FSCDR’s Experience with Voxelotor (GBT440) Treatment in Patients with Severe Sickle Cell Disease

ATLANTA — Lanetta Bronté, M.D., M.P.H., M.S.P.H., founder and chief health officer of the Foundation for Sickle Cell Disease Research (FSCDR) in Hollywood, Fla., presented results from seven adult sickle cell disease patients with severe anemia and multiple co-morbidities who were not eligible to participate in Global Blood Therapeutics’s (GBT) Phase 3 HOPE (Hemoglobin Oxygen Affinity Modulation to Inhibit HbS PolymErization) Study (abstract #3545), at the 59th American Society of Hematology Meeting & Exposition on Monday evening.

“Patients with severe SCD, who often suffer life-threatening complications, are refractory to conventional therapy and, thus, are very difficult to manage because treatment options are very limited,” said Dr. Bronté. The patients, four women and three men, age 22 to 67, received voxelotor for six to 17 months through single-patient compassionate access and monitored over 24 weeks at Dr. Bronté’s outpatient center. Results showed:

  • Improvements in multiple clinically important endpoints, including hemoglobin levels, daily pain, hospitalization for vaso-occlusive crisis (VOC), transfusions, depression and overall well-being.
  • Hemoglobin values rose in all patients, with an increase exceeding 1 g/dL in 5 of 7 patients.
  • Hospitalizations for VOC, the conventional measure of SCD pain, fell by 67 percent during 24 weeks of voxelotor treatment, compared with the 24-week period immediately before treatment was initiated (9 vs 28, respectfully), corroborating patient reports of improved well-being and quality of life.
  • The number of transfusions decreased by 60 percent during 24 weeks of voxelotor treatment compared with the 24-week period immediately before treatment initiation (13 vs 33, respectively). Of the six patients who received transfusions prior to voxelotor, two received no transfusions after treatment.
  • Improvements in blood oxygenation were observed in all four patients that had low room air oxygen saturations at baseline, and the two patients who were oxygen-dependent prior to treatment initiation no longer required continuous supplemental oxygen during 24 weeks of voxelotor treatment.
  • Two patients died while receiving voxelotor under compassionate access. Both had multiple co-morbidities and advanced organ injury prior to initiation of treatment (e.g., chronic kidney disease, hepatic dysfunction, iron overload), and the treating physicians concluded that voxelotor did not contribute to either death.
  • Voxelotor was well tolerated for up to 17 months at a dose of 9— mg with no discontinuations, and no voxelotor-related serious adverse events occured.

“We are grateful that these seven patients at our center were able to receive voxelotor through compassionate access and are so pleased with the clinical improvements we saw on meaningful endpoints,” said Dr. Bronté.

FSCDR is a leading innovator in sickle cell disease. Dr. Bronté opened the center in Nov. 2014 to address the growing trend of fragmented care and an increase in emergency room visits and inpatient utilization in adolescents and adults with SCD. FSCDR runs the U.S.’s only outpatient center solely devoted to sickle cell care and services and is independent from any hospital system or academic institution.

Compassionate access is an option facilitated by the U.S. Food and Drug Administration (FDA) to make available, prior to regulatory approval, investigational medicines for the treatment of serious or life-threatening disease or conditions for which there are no ongoing clinical trials and there is a lack of satisfactory therapeutic alternatives. Voxelotor is an investigational treatment and controlled clinical trials are needed to confirm the clinical benefits and safety seen in the case study of seven patients.

You can read the full poster, here.