EMA’s human medicines committee (CHMP) has recommended suspending the marketing authorisation for the sickle cell disease medicine Oxbryta (voxelotor); this measure is taken as a precaution while a review of emerging data is ongoing.
Oxbryta is a medication used to treat sickle cell disease individuals 12 years of age and older who have hemolytic anemia, or an excessive thinning of red blood cells. Oxbryta may be administered alone or in conjunction with hydroxycarbamide, another medication for sickle cell disease. Voxelotor is the active ingredient found in it.
Individuals with sickle cell disease, a genetic condition, generate an aberrant type of hemoglobin, the oxygen-carrying protein in red blood cells. In addition to changing from a disc shape to a crescent shape (like a sickle), the red blood cells become stiff and sticky.
The recommendation follows emerging safety data from two registry-based studies, which indicate that patients in the studies had a higher occurrence of vaso-occlusive crises (VOC) during treatment with Oxbryta than they did before starting the medicine. Vaso-occlusive crises are among the most common complications of sickle cell disease; they involve episodes of acute pain and can lead to further health complications, such as arthritis, kidney failure and stroke.
These new safety data emerged while EMA was already reviewing the benefits and risks of Oxbryta as part of an ongoing review started in July 2024. This was triggered as data from a clinical trial showed that a higher number of deaths occurred with Oxbryta than with placebo (dummy treatment) and another trial showed the total number of deaths was higher than anticipated.
In this context, the CHMP considered that, overall, these data raise serious concerns about the safety of Oxbryta; due to the increased uncertainties it therefore recommended that the authorisation, marketing and supply of the medicine be suspended until all the available data have been assessed in the ongoing review. In parallel, the company marketing Oxbryta has decided to withdraw and recall the medicine from all countries where it is available, and to discontinue ongoing clinical trials, compassionate use and early access programmes. While the review is ongoing, EMA recommended that:
- doctors should not start new patients on Oxbryta;
- doctors should contact patients currently treated with Oxbryta to stop treatment and discuss alternative treatment options;
- doctors should continue to monitor patients for adverse events after treatment with Oxbryta is stopped;
- patients must talk to their doctor before stopping their medicine;
- patients who have any questions should talk to their doctor.
More detailed recommendations will be sent to healthcare professionals prescribing, dispensing or administering the medicine in a direct healthcare professional communication (DHPC).The DHPC will also be published on the EMA website.
EMA’s recommendation for a suspension will be forwarded to the European Commission, which will issue a legally binding decision applicable in all EU Member States. EMA will continue its review of Oxbryta and issue a final recommendation in due course.
