Knopp Biosciences Announces FDA Orphan Drug Designation for Dexpramipexole in Hypereosinophilic Syndrome

VCBeat (WeChat Official Account: vcbeat) learned from foreign media that on April 24, U.S. local time, Knopp Biosciences, a biopharmaceutical company based in Pittsburgh, Pennsylvania, announced that its oral candidate drug dexpramipexole had received FDA Orphan Drug Designation for the treatment of hypereosinophilic syndrome (HES). HES is a rare disease with limited treatment options.

Knopp Biosciences is a pharmaceutical research and development company co-founded by Dr. Gregory Hebrank and Dr. Robert Bowser in 2005. The company primarily focuses on diseases within the nervous system, striving to provide breakthrough therapeutic solutions for patients with inflammatory and neurological disorders to address current high unmet medical needs. Currently, Knopp Biosciences has developed a small-molecule mediator discovery platform targeting epilepsy and neuropathic pain, and has also developed an investigational compound for the treatment of immune and hematologic diseases.

In the United States, fewer than 200,000 people suffer from hypereosinophilic syndrome. The FDA’s orphan drug designation for dexpramipexole has established the drug’s unique status in this field. Furthermore, Knopp Biosciences, the developer of the drug, has received incentives such as federal grants, tax credits, and waivers of PDUFA application fees, along with a seven-year period of marketing exclusivity.

Hypereosinophilic Syndrome (HES) primarily refers to a persistent elevation of eosinophil counts in the patient's blood (absolute eosinophil count > 0.5 × 10⁹/L), with clinical manifestations including fever, asthma, abdominal pain, splenomegaly, angioedema, and other symptoms. Complications vary depending on the underlying etiology. Currently, the precise etiology of this disease remains undetermined.

Dexpramipexole, an oral medication for the treatment of hypereosinophilic syndrome (HES), has demonstrated its efficacy in multiple clinical trials. In patients with HES, excessive eosinophils—a type of white blood cell that plays a role in killing bacteria and parasites—also serve as the underlying culprit in conditions such as asthma and eosinophilia. In Phase 2 clinical trials, dexpramipexole has shown the ability to effectively reduce eosinophil levels in both blood and tissues. Knopp Biosciences has submitted these research findings to the American Society of Hematology and published them in the journal Blood.

“We are pleased that dexpramipexole has received orphan drug designation for the treatment of HES,” said Dr. Michael Bozik, Chief Executive Officer of Knopp Biosciences. “Recognizing the urgent need for treatment is essential to helping these patients receive effective care. In particular, this FDA designation of dexpramipexole for HES represents a significant milestone in our company’s development, and we will advance this drug into late-stage clinical development.”

Knopp Biosciences has completed six rounds of financing to date, with the most recent being a $12.5 million debt financing closed on February 16, 2016.

(Compiled by Wang Chan)