How much is a life worth? $2.15m? That’s the staggering price of a drug produced by the pharmaceutical giant Novartis that has just come on the market. Zolgensma is a one-off gene therapy treatment for spinal muscular atrophy (SMA), a rare degenerative disorder. Infants with the most severe form usually die within two years. For parents of babies born with SMA, any price is worth paying to save the child’s life. Novartis argues that spread across a lifetime, $2.15m is “cost-effective”.

It points out, too, the expense of developing such innovative drugs. In this case, though, Novartis did not develop Zolgensma but bought up, for £8.7bn, AveXis Inc, the company that did. The Wall Street Journal described the acquisition as a “bet”. The price of Zolgensma is the return necessary for that gamble to be successful.

$2.1m Novartis gene therapy to become world's most expensive drug Read more

“The issue with many of these drugs is that they are expensive but also life-changing for those who need them,” observes Michael Sherman, chief medical officer of the US insurance company Harvard Pilgrim Health Care. “It’s not about saying no, but how do you say yes without bankrupting the system?”

That’s an even more acute question for the NHS. Particularly so as more than 60 gene therapies are expected on the market by 2024. The case of Zolgensma raises questions, too, about priorities. In 1983, the US Congress passed the Orphan Drug Act, designed to encourage research into rare diseases, by offering tax breaks and a lower bar for market approval. The consequence, critics suggest, is that it’s often more profitable for pharmaceutical companies to concentrate research on rare diseases rather than more common conditions.

Zolgensma illuminates the astonishing medical breakthroughs now possible – and asks profound questions about the economic and social systems within which medical research and healthcare are embedded.

• Kenan Malik is an Observer columnist