A first-line therapy’s success in treating rare mantle cell lymphoma

Two new clinical trials at MD Anderson are taking aim at mantle cell lymphoma – a rare form of non-Hodgkin’s lymphoma.

Most mantle cell lymphoma trials test new treatments on patients with relapsed disease, but MD Anderson’s trials are focusing on patients who are newly diagnosed.

“The first therapy is the most important,” said Michael Wang, M.D., professor of Lymphoma and Myeloma and the trial’s principal investigator. “If you do well with the first-line therapy, you can eliminate almost all of the cancer cells. They won’t have the opportunity to develop resistance, and remission can last longer.”

Trial for younger patients

The first trial is testing the drugs ibrutinib plus rituximab as a first-line therapy for newly diagnosed patients ages 65 years and younger. Traditionally, younger patients are given chemotherapy and sometimes a stem cell transplant before any other treatment. Receiving ibrutinib and rituximab first, researchers believe, may allow patients to undergo fewer cycles of chemotherapy later.

“If we take advantage of the window of time before the start of cytotoxic chemotherapy to administer targeted, biological therapy, then less chemotherapy will be needed. This could both decrease the toxicity of treatment and increase survival time,” said Wang, who is also co-leader of MD Anderson’s B Cell Lymphoma Moon Shot Program.

Among patients treated thus far, the overall response rate has been 100 percent, and the complete response rate has been 73 percent and is still rising. Further follow up is needed to determine survival outcomes, but after a median follow up of nine months, no patient has died or had disease progression or recurrence.

“This has been the first time a first-line chemotherapy-free regimen has had an overall response rate of 100 percent in younger patients with mantle cell lymphoma,” Wang said.

Trial for older patients

Patients older than 65 typically cannot tolerate high-dose chemo, and thus receive less intensive, and thus less effective, therapy than younger patients. Traditionally they are given two drugs – bendamustine plus rituximab, which are not as powerful as the treatment given to younger patients. As a result, survival times in older patients are usually shorter, averaging three to five years. To prolong survival without compromising safety in this older group, Wang and colleagues designed a trial which adds a third drug, ibrutinib, to their two existing drugs.

The trial recently completed enrolling patients and is preparing to launch. Results, when they are in, could lead to the approval of ibrutinib as a first-line treatment for mantle cell lymphoma.

“If the primary objective is achieved, this will be the new standard for elderly patients around the world,” Wang said.

Read more about these studies in Oncolog, MD Anderson’s report to physicians about the latest advances in cancer care and research.