Future Prize for the drug for pulmonary hypertension

High blood pressure is a common ailment. Less common is the more specific arterial pulmonary hypertension - high blood pressure in the lungs. It's a rare disease that affects about 50 out of a million people. But it can be extremely dangerous, if not fatal.

A generation ago, the average life expectancy after diagnosis was only about two-and-a-half years.

Fortunately, times have changed. A new class of substances is helping save the lives of many patients, such as Siegfried Hennecke. Suddenly, about a year ago, Hennecke started having difficulties climbing the 38 stairs up to his apartment.

"Up until Christmas [that year] I had had no problem climbing the stairs. Then - all of a sudden - three steps before the top of the stairs I could not get any further," he recalls. "It got worse by the day. My doctor sent me to a cardiologist and the cardiologist sent me to a local hospital."

A team of doctors discussed Hennecke's case and decided to send him to the Bonn's university hospital, where lung specialist Professor Dirk Skowasch made the diagnosis: arterial pulmonary hypertension.

A bottleneck of the lungs

Arterial pulmonary hypertension is a form of high blood pressure in the lungs. It develops when the arteries leading into the lungs narrow or contract. This "bottleneck" causes the pressure to rise and the blood backs up all the way into the heart's right ventricle. As a result, the heart is overburdened as it has to pump constantly against the pressure.

Meanwhile, in the lungs, insufficient oxygenated blood flows back to the heart and into the body. The left side of the heart has too little to do, and organs and muscles do not receive enough oxygen.

Hennecke had been aware of some of the symptoms before his diagnosis, but did not recognize them.

That's quite common, says Dr Skowasch.

"Diagnosis is difficult," he says, "because the illness is really rare and the symptoms aren't very specific."

"The patient will say he has difficulty breathing and that he feels weak - which can have all kinds of reasons. The cardiologist will say there's no coronary disease and the lung-specialist will say that the lungs seem to be working well. That's a lot of insecurity for the patient until he gets the news - which comes with a bad prognosis," Skowasch says.

Back in the early 1990s such a 'bad prognosis' meant an average life expectancy of about two-and-a-half years - comparable to the deadliest cancers.

New discovery

But in that same decade, research into pulmonary hypertension began to advance with a discovery that meant the tide would soon turn.

In 1994, Johannes-Peter Stasch discovered a promising molecule while working at the Bayer pharmaceutical company in Wuppertal.

The way it works is similar to a mechanism that has been known for 130 years. Nitroglycerin - when inhaled as a spray - offers relief to patients who suffer from angina pectoris, a cardiovascular illness.

But it was only in the mid 1990s that scientists found out why Nitroglycerin works.

"Nitroglycerin turns into nitrogen monoxide inside the human body," explains the pharmacologist Stasch. "That gas triggers the widening and relaxing of blood vessels, which leads to the disappearance of the angina pectoris."

But that's not the whole story

"The nitrogen monoxide is looking for a place to go and it finds an enzyme called soluble guanylyl cyclase (sCG), which exists in every cell of the human body," says Stasch.

This enzyme produces a messenger molecule cyclic guanosine monophosphate (cGMP).

"And this cGMP has many good properties. Generally it widens the blood vessels," says Stasch. "It also prevents the development of other cells inside the blood vessels that could clog them up even more. All this prevents the blood pressure from rising."

Stimulating messenger molecules

The new substance against pulmonary hypertensions works just like the nitrogen monoxide that emerges after using nitroglycerin spray - it connects to the SCG enzyme and triggers the production of the same cGMP messenger molecule.

The result is a novel drug. Its active substance is called Riociguat and the drug, developed by Bayer, is called Adempas. The new class of substances are called sCG stimulators.

For patients with pulmonary hypertension, the discovery is a life-saver, because nitroglycerin spray did not work for their chronic disease.

The new substance cannot heal pulmonary hypertension, but it allows patients to get it under control.

"Patients have to take a pill three times a day," says Dr Reiner Frey.

Frey was involved in the discovery of the substance at Bayer and pursued its development into a drug.

"That dosage keeps the levels of the drug constant and prevents peaks in the cells, which is where it needs to take effect," says Frey.

For the rest of your life

Patients have to take the medication for the rest of their lives. But if they do, the chances of survival increase dramatically.

"The long-term data we now have shows very promising results in terms of survival and in terms of symptoms," says lung specialist, Professor Ardeschir Ghofrani.

Ghofrani chaired the pre-clinical and clinical trials for the drug at Giessen University Hospital, starting with the first lab tests all the way to the licensing of the substance in the US in 2013 and in the EU in 2014.

"Among those who participated in the phase 3 study, the survival rate over periods of one and two years has been more than 95 and 90 percent, respectively," says Ghofrani. "In the past we could have expected rates of 70 and 50 percent."

Siegfried Hennecke is optimistic he can handle his illness. He still carries an oxygen dispenser with him as a precaution when he leaves the house. But he says it's vital he takes his pills regularly.

"I certainly notice it when I forget to take them," he says. "I hope my condition remains as is. But I have no illusions. I don't think I can do everything just as before. I have been riding my bike recently and will do so again. The only problem is the oxygen device is so heavy that I can't get it onto my bike without it moving."

The work of pharmacologist Johannes-Peter Stasch and the medical doctors, Reiner Frey and Ardeschir Ghofrani, improved many people's lives - and for this, they were awarded this year's #link:http://www.deutscher-zukunftspreis.de/en/news/2015-deutscher-zukunftspreis-just-few-days-away:German Future Award# ("Deutscher Zukunftpreis 2015"). German President Joachim Gauck awarded the prize on December 2 in Berlin.