April 6 (Reuters) - Neurocrine Biosciences will acquire rare disease drugmaker ‌Soleno Therapeutics for $2.9 billion in ‌cash, the companies said on Monday, marking ​the neuroscience-focused drugmaker's expansion into metabolic disorders.

Neurocrine has offered $53 per Soleno share held, which represents a premium ‌of about ⁠34% to stock's last close.

Soleno shares, which had risen ⁠more than 30% in premarket trading after the Financial Times first ​reported the ​news, were ​halted.

The deal gives ‌Neurocrine access to Vykat XR, the first drug approved in the U.S. to treat hyperphagia associated with Prader-Willi syndrome, a rare genetic disorder.

Hyperphagia, ‌or feelings of ​intense and persistent ​hunger, is ​the hallmark symptom of ‌Prader-Willi syndrome and can ​lead to ​severe obesity as well as physical, mental and behavioural problems.

(Reporting ​by Gnaneshwar ‌Rajan and Mariam Sunny in ​Bengaluru; Editing by Vijay Kishore ​and Sriraj Kalluvila)