Alnylam stock tumbled Thursday after a split advisory panel recommended that the Food and Drug Administration approve its heart disease treatment.
The FDA's Cardiovascular and Renal Drugs Advisory Committee voted 9 to 3, saying the benefits of Alnylam Pharmaceuticals' drug, Onpattro, outweigh the risks for patients with transthyretin amyloid cardiomyopathy. In this condition, abnormal plaque called amyloid builds up on the heart. This can lead to heart failure.
But panelists suggested Onpattro would only be useful for patients who worsen while receiving Pfizer's tafamidis, which sells as Vyndaqel and Vyndamax. Patients treated with Onpattro showed improvements in symptoms. But Pfizer's drug has a proven benefit on mortality.
RBC Capital Markets analyst Luca Issi remained upbeat, despite the tumble for Alnylam stock.
"The vote is nonbinding, but we think approval on Oct. 8 is likely at this point," he said in a note.
On today's stock market, Alnylam stock toppled 8.8% to 193.06. The move put shares below their 50-day moving average, according to MarketSmith.com.
Alnylam Stock: Expanding Onpattro's Uses
Onpattro already treats patients with the nerve component of the same disease. But cardiomyopathy is, by far, the bigger opportunity.
Onpattro will likely only be used in patients who worsen while taking Pfizer's tafamidis, those who can't afford that drug — which carries a high Medicare copay — and patients with a specific form of the disease. Onpattro's results were "impressive" for those patients, Issi said.
Needham analyst Joseph Stringer says there's an 80% chance the FDA will approve Onpattro for cardiomyopathy patients. But questions linger.
"We acknowledge that investors may have concerns over a potentially restrictive label or how FDA's relatively pessimistic tone on the treatment effect will impact the approval decision," he said in a report. "And we think the stock will trade down today on those concerns."
That said, he eventually expects Alnylam stock to recover if the drug wins approval. Stringer kept his buy rating and 240 price target on shares.
A Follow-Up To Onpattro
Importantly, Alnylam is also studying a drug called vutrisiran for the same heart condition. The company expects to have the results of a Phase 3 study called Helios-B in early 2024.
Chardan analyst Keay Nakae says vutrisiran appears to be a better drug than Onpattro. Alnylam designed it to stay in the body for three times longer than Onpattro. This means patients won't need injections as frequently. In final-phase testing, patients received Onpattro intravenously every three weeks. Vutrisiran is an under-the-skin injection given every three months.
Alnylam is also examining the mortality benefit of vutrisiran, which could help it rival Pfizer's drug, Nakae said in a report. He has a buy rating and 250 price target on Alnylam stock. Similarly, Leerink Partners analyst Mani Foroohar expects Alnylam shares to be volatile until the Helios-B results become available in early 2024.
This will be "a major binary event for the stock where success is broadly expected," Foroohar said in a note to clients.
It's 'Full Steam Ahead' For Alnylam Stock
Vyndaqel and Vyndamax brought in a combined $2.45 billion in sales last year, growing 21% on a strict, as-reported basis. Operationally, sales surged 29%. Issi, the RBC analyst, noted only about 20% of patients with cardiomyopathy due to amyloidosis have been diagnosed, giving Alnylam room to run.
He kept his buy rating and 270 price target on Alnylam stock.
"Overall, we remain buyers of Alnylam given a commercially validated platform, a growing top line, an opportunity in transthyretin amyloid cardiomyopathy where tafamidis is a $3 billion drug today and a pipeline that appears to be full steam ahead," he said.
Follow Allison Gatlin on X, the platform formerly known as Twitter, at @IBD_AGatlin.
