to measure if their eyesight actually improved. Biogen said it didn’t, nor did damaged retinal nerve cells show any physical improvement.
Biogen pointed to the 34 percent—as did UCSF’s Green and others—as a positive sign. But there were plenty of caveats: That percentage did not include everyone who started the trial. Those “intent to treat” patients are the “gold standard,” said an MS specialist who advises the MRF. Not including them—and not saying how many of the trial dropouts were in the patient group taking the drug or those taking placebo—opens up a lot of questions.
“We need to see the data,” the MS specialist said, speaking on condition of anonymity.
The secondary endpoints—repairing the optic nerve cells and improving vision—weren’t the main goal of the study. But missing those endpoints badly, as the study did, was also instructive, said Williams. The delay between the acute optic neuritis attack and getting the drug into patients might explain why it had no functional effect. By the time they were treated, was it already too late?
All these questions and more illustrate why Biogen is on the cutting edge with its clinical program. No one really knows how to design a program, or what exactly to look for.
But more data points are on the way. Green, the UCSF neurologist, is also running a small Phase 2 remyelination trial in MS patients. It’s about the same size as Biogen’s optic neuritis trial, and data could be available later this year. “There’s a big difference between their trial and ours,” Green said. “We’re swinging for the fences.”
Green praised Biogen for being a pioneer—and disclosed that he provided advice to the company before the AON trial—but his trial is “more ambitious” because it’s testing chronic MS patients, not just ones with a recent optic neuritis attack. He’s skipping the intermediate step of Biogen’s trial and hunting for bigger answers.
As an academic, Green can afford more risk. He also has little invested in the drug being tested; it’s an over-the-counter antihistamine that he and UCSF professor Jonah Chan discovered through a screening tool Chan invented (and which is now under license to Roche).
The MRF has also tapped an off-patent drug, approved for hypertension 20 years ago, in a myelin repair trial it launched recently with the National Institutes of Health.
With so many unknowns in myelin repair, that trial and Green’s trial will no doubt inform Biogen’s clinical course. The learning-as-you-go approach even extends to a much larger Phase 2 trial, dubbed SYNERGY, that Biogen is currently conducting with BIIB-033 in more than 400 MS patients.
That trial is testing for improvement across a range of functions. Evidence of myelin repair probably won’t be enough. Will patients’ various motor skills and cognition actually improve? The data, which Williams said “we really need to see to figure out what the next step in the clinical trial process will look like,” won’t be ready until 2016.
Will Biogen learn enough to proceed into a large, expensive Phase 3 trial? Williams seems ready and willing to push the boundaries. Biogen can keep testing drugs, like those it has brought to market, that benefit MS patients whose symptoms wax and wane. “We can keep doing those studies ’til the cows come home,” said Williams. “We know how to do those really well, but that’s not where the need is.”
Ben Fidler contributed to this report