France, Feb. 9 -- When France began its first large-scale experiment with medical marijuana, the expectation was that it could lead to legalisation. But three years on the experiment is ending with no clear path forward, leaving hundreds of patients who took part in the study in limbo.

In 2021, Nadine Attal was on the scientific committee that was putting in place France's first large-scale experiment with medical marijuana, recruiting patients, doctors and pharmacists to see how it could be prescribed and used in the health system.

Three years later, when it was becoming clear that the experiment would end without a legalisationof the use of medical marijuana, Attal had to break the news to her patients.

"I wanted them to receive the in...