The deadline for Roche’s $4.3bn purchase of CHOP's gene therapy developer Spark has been postponed until April 2020 amid regulatory scrutiny and pending lawsuits.

Pharmaceutical firm Roche has pushed back the deadline for its $4.3bn acquisition of Spark Therapeutics, a US-listed gene therapy developer originally spun out from Children’s Hospital of Philadelphia (CHOP), Reuters reported yesterday.

Roche and Spark Therapeutics have agreed to change the time limit for the merger agreement to April 30, 2020 from the original date of January 30.

The corporate had had its $114.50 per share bid for Spark Therapeutics accepted in February 2019, and the deal was expected to close in the second quarter.

Roche said in a regulatory filing that while it remained committed to the acquisition, a delay was needed to allow “additional time” for it to clear.

The transaction has been called in for scrutiny by US competition watchdog the Federal Trade Commission, and also faces three pending US lawsuits over alleged disclosure violations associated with Roche’s bid.

Founded in 2013 as AAVenue Therapeutics, Spark develops genetic medicines that target faulty cells to treat inherited retinal and neurodegenerative diseases, in addition to certain conditions targeted through the liver.

Spark’s lead asset, the Luxturna blindness therapy, has been granted US and European regulatory approval and is expected to be priced at about $850,000 per patient, according to Reuters.

The company’s pipeline also includes the SPK-8011 drug for the inherited clotting disorder haemophilia A, as well as candidates for blindness-causing choroideremia, Huntington’s disease and Pompe disease, inherited diseases which respectively affect the patient’s vision, brain function and muscle strength.

Spark Therapeutics publicly listed in 2015 following a $161m initial public offering priced at $23 per share.

CHOP featured in the company’s $72.8m series B round in 2014, which was led by VC firm Sofinnova Ventures and also included Deerfield Management, Brookside Capital, Rock Springs Capital, Wellington Management, accounts managed by T.Rowe Price Associates, and two unnamed healthcare-focused vehicles.

CHOP also committed $50m of series A financing to Spark in 2013, $10m of which was supplied to the spinout upfront. Bloomberg has estimated that, should the Roche deal be completed, CHOP would secure a return of approximately $456m.

Aside from CHOP research, Spark Therapeutics has also licensed intellectual assets from University of Iowa and University of Pennsylvania.