Amgen Remains Hush-Hush Over FDA Rejection of Parsabiv

Amgen Remains Hush-Hush Over FDA Rejection of Parsabiv August 25, 2016
By Mark Terry, BioSpace.com Breaking News Staff

Thousand Oaks, Calif.-based Amgen ’s Parsabiv (etelcalcetide) for secondary hyperparathyroidism (sHPT) was rejected by the U.S. Food and Drug Administration (FDA), but the company has held off on why or any other details.

Amgen indicates it is reviewing the FDA’s Complete Response Letter (CRL) and expects to meet with the FDA later this year. It also said that the CRL will not affect its regulatory submissions in other countries or regions.

Parsabiv is a calcimimetic agent for the treatment of sHPT in adult patients with chronic kidney disease (CKD) on hemodialysis. It mimics the action of calcium by activating calcium-sensing receptors on the parathyroid gland. Parsabiv acts by binding to and activating the calcium-sensing receptor, which results in decreased PTH levels. Approximately 88 percent of patients on dialysis and 79 percent of hemodialysis patients develop sHPT.

Adam Feuerstein, writing for TheStreet, says, “Parsabiv is not a make-or-break product for Amgen. If approved eventually, Parsabiv sales would likely come from patients already taking Sensipar, an older hyperparathyroidism drug from Amgen which brings in about $1 billion in annual revenue.”

On the other hand, Feuerstein seems furious over Amgen’s apparent lack of transparency regarding the CRL. “It’s standard and widely accepted practice for drug companies to provide investors with a basic summary of Complete Response Letters. An FDA drug rejection is a material event for any publicly traded company and, as such, investors deserve to know what happened and why when FDA says no.”

Amgen’s New Drug Application (NDA) for Parsabiv was based on three Phase III studies. One of the studies showed that 74 percent of the patients receiving the drug had a more than 30 percent drop in PTH from the baseline compared to an 8.3 percent drop in the placebo group.

Amgen acquired Parasabiv when it bought KAI Pharmaceuticals in July 2012 for $315 million.

It’s not the only recent bad news for Amgen. The company had plans to launch its cholesterol drug Repatha in India, but it was blocked by a panel of CV and renal specialists. Amgen was planning to use a waiver that exempted Repatha from pre-launch testing in patients in India. However, the Central Drugs Standard Control Organization (CDSCO) turned it down, and delayed approval.

The clinical waiver program in India was developed to speed the entry of specific drugs to the India market when they come from “well-regulated” markets like the U.S. and European Union. It allows drugs for rare diseases and specific other conditions to be approved without a Phase III trial in India, as long as the drug company conducts post-marketing studies to monitor the drugs’ safety and efficacy.

The CDSCO committee agreed that Repatha was safe and fit the bill of orphan drug status for high cholesterol, but said that it has “a very high potential for misuses in conditions other than the orphan condition.”

Amgen is currently trading at $171.12. This is dramatically up from its June 27, 2016 price of $144.58, but slightly down from its Aug. 23 high of $175.46.

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