From the Journals

Crizanlizumab relieves sickle cell crises across subgroups



Crizanlizumab effectively reduced vaso-occlusive crises among patients with sickle cell disease (SCD) who have numerous crises, exhibit the HbSS genotype, and take concomitant hydroxyurea, according to investigators.

Red blood cells in a blood specimen of a 6-year-old boy with sickle cell disease CDC/Janice Haney Carr

Across subgroups, crizanlizumab was safe and more effective than placebo at delaying time to first vaso-occlusive crisis (VOC) and eliminating crises, reported lead author Abdullah Kutlar, MD, of the Sickle Cell Center at the Medical College of Georgia, Augusta, and his colleagues.

The phase 2 SUSTAIN trial recently showed that crizanlizumab – a humanized, anti–P-selectin monoclonal antibody – reduced the frequency of VOCs by 45% and delayed time to first crisis by about 3 months (N Engl J Med. 2017;376:429-39).

Additionally, a subgroup analysis showed that there was a lower frequency of pain crises with crizanlizumab 5 mg/kg, compared with placebo, regardless of the number of prior VOCs, concomitant hydroxyurea use, or the SCD genotype.

The present post hoc analysis took a deeper look at these observations across the same subgroups; specifically, the investigators assessed elimination of VOCs, time to first crisis, and adverse events. They reported the findings in the American Journal of Hematology.

Crizanlizumab eliminated pain crises about seven times more frequently than did placebo in patients who had a high frequency of VOCs before the study (28.0% vs. 4.2%), and about twice as often in patients with the HbSS genotype (31.9% vs. 17.0%), and patients who were using concomitant hydroxyurea (33.3% vs. 17.5%).

Further analysis showed that crizanlizumab delayed time to first pain crisis across all subgroups, most dramatically in patients with the HbSS genotype (4.07 months for crizanlizumab vs. 1.12 months for placebo). Safety was comparable across subgroups.

“These findings provide supportive evidence that crizanlizumab provides a clinically meaningful treatment benefit when used alone or in combination with hydroxyurea for the prevention of VOCs,” the investigators wrote.

An ongoing phase 2 pharmacokinetic/pharmacodynamic study is evaluating a higher dose of crizanlizumab (7.5 mg/kg), and another trial seeks to evaluate pediatric doses of the drug.

The study was sponsored by Novartis. The authors reported financial relationships with Novartis, Bluebird Bio, AstraZeneca, and others.

SOURCE: Kutlar A et al. Am J Hematol. 2018 Oct 8. doi: 10.1002/ajh.25308.

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