA-paclitaxel

To determine the maximum tolerated dose, dose-limiting toxicity (DLT), and pharmacokinetics of weekly docosahexaenoic acid-paclitaxel (DHA-paclitaxel), a taxane fatty acid conjugate.

Docosahexaenoic acid-paclitaxel was administered by 2-hour i.v. infusion weekly for three out of four weeks. DHA-paclitaxel 200 mg/m(2) was dose escalated by 100 mg/m(2) per cohort to 600 mg/m(2). Blood samples for pharmacokinetics of DHA-paclitaxel and paclitaxel derived from DHA-paclitaxel were collected.

Twenty-one patients received 42 cycles of treatment over five dose levels. Grade 3/4 neutropenia occurred in five patients but was not dose limiting. Grade 3 hyperbilirubinemia, a DLT, and grade 1 sensory neuropathy occurred at the highest dose level. PK analyses demonstrated dose proportional C (max) and AUC(0-24). Limited accumulation of DHA-paclitaxel or paclitaxel occurred with weekly treatment. Increased DHA-paclitaxel and paclitaxel AUC(0-24) were associated with increased neutropenia. Of the 19 patients evaluable for response, three patients with esophageal, melanoma and colon carcinoma had stable disease for 11, 16, and 17 weeks, respectively.

Docosahexaenoic acid-paclitaxel administered weekly to a maximum dose of 600 mg/m(2) was well-tolerated. The slow release of paclitaxel from DHA-paclitaxel and the weekly schedule approximates continuous infusion paclitaxel which may be more active than every 3 week or weekly taxanes.

Combination chemotherapy regimens can improve survival in patients with advanced gastric and oesophageal adenocarcinoma. Docosahexaenoic acid (DHA)-paclitaxel is a novel conjugate formed by the covalent linkage of the fatty acid DHA to paclitaxel and may result in increased tumour exposure to paclitaxel without increased toxicity.

In this single arm, phase II study of DHA-paclitaxel, eligible patients with previously untreated, inoperable locally advanced or metastatic adenocarcinoma of the oesophagus, oesophago-gastric junction or stomach were treated with DHA-paclitaxel (1,100 mg/m(2)) administered by 2-h intravenous infusion every 21 days.

Fifty-four patients were recruited of whom 53 were evaluable for toxicity, and 48 for response. There were five confirmed partial responses (9.4%) by the RECIST criteria. The median duration of response was 87 days (range 49-97 days), the median time to progression was 84 days (95% CI 78-124 days), and median overall survival was 262 days (95% CI 205-357 days). Grade >or=3 neutropaenia occurred in 93% of patients, and febrile neutropaenia in 17% of patients.

DHA-paclitaxel has modest activity in patients with oesophago-gastric cancer and with haematological toxicity that is comparable to paclitaxel and docetaxel.