Physician Knowledge Regarding Voxelotor for the Treatment of Sickle Cell Disease in England and Wales - a National Survey

Voxelotor is a novel treatment for sickle cell disease (SCD) which acts to reduce haemoglobin polymerisation by improving the oxygen affinity of sickle haemoglobin. The phase 3 HOPE randomised controlled trial demonstrated a statistically significant increase in haemoglobin concentration without a statistically significant reduction in vaso-oclusive pain events compared to placebo (excluding subgroup analysis) in individuals with SCD treated with voxelotor.

In May 2024, the National Health Service (NHS) in England and Wales announced that voxelotor will be reimbursed for the treatment of haemolytic anaemia caused by SCD in people 12 years and over, in those who are ineligible for, or intolerant of hydroxycarbamide, or for whom hydroxycarbamide alone is insufficiently effective. A national survey of specialist and non-specialist haematologists involved in the treatment of patients with SCD in England and Wales was conducted to understand their awareness and knowledge of this novel disease modifying agent.

There were 67 respondents, the majority of which were resident haematology doctors (35, 52%) and attending haematology doctors (29, 43%), of which 22 (33%) were specialists in sickle cell disease. Forty-four (66%) respondents practice at a specialist haemoglobinopathy treatment centre - in the UK these are classified as haemoglobinopathy coordinating centres (HCC; 27, 40%) and specialist haemoglobinopathy teams (SHT; 17, 26%); the remainder cared for SCD patients at non-specialist centres. Nineteen (28%) reported being directly involved in the care of >100 SCD per year, 12 (18%) 50-100, 17 (26%) 10-50, 19 (28%) <10.

The majority (58, 87%) of respondents were aware of the existence of voxelotor as a treatment for SCD; 44 (66%) were aware of the recent decision by the NHS to reimburse this medication. Twenty-nine (43%) correctly identified the mechanism of action of voxelotor; 19 (28%) did not correctly identify the mechanism of action; 19 (28%) were not sure.

Thirty-eight (57%) of respondents correctly identified the efficacy results of the HOPE 3 study; 11 (16%) did not identify the correct result; 18 (27%) stated they were not sure. Seventeen (25%) correctly identified the safety (adverse events) results of the HOPE 3 study; the majority (33; 50%) were not sure; the remainder (17, 25%) did not identify the correct result.

Twenty-six (39%) of respondents correctly stated that voxelotor is reimbursed for the treatment of adults and children >12 years with SCD in the UK; 26 (39%) reported being unsure regarding the age of patients for which voxelotor is reimbursed; 14 (22%) selected an incorrect response. Forty-seven (70%) of respondents correctly understood that voxelotor can be administered alongside hydroxycarbamide; 19 (28%) were not sure, 1 (2%) incorrectly stated that the medications could not be given concurrently.

Thirty-one (46%) of respondents stated they have previously cared for SCD patients who take voxelotor. It should be noted that this medication was previously available via an Early Access to Medicines Scheme in England on an individual patient basis.

Thirty-two (48%) clinicians stated that the recent NICE decision to reimburse voxelotor will influence their decision to prescribe the medication for their patients. If they wanted to prescribe voxelotor for a patient with SCD, most (41; 61%) said they would obtain this medication from their patient's HCC or SHT.

This data provides valuable insights regarding the knowledge gaps around voxelotor among physicians treating patients with SCD. There is a high degree of unmet need in this patient group, with limited treatment options available. Our data suggests inadequate physician knowledge pertaining to the potential benefits and side effects of voxelotor, which may adversely affect appropriate patient selection and communication to patients considering treatment. In addition, physician attitudes towards access to this medication suggests a centralised model of access to this medication will predominate, which may affect timely access to treatment for those patients living in areas with low rates of SCD. This data will be used to develop efforts at a national level to improve physician knowledge regarding voxelotor and help achieve equitable access to treatment for all SCD patients regardless of geographical location.

Troy-Barnes:Roche Products Ltd: Ended employment in the past 24 months; Sermo Ltd: Honoraria; Iqvia Inc: Honoraria. Merrion:Iqvia: Honoraria. Buka:Sanofi: Consultancy; Sobi: Honoraria; AstraZeneca: Research Funding; Viatris: Honoraria; Bayer: Honoraria. Mullally:Pfizer/Global Blood Therapeutics: Other: conference attendance expenses - ASH 2022. Drasar:Pfizer: Consultancy; VERTEX therapeutics: Consultancy, Speakers Bureau.