Bayer's experimental anticoagulant asundexian could still be a blockbuster if its second trial for stroke prevention reads out positively, Oelrich told Reuters at the JPMorgan health conference in San Francisco.

He said there is also strong opportunity in the U.S. for the company's cardiovascular and menopause symptom relief treatments, including its experimental elinzanetant, which Bayer said on Sunday eased hot flashes and improved sleep in late-stage trials.

"When you look at any of the opportunities that we're talking about (in those areas), typically the reward for innovation in the U.S. is superior to the one in Europe," he said.

Bayer announced in late November that asundexian was shown to be inferior to Bristol-Myers Squibb and Pfizer's established Eliquis in preventing strokes in high-risk patients part-way into a late-stage trial called OCEANIC-AF.

The company earlier that month said it started a trial called OCEANIC-AFINA to test the experimental blood thinner in patients with a trial fibrillation who are ineligible for oral anticoagulant treatment because of increased risk of bleeding.

Oelrich said Bayer still plans to sell the drugs it is developing itself in the country, rather than partner with U.S. companies like it has in the past.

Bayer executive Sebastian Guth told Reuters last March that the drugmaker intended to move away from relying on partners in the U.S. and planned to spend $1 billion on drug research and development in the country in 2023.

Oelrich declined to say whether Bayer would revise its 5 billion euro forecast for asundexian after its trial setback.

(Reporting by Patrick Wingrove; Editing by Michael Perry)

By Patrick Wingrove