Soon after Phillip Lynn got married in 2014, he began to forget things. He'd repeat himself. He'd get lost in places close to the couple's home in a suburb of St. Louis.
Then in 2016, his spouse, Kurt Rehwinkel, realized that Lynn's memory problems had become more severe.
They'd just visited some friends who'd gone to Hawaii with them three months earlier. When they'd talked about the trip, Lynn had become confused.
"I said, 'Oh, do you not do you not remember going to Hawaii and spending time with them and going to see Pearl Harbor and going out to the Arizona Memorial,' " Rehwinkel says. "And he's like, 'No, don't remember any of that.' "
Lynn, still in his 50s, was diagnosed with early-onset Alzheimer's in 2017. That same year, he began receiving infusions of an experimental drug called aducanumab that he and Rehwinkel believe has halted or even reversed his memory loss.
In early June, the Food and Drug Administration approved the drug, based on its ability to reduce the sticky amyloid plaques that tend to accumulate in the brain of a person with Alzheimer's. But it's still not clear whether the drug, now called Aduhelm, can help preserve memory and thinking.
For many patients and their loved ones, though, the drug's approval is seen as a sign of progress.
"Now there's hope," Lynn says.
Unlike most Alzheimer's patients, Lynn was aware that he might develop the disease in middle age.
"My father died with Alzheimer's at the age of 60 and so I wasn't really so shocked or anything," he says. "It was just OK, this is something that has been handed to me and I'm going to have to deal with it."
Lynn and Rehwinkel started looking into studies of experimental drugs for Alzheimer's. Then a neurologist told them that Washington University in St. Louis was going to conduct part of a nationwide study of Aduhelm.
"My jaw kind of hit the floor because this was the first one that we'd read about that actually does anything to address the disease, not just the side effects or symptoms of Alzheimer's," Rehwinkel says.
Lynn got into the trial. And he says within a few months, there were hints that his memory might be getting better.
"People were noticing that there was something different," he says. "They said, 'Have you noticed that Phillip's not repeating himself.' "
But there's reason to be cautious about drugs like Aduhelm, says Dr. Joy Snider, the principal investigator for the Washington University study.
It's the latest in a long list of drugs that proved highly effective at removing amyloid plaque, but not at slowing down the memory and thinking problems that are the hallmarks of Alzheimer's.
"Every trial failed," Snider says. "It's been very discouraging."
And it remains unclear whether aducanumab is any better. One big study presented to the FDA showed it worked. Another showed it didn't.
After looking at those results, a panel of 11 scientists who advise the FDA voted overwhelmingly against approving the drug. When the FDA approved the drug anyway, several panel members resigned in protest.
The uncertainty about aducanumab puts physicians in an awkward position. They must weigh any potential benefit from the drug against known risks, including brain swelling, and a price tag of about $56,000 a year.
On Saturday, the Alzheimer's Association, which supported approval of the drug, said the price is "simply unacceptable" and called on Biogen, maker of the medicine, to lower it.
"It's going to be very hard as a clinician because patients and their families are already calling us and asking for this drug," Snider says
Snider is hoping that Aduhelm will help some patients in the earliest stages of the disease.
"There probably are people who do respond well to this drug," she says. "But it remains to be seen how big an effect that is in everybody."
Phillip Lynn may be that rare patient who is getting a dramatic response, Snider says.
Cognitive tests done outside the clinical trial have hinted that Lynn's mental function is stable, and perhaps better than it was before he started taking Aduhelm.
"Phillip might be an aberration," Rehwinkel says, adding that he doesn't want other patients and their families to have unrealistic expectations for the drug.
Still, Rehwinkel is puzzled by people who think Aduhelm should be kept off the market.
"I wondered, do these people really have loved ones who have a stake in the game?" he says. "Are they losing a little bit more of their loved one every day to the disease?"