AP5280 was well tolerated at platinum doses in phase I trial.(ACCESS Pharmaceuticals Inc.'s Polymer Platinate AP5280 for cancer treatment)

2003 JAN 2 - (NewsRx.com & NewsRx.net) -- Access Pharmaceuticals, Inc., (AKC) announced the commencement of the next phase in the clinical development of Polymer Platinate AP5280.

In addition, the company released a summary of the phase I clinical study findings.

The phase I study findings confirmed the preclinical data. AP5280 was well tolerated at platinum doses significantly greater than the clinical doses of currently marketed platinum drugs. The dose limiting toxicity was nausea and vomiting, as opposed to the more typical severe toxicity, including renal toxicity and myelosuppression observed with cisplatin and carboplatin.

No prehydration of patients was used in the study to minimize the side effects of AP5280. The dosing regimen for this study was treatment every 3 weeks, which is the standard dosing schedule for carboplatin and cisplatin. Based on this dosing regimen, the safe clinical dose is estimated to be 3300 mg/platinum per meter squared.

Additional findings of the phase I study included:

* In preclinical models, it has been demonstrated that AP5280 forms in excess of 11 times more tumor platinum DNA adducts, the mechanism of action of platinum drugs. In the phase I study, when it was possible to measure the tumor platinum DNA adduct level from patients dosed at various platinum doses, tumor platinum DNA adduct formation was observed at all dose levels. Tumor platinum DNA adduct levels at the higher doses were greater than those observed at clinical doses of carboplatin.

* The drug elimination time was much slower than has been observed with small molecule platinum agents, providing potential for longer exposure of the drug to the tumor.