November 7, 2008
Poniard Announces Positive Top-Line Results From Phase I Study of Tumor Drug
Poniard Pharmaceuticals, a biopharmaceutical company focused on oncology, has announced top-line results from its Phase I clinical trial of an oral formulation of picoplatin in patients with solid tumors showing that picoplatin achieves linear and dose-dependent plasma exposure when given orally.
Poniard's randomized, open-label, dose-ranging Phase I study was conducted at clinical sites in the US. The trial compared the bioavailability, pharmacokinetics, pharmacodynamics and safety of picoplatin administered orally with picoplatin administered intravenously in patients with advanced solid tumor malignancies. Bioavailability refers to the fraction of an administered dose of an unchanged drug that reaches systemic circulation.
In the first part of this two-part trial, patients with advanced solid tumor malignancies were randomized to a single dose of either intravenous (120mg/m squared) or oral picoplatin (200, 300 or 400mg). Four weeks later, they were crossed over to a second single picoplatin dose administered via the alternative route. In the second part of the trial, patients received only a single oral dose of picoplatin (including doses of 50 and 100mg).
Results showed that oral picoplatin can achieve oral bioavailability of up to 44% in the doses tested in the first arm. Results also showed that picoplatin oral bioavailability is linear, and maximum exposure to orally administered picoplatin was achieved at doses of 200mg or greater. Additionally, following four weeks of dosing with either oral or intravenous picoplatin, only background levels of circulating platinum could be detected, suggesting no drug accumulation between dosing cycles.
There were no differences in pharmacokinetics observed, and all doses were well tolerated with no serious adverse events related to treatment noted following the oral dose. No myelosuppression occurred after oral dosing, the company said.
Robert De Jager, chief medical officer of Poniard, said: "Achieving sufficient bioavailability with oral picoplatin is extremely encouraging and supports further clinical development of an oral formulation of the drug, as it may provide a more convenient, flexible dosing routine for patients who would benefit from picoplatin. Orally administered picoplatin may be desirable for cancer patients receiving radiation therapy and in combination with other oral therapies."