Billed as potential blockbuster, Novartis' sickle cell drug scores FDA's breakthrough therapy status
Touted by Novartis chief Vas Narasimhan as a potential blockbuster, the Swiss drugmaker’s sickle cell disease (SCD) drug has secured the FDA’s breakthrough therapy designation for its ability to prevent debilitatingly painful vaso-occlusive crisis for patients affected by the group of inherited red blood cell disorders that typically afflict those of African ancestry.
SCD patients have atypical hemoglobin molecules, which can distort red blood cells into a sickle, or crescent, shape. Symptoms such as anemia, repeated infections and periodic episodes of pain called vaso-occlusive crises (VOC) when sickle shaped red blood cells get stuck inside blood vessels begin to appear in early childhood. These episodes deprive the body of oxygen-rich blood, which can culminate in widespread tissue and organ damage — particularly in the lungs, kidneys, spleen, heart and brain — and drastically diminish life expectancy.
The drug, called crizanlizumab or SEG101, came to Novartis in 2016 via an acquisition of Selexys Pharmaceuticals in a deal valued at up to $665 million. Data showed the drug reduced the median annual rate of VOCs leading to health care visits, and an analysis of Phase II data presented at the ASH conference last year also showed that 35.8% of those given the experimental treatment did not experience a VOC, versus 16.9% on the placebo arm in patients with a history of 2-10 VOCs in the preceding year. After initially suggesting a marketing application would be submitted in 2018, Novartis said it would make its case for the drug in 2019.
Existing SCD therapies are daily oral medications, but compliance is low at about 50%, Cowen analysts wrote in a note in 2018 following Novartis’ R&D day in November.
“Conversely, crizanlizumab is a once per month IV infusion, resulting in advantageous dosing but with the obvious administration hurdle. Novartis believes that the monthly administration could facilitate compliance through regular healthcare visits,” the analysts noted, adding that they had forecast sales of $200 million in 2024 for the drug.
Novartis, which estimates there are about 100,000 SCD patients in the United States with roughly 60% experiencing 2 or more VOCs annually, on Tuesday reiterated it was planning a regulatory submission in the first half of 2019.
Last month, in yet another sign of the FDA’s enhanced flexibility under commissioner Scott Gottlieb, Global Blood Therapeutics $GBT managed to convince regulators to allow its experimental drug, voxelotor, to be evaluated under the accelerated approval pathway for sickle cell disease on the basis of early data from an ongoing late-stage study.