According to a new study reported in The Lancet Haematology, the USFDA approved the use of L-glutamine for the treatment of patients aged 5 years and older with sickle cell disease, on the basis of the results of a randomised phase 3 clinical trial. The trial demonstrated that patients treated with L-glutamine for 48 weeks had reduced frequency and length of hospital visits for sickle cell pain crisis compared with patients treated with placebo.

As increased oxidant stress is a major contributor to the pathophysiology of sickle cell disease, increasing the amount of circulating glutamine helps red blood cells produce more of the antioxidant nicotinamide adenine dinucleotide, allowing sickle-shaped red blood cells to regain flexibility. L-glutamine is the first new treatment for sickle cell disease to secure FDA approval in almost 20 years. A company produces the licensed version of L-glutamine. Ultimately, it will be interesting to see whether generic L-glutamine can be as efficacious as the drug that has already been tested.

Although it is heartening that there is now another treatment for patients with sickle cell disease beyond hydroxyurea and blood transfusions, social challenges persist. Blood transfusions remain a common method of treatment for patients with sickle cell disease, but the majority of blood donors in countries like the USA and the UK are white, whereas the majority of those with the sickle cell disease are black. Racism has been highlighted as a barrier to the provision of care in the USA, and there are issues with inadequate training for those in emergency departments who are generalists who know little about sickle cell disease and their patients' need for pain relief.

These issues are compounded by the opioid addiction crisis sweeping the USA, which has made doctors wary of prescribing pain relief medication. Although there are obviously many challenges for patients with sickle cell disease, there are several promising therapies in development. Several early-phase clinical studies showed encouraging activity, from gene therapy to immunotherapy. The phase 1/2 HGB-206 study used the LentiGlobin BB305 lentiviral vector for the production of β-A-Thr87Gln globin protein, which allows cells to overcome the shortage in globin synthesis and prevent cells from sickling.

The phase 2 SUSTAIN study tested the anti-P-selectin antibody crizanlizumab to block the vaso-occlusive process with the aim of delaying the time to first sickle cell pain crisis in adults. Voxelotor, a haemoglobin S allosteric modulator, has just been granted breakthrough therapy designation by the FDA. Voxelotor works by increasing haemoglobin's affinity for oxygen, preventing the polymerisation of haemoglobin that results in the sickling of red blood cells.

In conclusion, sickle cell disease remains a challenging disease to manage and to treat. It is imperative that resources are allocated to allow further research and supportive care for patients with the disease. While steps are being taken in the right direction, now is the time to turn around the rising mortality and provide adequate care for all individuals with sickle cell disease.