Bellus Health




BLU-5937 is a highly selective P2X3 antagonist being developed for the treatment of chronic cough and chronic pruritus. P2X3 is a key sensory receptor, responsible for irritation and pain, and a highly selective P2X3 antagonist may be beneficial for treating the symptoms of either condition. The P2X3 receptor in the cough reflex pathway is a rational target for treating chronic cough, and it has been validated in multiple clinical trials.

BELLUS Health has completed its Phase 2 RELIEF clinical trial in refractory chronic cough and plans to initiate an adaptive Phase 2b trial enriched for higher cough count patients in the fourth quarter of 2020. The Company also expects to initiate a Phase 2 trial in chronic pruritus associated with atopic dermatitis (eczema) in the second half of 2020.

Developing BLU-5937 for Chronic Cough

Lasting more than eight weeks, chronic cough can cause adverse physical, social, and psychosocial effects on health and quality of life. It is estimated that approximately 26 million adults in the United States suffer from chronic cough, with more than 2.6 million having refractory chronic cough lasting for more than a year. There is no specific therapy approved for refractory chronic cough and treatment options are limited. Currently, the most advanced therapy in development has substantial tolerability issues, including significant taste alteration or loss. BLU-5937 has the potential to be a differentiated treatment option for chronic cough, with little to no effect on taste.

Ongoing Phase 2 RELIEF Trial in Refractory Chronic Cough

The Phase 2 RELIEF (A Randomized, Double-Blind, Placebo-Controlled, Crossover, Dose Escalation Study of BLU-5937 in Subjects with Unexplained or Refractory Chronic Cough) trial assessed the efficacy, safety, and tolerability of BLU-5937 in patients with refractory chronic cough, and was completed in July of 2020. BLU-5937 did not achieve statistical significance for the primary endpoint of reduction in placebo adjusted cough frequency at any dose tested. However, the trial did show a clinically meaningful and statistically significant placebo-adjusted reduction in cough in patients with a higher baseline cough count, a pre-specified sub-group in the study (all patients at or above the baseline median average of 32.4 coughs per hour). BLU-5937 was safe and well tolerated, and taste effects were uncommon at all dose levels.

Phase 1
Trial Results

Positive results from the placebo-controlled Phase 1 trial of orally administered BLU-5937 demonstrated it had a favorable tolerability and safety profile at all doses tested, with a pharmacokinetic profile supporting twice-daily dosing. There was no loss of taste perception at the anticipated therapeutic doses and no subject reported total loss of taste at any dose.

Developing BLU-5937 for Chronic Pruritus

Chronic pruritus – commonly known as chronic itch – is a persistent condition that lasts longer than six weeks which can be debilitating and significantly impacts quality of life. It is a hallmark of many conditions, including atopic dermatitis (eczema). It is estimated that atopic dermatitis affects more than 16.9 million adults in the United States. Despite currently available treatments, an estimated 40-50% of atopic dermatitis patients have inadequate relief of their pruritus and are in need of new, efficacious pruritus therapies.

BELLUS Health believes BLU-5937 may be a viable treatment option for patients with chronic pruritus associated with atopic dermatitis. The Company has conducted preclinical studies of BLU-5937 in pruritus, and expects to initiate a Phase 2 trial to assess the efficacy, safety, and tolerability of BLU-5937 versus placebo in approximately 100 patients suffering from chronic pruritus associated with mild to moderate atopic dermatitis in the second half of 2020.

Chronic Itch Diagram 1

Developing BLU-5937 for Chronic Itch

Chronic Itch Diagram 2

Developing BLU-5937 for Chronic Itch