Half of the patients in a Wisconsin Oncology Network (WON) clinical trial for a rare blood cancer are still in remission eight years after beginning treatment, according to new results of a follow-up to the study.
The results were presented at the annual meeting of the American Society of Hematology conference in San Diego earlier in December.
Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin’s lymphoma. Because it is so rare, finding enough patients to test a new treatment can be a challenge, said Dr. Julie Chang, a hematologist with the UW Carbone Cancer Center.
But this trial was offered through WON, a network of regional clinics that allows patients throughout Wisconsin to participate in UW Carbone clinical trials. Patients at Aspirus Hospital in Wausau, St. Vincent’s Oncology in Green Bay, Gundersen Lutheran in La Crosse and UW Carbone in Madison took part in the trial. Chang said the network was helpful when studying such a rare disease.
“The study had 30 patients, which doesn’t seem like a lot, but MCL is a very uncommon disease,” Chang said. “Yet between the UW and WON we were able to accrue to the study and get meaningful data.”
Despite its name, MCL behaves differently than many lymphomas and, consequently, needs to be treated differently. The first line of therapy, known as R-CHOP, can cure some types of lymphoma, but it is not curative for MCL. After treatment, MCL patients see an average first remission of 18 months.
“Your first remission is always your best, and its length can be extremely telling for how the disease is going to behave,” said Chang, who led the study. “Each successive treatment will give shorter and shorter remissions, so the goal of this particular trial was to give a little bit more intensive first-line therapy and hopefully help these people stay in remission a little bit longer.”
In this study, which started in 2005 and closed to accrual in 2008, Chang and colleagues gave MCL patients the same combination of chemotherapy drugs as in R-CHOP but in higher doses. They added another drug, bortezomib (Velcade™), that has been FDA-approved for treatment of MCL. After treatment, they gave patients five years of maintenance therapy with rituximab (Rituxan™).
“When we initially published results of the trial in 2011, 63 percent of patients were still in remission three years after treatment,” Chang said. “We followed patients on the trial until this year, and now eight years after the last person accrued on the trial, 50 percent of patients are still in remission, indicating that there was a remarkably small margin of people who relapsed after three years. In fact, everyone who was in remission after five years was still in remission after eight.”
Based on the results first published in 2011, the WON treatment protocol was developed for a larger Eastern Cooperative Oncology Group (ECOG) trial (ECOG E1405). That study is currently being analyzed, and the results are expected to be reported in 2017. Chang said if the ECOG trial’s results agree with those of the WON trial, then the combined results will be a major factor in deciding if this intermediate-intensity chemotherapy moves forward for the treatment of MCL.