Strongbridge Biopharma plc Announces Publication of Long-term Efficacy and Safety Results for KEVEYIS® (dichlorphenamide) for the Treatment of Primary Periodic Paralysis in Muscle & Nerve

DUBLIN, Ireland and TREVOSE, Pa. – Strongbridge Biopharma plc, (Nasdaq: SBBP), a global commercial-stage biopharmaceutical company focused on the development and commercialization of therapies for rare diseases with significant unmet needs, today announced that post hoc analyses from a one year open-label study evaluating daily use of KEVEYIS® (dichlorphenamide) for the treatment of Primary Periodic Paralysis (PPP) following a nine-week randomized, controlled study were published in the peer-reviewed journal, Muscle & Nerve. The results confirmed that long-term treatment with KEVEYIS is safe and effective for chronic use.

“The published results from the post hoc analyses of the HYPHOP study extend the positive findings from the original KEVEYIS® (dichlorphenamide) HYPHOP study by demonstrating that efficacy was maintained over the entire 61-week study with no evidence of waning over time,” said Fredric Cohen, M.D., chief medical officer of Strongbridge Biopharma. “Moreover, there was evidence of further reduction in median weekly attacks among continuous KEVEYIS users to nearly none by the end of the study, and patients who were switched from placebo to open-label KEVEYIS after week nine had reduced attack rates that were similar in frequency at the end of the study to those who had been continuously treated with KEVEYIS over the entire study. Collectively, these results reinforce the utility of KEVEYIS as an effective option in treating PPP, a life-long rare, hereditary skeletal muscle disorder that leads to debilitating attacks of muscle weakness.”

The open label extension results of HYPHOP add to previously reported results from the short-term randomized, double-blind, placebo-controlled phase of the study, with hyperkalemic and hypokalemic PPP sub-studies, which demonstrated the effectiveness of KEVEYIS to prevent attacks of muscle weakness.

Adverse event analyses indicated no new safety signals during the final 52 weeks of the study versus the first nine weeks, with the common adverse events of paresthesia and cognition impairment, reported at lower frequencies during the extension as compared with the first 9 weeks. Clinicians can advise patients starting KEVEYIS that most patients who had one of these events initially reported it within the first month of treatment. Temporary dose reduction appeared to be a reasonable approach to manage bothersome paresthesia or cognition-related AEs, as patients with these AEs who were managed with dosage reduction often had subsequent symptom resolution.

The manuscript, entitled “Long-term efficacy and safety of dichlorphenamide for treatment of primary periodic paralysis,” can be accessed here.


KEVEYIS® (dichlorphenamide) is indicated for the treatment of primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants. In clinical studies, the most common side effects of KEVEYIS were a numbness or tingling, difficulty thinking and paying attention, changes in taste, and confusion. These are not all of the possible side effects that you may experience with KEVEYIS. Talk to your doctor if you have any symptoms that bother you or do not go away. You are encouraged to report side effects to Strongbridge Biopharma at 1-855-324-8912, or to the FDA at 1-800-FDA-1088 or visit For additional KEVEYIS important safety information and the full prescribing information visit

About Strongbridge Biopharma

Strongbridge Biopharma is a global commercial-stage biopharmaceutical company focused on the development and commercialization of therapies for rare diseases with significant unmet needs. Strongbridge’s rare endocrine franchise includes RECORLEV® (levoketoconazole), an adrenal steroidogenesis inhibitor with a New Drug Application that is currently under review by the FDA for the treatment of endogenous Cushing’s syndrome, and veldoreotide extended release, a pre-clinical next-generation somatostatin analog being investigated for the treatment of acromegaly and potential additional applications in other conditions amenable to somatostatin receptor activation. Both RECORLEV and veldoreotide have received orphan drug designation from the FDA and the European Medicines Agency. The company’s rare neuromuscular franchise includes KEVEYIS® (dichlorphenamide), the first and only FDA-approved treatment for hyperkalemic, hypokalemic, and related variants of primary periodic paralysis. KEVEYIS has orphan drug exclusivity in the United States.


Corporate and Media Relations
Elixir Health Public Relations
Lindsay Rocco
+1 862-596-1304
[email protected]

Investor Relations
Solebury Trout
Mike Biega
+1 617-221-9660
[email protected]