A new study published in the Journal of Blood Medicine presents practical guidance on using voxelotor, an effective and well-tolerated component of multimodal treatment for sickle cell disease (SCD).
The disease-modifying medication is indicated in individuals with SCD with a hemoglobin of 10.5 g/dL or less, persistent anemia despite a maximum tolerated dose of hydroxyurea, adverse side effects to hydroxyurea or other disease-modifying sickle cell therapy agents, as well as those with hemoglobin and red blood cell alloimmunization. Voxelotor should not be considered in patients with short gut syndrome, complex gastrointestinal history, and liver or kidney impairment.
Voxelotor is an oral medication available in the form of as a regular tablet and as a tablet for oral suspension. A starting daily dose of 1500 mg is recommended for patients aged 12 years and older, while children aged 4 to 12 years should resort to weight-based dosing following the pattern of 600 mg for a weight of 10 to less than 20 kg, 900 mg for a weight of 20 to less than 40 kg, and 1500 mg for a weight of 40 kg or more. Physicians should carefully adjust the dosing for patients with diarrhea or loose stools, severe hepatic impairment, or those on concomitant CYP3A4 inducers.
Treatment with voxelotor is associated with minor side effects such as headache, diarrhea, nausea, abdominal pain, and rash. However, a case of rebound hemolysis and multiple organ dysfunction was reported after the abrupt discontinuation of voxelotor in a HbSS patient with pulmonary hypertension and renal disease.
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Of important note is the cost-effective analysis conducted by the Institute for Economic and Clinical Review, which found that voxelotor was not cost-effective at the current price of $138.89 USD per 500 mg tablet and $208.34 USD per 300 mg soluble tablet as of November 2022.
“Voxelotor received initial FDA approval in November 2019 for individuals with SCD age 12 years and older, and recently received FDA approval for children with SCD age 4 years and older,“ Barriteau and Badawy wrote. “With the recent expansion of FDA approval, practical guidance for use of voxelotor in SCD is essential to aid SCD providers considering this disease-modifying therapy for their patients.“
Curative approaches such as hematopoietic stem cell transplant and gene therapy are still not widely available, hence disease-modifying therapies including hydroxyurea, L-glutamine, crizanlizumab, and voxelotor will likely remain the most crucial agents in SCD management.
Barriteau CM, Badawy SM. Practical guidance for the use of voxelotor in the management of sickle cell disease. J Blood Med. Published online November 29, 2022. doi:10.2147/JBM.S362222