Biogen strikes $877M Nightstar gene therapy buyout

Biogen is set to pay $877 million (€772 million) to buy Nightstar Therapeutics for its pipeline of gene therapies. The takeover will give Biogen control of clinical-phase ophthalmology assets that could get to market ahead of drugs in development at rival gene therapy shops.

Since spinning out of Oxford University in 2013, Nightstar has advanced two gene therapies targeting retinal indications through the clinic using VC and IPO monies. A phase 3 trial of the lead candidate, NSR-REP1, is set to finish enrolling choroideremia patients in the coming months, teeing Nightstar up to find out if it it can tackle the currently-untreatable form of progressive vision loss. Nightstar also has an X-linked retinitis pigmentosa (XLRP) gene therapy in earlier-phase development.

Biogen signaled its interest in using gene therapies to treat eye diseases such as choroideremia and XLRP when it paid $124 million upfront to partner with AGTC. The big biotech pulled the plug on the AGTC deal following a clinical setback last year but its interest in the field remains undiminished.  

“Ophthalmology is an emerging growth area for Biogen,” Biogen CEO Michel Vounatsos said in a statement. “Nightstar would accelerate our entry into ophthalmology by contributing two mid- to late-stage gene therapy assets”

Biogen has offered $25.50 per share in cash to land Nightstar. That represents a 70% premium to the 30 trading day volume-weighted average price per share but is below the highs Nightstar hit in September. The stock’s slide began around the time Nightstar posted proof-of-concept data on its XLRP candidate and held a stock offering. The study found one-third of patients who received higher doses of NSR-REP1 experienced notable improvements, although the response rate was higher at a lower dose. 

The mixed data raised questions about why Nightstar saw an inverse dose response but still left it with a shot at getting the XLRP therapy to market ahead of rival assets in development at AGTC and MeiraGTx. Nightstar is better placed still in the race for the choroideremia market. Spark Therapeutics is the most advanced rival but its drug is still in phase 1/2. 

Spark has the benefit of the experience of already bringing an eye disease gene therapy to market and will have the resources of Roche behind it once the Swiss pharma’s $4.3 billion takeover closes. 

The back-to-back acquisitions of Spark and Nightstar will turn the choroideremia race into a scrap between Roche and Biogen while furthering the reshaping the broader gene therapy sector. Having once largely been the domain of small biotechs with pharma partners, the gene therapy landscape has been transformed over the past year as Novartis, Roche and now Biogen have bought their way deeper into the field.