FDA Approves Voxelotor for Pediatric Sickle Cell Patients

The US Food and Drug Administration (FDA) has approved voxelotor (Oxbryta) for patients with sickle cell disease (SCD) in pediatric patients aged 4-12 years.

The supplemental New Drug Application (sNDA) was awarded to Global Blood Therapeutics, expanding on a previous approval for patients with sickle cell aged 12 years and older.

The treatment represents the first approved treatment that directly targets sickle hemoglobin polymerization, the root cause of the sickling and destruction of red blood cells in SCD.

“For decades, the sickle cell disease community has been profoundly underserved, and there have been limited treatment options for younger patients with their whole lives ahead of them. Complications of SCD that can cause irreversible organ damage are known to begin in the first few years of life, which is why earlier intervention is critical,” said Ted W. Love, MD, president and chief executive officer of GBT, in a statement.

“Today’s FDA approval of Oxbryta for children as young as 4 years old – and with a pediatric-friendly dosage form – is an important advance in the treatment of this devastating, lifelong condition. GBT is proud to lead the development of new medicines to address the inadequacies of care for SCD patients.”

The FDA also approved a separate New Drug Application (NDA) for voxelotor tablets for oral suspension, a dispersible, once-daily tablet dosage form suitable for patients aged 4-12 years as well as for older patients who have difficulty swallowing entire tablets.

Recently, investigators observed voxelotor increased hemoglobin (Hb) by ≥1 g/dL, with study data suggesting statistically significant reductions in transfusions, vaso-occlusive crises (VOCs), and all-cause VOC-related hospitalizations after voxelotor use.

The study was presented at the 2021 American Society of Hematology (ASH) Annual Meeting & Exposition.

Of the subset of patients with pre- and post-voxelotor Hb measurements (n = 63), the mean Hb (95% confidence interval) was 7.9 (7.5 - 8.2) g/dL at baseline and the final Hb 8.9 (8.4 - 9.4) g/dL after voxelotor initiation.

Data show most patients (38 of 63, 60.3%) achieved Hb increase of >1 g/dL at any point during the follow-up period.

In patients who received ≥1 transfusion (n = 357) in the year before voxelotor initiation, the mean transfusion rate decreased by 43% from 3.2 (2.8 - 3.7) to 1.8 (1.4 - 2.3) PPY (P <.001).

Further, in 40 patients receiving chronic transfusions (≥8), the mean transfusion rate decreased by 34%, from 9.8 (8.3 - 11.4) to 6.5 (4.4 - 8.5) PPY (P = .007).

Among those who had ≥1 VOC in the 3 months prior to voxelator initiation, the mean annualized VOC rate decreased by 22%, from 10.9 (10.4 - 11.5) to 8.5 (7.8 - 9.3), (P <.001). In addition, the mean rate of VOC-related hospitalizations decreased by 32%, from 7.3 (6.9 - 7.7) to 5.0 (4.4 - 5.6) (P <.001).

Then, in 636 patients previously hospitalized in 3 months prior to voxelotor initiation, the mean all-cause hospitalization rate was reduced by 36%, from 7.5 (7.1 - 7.9) to 4.8 (4.3 - 5.3) after treatment (P <.001).