Roche confirms visit to office by investigators

"What is a bit surprising, though, is the harshness of recent allegations and actions against what had been widely perceived as the 'cardinal sin' in the industry," Liu added.

Roche boosted by strong drug sales in US and China

China accuses former GSK head of bribing doctors

Against this backdrop, and with uncertainty over regulatory developments, some drug companies have started to shift away from traditional sales practices.

GSK said at the end of 2013 that it will no longer compensate its Chinese sales representatives based on sales volume.

"I believe that patients and patient groups, payers and disease management platforms are among the increasingly important stakeholders to engage going forward. It will always take investments, efforts and courage to break out of the mold, but that has become an imperative to stay away from the systemic risks," said Liu.

Roche, the world's largest maker of cancer drugs, said it had seen continued strong growth in China in recent years.

In 2013, the company's key emerging markets showed growth of 12 percent, boosted by 21 percent sales growth in China. Diagnostics sales grew 4 percent, consolidating the division's leading market position, according to its financial report.