Multiple dose gene therapy yields best results in recurrent ovarian cancer.

2002 JUL 25 - (NewsRx.com & NewsRx.net) -- by Sonia Nichols, senior medical writer - Long-term evaluations of ovarian cancer patients treated with p53 gene replacement therapy in a phase I/II clinical trial indicate the therapy is more effective when administered in multiple doses.

Members of an international research team have issued the results of using a p53 gene replacement therapy known as SCH 58500 to treat women with recurrent ovarian cancer in a set of reports published in the July 2002 issue of Cancer Gene Therapy. According to these investigators, long-term follow-up of treated patients suggests that multiple doses of the therapy tends to extend survival better than single-dose therapy does in patients who have been previously treated for ovarian cancer.

SCH 5800, which is delivered in an adenovirus vector, contains a recombinant wild-type p53 or tumor suppressor gene and is therapy meant for replacing mutated or aberrant p53 genes in cancer patients, according to Richard E. Buller of the University of Iowa Hospitals and Clinics in Iowa City. Buller's team comprised investigators from a number of research facilities across the U.S. and in Germany. When Buller and fellow investigators administered multiple or single doses of SCH 5800 to patients with recurrent ovarian cancer, primary peritoneal cancer, or fallopian tube cancer in a phase I trial, it produced some side effects such as nausea or vomiting, but was otherwise tolerated by the patients.

Following SCH 58500 introduction into the peritoneal cavity, wild-type p53 expression was detectable in the abdominal cavity fluid within a day and persisted for up to a week, according to investigators.

Buller and colleagues found that using CT scans for assessing tumor response was not productive, given the nature of inflammatory response in the abdomen after treatment, however, measuring patients for serum levels of the cancer antigen CA125 was, and at least half the treated patients in the initial trial experienced reduced levels of CA125 after receiving three cycles of therapy, with the therapy working most effectively when combined with a platinum-based chemotherapy (A phase I/II trial of rAd/p53 (SCH 58500) gene replacement in recurrent ovarian cancer, Cancer Gene Ther, July 2002;9(7):553-566).

In long-term follow-up evaluations of women with ...