FDA accelerates review of Novartis' sickle cell drug

The FDA has accelerated its review of Novartis’ sickle cell drug crizanlizumab after the company filed phase 2 results showing its effectiveness as a treatment for life threatening and painful crises associated with the condition.

The Swiss company has filed the drug as a preventive treatment for vaso-occlusive crises (VOCs) and the FDA has shortened its review to six months from the standard ten months.

The FDA had already earmarked crizanlizumab as a Breakthrough Therapy, based on promising data from earlier trials, and went on to grant the six-month Priority Review following strong results at phase 2.

Priority Reviews are granted to drugs that could represent a significant improvement over available therapies for serious diseases.

Phase 2 results from the SUSTAIN study showed that crizanlizumab cut the median annual rate of VOCs leading to healthcare visits from 2.98 in a placebo group, to 1.63 in the treatment group of 111 patients, a reduction of 45.3%.

Clinically significant reductions in the frequency of VOCs were observed among patients regardless of sickle cell disease genotype or hydroxyurea use, Novartis said.

There was also a two-fold increase in the percentage of patients who were free of VOCs versus placebo (36% vs. 17%), and a three-fold longer median time to first VOC compared with placebo (4.07 months vs. 1.38 months).

Patients in the treatment group saw a 42% reduction in the median annual rate of days hospitalised versus placebo.

The most frequently reported adverse reactions in those treated with crizanlizumab were back pain, nausea, fever, and joint pain, and the majority were mild to moderate. There were two severe events involving fever and joint pain respectively.

While Novartis looks set for a valuable approval, there are several competitors that could hit the market, and work in different ways to Novartis’ antibody-based therapy.

Crizanlizumab binds to a molecule called P-selectin on the surface of platelets and endothelium in the blood vessels, and has been shown to inhibit interactions between endothelial cells, platelets, red blood cells, sickled red blood cells, and leukocytes. P-selectin is one of the major drivers of the vaso-occlusive process.

There are high hopes for Global Blood Therapeutics’ voxelotor that aims to treat the underlying cause of sickle cell disease, instead of just the VOCs like crizanlizumab.

bluebird bio is developing a gene therapy, Lentiglobin, which also aims to fix the disease at a molecular level and do away with the need for VOC targeting drugs.

Novo Nordisk last year bought EP101, a developmental sickle cell drug from Epidestiny.