If successful, efforts to reduce the 12 years of data exclusivity granted under the Affordable Care Act for innovative biologics could prove to be costly for patients, payers and the companies that make the drugs.Reducing data exclusivity to seven years, as the president and a number of lawmakers have proposed, would be disruptive to the marketplace as it would encourage at-risk launches of biosimilars and lead to unnecessary patent litigation, said Dave Fox, former associate chief counsel for drugs at the FDA and a partner at Hogan Lovells.