Preclinical antisense biotech, led by former Sarepta CEO Kaye, vaults on to Nasdaq with upsized IPO
Less than a year after raising $90 million in its second round of financing, former Sarepta chief Edward Kaye is making the leap to the Nasdaq on Wednesday with an upsized offering for his preclinical antisense biotech, Stoke Therapeutics.
The company in-licensed its technology: Targeted Augmentation of Nuclear Gene Output (TANGO) from Cold Spring Harbor Laboratory’s Adrian Krainer, who is credited as the inventor of Biogen’s $BIIB spinal muscular atrophy drug Spinraza. Krainer co-founded Stoke and serves on its board.
As it preps an application to test its lead experimental therapy next year, Stoke raised gross proceeds of $142 million by offering 7.9 million shares at $18, above the range of $14 to $16. It had previously filed to offer 6.7 million shares, and plans to list on the Nasdaq under the symbol “$STOK.”
The holy grail of gene therapies is to develop a treatment that is curative with a single dose, but so far, research has shown that the level of protein produced as a result of this type of therapeutic intervention can fluctuate from patient to patient, its durability remains in question and is expensive to manufacture because scientists must engineer viruses to deliver the gene therapy to the patient.
Stoke is developing antisense oligonucleotide medicines, by taking aim at diseases areas that are often not amenable to traditional gene therapy — because the gene size is too big — or to gene editing, as the therapeutic needs to be titratable. It is betting on stabilizing the protein manufactured by treated cells with its TANGO technology, which is designed to identify gene segments that can be targeted by drugs to dial up the level of protein produced. The Bedford, Massachusetts-based company then develops RNA drugs to harness these targets.
Like GW Pharmaceuticals’ $GWPH keenly watched and 2018 approved cannabis-derived therapeutic Epidiolex, Stoke is targeting Dravet syndrome, a rare and catastrophic form of intractable epilepsy that begins in infancy.
Controlling the amount of protein produced following therapy is particularly significant in autosomal dominant diseases — such as genetic causes of epilepsy — in which mutations in just one copy of a gene adversely impact protein production. An over-production of protein in such cases could be just as sinister. Stoke’s drug is designed to up-regulate production of a protein missing in patients with Dravet syndrome by targeting RNA splicing. The antisense oligonucleotide is suspended in saline and delivered via spinal injection, and will likely be administered every four months or so.
If the FDA sanctions an in-human study, the biotech expects to initiate a Phase I/II clinical trial in children and adolescents in the first half of 2020 and anticipates to have clinical data, including preliminary efficacy data, in 2021.
As of March 31, Stoke has raised over $130 million in funding, including investments from Apple Tree Partners, RTW Investments, RA Capital Management, Cormorant Asset Management, Perceptive Advisors and funds managed by Janus Henderson Investors, Redmile Group, Sphera Funds Management and Alexandria Venture Investments.