Is RTXM83 as effective as rituximab for patients with diffuse large B-cell lymphoma?

This study compared RTXM83 to rituximab (Rituxan) to see if it is as effective and safe for patients with diffuse large B-cell lymphoma.  This study concluded that RTXM83 is as effective and safe as rituximab.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive type of non-Hodgkin’s lymphoma.  This type of cancer comes from B-cells in the body that make antibodies and fight infections.  Newly diagnosed patients are often given CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone). This regimen is commonly combined with rituximab.

Rituximab is an antibody drug that binds to cancer cells and causes the immune system to kill them.  Adding rituximab to CHOP chemotherapy helps make it more effective. However, rituximab is expensive, meaning that some patients cannot receive it.  RTXM83 is a new drug that is similar to rituximab and is cheaper. Whether RTXM83 is just as safe and effective as rituximab for patients with DLBCL is unclear.

This study had 272 patients with newly diagnosed with DLBCL. Patients were divided into two groups. Group A received RTXM83 (136 patients) and Group B received rituximab (136 patients). Both groups also received 6 to 8 cycles of CHOP chemotherapy. Patients were followed-up for an average of 12.5 months.

This study found that RTXM83 was as effective as rituximab. Similar numbers of patients in Group A responded to treatment compared to Group B (83.6% vs. 82.9%).

In both groups, the same number of patients reported side effects (96%, 131 patients each).  Overall, 48% of all patients reported serious side effects. Slightly more patients in Group A reported serious side effects compared to Group B (35% vs. 33%). Seriously low white blood cell count (27% vs. 29%) and serious infections (11% vs. 10%) were the most common.

Allergic reactions to treatment injection were also reported. Similar numbers of patients in Group A versus Group B had allergic reactions (2.3% vs. 3.2%). Mild infusion-related reactions were also reported (17% vs. 20%).

On average, patients in Group A survived for longer without the cancer coming back (relapse) compared to patients in Group B (12.5 months vs. 8.6 months). Treatment with RTXM83 was associated with a 13% lower risk of relapse or mortality.

The authors concluded that RTXM83 is as effective and as safe as rituximab for the treatment of DLBCL.

This study was funded by the manufacturers of RTXM83 (mAbxience Research SL.).  This study was limited by the short follow up time (12.5 months). More studies with a longer follow-up are needed to confirm these results.