GBT publish successful results from sickle cell disease study
pharmafile | April 8, 2021 | News story | |
Global Blood Therapeutics (GBT) have published the successful results from their Phase III study of Oxbryta (voxelotor) tablets in patients with sickle cell disease (SCD), in The Lancet Haematology.
The results showed significant and sustained improvement in haemoglobin levels, reduction in haemolysis and improved overall health status in patients treated with Oxbryta, thereby supporting the long-term use of Oxbryta to mitigate the life-threatening complications of SCD.
Oxbryta is a once-daily oral therapy and directly inhibits haemoglobin polymerization, the root cause of the sickling and destruction of red blood cells in SCD. It has already been approved for use in the US for the treatment of SCD in patients ages 12 years and older.
Lead author Professor Jo Howard, of Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London, said: “Sickle cell disease is a devastating disease that can lead to organ damage and a shortened life expectancy and is complicated by significant disparities in access to quality care.
“Fortunately, we have entered a new era of treatment. The HOPE Study is the longest registrational trial to date among recently approved therapies for sickle cell disease, and these results further demonstrate that by sustainably improving both the haemolysis and anaemia manifestations of the disease, Oxbryta has the potential to be a safe and effective disease modifying treatment in patients with sickle cell disease.”
The Phase III HOPE study, spanned across 72 weeks and looked at 274 patients between the ages of 12 to 65 years with SCD. Approximately 90% of patients treated with Oxbryta achieved a haemoglobin improvement of >1 g/dL from baseline at one or more time points during the study, compared to placebo.
The analysis also showed that study participants treated with Oxbryta had numerically fewer vaso-occlusive crises (VOCs), consistent with the trends at 24 weeks, and were three times less likely to experience an acute anaemic episode.
Additionally, approximately 74% of patients taking Oxbryta had their overall clinical status rated as “moderately improved” or “very much improved” by their clinician compared with approximately 47% of the placebo group, a statistically significant difference.
Treatment with Oxbryta remained generally well tolerated, and rates of adverse events were similar between treatment groups over 72 weeks.
SCD affects around 100,000 people in the US, an estimated 52,000 people in Europe, and millions of people throughout the world, particularly among those whose ancestors are from sub-Saharan Africa.
SCD is a lifelong inherited rare blood disorder that impacts haemoglobin, a protein carried by red blood cells that delivers oxygen to tissues and organs throughout the body. Due to a genetic mutation, individuals with SCD form abnormal haemoglobin known as sickle haemoglobin.
Through a process called haemoglobin polymerization, red blood cells become sickled – deoxygenated, crescent-shaped and rigid. The sickling process causes haemolytic anaemia (low haemoglobin due to red blood cell destruction) and blockages in capillaries and small blood vessels, which impede the flow of blood and oxygen throughout the body. The diminished oxygen delivery to tissues and organs can lead to life-threatening complications, including stroke and irreversible organ damage.
Ted W. Love, MD, president and chief executive officer of GBT, said: “The sickle cell disease community, which for decades has been dramatically underserved, deserves treatments that address the sickling and destruction of red blood cells due to haemoglobin polymerisation – the root cause of this disease.
“The HOPE Study represents a significant milestone in advancing the treatment of SCD, and we are building on this ground-breaking trial with our commitment to increase access to Oxbryta and develop novel therapeutics that can transform SCD into a well-managed disease.”
Kat Jenkins
