Novartis says deep regret over Japan drug trials scandal TOKYO (Reuters) - The pharmaceutical head at Swiss firm Novartis AG apologized to the Japanese public for alleged manipulation of data in trials of its best-selling blood pressure drug Diovan, saying an employee had acted inappropriately. Divisional head David Epstein made the comments after meeting with Japanese health minister Norihisa Tamura in Tokyo. He agreed to cooperate with the ministry to resolve the issue. "We express our deep regret for the concern that the issue has brought to patients, to the medical society as well as the ministry," Epstein said. "We are very willing to work with them and take additional actions and potential sanctions in order to bring the issue to a good conclusion," he added, but said he could not specify the type of sanctions ahead of the release of the ministry's findings at the end of this month. Several Japanese hospitals have stopped offering Diovan after two universities retracted papers printed in foreign medical journals on the drug's efficacy for preventing strokes and heart disease. The other three universities that published research on Diovan are still investigating the matter. Epstein said that a former Novartis employee who assisted in all five trials had acted "way beyond what we consider appropriate" and that the company had responded by strengthening its training and oversight procedures at Novartis Pharma, its Japanese arm, under new head Yoshiyasu Ninomiya. Japan is an important market for Novartis, accounting for around a quarter of Diovan's global sales before the scandal. Novartis Pharma declined to disclose the impact on sales of the drug, whose patent is due to end in Japan later this year, allowing competition from generic copycats. Novartis says the drug is effective for reducing blood pressure and says patients should consult their doctors before they stop taking it.