Mantle cell lymphoma progression during ibrutinib treatment leads to poor outcomes
Tuesday, May 17, 2016
Patients with mantle cell lymphoma who progressed on ibrutinib have poor outcomes and no effective therapies following ibrutinib treatment, according to results of a retrospective cohort study.
“The first key point is that we observed, fairly consistently in multiple international centers, that people with mantle cell lymphoma that progressed while receiving ibrutinib [Imbruvica, Pharmacyclics] tended to do poorly with post-ibrutinib therapies,” said Peter Martin, M.D., assistant professor of medicine at Weill Cornell Medicine and medical oncologist at NewYork-Presbyterian. “We thought that this was important information both from a patient perspective and a physician perspective, since it might inform decisions, including timing of transplant, post-ibrutinib treatments, end-of-life care and clinical trial design.”
Ibrutinib appears very effective in some patients with mantle cell lymphoma, garnering a 68% response rate and a median PFS of 13.9 months in a phase 2 trial. Further, long-term follow-up demonstrated 47% of patients were alive at 2 years and 31% remained progression free.
However, primary resistance to the enzyme inhibitor occurs in about 33% of all patients and acquired resistance is universal.
Because the mechanism for this resistance remains unclear and likely to be multifactorial, Martin and colleagues sought to improve the understanding of patient outcomes and to identify risk factors associated with survival in this setting.
“I suspect that the factors that make mantle cell lymphoma more aggressive tend to migrate along with the factors that make it resistant to ibrutinib, and that these factors tend to be more common in people that start with more aggressive disease and have received multiple lines of therapy,” Martin said. “We will have an opportunity to pick apart these mysteries with more research looking at ibrutinib used in different combinations and in different lines of therapy.”
This is an excerpt of an article that appeared in HemOnc Today. Read the full story here.