Multicentre phase I/II study of PI-88, a heparanase inhibitor in combination with docetaxel in patients with metastatic castrate-resistant prostate cancer

BACKGROUND

Docetaxel (Taxotere) improve survival and prostate-specific antigen (PSA) response rates in patients with metastatic castrate-resistant prostate cancer (CRPC). We studied the combination of PI-88, an inhibitor of angiogenesis and heparanase activity, and docetaxel in chemotherapy-naive CRPC.

PATIENTS AND METHODS

We conducted a multicentre open-label phase I/II trial of PI-88 in combination with docetaxel. The primary end point was PSA response. Secondary end points included toxicity, radiologic response and overall survival. Doses of PI-88 were escalated to the maximum tolerated dose; whereas docetaxel was given at a fixed 75 mg/m(2) dose every three weeks

RESULTS

Twenty-one patients were enrolled in the dose-escalation component. A further 35 patients were randomly allocated to the study to evaluate the two schedules in phase II trial. The trial was stopped early by the Safety Data Review Board due to a higher-than-expected febrile neutropenia of 27%. In the pooled population, the PSA response (50% reduction) was 70%, median survival was 61 weeks (6-99 weeks) and 1-year survival was 71%.

CONCLUSIONS

The regimen of docetaxel and PI-88 is active in CRPC but associated with significant haematologic toxicity. Further evaluation of different scheduling and dosing of PI-88 and docetaxel may be warranted to optimise efficacy with a more manageable safety profile.

Phase II study of thalidomide in the treatment of recurrent glioblastoma multiforme

Treatment options and prognosis remains poor for patients with recurrent glioblastoma multiforme. These tumors are highly vascularised and over express angiogenic factors such as vascular endothelial growth factor and may potentially be responsive to antiangiogenic therapies. We present the results of a phase II trial of Thalidomide, an antiangiogenic agent, in the treatment of recurrent glioblastoma multiforme. Patients were treated with 100 mg/day of Thalidomide, increased at weekly intervals by 100 mg to a maximum tolerated dose of 500 mg/d. Forty-two patients were enrolled, with 38 patients being assessable for response and 39 for toxicity. Two patients (5%) achieved a partial response and 16 (42%) had stable disease. The median survival was 31 weeks and the 1-year survival was 35%. Patients who had a partial response or stable disease had either a stabilisation or improvement in quality of life scores or performance status. Overall Thalidomide was well tolerated with no grade 4 toxicities and no treatment related deaths. The median maximum tolerated dose was 300 mg/day. The most common toxicity was fatigue to which patients developed tachyphylaxis. There was no correlation demonstrated with plasma vascular endothelial growth factor levels and response or survival. Thalidomide is a well-tolerated drug that may have some activity in the treatment of recurrent glioblastoma. Optimum dosing with antiangiogenic agents is currently under investigation. Chronic low dose therapy may be required to see conventional responses or improvements in time to progression. The dose required to achieve optimal biological impact may be better defined once we have established reliable surrogate endpoints.