Developing novel therapeutics for rare diseases is increasingly important. Understanding the unmet needs of rare disease communities and providing effective, accessible therapies can significantly improve the lives of those affected. One way to enhance drug development in rare disease is through the Orphan Drug program. Granted to therapies for rare conditions affecting fewer than 200,000 people nationwide, Orphan Drug designation facilitates drug development in this sphere. Drug developers receive benefits like fee waivers, tax credits, and seven years of market exclusivity if/when the drug is approved; these benefits may incentivize development in this space. According to Yahoo! Finance, the FDA recently granted Orphan Drug designation to ruxoprubart (NM8074) for paroxysmal nocturnal hemoglobinuria (PNH).
What is Ruxoprubart?
Developed by privately held biotechnology company NovelMed Therapeutics, ruxoprubart is an alternative pathway blocker anti-Bb antibody. While it blocks the alternative pathway, ruxoprubart allows the classical pathway to maintain its function and clear infection. Researchers believe that ruxoprubart could have benefits over the existing standards-of-care by reducing side effects and improving accessibility.
The Orphan Drug designation comes following a completed Phase 1 study which evaluated ruxoprubart in healthy volunteers. The study found ruxoprubart to be both safe and well-tolerated. Now, researchers are exploring the therapy in a Phase 2 study. Participants have PNH that is previously untreated.
Outside of PNH, ruxoprubart is being explored as a potential therapy for atypical hemolytic uremic syndrome, ANCA vasculitis, and C3 glomerulopathy.
The Basics of Paroxysmal Nocturnal Hemoglobinuria (PNH)
Paroxysmal nocturnal hemoglobinuria is a rare acquired hematologic disorder. Caused by PIGA mutations, PNH causes the rapid proliferation of abnormal cells. The immune system attacks stem cells, killing healthy cells while allowing abnormal cell survival. PNH causes red blood cell destruction (hemolysis), impaired bone marrow function, and blood clots.
The hallmark symptom of PNH is hemoglobinuria, which means excess hemoglobin is found in the urine. This may lead to red, dark, bloody, or rust-colored urine that is particularly prominent in the mornings. Additional characteristics of PNH include difficulty breathing and swallowing, low red blood cell count (anemia), abdominal discomfort, fatigue, high heart rate, male sexual dysfunction, chest pain, headaches, kidney disease, and potentially life-threatening blood clots.
Paroxysmal nocturnal hemoglobinuria is often diagnosed between ages 35-40 with an average survival rate of 10 years after diagnosis. Treatment involves medications to reduce blood clots and hemolysis; certain medications and bone marrow transplants may be leveraged for treatment. Identifying novel treatments could advance survival rates.
