Alternating R-CHOP and R-cytarabine for transplant-ineligible MCL patients

This study investigated the safety and effectiveness of a chemotherapy regimen alternating R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) and R-cytarabine (rituximab combined with cytarabine) for mantle cell lymphoma (MCL) patients ineligible for stem cell transplant (SCT). This study concluded that alternating R-CHOP and R-cytarabine is a feasible, very effective regimen for these patients.

Mantle cell lymphoma (MCL) is a rare but aggressive type of non-Hodgkin’s lymphoma (NHL). This type represents about 6% of all new NHL cases in the U.S. and is more common in older adults.

R-CHOP or R-bendamustine (rituximab, bendamustine) are the current standards of front-line treatment for MCL patients who are elderly or have comorbidities (other conditions). These patients are usually ineligible for a stem cell transplant (SCT), which requires high-dose chemotherapy such as cytarabine (Cytosar-U).

Low-dose cytarabine has been successfully added to first-line treatments for transplant-ineligible patients. Whether R-cytarabine (rituximab combined with cytarabine) is also successful combined with R-CHOP remains under investigation.

This study involved 73 patients with MCL. 90.4% of patients had stage 3 – 4 disease. 57.5% of patients had high-risk disease. Patients received R-cytarabine with R-CHOP (89%) or R-COEP (11%; rituximab, cyclophosphamide, epirubicin, vincristine, prednisone). 91.8% of patients completed therapy. The average follow-up period was 44 months.

89% of patients responded to treatment. Of these, 75.3% achieved a complete response (CR; complete disappearance of cancer). 13.7% achieved a partial response (shrinkage of tumors). 4.1% had disease progression.

At follow-up, 43.8% of patients had relapsed or progressed. At 4 years, the progression-free survival (PFS; time from treatment before disease progression) was 51.3%. 4-year overall survival (OS; time from treatment until death from any cause) was 68.6%.

Pre-treatment bulky disease (tumors 5 centimeters or larger) increased risk of disease progression (3.7-fold) and mortality (3.0-fold). Post-treatment, positive PET scan results increased risk of disease progression by 8.4 – 9.2 fold. These were statistically significant.

48% of patients reported severely low neutrophil count (neutropenia), and low white blood cell count. 20.5% reported fever with low neutrophil count (febrile neutropenia), pneumonia, irregular heartbeat, and blood clots. No patient died as a result of these side effects.

This study concluded that alternating R-CHOP and R-cytarabine is a feasible, very effective regimen for transplant-ineligible MCL patients, especially those who are elderly.

The sample size of this study is quite small. This limits the conclusions that may be drawn from these results. More studies with larger patient populations are needed to confirm these results.

If you are a newly diagnosed MCL patient and are ineligible for a stem cell transplant, talk to your care team about the R-CHOP/R-cytarabine regimen.