Drugmaker Vectura Group Plc (VEC.L) said it raised its revenue expectations for the nine months to Dec. 31 following strong trading to the end of August.
Shares in the company rose more than 10 percent in morning trade, making them the biggest gainers on the FTSE midcap index .FTMC in heavy volume.
Vectura said revenue for the period was ahead of its expectations, helped by strong sales from respiratory drugs marketed by GlaxoSmithKline Plc (GSK.L) and Novartis AG (NOVN.S).
The company has not disclosed revenue guidance, a spokesman said. It is expected to report 2016 revenue of 141.68 million pounds ($189.96 million), with estimates ranging from 70.8 million pounds to 188 million pounds, according to Thomson Reuters I/B/E/S.
The company, which agreed to buy rival SkyePharma in March for 441 million pounds, said revenue from oral, inhaled, and non-inhaled products was ahead of its expectations.
Novartis said in July second-quarter total net sales for respiratory therapy Ultibro Breezhaler jumped 52 percent to $100 million, while GSK said sales of Ellipta products more than tripled to 220 million pounds.
"We believe recent share price weakness has been overdone," analysts at Stifel said in a note, rating the stock a "buy".
Shares tumbled to their lowest in 21 months in August after the company's asthma therapy Flutiform failed to meet the main goal in a late-stage trial.
Vectura's stock was up 10.1 percent at 140.9 pence at 0834 GMT, and was set for its best single-day rise since December 2013.
(Reporting by Mamidipudi Soumithri in Bengaluru; Editing by Gopakumar Warrier and Sunil Nair)