A subcutaneous formulation of rituximab has been shown to have a similar efficacy and safety profile as intravenous rituximab in the treatment of follicular lymphoma.
The international, phase 3 SABRINA study of more than 400 patients found 1400mg subcutaneous or 375mg/m2 intravenous rituximab in addition to chemotherapy achieved similar overall response rates at the end of induction therapy (84.4 v 84.9%).
Patients who continued on rituximab alone as maintenance therapy also had similar overall response rates after two years – 77.9% for subcutaneous and 78.1% for intravenous administration.
Both treatments were associated with similar rates of all adverse events (96 v 95%), severe adverse events (35 v 34%) and grade ≥3 adverse events (56 v 55%) although administration-related reactions were more common with subcutaneous rituximab (48 v 35%).
Professor Miles Prince, director of the Centre for Blood Cell Therapies at the Peter MacCallum Cancer Centre, told the limbic subcutaneous rituximab had one major advantage over intravenous rituximab.
“It is all about resources. Typically patients are in the chair for 90 min, even up to 3-4hrs, getting the IV. The subcut cuts that time down to just a few minutes.”
He added that uptake of the subcutaneous formulation still required some nursing education.
The researchers said the subcutaneous rituximab was 12 times the concentration of IV rituximab in order to deliver a therapeutic dose.
It also included a recombinant human hyaluronidase to help disperse larger than normal volumes of the subcutaneous drug.
The study concluded subcutaneous formulation was comparable in clinical activity to standard rituximab, a more convenient option for patients in terms of shorter chair time and consequently required fewer health resources.
They added that studies in CLL and diffuse large B-cell lymphoma suggested subcutaneous rituximab was also promising for other disease states.