Mineralys polishes $100M IPO plans ahead of phase 3 in hypertension

If we’re looking for good omens for biotech in 2023, then a planned $100 million IPO seems as good a sign as any. That’s how much Mineralys Therapeutics is currently aiming to bring in if the hypertension-focused biotech goes public as planned.

The company revealed its Nasdaq ambitions in a Securities and Exchange Commission filing that didn’t specify how many shares it planned to sell or at what price. However, in a related filing fee schedule, the biotech suggested the standard maximum aggregate offering price of $100 million.

While it remains to be seen whether Mineralys will stick to that figure as the IPO draws nearer, whatever money the company does raise will likely be used to push its lead product lorundrostat through the clinic. The highly selective aldosterone synthase inhibitor (ASI), which is licensed from Mitsubishi Tanabe, has been developed for patients with uncontrolled hypertension or resistant hypertension.

Despite the “growing need” in the U.S. spurred by rising levels of obesity, no new class of antihypertensive treatment has been approved by the FDA in the last 15 years, Mineralys said in the filing.

Lorundrostat is designed to reduce aldosterone levels by inhibiting CYP11B2, the enzyme responsible for producing the hormone. A phase 2 trial conducted by the biotech demonstrated a clinically meaningful 9.6-mmHg and 7.8-mmHg reduction in systolic blood pressure in the 50-mg and 100-mg once-daily cohorts, respectively.

Now, the company plans to launch another phase 2 in the first half of the year to evaluate lorundrostat as an add-on therapy to background treatment of two or three antihypertensive medications, with a top-line readout expected in the first half of 2024. A larger phase 3 trial of around 1,000 patients is also expected to begin in the second half of 2023.

While pointing out in the filing that “abnormally elevated aldosterone levels may be a key factor in driving hypertension in approximately 25% of hypertensive patients,” the company warned potential investors that “developing an effective hypertension therapy that targets aldosterone synthase remains a significant challenge.”

“Several large pharmaceutical companies have tried to develop ASIs, but their efforts have been hampered due to insufficient selectivity for aldosterone, resulting in off-target toxicities associated with cortisol inhibition,” Mineralys added. “These challenges have led to the discontinuation of many ASIs in development to date.” 

That doesn’t mean the biotech will face an open field, though. Only this month, AstraZeneca pounced on CinCor Pharma. CinCor’s share price had been battered by the failure of its ASI baxdrostat—which was in-licensed from Roche—in a phase 2 trial last November, making the company easy pickings for the U.K.-based Big Pharma.

Mineralys has raised around $158 million since it was founded by Catalys Pacific in 2019, and the biotech’s latest plans could be viewed as a welcome show of faith in the biotech IPO market. While 2021 saw record-breaking listings, valuations began to cool toward the end of the year, with experts’ predictions of a slump in 2022 proving correct as emerging biotechs watched their peers list their tickers just to take a beating and ultimately trade well below their initial price

Still, there were some signs the scene was beginning to heat up again later in 2022, with Third Harmonic’s $185 million IPO in late August and Prime Medicine’s $175 million offering in October being two notable examples. Mineralys’ filing came the same day that Alzheimer’s-focused Aprinoia Therapeutics inked a SPAC merger—a once popular way for biotechs to go public while avoiding the traditional IPO route.