European Union watchdog puts sickle cell disease drug on ice

File photograph used for representational purposes only
| Photo Credit: REUTERS

The European Union’s drug watchdog on Thursday, September 26, 2024, called for the suspension of approval for Pfizer’s medicine to treat sickle cell disease, saying doctors should stop using the drug.

The European Medicines Agency’s call came a day after the U.S. pharmaceutical giant said it was “voluntarily withdrawing” Oxbryta from global markets.

Oxbryta is used to treat sickle cell disease (SCD), the potentially fatal blood disorder that primarily affects millions of people of African, Middle Eastern or South Asian descent.

“The EMA’s human medicines committee (CHMP) has recommended suspending marketing authorisation for … Oxbryta,” the Amsterdam-based agency said. “This measure is taken as a precaution while a review of emerging data is ongoing,” it added in a statement.

Two studies said patients who used Oxbryta showed a higher occurrence of so-called “vaso-occlusive crises” — acute pain and potential complications such as arthritis, kidney failure and stroke.

The EMA was already reviewing the risks of Oxbryta in a probe that started in July.

“This was triggered as data from a clinical trial showed that a higher number of deaths occurred with Oxbryta than with placebo treatment,” the EMA said. “Another trial showed the total number of deaths was higher than anticipated,” it added.

The EMA recommended no new treatment with Oxbryta should be started.

Doctors should also tell patients to stop treatment with Oxbryta “and monitor patients for adverse events after treatment is stopped,” the EMA said.

Sickle cell disease is a group of inherited blood disorders that produce abnormal haemoglobin, a protein that carries oxygen. Healthy blood cells move through small blood vessels to carry oxygen to all parts of the body, the US-based Centres for Disease Control said.

In someone who has SCD, the haemoglobin is abnormal, which causes the red blood cells to become hard and sticky and look like a C-shaped farm tool called a sickle, clogging blood flow. “This can cause pain and other serious complications such as infection, acute chest syndrome and stroke,” the CDC said.

Pfizer said Wednesday it was “voluntarily withdrawing Oxbryta in all markets where it has been approved.”

“Pfizer’s decision is based on the totality of clinical data that now indicates the overall benefit of Oxbryta no longer outweighs the risk in the approved sickle cell patient population,” the US-based pharmaceutical said.