FORT LAUDERDALE, FLA. – Sickle cell patients who received high-dose crizanlizumab had fewer vaso-occlusive crises (VOCs) than patients on a low-dose regimen a year after stopping the treatment, findings from a real-world follow-up study suggest.
But hospitalization rates and use of other health care resources were similar during and after therapy, regardless of dose,, of Duke Health in Durham, N.C., reported at the annual meeting of the Foundation for Sickle Cell Disease Research.
“This is our attempt at a real-world study of patients after being in a big study that has good results and what happens to them afterward in regard to VOCs and health care utilization,” Dr. Shah said.
He reported results from the SUCCESSOR trial – a multicenter, retrospective cohort study – that evaluated a subset of 48 adult patients up to a year after they completed the SUSTAIN placebo-controlled phase 2 trial of crizanlizumab, a P-selectin inhibitor designed to control sickle cell pain crises.
In SUSTAIN, researchers evaluated two different dosages of crizanlizumab: 5 mg/kg and 2.5 mg/kg.
In the follow-up study, researchers obtained data from medical records over the study period November 2014 to March 2017. Crizanlizumab was not administered in the 52 weeks following the SUSTAIN trial.
They found that the subset of patients on the high dose of crizanlizumab had annual VOC rates of 2.7, compared with 4.0 among patients on the low dose of the drug. By comparison, VOC rates in SUSTAIN were 1.7 per year for the 5-mg/kg–dose group and 3.2 per year for the 2.5-mg/kg–dose group.
Overall, at least 60% of patients in the follow-up study had at least one hospitalization in the year after SUSTAIN. In the higher-dose group, the rates of hospitalization were similar in both SUSTAIN and SUCCESSOR – 53%. In the lower-dose group, hospitalization rates were 67% and 61% in SUCCESSOR and SUSTAIN, respectively.
“Among the previously treated patients with crizanlizumab, the total number of emergency department visits did seem to be higher in SUCCESSOR,” Dr. Shah said.
The study was limited by its retrospective nature and the fact that full data sets and follow-up were available on only a small number of patients, Dr. Shah said. “It was underpowered for a statistical analysis between groups,” he said. The goal was to determine the drug’s effect after treatment is discontinued, he said.
Dr. Shah reported a financial relationship with Novartis, which is developing crizanlizumab.
SOURCE: Shah N et al. FSCDR 2019, .