Crossover round? Check. Top team? Check. Taysha sails to an IPO with $100M initial ask
On the same day Novartis erased the AveXis brand from the company, the ex-AveXis crew says their new gene therapy startup is ready for an IPO.
Taysha Gene Therapies has left enough bread crumbs for biotech sleuths to figure out that it’s going down this path. CEO RA Session II, who happily chatted to multiple reporters at launch, declined interviews for the recent Series B (and presumed crossover round); the biotech brought in a gene therapy program developed by its co-founder Steven Gray from Abeona; and days ago it tapped the ex-CMO and ex-CFO of AveXis to join the board, chaired by their former boss Sean Nolan.
What’s still remarkable is the speed at which Dallas-based Taysha has moved. It’s been just a year since the company was formed, a little over four months since Taysha launched with $30 million and a slate of 15 programs, and barely a month after it closed a $95 million Series B. The accumulated deficit so far is just $27.8 million.
That casts a unique spotlight on Taysha compared to the 48 players that have ridden to a public listing on the biotech boom so far this year. Even Passage Bio, the Philadelphia-based startup that has a similar pact with gene therapy guru Jim Wilson, took a year from Series A to go public.
For now Taysha is penciling in a $100 million raise, but these days the placeholder figure could mean little.
Other than laying out the clinical trial timelines for the lead programs — the first study, a Phase I/II of TSHA-101 for GM2 gangliosidosis, is planned in Canada for later this year — the S-1 reveals some interesting details about the partnerships that are core to the biotech.
To get UT Southwestern on board, it turned out Taysha didn’t pay a penny. Instead, it issued 2 million shares of its stock to the university, with no future milestones or royalty promises attached other than costs of maintaining patents. Gray, an expert in AAV-based gene therapies for CNS disorders, is leading the collaboration alongside child neurology division chief Berge Minassian.
By the end of 2021, Taysha also expects to file INDs in the US for four programs, all packaged in an AAV9 vector and spanning the three pillars of neurodegenerative, neurodevelopmental and epileptic disorders:
TSHA-101, a bicistronic HexBP2A-HexA transgene packaged into an AAV9 vector under the control of a CAG promoter designed for conditions like Tay-Sachs and Sandhoff disease. TSHA-102, which combines a neuronal specific promoter, MeP426, with the miniMECP2 transgene, plus a miRNA-Responsive Auto-Regulatory Element for the treatment of Rett syndrome. TSHA-103, which targets a genetic form of epilepsy caused by SLC6A1 haploinsufficiency disorder, is constructed from a codon-optimized version of the human SLC6A1 gene under the control of a JeT promoter. TSHA-104, which addresses SURF1 deficiency, adopts a version of the human SURF1 gene under the control of a modified version of the promoter CBA hybrid intron, or CBh.
With 18 programs now in the pipeline reflecting a portfolio approach, Taysha is entitled to an option for four more programs under the research pact with UT Southwestern, which expires in November 2021.
Then there’s TSHA-118, a potential treatment of infantile Batten disease invented by Gray that Taysha recently licensed from Abeona. Taysha is paid only $7 million upfront to get its hands on the clinic-ready drug, then known as ABO-202, with $3 million in license fees and $4 million for the inventory — including clinical-grade CLN1 plasmid. Milestones add up to $56 million.
In its filing, Taysha disclosed that it’s also struck a deal with Queen’s University at Kingston to access some of its technologies, including plasmid production, for next-generation gene therapies. In addition to $3 million upfront, it reimbursed around $220,000 in costs and agreed to pay another $20 million for milestones.