Amgen has been dealt a blow to its late-stage pipeline by the FDA, which has declined to approve a follow-up to blockbuster Sensipar/Mimpara.
Like its predecessor, the new calcimimetic drug – called Parsabiv (etelcalcetide) – has been developed for the treatment of secondary hyperparathyroidism (sHPT) in patients with chronic kidney disease (CKD) who are on dialysis.
In a short statement, Amgen confirmed that it had received a complete response letter from the FDA and that the agency had not approved Parsabiv, without going into any further detail. It said it would seek a meeting with agency later in the year to discuss the next steps with the drug.
The rejection is a big disappointment for Amgen, which had suggested that Parsabiv (also known as velcalcetide and AMG 416) could equal and potentially exceed Sensipar (cinacalcet) as a revenue driver. Sensipar has been a solid earner for Amgen for years, with sales of more than $1.4bn last year, although it is starting to face generic competition in some markets.
Amgen says Sensipar only has around 25% market penetration, mainly because of compliance issues associated with the need to dose the tablets orally every day. In contrast, Parsabiv is administered as an infusion during dialysis, side-stepping the compliance issue.
Clinical trials also suggest it is as good as Sensipar in reducing parathyroid hormone levels in sHPT, and more effective than the oral drug in terms of the number of patients experiencing high-level responses. Sadly, Amgen failed to show that Sensipar could reduce the risk of death and cardiovascular events in patients in CKD patients on dialysis.
There are around 2 million people worldwide who are on dialysis as a result of kidney failure and, as sHPT is a frequent complication, analysts have backed significant sales for Parsabiv if approved.
A recent EP Vantage report listed the drug among the most valuable filed assets in the pharma industry for 2017, assuming Amgen can persuade Medicare in the critical US market that the drug can slot into the bundled payment system set aside for dialysis care.
Amgen picked up rights to the drug when it acquired Kai Pharmaceuticals for $315m in 2012.