Safety worries loom for Bayer’s Adempas

To say that Bayer’s hypertension drug Adempas is a disappointment is an understatement. The product, once expected to bring in $870m by 2018, now has a 2022 forecast of just $459m according to EvaluatePharma sellside consensus.

And this looks set to fall further after Bayer’s attempts to expand the drug’s label uncovered potential safety issues. The German group has stopped a phase II study in pulmonary hypertension associated with idiopathic interstitial pneumonias after the data monitoring committee reported a possible increased risk of death and other severe adverse events with Adempas.

It is unclear what these adverse events are and what could be causing them – but Bayer did say that many of the patients who died “appeared to have more serious and advanced underlying lung disease than the study population as a whole”.

The safety signal could hit existing pulmonary hypertension sales, and might also put paid to other ongoing phase II trials in new uses, including cystic fibrosis and systemic sclerosis. However, Bayer stated that monitoring in ongoing studies in other patient populations “supports the continuation of those studies”. 

Meanwhile, patients in the study in question will be monitored for at least four months after stopping treatment.

Perhaps more worryingly for Bayer, the news raises concerns about its related compound vericiguat, currently in phase II for heart failure (Upcoming events: Bayer takes chronic heart failure data and Trevena acute, August 6, 2015). 

News of the trial termination sent Bayer’s shares down 4% yesterday.

Heart failure failure

Adempas was approved in the US in 2013 for two forms of pulmonary hypertension: chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension.

Bayer has previously trialled the drug in heart failure but it did not show a benefit, and the company has switched its attention to another guanylate cyclase activator, vericiguat. The group will be hoping that the latest safety concerns with Adempas do not represent a class effect, and observers will no doubt be closely watching the outcomes of the two Socrates trials of vericiguat.

Even if vericiguat is linked with the same issues, it should not be too much of a disappointment for Bayer. Expectations are currently low, with the 2022 EvaluatePharma consensus forecast at $172m.

As for Adempas, it was outsold by older Bayer products including aspirin and AlkaSeltzer in 2015. With its safety now in question, things do not look set to improve.

Trial Indication ID
Rise-IIP PH associated with idiopathic interstitial pneumonias NCT02138825
- Cystic fibrosis NCT02170025
- Systemic sclerosis NCT02283762
- Interstitial lung disease-associated PH NCT00694850

To contact the writer of this story email Madeleine Armstrong in London at or follow  @medtech_ma on Twitter

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