This National Cancer Institute (NCI)-sponsored phase II trial was designed to evaluate the efficacy and safety of HspE7 against CIN III (high grade cervical dysplasia). In the trial, a complete pathologic response was defined as no evidence of high grade cervical dysplasia and a partial response was defined as colposcopic regression of the lesion by more than 50%.
Of the 31 patients, 32% had a complete pathologic response, 39% had a partial response and 29% had stable disease. The overall response rate was 71%.
“Among women with high grade cervical dysplasia (CIN III), HspE7 treatment resulted in a clinically significant pathologic response rate higher than the spontaneous regression rate anticipated in the protocol,” said Dr Mark Einstein, the principal investigator in the trial. “The fact that so many women with CIN III responded to HspE7 alone prior to surgery warrants further testing in women with CIN III and cervical cancer.”
Nine women in this trial had a prior history of LEEP (laser surgery) and subsequent recurrence. The response rate with HspE7 was 56% in these patients. This observation is important because it suggests that the patients who are difficult to treat because they have relapsed after LEEP may respond very well to HspE7.
These data, as well as previously announced data, will be used to guide Stressgen’s phase III development plans in high grade dysplasia.
Although the data obtained so far are encouraging, further studies will need to be done to determine if women with complete responses may safely avoid the surgical procedures that are now standard treatments for high grade cervical dysplasia.