Efficacy and safety profiles were similar for subcutaneous and standard IV rituximab when given as first-line therapy to adults with follicular lymphoma, based on results of a phase III clinical trial published online in Lancet Haematology.
Administering rituximab by IV infusion can take up to 6 hours to complete and requires continuous monitoring. Subcutaneous delivery takes approximately 6 minutes using a new rituximab formulation that is 12 times more concentrated to reduce the administered volume. The new formulation is expected to reduce the burden of treatment for patients, as well as for the health care system, said Andrew Davies, PhD, of the Cancer Research UK Centre, Southampton, and his associates.
They compared the two agents in an international open-label trial funded by Hoffmann-La Roche, maker of the subcutaneous formulation. Adult patients at 113 medical centers in 30 countries were randomly assigned to receive either IV (205 patients) or subcutaneous (205 patients) rituximab during induction therapy with six to eight cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or CVP (cyclophosphamide, vincristine, and prednisone). They continued with rituximab as maintenance therapy every 2 months for 2 years. The median duration of treatment was 27 months, and median follow-up was 37 months.
The primary efficacy end point – overall (complete or partial) response rate at the end of induction, based on investigator assessment confirmed by an independent review panel of radiologists – was 84.9% with IV and 84.4% with subcutaneous rituximab, a nonsignificant difference. Similarly, the overall response rate at the end of maintenance therapy was not significantly different between the two groups, at 78.1% and 77.9%, respectively.
Progression-free survival (hazard ratio, 0.84) and event-free survival (HR, 0.91) also did not differ significantly between the two study groups, the investigators said (Lancet Haematol. 2017 doi: 10.1016/S2352.3026(17)30078-9).
The rates of adverse events, grade 3 or higher adverse events, and serious adverse events also were similar for IV and subcutaneous formulations of rituximab. “Administration-related reactions were more common in the subcutaneous group but were predominantly mild-to-moderate local injection-site reactions, such as mild pain, swelling and erythema, reflecting the expected change in safety profile when switching to the subcutaneous route of administration,” Dr. Davies and his associates said.
These results indicate that subcutaneous administration of rituximab along with chemotherapy doesn’t compromise the agent’s antilymphoma activity, they added.