- The Food and Drug Administration on Monday approved Global Blood Therapeutics' sickle cell drug voxelotor, completing a rapid review that took the regulator about 90 days. The accelerated OK is conditional on the biotech completing a study to confirm the rise in hemoglobin measured in trials so far yields clinical benefit.
- Global Blood set a list price of $10,417 a month for the drug, which it said will result in a net price of about $8,000 for roughly two-thirds of payers. Voxelotor, which will be sold as Oxbryta, will be available within two weeks, the company said.
- Approval comes just 10 days after the FDA cleared Novartis' Adakveo for use in the same condition. Emmaus Medical's Endari was approved in 2017 as the first new sickle cell treatment in 20 years.
Like spinal muscular atrophy, sickle cell disease is a rare disorder going through rapid change thanks to a number of new treatments coming onto market and experimental drugs progressing through the clinic.
Oxbryta helps patients with sickle cell disease by increasing hemoglobin's affinity for oxygen, which is thought to block the characteristic sickling and improve blood flow. The pivotal HOPE trial showed that 51% of patients taking Oxybryta experienced a 1 gram per deciliter increase in hemoglobin compared with just under 7% of patients receiving placebo.
Cantor Fitzgerald analyst Alethia Young wrote in a Nov. 25 note to clients that the initial eligible population is roughly 22,000 patients with hemoglobin levels of 8 grams per deciliter or less, compared with normal levels of at least 13.5 for men and 12 for women.
Based on the price announced by Global Blood Therapeutics, Young wrote that she expects $60 million in sales in 2020. As patient experience grows and the FDA grants label expansions, she forecasts U.S. sales could reach $2.2 billion by 2027.
Shares in the South San Francisco, California-based company rose 2% in early trading Nov. 26 to $61.13 apiece.
Anemia, a deficiency of health red blood cells, is one symptom of sickle cell disorder, with patients also often suffering painful episodes called vaso-occlusive crises resulting from the misshapen cells sticking to each other and blood vessel walls. Those are the episodes that Novartis' Adakveo (crizanlizumab) intends to prevent.
Depending on patient weight, Adakveo will cost between $7,000 and $9,500 per month, Novartis said.
With accelerated approval, Global Blood Therapeutics will have to confirm the benefit of the drug with a follow-up study. The HOPE-KIDS 2 study to be initiated later this year will measure transcranial doppler flow velocity to determine whether Oxbryta decreases stroke risk in children between age 2 and 15.
The sickle cell space could see yet more change in the near future. Bluebird Bio has planned to start enrolling a Phase 3 trial of its LentiGlobin gene therapy for sickle cell disease by the end of the year, and has a second gene therapy project called BCL11A shRNA in early clinical study.
Bluebird will be presenting early data from the latter of those two experimental treatments as a late-breaking abstract at the American Society of Hematology meeting next month.