Janssen Pharmaceuticals terminates agreement with Achillion Pharmaceutical By: MarketMinute.com Stock News September 11, 2017 at 19:22 PM EDT Janssen Pharmaceuticals terminated its collaboration agreement with Achillion Pharmaceuticals Inc. (Nasdaq: ACHN) to develop a hepatitis C treatment. Achillion stock plunged $1.08 to close at $3.82. Related Stocks: Achison Inc