When writing a blockbuster movie script, screenplay writers are sure to include all the essential elements of a hit film. In the biotech world, the launch of Serapha Bio seems to follow this formula, touching on many of the big themes present in the industry today.
A licensing deal involving a China asset, an investment worth hundreds of millions of dollars and a genetic disorder with high unmet need are present in this story. And a previous Fierce 15 winner plays a part via a reverse merger, to boot.
Serapha has launched with $230 million in funding commitments from an investor group led by RA Capital Management and RTW Investments, with participation from Janus Henderson Investors, Decheng Capital, Vivo Capital, Casdin Capital, LifeSci Venture Partners, Logos Capital, Balyasny Asset Management, and Eventide Asset Management, according to a June 23 release.
The focus of the company is SERP-01, an in vivo base editing program developed in China and licensed from YolTech Therapeutics. The asset, which is being investigated as a potential treatment for alpha-1-antitrypsin deficiency (AATD), targets the SERPINA1 E342K (PiZZ) mutation.
Patients with AATD aren’t able to produce sufficient, properly formed levels of the alpha-1 antitrypsin (AAT) protein, which is generated by the liver to protect the lungs from inflammation and damage. The hereditary disorder is most commonly caused by the SERPINA1 E342K point mutation, which causes the production of a misfolded form of AAT called Z-AAT, according to Serapha. It’s estimated there are up to 100,000 patients with the severe PiZZ genotype in the U.S., who lack a treatment for their underlying condition.
China’s YolTech has been enrolling patients in an investigator-initiated trial of the drug candidate in Shanghai and scored a minority equity stake and upfront payment from Serapha as part of the licensing deal. The company further retains China rights to the drug and is eligible to receive milestones of more than $2 billion dollars related to its potential success.
Early clinical data on SERP-01 “give us confidence that this is a potentially best-in-class base editing therapy that can restore AAT to physiologic levels in patients with the most severe form of this disease,” Roderick Wong, M.D., Managing Partner and Chief Investment Officer at RTW Investments, said in a statement.
Serapha’s $230 million fundraise consists of a $138 million Series A plus $92 million in additional funding expected to close upon the finalization of the merger. Serapha expects this haul will propel its operations into the second half of 2029, enabling it to complete phase 2 testing and start phase 3.
Serapha is essentially consuming Boundless Bio to advance its aims. Boundless, a Fierce 15 winner in 2023, has decided against further development of its cancer asset BBI-940, CEO Zachary Hornby said in a statement. The company is merging with Serapha, with its pre-merger investors set to inherit a 3.7% share in the combined company. Boundless expects to pay its existing investors between $44 million and $48 million in a cash dividend.
“We believe this transaction represents a strong opportunity to deliver meaningful value for our stakeholders, while providing Serapha with a public-market platform to advance novel therapies for people with rare diseases,” Hornby said in a statement.
Serapha enters the scene at a promising time in the AATD field. Last month at the annual meeting of the American Thoracic Society in Orlando, both Sanofi and Wave Life Sciences shared updates on their respective attempts to end the disease’s 40-year new treatment drought.
Sanofi provided detailed data behind its phase 2 win for recombinant protein efdoralprin alfa, which beat out CSL’s standard-of-care Zemaira at boosting levels of AAT in the trial. As for Wave, the company’s RNA editor WVE-006, given as a 400-mg monthly dose, helped patients produce healthy AAT protein and reduce the mutant Z variant in a phase 1/2 study. Besides those two companies, Beam Therapeutics and Regeneron are taking genetic medicine approaches to treating the liver and lung disease.
Serapha’s debut drew buzz on Wall Street, with Boundless Bio’s stock price shooting up 87% in the wake of the announcement. The combined company will trade under the ticker “AATD” when the deal is complete.