Roche (NASDAQ: RHHBY) took another big stride today in its long march toward a regulatory filing for the likely diabetes blockbuster taspoglutide. The pharma giant said that the experimental medicine produced promising Phase III data, proving significantly superior to a placebo. Fresh evidence of safety and efficacy is steadily boosting analysts' estimates of likely sales. "We believe taspoglutide has the potential to develop substantial sales over time, which we believe could reach a peak of 3 billion Swiss francs ($2.8 billion)," said Karl-Heinz Koch, analyst at brokerage Helvea in Zurich. Roche is expected to file for approval in Europe and the U.S. in 2011. Report