Long-term outcomes of ibrutinib plus rituximab for relapsed or refractory mantle cell lymphoma

This study investigated the long-term safety and effectiveness of ibrutinib (Imbruvica) plus rituximab (Rituxan) for relapsed or refractory (does not respond to treatment) mantle cell lymphoma. This study concluded that this treatment is safe and effective for relapsed or refractory mantle cell lymphoma.

Mantle cell lymphoma is a rare but aggressive type of non-Hodgkin’s lymphoma. For patients with relapsed or refractory disease, ibrutinib has become the preferred standard of care. This type of treatment only targets cancer cells, and blocks their growth. This leads to cancer cell death.

Ibrutinib combined with rituximab (IR) has shown promising results in patients with mantle cell lymphoma. However, the long-term safety and effectiveness of this regimen in patients with relapsed or refractory disease remains under investigation.

This study involved 50 patients with relapsed or refractory mantle cell lymphoma. Most patients had intermediate risk (50%) or high risk (36%) disease. All patients received the IR regimen. Treatment duration was an average of 16 months. The average follow-up time was 47 months.

Overall, 88% of patients responded to treatment. 58% showed complete remission and 30% showed partial remission (tumor shrinkage). Of those who stopped treatment (76%), 28% were due to disease progression and 18% due to ibrutinib intolerance.

At follow-up, the average duration of response was 46 months. 68% of patients responded to treatment for at least 24 months. The average progression-free survival (time from treatment until disease progression) was 43 months. Three-year progression-free survival was 54%. Three-year overall survival (time from treatment until death from any cause) was 69%.

36% of patients required ibrutinib dose reduction due to side effects. Most of the reported side effects were mild. These included fatigue, diarrhea, muscle pain, and nausea. Severe infection (28%) and low platelet count (cells involved in blood clotting; 4%) were also reported.

This study concluded that ibrutinib plus rituximab is safe and effective for relapsed or refractory mantle cell lymphoma. The authors suggest that this treatment may not be curative for some types of high-risk mantle cell lymphoma.

This study received funding support from Pharmacyclics LLC, one of the manufacturers for ibrutinib The patient population in this study was also quite small. Larger studies are needed to confirm these results.