ORLANDO – , and could be approved for the indication soon.
With approval pending, “rituximab is quickly emerging as frontline therapy” for pemphigus, so “we should begin to prepare to answer our patients’ questions. It’s likely they will be interested in its use,” said Carolyn Kushner, a medical student and dermatology research fellow at the University of Pennsylvania, Philadelphia. Rituximab manufacturer Genentech announced the priority review for this indication in a Feb. 2018.
“We get a lot of questions in the clinic,” she said at the International Investigative Dermatology meeting. Patients with pemphigus want to know how well rituximab will work, and if they’ll be able to go off other medications. They wonder if it’s safe, and when they’ll need to be retreated. The goal of the study was to provide information for both clinicians and patients regarding what to expect from the treatment.
Overall, 54 patients (48%) achieved a complete response off therapy (CROT) after their first treatment cycle, meaning they had no new lesions for at least 2 months off of all systemic and topical treatments. The median time to a complete response was 7.4 months, and the median time to relapse was 20.9 months after the first infusion. An additional 15 patients (13%) had a complete remission with minimal therapy after one cycle.
In short, “61% of patients achieved complete healing of their skin after one cycle,” Ms. Kushner said. The number rose to 82% (93 patients) when those who had more than one cycle were included. The maximum in the study was seven. Among all patients, the median time from the first to second rituximab dose was 25.1 months.
When age, sex, and disease duration were controlled for, patients who received lymphoma dosing – 375 mg/m2 weekly for 4 weeks – were 2.7 times more likely to achieve CROT than those on the rheumatoid arthritis dosing, two 1,000 mg IV infusions 2 weeks apart (P = .037). “We almost never use RA dosing now,” she said.