A US company, which is refusing to drop its price for the life-changing cystic fibrosis drug Orkambi to make it affordable to NHS England, is set to make $21bn (£17bn) in profit from that and a sister medicine, according to research.

Countries around the world are struggling to pay for Orkambi, made by Vertex, which has a list price of £104,000 per patient per year and is not a cure. The National Institute of Health and Care Excellence (Nice) in England has said it is not cost effective. On Monday, the Scottish Medicines Consortium will decide whether to approve the drug for children.

Parents in England have campaigned, demonstrated on the streets and pleaded for their children with cystic fibrosis to be allowed Orkambi for more than three years since it was licensed. Vertex claims it has invested billions in research, has made a loss and needs a price that will allow it to invest in future drugs for the disease.

But a research paper by Aidan Hollis, professor of economics at Calgary University in Canada, disputes that. It estimated that Vertex will make $21.1bn in profit over the lifetime of Orkambi and an earlier drug called Kalydeco that is available on the NHS but treats only a small proportion of patients.

Early funding for research into the two drugs came from a cystic fibrosis foundation in the US, which received a royalty on future profits in exchange. That was bought by a company called Royalty Pharma in 2013 for $3.3bn. Hollis calculated in his paper, shortly to be published in the journal Healthcare Policy, that the anticipated future profits at that time were $33bn. Deducting Vertex’s costs, he calculates the figure to be $21.1bn.

“They are earning profits on those drugs. There is no question about it compared to what they put in,” Hollissaid.

Vertex argues it has invested $11.8bn in the research and development of cystic fibrosis drugs, but, said Hollis, that was a strategy for making more money.

“You put all this money into R&D because it has been enormously profitable for you and you think you are going to be able to charge a lot of money in the future. If you choose to take your money and reinvest it in something, it doesn’t mean you didn’t make profits,” said Hollis.

Pharma watchers believe the strategy will pay off. Vertex is developing a triple combination drug, which includes two of the medicines already on the market with a third it is developing. The drugs only work in a limited proportion of cystic fibrosis cases, but the triple is expected to benefit 90% of patients. Evaluate Pharma’s World Preview 2019, released last month, predicted that Vertex’s triple combination would make more money than any other drug for any condition in the pipeline: $20bn over its lifetime.

Vertex’s latest financial results, for the second quarter of 2019, show product revenues are up 25% from last year, with an increase in the expected revenue for the whole year from $3.6bn to $3.7bn.

Orkambi and the other cystic fibrosis drugs made by Vertex are the first that target the underlying causes of the genetic disease that clogs children’s and young adults’ lungs and shortens lives. The parents of children who could benefit from the treatment are distressed by the delay, aware that children do better the sooner they can get the drug.

Rob Long, who has been buying Orkambi privately for his nine-year-old son Aidan, says he is appalled by the high prices of the drugs from a company making such profits.

“It’s the obscene face of capitalism, where a drug company makes up its prices based on what it thinks it can get away with,” he said. “The present system is broken and not working. There needs to be an independent system of fair evaluation and binding arbitration to ensure lives are put before profit. The present situation is nothing short of torture and there is a UN convention against that.

“Vertex is consistently considered an outlier, even by the pharmaceutical industry, so the current situation is intolerable. With no end in sight, how can the government allow this impasse to continue. So far, over 250 have died who could have been helped.”

NHS England said it was still in negotiations with the company. “NHS has made two of the most generous offers of its kind to this company and intensive work continues on a daily basis but the quickest way for patients to get access to Orkambi is still for Vertex to accept our offer and engage with Nice,” said a spokesperson.

“Vertex is an extreme outlier in both pricing and behaviour. In fact, the pharmaceutical trade body said the current offer represents exactly the sort of flexibility industry wants and warned companies they cannot just pick any price they like for a new medicine.”

Vertex said it disagreed with Hollis’s paper. “We have been relentless in our pursuit of a cure for cystic fibrosis and invested significantly in this area when other companies would not because the risk was too high,” it said in a statement. “Vertex scientists have worked for over 20 years to do what was once thought impossible—develop medicines that treat the underlying cause of cystic fibrosis.

“Since 2000, Vertex’s investment in drug discovery research and development has totalled $11.8bn. In fact, between 2012 and 2017 our research and development costs represented over 70% of our total operating expenses.

“The price of our medicines is based on the value they bring and the difference they make to patients’ lives, their families and societies, as well as the significant R&D investment we have made to develop them and our commitment to finding future treatments. As our medicines treat the underlying cause of disease they not only treat the symptoms but also impact long-term progression.”

• This article was amended on 12 August 2019 to correct a quote.