Eye specialists are calling for trials which would set a hugely expensive new blindness-preventing drug against a cheap alternative which many doctors are already using on their patients.
The issue spilled over into the pages of the New England Journal of Medicine (NEJM) yesterday, with the publication of official studies showing that Lucentis, costing about $2,000 (£1,062) a dose, is an effective treatment for age-related "wet" macular degeneration.
While news of the successful trials is widely welcomed, editorials in the same journal point out - as the Guardian revealed in June - that ophthalmologists around the world have treated thousands of patients with tiny doses of a similar drug, Avastin, which is licensed not for eyes but for bowel cancer. Although it, too, is very expensive in the large dose used in cancer, doctors can split one phial into the tiny quantities they need for injecting into the eye, bringing down the cost to only about $150 (£79) a time.
Genentech, the manufacturer of both drugs, does not want Avastin used in this way and has propelled Lucentis into trials, arguing that it is specially modified for use in eyes.
Yesterday, one of the two NEJM commentators, Edwin Stone of the University of Iowa, said that now the trials had shown the "miraculous" effect of the drugs on patients' sight, it was crucial to hold trials comparing Avastin and Lucentis.
While they were waiting for Lucentis to be approved, doctors were using Avastin in patients who would otherwise soon go blind, and they published papers about their results. "These were not randomised, double-masked trials," he said, "but to those of us who had been taking care of people with this disease for a while, it was evident that this was pretty potent stuff - the best we'd ever had.
"Tens of thousands of doses of Avastin were given nationwide, while doctors were waiting for ranibizumab [Lucentis] to get approved, and it often worked very well."
Nobody at the moment knows whether Lucentis works better than Avastin and a further question needed to be sorted out, he said. Lucentis was given once a month for two years in the trials, but the doctors' experience with Avastin suggested that may be more than is necessary.
It was important to find out whether Avastin worked as well as Lucentis, he said, because of the huge difference in price. "It does matter how much it costs," he said. "Ranibizumab [Lucentis] is an absolutely spectacular drug compared to treatments we had in the past. But what if it turns out that the $150 stuff is just as good?"
Robert Steinbrook, a doctor and national correspondent with the NEJM, also calls for head to head trials in a second article. "In many parts of the world, a medication that costs $1,950 for a monthly injection is unaffordable," he writes.
