This article is more than 5 years old. Information may no longer be current.
Dactinomycin showed higher complete response rate than methotrexate in low-risk gestational trophoblastic neoplasia
Osborne RJ. J Clin Oncol. 2011;29:825-831.
Click Here to Manage Email Alerts
Results of a phase 3 study of 216 women showed that a biweekly course of dactinomycin produced a higher rate of complete response than a weekly regimen of methotrexate for patients with low-risk gestational trophoblastic neoplasia.
From June 1999 to February 2007, 107 women were randomly assigned to biweekly 1.25 mg/m2 IV dactinomycin, and 109 women were assigned to 30 mg/m2 weekly intramuscular methotrexate.
Patients in the dactinomycin group showed a statistically superior rate of complete response, 70% vs. 53%. In total, 77 women did not respond and six others were not evaluable. Women who had complete response received an average of eight cycles of treatment with dactinomycin and four with methotrexate.
Researchers performed a secondary analysis of outcome in patients with a risk score of 0 to 4 and excluding choriocarcinoma. They observed a statistically significant primary response in 56 of 96 (58%) eligible patients in the methotrexate arm and 71 of 97 (73%) patients in the dactinomycin arm (P=.03).
Beta-human chorionic gonadotropin (B-hCG) levels decreased on the first day of treatment compared with baseline in 63% of patients assigned to methotrexate and 52% of patients assigned to dactinomycin. Levels rose in 74% of women in the methotrexate group and 63% of the dactinomycin group. The proportion of responding patients whose B-hCG level changed was not significantly different in either regimen.
Researchers said grade-3/grade-4 adverse events were infrequent overall — no patient discontinued treatment due to toxicity. There was more grade-2 nausea, grade-1/grade-2 vomiting, dermatologic events and neutropenia associated with dactinomycin compared with methotrexate.
Writing in an accompanying editorial, Carol Aghajanian, MD, chief of the gynecologic medical oncology service at Memorial Sloan-Kettering Cancer Center, said dactinomycin is probably an acceptable substitute to methotrexate when dactinomycin is administered daily for five days, but it is also associated with more toxicity and, because dactinomycin is a vesicant, administration is more difficult and local tissue injury is possible.
“Long-term safety and reproductive data is not yet mature with respect to the current study. Minimizing both long- and short-term toxicity is paramount in low-risk gestational trophoblastic neoplasm, for which the cure rate is high (nearly 100%), and patients are often desirous of future childbearing,” she wrote. “The study by Osborne et al does not change standard practice at this time. Most treating physicians will continue to use single-agent methotrexate, giving it daily for a period of 5 days or via the 8-day alternating methotrexate/leucovorin regimen, and will reserve the use of dactinomycin given daily for 5 days for methotrexate resistance or toxicity.”
 |
Follow HemOncToday.com on Twitter. |