Zebra Therapeutics’ CEO believes the launch could change the treatment landscape for Niemann-Pick disease type C (NPC) in the United States to resemble that in Europe, as the ultra-rare disease drug Miprifa strengthens its foothold in the United States. Most cases are diagnosed in Europe, where Johnson & Johnson’s enzyme inhibitor Zabesca (miglustat) has been a treatment option since 2009.
Last month, Zebra reported quarterly net revenue of $24.6 million for Miprifa, which was given the green light by the FDA to treat NPC alongside Zabesca in fall 2024. Over the past year, Miplyffa earned $87.4 million in Lasso, contributing to companywide sales of $106.5 million in 2025.
In the first three months of 2026, Zevra received nine new Miplyffa prescription registration forms for NPCs, bringing the total number since launch to 170.
In a recent interview with Fierce Pharma, company CEO Neil MacFarlane said Zebra is well-positioned for long-term growth in the rare disease ecosystem, with multiple commercial products currently in the pipeline and another late-stage program in the hopper.
Much of the company’s current focus naturally revolves around Miprifa, and MacFarlane emphasized that Zebra relies heavily on its approximately 40 centers of excellence, including academic institutions and children’s hospitals, to help NPC patients access diagnosis and treatment.
The CEO said that working closely with the multidisciplinary experts at these centers is paramount to successful product deployment in the rare disease space.
“Nine times out of 10 with ultra-rare diseases, patients go through a very difficult diagnostic journey, but they end up in one of these centers of excellence,” MacFarlane explained.
He continued, “It’s important that all of these pieces work together, and that’s what we’ve brought together here, and each touchpoint provides us with an opportunity to become the partner of choice in the rare disease community.”
With the FDA’s nod to Miprifa in late 2024, U.S. patients will receive the first treatment approved to treat the neurological symptoms of NPC, which interfere with the body’s movement and use of cholesterol and other fat cells.
The condition causes a buildup of cholesterol and other lipids in the liver, spleen, and lungs, causing problems with speech, cognition, swallowing, movement, and fine motor skills.
Delving into the product launch, MacFarlane reiterated Zebra’s estimate that there are approximately 900 addressable NPC patients in the United States, of which approximately 300 to 350 have been identified and diagnosed.
McFarlane said that during the early stages of Miprifa’s rollout, Zebra focused on rapidly securing supplies, including for patients in the Expanded Access Program and those participating in clinical trials. Currently, the company is focused on reaching patients with other diagnoses by broadening Miprifa’s profile as a novel disease-modifying agent, and in parallel attempts to increase the number of diagnoses for remaining patients.
McFarlane said Zebra’s efforts to improve diagnostic rates are starting to bear fruit, adding that trends in recent quarters “give us further confidence” in the company’s ability to build the U.S. NPC market.
“During the second quarter, our efforts also resulted in several newly diagnosed patients,” he said. “We saw a few more things in Q3, we saw a lot more in Q4, and the same thing happened in Q1.
“In doing so, we believe we can build a market of 300 to 350 to 900 patients,” he said, adding that Zebra hopes to create a U.S. NPC market more similar to Europe, where there are about 1,100 patients, most of whom have been diagnosed.
Regarding Johnson & Johnson’s oral drug Zabesca, MacFarlane said patients in Europe are “not in the diagnostic adventure. They’re visiting a reference center, but that’s also because of miglustat, which has been approved there for over 10 years.”
Zebra is now aiming to sell Miprifa online in Europe, where the drug is under review by the European Medicines Agency, but McFarlane acknowledged that the company’s “go-to-market strategy is still open.”
Zevra will have to wait for regulatory announcements to know where it stands price-wise, which will determine whether it pursues its own launch through some kind of “hybrid” model or “outsources it to a multinational,” the CEO explained.
Still, the company’s global expanded access program for Miprifa has already attracted about 122 patients, and McFarlane estimates there is demand outside the U.S. as well.
Reflecting on the broader rare disease landscape, MacFarlane said connectivity and patient empowerment remain essential to Zebra’s work.
“Rare diseases often start with a patient advocacy group that includes patients with previously uncharacterized diseases, including the ones we work on, and then the product or drug is developed, and then it goes through development and regulatory approval, to launch and commercialization, to payers, to physician education, and everything else, and it comes full circle,” MacFarlane said, emphasizing that “we have to start with disease advocacy.” This space. ”
