CHICAGO – , finds a phase 3 randomized controlled trial of the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG).
Rhabdomyosarcoma is a rare but very aggressive tumor, lead study author Gianni Bisogno, MD, PhD, a professor at the University Hospital of Padova, Italy, and chair of the EpSSG, noted in a press briefing at the annual meeting of the American Society of Clinical Oncology, wherewere reported. Among pediatric patients who achieve complete response to standard therapy, “we know that after 1 or 2 years, one-third of these children relapse, and most of them die,” he said.
The EpSSG trial, which took about 10 years to conduct, enrolled 371 patients aged 0-21 years with high-risk rhabdomyosarcoma who had had a complete response to standard intensive therapy. They were randomized evenly to stop treatment or to receive 6 months of maintenance treatment consisting of low-dose vinorelbine and cyclophosphamide.
Results reported in the meeting’s plenary session showed that giving maintenance chemotherapy improved the 5-year overall survival rate by an absolute 12.8%, which translated to a near halving of the risk of death. And the maintenance regimen used was generally well tolerated.
“At the end of this long, not-easy study, we concluded that maintenance chemotherapy is an effective and well tolerated treatment for children with high-risk rhabdomyosarcoma,” Dr. Bisogno said.
There are three possibilities for its efficacy, he speculated. “It may be the duration, the type of drugs used, or the metronomic approach. Maybe altogether, these three different actions have a benefit to increase survival.
“Our group has decided this is the new standard treatment for patients. At least in Europe, we give standard intensive therapy and then we continue with 6 more months of low-dose chemotherapy,” Dr. Bisogno concluded. “We think that this approach – a new way of using old drugs – can be of interest also for other pediatric tumors.”
The trial is noteworthy in that it shows “how to successfully conduct large and important trials in rare diseases,” said ASCO Expert Warren Chow, MD.