Schwan on Thursday said he now expects 2019 sales to rise at the mid- to high-single digit percentage rate at constant exchange rates, from mid-single digit sales growth seen previously. Profit in the first half rose 18 percent to 8.8 billion Swiss francs ( £7.16 billion ), while sales rose 8 percent to 30.5 billion francs.

Sales of Herceptin and Rituxumab, two longtime Roche mainstays with more than $7 billion annual sales each, dropped off in the period as biosimilar copies from rivals including Novartis made inroads. Still, Schwan said Roche's strategy of replacing that revenue with new medicines is working well, so far.

"Given the very strong performance of our new medicines and also the performance in the product pipeline, I'm not only confident to grow this year, but to continue our growth also beyond the current year, despite the further market entries of biosimilars," the CEO said on a call with reporters.

Roche shares rose 1%, bringing their full-year advance to 8%.

Schwan added that Roche's delayed $4.3 billion takeover of gene therapy maker Spark Therapeutics is currently expected to be completed in 2019 and that the company is working with U.S. and British regulators who are scrutinizing the deal.

"We are committed to this transaction and the portfolio of Spark, without any question," he said.

(Reporting by John Miller, editing by John Revill)

By John Miller