FDA Nod for Keveyis in Primary Periodic Paralysis

Susan Jeffrey


August 25, 2015

The US Food and Drug Administration (FDA) has approved dichlorphenamide (Keveyis, Taro Pharmaceutical Industries Ltd) 50-mg tablets, the first treatment for primary hyperkalemic and primary hypokalemic periodic paralysis, and related variants, the company has announced.

Primary paralyses are a group of rare hereditary disorders that cause episodes of muscle weakness or paralysis, the company release, dated August 10, notes. Types of periodic paralyses are differentiated by criteria that include underlying genetic mutations and changes in blood potassium during attack, the statement notes; hyperkalemic and hypokalemic are two common types of periodic paralyses, it adds. Primary periodic paralysis is estimated to affect approximately 5000 people in the United States.

"Because of the very-rare nature of periodic paralysis, it is not unusual for patients to go years before receiving an accurate diagnosis," said Robert Griggs, MD, principal investigator and professor, Department of Neurology, University of Rochester Medical Center, said in the company release. "For those living with often debilitating symptoms, the approval of Keveyis is both an important and much needed treatment advance and an opportunity for greater disease awareness and understanding, something that has long been a challenge for these people."

In clinical studies, the most common adverse events were paresthesias, cognitive disorder, changes in taste (dysgeusia), and confusional state, the statement notes. Patients are encouraged to report these or any other side effects to their treating physician.

Treatment is contraindicated for patients who are receiving a high-dose aspirin regimen; are allergic to sulfa-based drugs; have liver, kidney, or certain lung conditions; are pregnant or planning to become pregnant or are nursing; or are younger than 18 years of age.

Warnings include the risk for hypersensitivity, anaphylaxis, or idiosyncratic reactions; patients should discontinue use at the first appearance of a skin rash or any sign of immune-mediated or idiosyncratic adverse reactions, prescribing information notes.

Patients taking dichlorphenamide may have a drop in potassium (hypokalemia), which can lead to cardiac problems; baseline and periodic measurements of serum potassium are recommended. If hypokalemia develops or persists, the recommendation is to consider reducing the dose or discontinuing treatment.

Because of the risk for metabolic acidosis, baseline and periodic measurements of serum bicarbonate are recommended; again, if metabolic acidosis develops or persists, it is recommended to reduce the dose or discontinue treatment. Finally, prescribing information notes that the dose may need to be reduced or treatment discontinued in patients who experience falls.

"The approval of Keveyis demonstrates the importance of industry, scientific researchers, patient advocates and the FDA working together to identify and bring to market a treatment for primary periodic paralysis," said Kal Sundaram, chief executive officer of Taro. "Taro is proud of its commitment to this community, which has been waiting for a new, effective treatment option for many years. We thank the FDA for their continued partnership in making this important day a reality."

"Taro expects Keveyis will be available for patients during the third quarter of 2015," the company said. A program called Keys2Care will provide a suite of patient support services to ensure people diagnosed with periodic paralysis can receive treatment with the drug as soon as possible. As part of the program, the company is working with Diplomat Pharmacy Inc, a specialty pharmacy, to offer access and support to patients who are prescribed this product and to their caregivers, the company statement notes.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.