Eli Lilly won Food and Drug Administration approval for its Alzheimer's treatment, donanemab, on Tuesday. But Eli Lilly stock remained in the red.
The approval comes after a panel of experts voted unanimously to back donanemab — now known by the brand name Kisunla — as a treatment for patients with early symptomatic Alzheimer's disease. The drug slowed cognitive decline compared to a placebo over 18 months.
Kisunla will rival Biogen and Eisai's Leqembi, which won FDA approval last July. Both drugs target built-up plaque known as beta amyloid, a hallmark of Alzheimer's disease. But while Leqembi is a chronic treatment, Kisunla is only given while the plaque remains present. In the Phase 3 study, almost half of patients finished their treatment within 12 months.
On today's stock market, Eli Lilly stock closed down less than 1% at 906.87. The stock moved much lower in earlier action after President Joe Biden and Sen. Bernie Sanders called out Lilly and rival Novo Nordisk for the "unconscionably high" prices of their weight-loss drugs.
Biogen stock also fell 1.3% to 228.82, while Eisai stock dipped 1% to 10.19.
Eli Lilly Stock: Label Is 'Generally Clean'
RBC Capital Markets analyst Brian Abrahams said the FDA label for Kisunla was "generally clean."
It warns against amyloid-related imaging abnormalities, or ARIA. ARIA is swelling in the brain. It's often asymptomatic and temporary, but can be serious. ARIA occurred at a higher rate in Lilly's Kisunla studies than Biogen and Eisai's Leqembi studies. ARIA-E is considered to be more serious than ARIA-H.
"But (adverse events) cited in the label may reinforce to practitioners that Kisunla's symptomatic ARIA rate is double Leqembi's (6% vs. 3%) and ARIA-E is triple (36% vs. 13%) — we believe highlighting an edge for Biogen," Abrahams said in a report.
ARIA tends to occur within six months for Kisunla and within three months in Leqembi recipients.
He has an outperform rating on Biogen stock, but doesn't list a rating for Eli Lilly stock.
Third Bridge analyst Lee Brown says Leqembi appears to be the safer option in Alzheimer's treatment.
"Our specialists believe Leqembi may have a superior safety profile relative to Kisunla given a slightly different mechanism of action," he said in an email. He notes the two drugs target different elements to remove built-up beta amyloid.
Alzheimer's Treatment Isn't Limited By Tau
Notably, the FDA didn't limit Kisunla to patients whose beta amyloid has evidence of a protein called tau. In clinical testing, Kisunla slowed cognitive decline by 35% to 36% for patients with an intermediate level of tau. Across all patients, Kisunla slowed cognitive decline by 22% to 29%.
This is a bullish point for Eli Lilly stock. Brown notes a potential tau requirement — which was discussed at the FDA advisory committee meeting — would have created a logistical burden for patients.
The label contains suggestions about stopping therapy based on PET imaging. But PET imaging isn't a requirement. This will likely benefit Eli Lilly as some patients won't have access to regular PET scans. But Kisunla requires more MRI scans than Leqembi, RBC's Abrahams said.
For now, it seems Lilly has the edge over Biogen. Kisunla is given as a 30-minute intravenous infusion once a month. Leqembi is administered biweekly as an hourlong infusion. But Biogen is working on a subcutaneous — under-the-skin shot — of Leqembi.
"This should offset this dosing advantage," Abrahams said.
Follow Allison Gatlin on X, the platform formerly known as Twitter, at @IBD_AGatlin.
