The standard therapy for rhabdomyosarcomas is somewhat different in the United States, typically a regimen containing vincristine, actinomycin D, cyclophosphamide, and (more recently) irinotecan, he noted. “We have not been traditionally using maintenance chemo for any of the pediatric sarcomas, so this is a paradigm shift. These results will need to be tested with U.S.-based protocols before becoming standard of care in the United States. Also, we will need to determine if these results are applicable to patients older than 21 years of age who are considered high risk based solely on their age.
“Even with these caveats, this is the first significant treatment advance in this rare cancer in more than 30 years,” concluded Dr. Chow, a medical oncologist and clinical professor at City of Hope, Duarte, Calif. “No doubt, this trial was a home run.”
Study details
Patients enrolled in the EpSSG trial had had a complete response to the standard intensive therapy used in Europe: high-dose chemotherapy (ifosfamide, vincristine, and actinomycin D, with or without doxorubicin), radiation therapy, and surgery.
The maintenance chemotherapy consisted of a combination of low-dose intravenous vinorelbine given weekly and oral cyclophosphamide given daily. The 6-month duration was somewhat arbitrary, according to Dr. Bisogno. “We had to start somewhere. So when we started, we decided to use 6 months because there was some evidence in the past for regimens that long. In our next European trial, we are going to test different kinds and durations of maintenance because this is very important.”