Actelion was founded in 1997 by a small group of researchers and managers from Roche. CEO Jean-Paul Clozel and the other founding members built the company’s legacy on ground-breaking innovation and an unwavering commitment to patients. Actelion fundamentally changed the way pulmonary arterial hypertension is treated and became a recognized global leader in this space. The company  also has a number of specialty therapies and compounds in late-stage development for pulmonary hypertension and multiple sclerosis.

Actelion went public in April 2000, with registered shares listed on the SWX New Market. During its 20-year history, Actelion grew to more than 2,600 employees in over 30 affiliates, reaching more than 50 markets with its medicines.

In January 2017, Johnson & Johnson (J&J) and Actelion announced a definitive transaction agreement under which J&J would acquire Actelion.

In June 2017, the acquisition was completed and Actelion became part of the Janssen Pharmaceutical Companies of Johnson and Johnson. Actelion's medicines help expand and strengthen Janssen’s portfolio with leading, differentiated in-market medicines and promising late-stage compounds. Janssen has added Pulmonary Hypertension as a therapeutic area of focus to maintain the leadership position Actelion has built in this important disease area.

By decision dated October 25, 2017, the Cantonal Court of the Canton of Basel-Landschaft cancelled all publicly held registered shares of Actelion Ltd based on article 137 of the Federal Act on Financial Market Infrastructures and Market Conduct in Securities and Derivatives Trading .

The holders of the cancelled Actelion Shares were paid a cash compensation in the amount of USD 280 for each cancelled Actelion Share, corresponding to the offer price paid by Janssen Holding GmbH,  in its public tender offer for all publicly held Actelion Shares. The settlement and payment of the compensation to the remaining minority shareholders of Actelion took place in early November, 2017.

The last day of trading of the Actelion Shares was November 6, 2017 and  the shares were delisted from SIX Swiss Exchange on November 7, 2017.