According to a story from Newswise, a recent phase 2 clinical trial testing a combination treatment for the rare cancer rhabdomyosarcoma has displayed encouraging results. The combination consists of the targeted drug temsirolimus and chemotherapy. The findings could represent the first step forward for the treatment of this rare cancer in decades. The study included patients that had already experienced disease relapse following their first attempt at treatment.
Rhabdomyosarcoma is a type of soft tissue sarcoma cancer. It is highly aggressive and affects skeletal muscle cells that are not yet fully differentiated. Most people affected by the disease are under age 18. In many cases, the cause of rhabdosarcoma remains a mystery, and the cancer often appears sporadically. However, increased risk has been associated with certain genetic disorders, and parental use of cocaine and marijuana may also increase the risk. The symptoms and presentation of this cancer vary widely and often depend on where the tumor appears; often a prominent lump is noticeable. This means that this cancer can, in some cases, be diagnosed early. Treatment approaches include surgery, chemotherapy, radiation, and immunotherapy. Outcomes vary substantially depending on location, but the cure rate for cancer that hasn’t spread is 75 percent. Relapsed or metastatic cancer has much worse survival rates. To learn more about rhabdomyosarcoma, click here.
Testing Targeted Therapies
The ultimate goal of this trial was the testing of targeted therapies with chemo to determine if they would improve outcomes for patients. The researchers compared two different targeted drugs: bevacizumab and temsirolimus. These drugs were tested alongside a chemotherapy regimen that included the agents cyclophosphamide and vinorelbine. The study included a total of 86 patients with rhabdomyosarcoma.
Enrollment for the trial was halted early after interim findings gave a clear advantage to temsirolimus; during a six month treatment period, event free survival for bevacizumab patients was 54.6 percent, but for patients temsirolimus, the figure was 69.1 percent. It should be noted, however, that these relapsed patients did not see significant improvements in long term survival.
Future studies will test the combination in patients that have yet to be treated and face intermediate risk disease. The effectiveness of temsirolimus can be linked to its mechanism of action, which targets a pathway called mammalian target of rapamycin (mTOR).