Swiss drugs giant Roche has agreed to pay $4.3 billion for Spark Therapeutics, marking the latest purchase of a biotech company by big pharma.

The deal gives Roche the first US-approved gene therapy Luxturna and some hemophilia candidates, among others. Spark’s blindness treatment Luxturna also gained EU marketing approval last year.

“As the only biotechnology company that has successfully commercialized a gene therapy for a genetic disease in the US, we have built unmatched competencies in the discovery, development and delivery of genetic medicines,” said Jeffrey Marrazzo, Spark’s CEO. “With its worldwide reach and extensive resources, Roche will help us accelerate the development of more gene therapies for more patients for more diseases and further expedite our vision of a world where no life is limited by genetic disease,” he said.

Spark Therapeutics was founded in March 2013 out of the Children’s Hospital of Philadelphia in Pennsylvania, USA. Its lead clinical asset is SPK-8011, a novel gene therapy for hemophilia A, which is expected to start Phase 3 trials this year. The company also has SPK-8016 in a Phase 1/2 trial, aimed at addressing the hemophilia A inhibitor population. Spark is also developing therapies for Pompe disease, CLN2 disease, Huntington’s disease and Stargardt disease.

Both companies’ boards have approved the merger, which is expected to close in the second quarter of 2019. Under the terms of the agreement, Roche will promptly commence a tender offer to acquire all outstanding shares of Spark common stock, and Spark will file a statement recommending that its shareholders tender their shares to the Swiss pharma.

After closing, Spark will continue to operate in Philadelphia as an independent company within the Roche Group.

Raju Prasad, an analyst with US financial services company William Blair, said the deal is a “sound strategic fit” for Spark. Analysts at Jefferies added that the acquisition offers a “compelling strategic rationale” for Roche and hands the drugmaker a “validated gene therapy platform and manufacturing capability”.

Recent pharma-biotech deals include Bristol-Myers Squibb’s proposed takeover of Celgene for $74 billion in January, which was swiftly followed by Eli Lilly’s plans to buy Loxo Oncology for $8 billion.