Cara, Vifor get EU okay for drug to treat itching in dialysis patients

Vifor Pharma and Cara Therapeutics' Kapruvia has become the first drug to be approved in the EU to treat one of the most common and challenging side effects for people undergoing dialysis for chronic kidney disease (CKD) – chronic itching.

The European Commission has cleared Kapruvia (difelikefalin) as an injectable treatment for chronic itching, also known as pruritus, in adult CKD patients on dialysis. First launches are due in the latter half of the year after price and reimbursement negotiations, said the two partners.

The drug – which is injected three times weekly – was approved in the US last year as Korsuva, and is due to be launched there this month.

It acts as an opioid agonist, targeting the kappa opioid receptor in the peripheral nervous system, dampening down itching whilst avoiding the side effects of typical opioid agonists, which act mainly via the mu receptor.

Around 40% of patients on dialysis for CKD gave moderate to severe pruritus, making the new drug an option for an estimated 250,000-plus patients in Europe. Jefferies analyst Christopher Howerton has estimated that Korsuva could see peak sales of around $900 million in 2030.

The approval in Europe is based on data from two phase 3 trials, KALM-1 and KALM-2, which showed that treatment with Kapruvia resulted in clinically meaningful improvements in pruritus severity and in pruritus-related quality of life.

It puts Cara in line for up to $440 million in tiered commercial milestones from a joint venture between Vifor and Fresenius Medical Care, which will commercialise Kapruvia in the EU.

Cara and Vifor are meanwhile planning a new phase 3 trial of oral difelikefalin in pre-dialysis CKD patients, which could expand the market for the drug significantly.

An oral formulation of difelikefalin, meanwhile, is also in development for pruritus associated with atopic dermatitis. It generated mixed results in the phase 2 KARE study last year, but an updated subgroup analysis reported last month found that it improved itch and inflammatory biomarkers.