Matrix Pharmaceutical Inc. reported data from ongoing studies of its implant products for site-specific delivery of chemotherapeutic drugs at two separate scientific conferences last week.
Data from preclinical animal studies on the ability of Matrix's technology to sustain drug distribution within a targeted site were presented Friday at the annual meeting of the American Association for Cancer Research (AACR) in Orlando, Fla. And Phase II clinical trial data on Matrix's MPI 5003 (5- fluorouracil-containing implant) for treating genital warts were presented Thursday at the Clinical Dermatology in the Year 2000 meeting in Vienna, Austria.
In one of the preclinical studies presented at AACR, the researchers analyzed the retention and distribution of the compound MPI 5010 (a therapeutic implant consisting of a biodegradable protein matrix, a chemical modifier and cisplatin) in solid liver tumors in rabbits. They found that high concentrations of platinum (50-400 micrograms per gram) were well-distributed throughout the tumor and sustained for at least 24 hours. As well, platinum was effectively localized to the tumor with only trace levels of the drug detected in adjacent tissue, kidney or blood.
In a separate study in rats with prostate tumors, the investigators found that both 5-fluorouracil (5-FU) and methotrexate (MTX) were better retained in the target tissue when delivered via Matrix's implant technology than when delivered as free drugs. Thirty minutes after direct prostate injection, 62 percent of the 5-FU was retained if delivered via implant compared to 8 percent when delivered as free drug; for MTX, the values were 76 percent and 44 percent, respectively.
As well, Matrix scientists presented data at the AACR meeting on the ability of its therapeutic implants -- containing 5-FU or cisplatin -- for treating spontaneous feline squamous cell carcinoma. They found that 86 percent of the lesions treated with cisplatin implants and 58 percent treated with 5-FU demonstrated complete response -- clearance of lesions.
Matrix of Menlo Park, Calif., is currently conducting Phase I/II clinical trials of its compound MPI 5010 in patients with liver cancer, and Phase I/IIs of 5-FU and MTX-containing products in patients with prostate cancer and head and neck cancer.
The Phase II data on MPI 5003 for treating genital warts reported at the Vienna meeting indicated that this therapeutic implant is capable of releasing 5-FU for extended periods of time. This analysis focused on data from 187 evaluable patients of the 200 enrolled in one of two separate placebo-controlled double blind trials. Overall, 61 percent of the patients who had complete clearing of all genital warts remained disease-free for three months. The treatments were well-tolerated and there were no systemic side effects.
Matrix (NASDAQ:MATX) expects to begin Phase III clinicals in the near future, according to Andrew Korey, vice president of medical and regulatory affairs.
The company's stock was up 75 cents a share on Friday, closing at $10.25.
-- Jennifer Van Brunt Senior Editor
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