Physicians who are less experienced in the use of rituximab to treat B-cell non-Hodgkin lymphoma were more likely to discontinue its use early in Medicare beneficiaries, according to a retrospective population-based study.1

Additionally, this early discontinuation of rituximab ― which was first approved in 1997 ― was associated with worse survival (adjusted relative risk, 1.39; 95% CI, 1.28-1.52; P <.001).

“Given the increasing number of newer anticancer therapies with unique and potentially life-threatening adverse effects, future studies should explore the impact of physician-level volume on therapeutic and clinical outcomes,” the researchers wrote.

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The study looked at patients diagnosed with B-cell NHL aged 66 or older between 2004 and 2011 using data from the SEER-Medicare database. To categorize physician volume, the researchers looked back for prior rituximab initiations 12 months from each initiation of rituximab.

In all, 15,110 patients initiated treatment with rituximab with 2684 physicians. Of those, 7.6% experience early discontinuation, defined as receipt of only 1 or 2 doses during a 180-day period. According to the researchers, this is a rate 2- to 3-times higher than that typically reported in clinical trials.

More than one-quarter (26.1%) of patients initiated rituximab with a physician who had not used the drug at all in the prior 12 months. These patients were 57% more likely to experience early discontinuation than patients who initiated rituximab with a physician with 3 or more initiations in the prior 12 months (adjusted relative risk, 1.57; 95% CI, 1.35-1.82; P <.001).

“This is not surprising, given that multiple placebo-controlled clinical trials have established that rituximab-containing regimens improve survival in older adults with NHL,” the researchers wrote. “This association between discontinuation and survival persisted on multiple sensitivity analyses, including a survival analysis limited to patients who remained on chemotherapy after discontinuing rituximab alone.”

Reference

  1. Huntington SF, Hoag JR, Wang R, et al. Physician experience and risk of rituximab discontinuation in older adults with non-Hodgkin’s lymphoma. J Natl Compr Canc Netw. 2019;17:1194-1202.