Rare Disease Biotechs Avrobio, Eidos Therapeutics File for IPOs

Xconomy Boston — 

Avrobio and Eidos Therapeutics, rare disease drug developers on opposite sides of the country, have filed for initial public offerings, each company aiming to raise cash to finance more clinical tests of its lead drug.

Cambridge, MA-based Avrobio set a preliminary $86 million target for its IPO, according to its prospectus filed Friday. The gene therapy developer has applied for a listing on the Nasdaq under the stock symbol “AVRO.” Eidos Therapeutics of San Francisco, which develops treatments for a family of rare diseases linked to the buildup of a certain protein in the body, set an initial IPO goal of $115 million. The company applied to list on the Nasdaq under the symbol “EIDX.”

Avrobio’s IPO filing comes nearly four months after the company raised $60 million in a Series B round of financing. The company’s lead drug, AVR-RD-01, is a gene therapy developed to treat Fabry disease, an inherited enzyme deficiency that leads to the buildup of a fatty substance throughout the body. Avrobio aims to treat the disease by fixing the genetic defect. The company’s approach entails harvesting stem cells from the patient, then introducing a functioning version of the gene responsible for producing the enzyme that Fabry patients lack. The stem cells are then infused back into the patient. Avrobio says in its filing that it expects to start Phase 2 studies of this gene therapy in the middle of this year.

Last year, Avrobio spent $15.2 million on research and development, according to its prospectus. As of March 31, the company reported having $57.9 million in cash. The company says it will use the IPO proceeds to advance its lead gene therapy into mid-stage studies, and support the rest of its drug pipeline, which includes three preclinical gene therapies for other rare diseases.

Eidos Therapeutics is a subsidiary of BridgeBio, a Palo Alto, CA, company that oversees a number of different biotech companies in what it calls a “hub and spoke” model. BridgeBio functions as a central hub, providing services to its subsidiaries. BridgeBio launched Eidos just over a year ago to advance AG10, a drug to treat transthyretin (TTR) amyloidosis, a progressive, fatal condition caused by the buildup of the amyloid protein in the heart. The company estimates the condition affects 200,000 worldwide.

Eidos spent $9.3 million on R&D last year, according to its filing. As of March 31, the company reported having $25.3 million in cash. The company plans to use proceeds from its IPO for the Phase 2 studies of AG10 in the form of TTR affecting the heart. That study began last month; preliminary data are expected by the end of this year. Eidos also plans to apply the IPO cash toward a separate Phase 3 study of the drug in a form of TTR that affects the peripheral nerves, a condition that affects an estimated 10,000 people worldwide.

The Avrobio and Eidos filings come on the heels of the Thursday IPO filing by Magenta Therapeutics. The Cambridge biotech set a preliminary $100 million target to finance its work developing therapies intended to improve bone marrow transplants.