Alnylam Pharmaceuticals Inc., the developer of a treatment for a rare genetic disorder, rose the most ever after the drug showed promise in an early clinical trial.
Alnylam increased 53 percent to $19.16 at the close in New York, the largest one-day gain since it began trading in 2004. The Cambridge, Massachusetts-based company said today that its experimental drug for TTR-mediated amyloidosis reduced levels of the protein that causes the disease by as much as 94 percent in 17 healthy volunteers.
The company’s trial looked at safety, as well as different doses and the drug’s effectiveness in reducing the protein. The treatment targets the mutated gene, TTR, which causes a harmful accumulation of the protein in the heart, nervous system and gastrointestinal tract.
“It’s Phase I but you should think of it as Phase II,” Michael King, an analyst with Rodman & Renshaw in New York. The trial’s results also suggest that Alnylam could use its technology to block genes from performing their function in other diseases, he said.
Alnylam has now started a second of three phases of clinical trials usually needed for regulatory approval and will treat 20 patients. The company plans to start the third and final stage of trials in 2013, with about 120 patients, Chief Executive Officer John Maraganore said in a telephone interview.
The company will stay independent and plans to develop the treatment without a partner, Maraganore said.
“We intend to keep the rights and develop the company based around these drugs,” he said.
King was one of two analysts who follows the company to say that’s possible, given the small number of patients to treat. “In orphan disorders, small companies have proven themselves highly capable,” said King.
The disease is caused by a mutation in the gene responsible for producing the transthyretin protein. In people with the genetic defect, transthyretin made by the liver breaks apart, forms into clumps, and damages the nerves and heart. Currently a liver transplant is the only available treatment.
Alnylam’s drug, called ALN-TTR02, stops production of transthyretin. The company is focusing on patients with TTR-FAP, or transthyretin familial amyloid polyneuropathy. The company estimates that as many as 10,000 patients have the disease. In TTR-FAP, the protein attacks the body’s longest nerves first, often killing them within a decade as the body shuts down.
In patients with familial amyloidotic cardiomyopathy, the protein clumps damage the heart. About 40,000 people have that version of the disease, Alnylam estimates.
“This is a good indication for a biotech company of this size,” Marko Kozul, an analyst with Leerink Swann in Boston, said in a telephone interview. Alnylam has a “rapid path” to develop the drug and bring it to market, he said. “You’re not talking about a 3,000 patient breast cancer study. You’re talking about a 150 patient phase III.”
Pfizer Inc., the world’s largest drugmaker, saw its drug, Tafamidis, for the same disease rejected by the U.S. Food and Drug Administration in June. It is approved for sale in Europe under the name Vyndaqel. The FDA has asked for more data showing the drug’s effectiveness. Pfizer has said it will continue talking with the FDA about the drug.
“Tafamidis unfortunately, was a bit underpowered as a study,” Maraganore said. “The FDA took a more conservative approach than the Europeans did.” He predicted that if both drugs are approved, they could end up being used in tandem.