Sanofi shares have yet to recover from a plunge in August following disappointing trial results of a once-promising breast cancer drug candidate put the strength of its development pipeline in doubt. Legal claims that heartburn drug Zantac caused cancer have also weighed on the stock. Analysts have said that this year's expected market debut of two new products, to balance out reliance on Dupixent, would be important tests of the company's marketing prowess and a chance to regain investor confidence. These products are haemophilia A treatment Altuviiio, requiring fewer injections than standard therapy, and Beyfortus from a partnership with AstraZeneca, which is a preventive once-a-year shot against the common RSV airways infection in infants. But for this year, marketing and sales expenses to boost those launches would drag earnings lower, finance chief Jean-Baptiste de Chatillon said in a media briefing.