UPDATE 1-Roivant's anti-inflammatory drug succeeds in mid-stage study

(Adds share movement in paragraph 1)

By Bhanvi Satija

April 2 (Reuters) - Roivant Sciences said on Tuesday its experimental drug to treat non-infectious uveitis helped reduce symptoms of the inflammatory eye disease in a mid-stage study, sending the biotech firm's shares up 8% in premarket trading.

In the study testing 26 patients, 29% of those who received a higher-strength 45 milligram (mg) dose and 44% of those who received a 15 mg dose experienced treatment failure, with a lower rate implying a greater benefit from the drug.

The drug, brepocitinib, also helped reduce a type of swelling known as macular edema, in some patients who received the higher dose.

Brepocitinib is designed to target and inhibit two proteins - TYK2 and JAK1 - which play a role in immune responses and targets the cause of the disease that can lead to severe and irreversible vision impairment and blindness.

The only approved therapy that targets the cause of non-infectious uveitis is Abbvie's Humira, which lost key patents in the United States in 2023.

Brepocitinib could become the first oral therapy for the condition if it succeeds and eventually approved, Leerink analyst David Risinger said in a recent note.

That would highly benefit Priovant Therapeutics, a joint venture between Roivant and Pfizer, owns global rights to develop oral and topical forms of the drug.

The company plans to start a late-stage study in the second half of this year and is also testing the drug in another late-stage study to treat patients with a muscle inflammatory condition known as dermatomyositis.

Roivant also said on Tuesday its board has approved a program to repurchase up to $1.5 billion worth of the company's shares, including a $648 million buy back from Sumitomo Pharma . (Reporting by Bhanvi Satija in Bengaluru; Editing by Shinjini Ganguli)