Two months ago, the narcolepsy therapy Wakix propelled Harmony Biosciences to a $128 million debut on Nasdaq. Now, the same drug is serving as the foundation for a Chinese biotech looking to pioneer a rare disease platform in the country.

Citrine Medicine — which closed $80 million in Series A funding in July — was incubated by F-Prime and Eight Roads, two VC funds affiliated with Fidelity Investments, and Vivo Capital. The trio saw an opening in China to replicate in the vibrant orphan drug landscape in the US and, to a lesser extent, Europe.
“Of all approved orphan drugs and indications in the US and Europe, less than a third of them are available in China,” CEO Ben Wu told Endpoints News.
Until three years ago, there wasn’t even a precise definition of what constitutes a rare disease in China. But things have moved quickly since a regulatory overhaul paved the way for overseas data to be accepted for registration purposes. The government published a list of rare diseases as well as corresponding treatments, while starting to devise ways to pay for these drugs — all significant developments for Wu, who’s previously served as Sanofi Genzyme’s general manager in China.
But it’s early days and much remains to be built, according to Chong Xu, principal at F-Prime Capital and a board member of Citrine.

“There’s obviously the need for public health policy to help enable some of this,” he said. “On the other hand, I think we’re happy to see that more people, whether it’s patients, groups, physicians, or frankly fellow investors as well as other potential companies, that are paying more attention to rare disease these days.”
Bringing in drugs, even those that have already been approved elsewhere, without the supporting infrastructure isn’t going to magically reach patients after all. From patient identification, diagnosis, support to payment and access, Citrine is being positioned as a platform company that will lend a hand to creating the whole ecosystem. While a handful of other domestic players like CANbridge have made rare disease a focus in their pipeline amid a flurry of cancer and immunology deals, Citrine believes that represents a unique proposition.

China has the benefit of a population size — there are an estimated 20 million patients with rare disease — and potential volume that makes even lower prices tenable, CBO Melissa Bradford-Klug noted.
The country is also at the forefront of adopting genetic screening to inform decision making, something Citrine can tap into as it broadens its scope.
But it’s first starting out with narcolepsy and its “beachhead asset,” Wakix. Originally developed by France’s Bioprojet (which knew Vivo as an investor of Harmony) and approved on both sides of the Atlantic, the drug is designed to treat excessive daytime sleepiness or cataplexy by modulating the histamine system.
A community of around 2,000 sleep centers already exist in China to drive patients to seek treatment, Wu said. As they work to bring the drug to the National Medical Products Administration, a team led by Wu in Beijing and Shanghai will work with those centers to raise the bar on standard of care for narcolepsy, he added. Meanwhile, Bradford-Klug and the US team will direct much of that Series A cash toward more deals.
“We collectively never sleep,” joked Bradford-Klug, who’s based in Cambridge, MA.
Aside from F-Prime, Eight Roads and Vivo Capital, Quan Capital led the $80 million round with help from 3H Health Investment and WU Capital.