Crystalys Therapeutics has secured $130m in a Series B raise to push its gout therapy, dotinurad, further down the pipeline, while gearing the drug up for commercialisation – potentially poising it to become a new treatment option for patients who don’t respond to standard of care (SoC).
With cash in hand from the Novo Holdings-contributed, Frazier Life Sciences-led financing, Crystalys will take several steps to establish dotinurad’s potential role across the broader gout treatment paradigm, primarily in the second-line setting.
Go deeper with GlobalData
Discover B2B Marketing That Performs
Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.
One of these steps, CEO James Mackay tells Clinical Trials Arena, will be to conduct an open-label extension (OLE) study lasting around two years post-completion of the Phase III RUBY (NCT07089875) and TOPAZ (NCT07089888) trials, which were funded by a $205m Series A raise back in September 2025. The OLE portion of each trial will allow Crystalys to collect long-term safety and durability data.
On top of its Phase III efforts, Crystalys is hoping to chart a course for dotinurad into the SoC-intolerant patients, which currently make up 10-15% of the total population with gout. The biotech plans to achieve this through the Phase II AMETHYST study (NCT07535034), which will assess whether the drug could benefit patients who are ineligible for treatment with commonly prescribed xanthine oxidase inhibitors such as allopurinol.
AMETHYST will also look at dotinurad’s efficacy and safety in patients who are unresponsive to Amgen’s marketed gout therapy, Krystexxa (pegloticase), which is considered a final option for patients with gout – meaning those who do not respond to the drug currently have no alternative treatments available to them. The study will enrol 90 patients, Makay says, and is set to read out in Q3 2027.
It is currently estimated that around half of patients treated with SoC therapies like allopurinol do not respond to treatment.
Dotinurad’s place in the gout market
In recent years, there have been multiple new developments in the gout space – one of them being dotinurad’s approval in several countries such as Japan, China, Thailand, the Philippines and Taiwan, where it’s marketed as Urece.
Now, Crystalys is looking to commercialise the drug across the US, UK and Europe after securing the rights from Fortress Biotech’s subsidiary, Urica Therapeutics, back in 2024.
Dotinurad, a selective urate transporter I (URAT1) inhibitor, is designed to block the reabsorption of uric acid – a key molecule linked to gout – by the kidneys. Crystalys’ approach represents a new mechanism in gout, as current treatments like allopurinol focus on decreasing the production of uric acid, rather than tackling the root cause of the disease, Mackay comments.
If approved, GlobalData forecasts that dotinurad will bring in $318m in global sales during 2032. In 2022, the gout market across the seven major markets (7MM: the US, France, Germany, Italy, Spain, the UK, and Japan) was valued at $4.63bn in 2022.
GlobalData is the parent company of Clinical Trials Arena.
