Novartis could be just a few months away from getting FDA approval for its first-in-class antibody for sickle cell disease, which it thinks has blockbuster potential.
The US regulator has started a priority review of Novartis’ marketing application for crizanlizumab, an anti-P-selectin antibody designed to prevent blood cells sticking together and blocking blood vessels.
That clumping causes the painful and sometimes life-threatening vaso-occlusive crises (VOCs) that afflict patients with sickle cell disease, which is most common in people with African ancestry.
VOCs are the most common cause of hospital visits in sickle cell patients, and are estimated to cost the US healthcare system more than $1.1bn a year, says Novartis. It estimates there are about 100,000 patients in the US with the disease, and that around 60% experiencing two or more VOCs a year.
The accelerated review is based on phase 2 data from the SUSTAIN trial which showed that a once-monthly intravenous dose of crizanlizumab made patients significantly less likely to have a VOC in a 12-month period compared to placebo.
Almost 36% of patients on the drug who had suffered between two and 10 VOCs in the prior year had no crises after starting treatment with the antibody, compared to 17% of the placebo group. Healthcare visits were also reduced by 45% and there was a 42% reduction in hospitalised days compared to placebo.
The benefits were seen regardless of whether patients were also being treated with hydroxyurea, currently the standard therapy for sickle cell.
John Tsai
Novartis’ chief medical officer John Tsai said that if crizanlizumab is approved, it could “reimagine medicine in sickle cell disease for patients who live with this condition every day of their lives.”
Crizanlizumab is one of several new therapies coming through the industry pipeline for sickle cell after years of stagnation. Earlier this year, Global Blood Therapeutics reported phase 3 data with its once-daily or candidate voxelator showing it could reduce red blood cell destruction in patients, setting up regulatory filings later this year.
Hope of a long-term cure for the disease lies with gene therapy, and there has been encouraging progress on that front as well.
Bluebird Bio just got its first approval for Zynteglo in transfusion-dependent β-thalassaemia (TDT), another rare blood disease, and already has mid-stage data in hand showing that it can eliminate VOCs in some sickle cell patients. A phase 3 trial in the latter is due to start this year.
Meanwhile, a CRISPR-based gene-editing therapy is in development at CRISPR Therapeutics and Vertex, with trials of the therapy – called CTX001 – already on the go in thalassaemia and due to start in sickle cell shortly.
These potentially curative approaches are still some way down the line, and Novartis thinks there is still plenty of commercial opportunity for its drug therapy.
Crizanlizumab is one of several drugs on or near the market that Novartis reckons will be $1bn-plus products in what CEO Vas Narasimhan has called an unprecedented period of new launches for Novartis.