These are heady days for PharmaEssentia, a biotech that got its start 23 years ago in Taiwan, went public 10 years later and is now deepening the foothold of its first commercial product, Besremi.
“There’s a lot of electricity in the air in the organization right now,” Samuel Lin, PharmaEssentia’s Head of U.S. Global Operations, said in an interview with Fierce. “Sometimes you have to stop and pinch yourself a little bit.”
The excitement ramped up on Monday as the FDA signed off on a key label expansion for Besremi, endorsing it as a treatment for the rare bone marrow disorder essential thrombocythemia (ET).
The label specifically covers adults with ET regardless of their genotype or disease status, including newly diagnosed patients who haven't received cytoreductive therapy, according to an Aug. 31 release.
Besremi now becomes the first new product approved in the indication since 1997 and gets PharmaEssentia one step closer to achieving its goal of going “full spectrum,” as Lin put it, to become the world’s first drugmaker to gain clearance to treat all four bone marrow cancers, also referred to as myeloproliferative neoplasms (MPNs).
The other bone marrow disorders are myelofibrosis, chronic myelogenous leukemia (CML) and polycythemia vera (PV), the latter of which Besremi was cleared to treat in 2021.
Making waves in MPN is particularly satisfying for PharmaEssentia, which is swimming in the deep end of the industry pool, competing with powerhouse companies such as Takeda, Merck, Novartis and Incyte.
“What we’ve seen is proof positive. There’s interest from larger players,” Lin said. “It affirms what we already know—MPN is an opportunity to serve a broad cohort of patients and it’s a really robust opportunity.”
As a monopegylated, long-acting interferon, Besremi works by binding to transmembrane interferon alpha receptors (IFNAR) to activate the JAK-STAT signaling pathway, which triggers anti-proliferative, pro-apoptotic and immunomodulatory effects.
The first-in-class treatment, which is injected every two to four weeks, combats ET by modulating the overproduction of platelets. Too many platelets can lead to blood clots, abnormal bleeding, stroke and organ damage. With PV, Besremi curbs the overproduction of red blood cells.
PharmaEssentia’s ET nod was backed by data from two trials, including the phase 3 Surpass-ET study, which evaluated Besremi against Takeda’s Agrylin, the last drug approved in the indication some 29 years ago. In the trial, which included high-risk ET patients who were resistant to the chemotherapy hydroxyurea, Besremi had a significantly higher response rate at 43% versus 6% for Agrylin at months 9 and 12.
The secondary endpoint, which examined reductions in JAK2 V617F allelic burden, was also met, suggesting that Besremi may have a greater effect on underlying disease pathology than the comparator drug, PharmaEssentia explained.
The ET indication adds a patient population of about 148,000 in the U.S, compared to the roughly 6,200 who are affected annually by PV, according to the company.
“We’ve learned a lot with the launch of Besremi in PV,” Lin said. “And with ET, ultimately, it’s the same treatment mix and a lot of the areas where the business is driven—both from the physician side and also the patient side—there’s enough overlap, so we’re confident.”
Incyte and Novartis’ JAK inhibitor Jakafi—which has been on the market for more than a decade for PV and myelofibrosis—is the top-selling drug in the MPN space, accounting for sales of $3.1 billion last year.
Also on its way to the market is Takeda and Protagonist’s once-weekly injectable hepcidin mimetic peptide rusfertide, which won an FDA nod for PV on Friday. The drug will now carry the brand name Mimrylo. Meanwhile, as a treatment for PV and ET, Merck is investigating oral lysine-specific demethylase 1 (LSD1) inhibitor bomedemstat, which it acquired in its $1.4 billion buyout of Imago BioSciences in 2022.
With Besremi its lone commercial product, PharmaEssentia reported revenue of $15.63 billion new Taiwan dollars ($494 million) last year, which was up 61% from 2024. With sales continuing to track upward, Lin said that Besremi has an outside chance of reaching the $1 billion revenue mark this year.
“I think we’re a company on the cusp. We’re just a couple different adjustments away from really Besremi entering its blockbuster era,” Lin said, adding, "I do firmly believe we should be on a lot of people’s radar because we are making an impact.”