Merck KGaA to focus on its oncology business

"The company is in a pretty critical time, with a late-stage pipeline in which there could be important filings and launches," he said.

Rossetti, who joined the company from U.S. drugmaker Merck & Co 15 months ago, said the innovation taking place at the German Merck was generating enthusiasm among its employees.

"We see people who want to work with us in R&D. This wasn't true a few years ago," he said.

Rebif, an established injectable MS drug, faces competition from a new generation of oral drugs. Rebif sales dropped a currency-adjusted 12 percent in the second quarter.

At the forefront of Merck's cancer pipeline is avelumab, a treatment that harnesses the power of the immune system, which it is developing with Pfizer. Bristol-Myers Squibb and Merck & Co already have already received approval for cancer immunotherapies, a field that is developing quickly.

Avelumab is in an advanced Phase 3 trial for the treatment of non-small cell lung cancer and has been fast-tracked by the U.S. Food and Drug Administration (FDA) for Merkel cell carcinoma, a rare form of skin cancer.

Merck expects the first commercial launch of the antibody in 2017 and is working towards at least one additional launch for different cancers every year through 2022.

Another cancer drug is evofosfamide, with data from two Phase III trials expected by year-end. Merck and its partner Threshold Pharmaceuticals may file for regulatory approval in mid-2016, with a 2017 launch possible to treat pancreatic cancer and soft tissue sarcoma.

"Even though we are mid-sized, our pipeline is very rich," Rossetti said, adding that the alliance with Pfizer will enable the companies to combine compounds with avelumab to treat various cancers.

"That is the strength of the alliance," he said. "We have more than enough critical mass in oncology."