The withdrawal of Oxbryta (voxelotor) from global markets, announced by Pfizer after a recent data review revealed a rise in deaths and complications, has left sickle cell disease (SCD) patients in a precarious situation. The sudden nature of the announcement caught the patient and physician community off guard, as there was no prewarning. For an already narrow world of options available to people with sickle cell disease, this came as a devastating blow.
Oxbryta, a hemoglobin oxygen affinity modifier, was purported to reduce the sickling of red blood cells and had been in use since FDA approval in 2019. Health care providers now face the challenge of transitioning patients to other therapies—such as hydroxyurea, blood transfusions, or emerging treatments—many of which may not offer the same level of efficacy or convenience. Unique therapeutic challenges include concerns over a sudden rebound in vaso-occlusive crises if patients, concerned by the announcement, abruptly stop taking the drug. Additionally, maintaining patient trust as they transition to alternative treatments has been and will continue to be key through this difficult transition. Furthermore, identifying candidates for clinical trials of new therapies could be one avenue to explore for those patients who were benefiting from Oxbryta.
Rebuilding trust in biologics: a strained relationship
The decision to pull Oxbryta from the market has shaken the confidence of many patients and caregivers, not just in the drug itself but in the broader medical establishment, including the approval process of biologics. Oxbryta, approved by the FDA in 2019, represented hope for a disease that disproportionately affects marginalized populations. Now, with the revelation that the drug may be linked to higher incidences of death and complications, many patients are left wondering: can they trust new biologic therapies currently in development?
This event further strains an already tenuous relationship between patients with sickle cell disease and the health care system. These patients have long faced health care inequities and systemic gaps in the availability of comprehensive care. The Oxbryta withdrawal risks reinforcing a narrative of distrust—where drugs seen as “breakthroughs” ultimately fail them. For future biologics and gene therapies in the pipeline, restoring this trust will require a commitment to transparency and patient engagement at every level of the drug development and regulatory process.
Awaiting data: Avoiding speculation until full findings are shared
While Pfizer has cited increased risks of death and complications as the basis for withdrawing Oxbryta, the full data that led to this decision has not yet been shared with the scientific community. Without these details, it is crucial to avoid speculation or misinterpretation of the situation. What we do know is that an “imbalance” in deaths and severe complications—conditions already prevalent in sickle cell disease—prompted this urgent decision. However, until the comprehensive analysis is made public, assumptions about the exact nature and extent of these risks should be withheld.
It is vital for Pfizer and regulatory bodies to release the data behind their decision as soon as possible, enabling independent experts to scrutinize the findings and provide more informed guidance. The scientific community must prioritize transparency, especially when the stakes are so high for vulnerable patient populations.
In the meantime, patients and providers must collaborate to devise evidence-based practices for this significant transition of care. The withdrawal of Oxbryta is a significant setback, but it should not deter the ongoing pursuit of safer and more effective therapies for sickle cell disease.
Akshat Jain is a pediatric hematology-oncology physician.
