The first of two Enbrel Phase III trials in psoriasis hit its primary and secondary endpoints, pushing Amgen Inc. to the halfway point in its quest to grow the blockbuster drug through the addition of another large market.
The trial showed that nearly half of the patients in the study responded with at least a 75 percent improvement in their Psoriasis Area and Severity Index score after 12 weeks of treatment. Nearly 60 percent of patients reached that endpoint after 24 weeks, the company said.
"This first Phase III in psoriasis showed we are seeing the same type of excellent results with Enbrel that we have over the last five years in both rheumatoid arthritis and psoriatic arthritis," said Rebecca Hamm, Amgen spokeswoman. "We are encouraged that this is another potential indication for Enbrel."
The second Phase III trial is under way. At the time of initiating the Phase III program, it was expected that both arms of the trial would enroll about 600 patients. Hamm said Amgen, of Thousand Oaks, Calif., expects to complete the second trial this year, but she said, "As of right now, we have not disclosed a filing timeline." (See BioWorld Today, July 8, 2002.)
Amgen gained Enbrel through its acquisition of Seattle-based Immunex Corp., a deal that was valued at $16 billion in stock and cash when it was first announced in December 2001. The record-setting price of the merger was attributed mainly to Enbrel - both the sales levels it had achieved and the higher ones it might achieve. The product, which acts by binding tumor necrosis factor, is approved for reducing the signs and symptoms and inhibiting the progression of structural damage in patients with moderately to severely active rheumatoid arthritis. It also is approved for psoriatic arthritis, and to reduce the signs and symptoms of moderately to severely active polyarticular-course juvenile rheumatoid arthritis in patients who have had an inadequate response to disease-modifying medicines. And it is being developed in additional indications. (See BioWorld Today, Dec. 18, 2001.)
Amgen's fourth-quarter earnings are scheduled to be released after the markets close Jan. 23. The company's guidance for Enbrel sales is between $1.2 billion and $1.4 billion for the year. SG Cowen Securities Corp. analysts Eric Schmidt and Yaron Werber forecast $1.2 billion for Enbrel sales in 2003, but said, "Enbrel looks to be the drug of choice in the rapidly growing rheumatoid arthritis and psoriatic arthritis markets with estimated 2006 sales of $2 billion-plus." (See BioWorld Today, July 23, 2002.)
Throw in the Amgen products Aranesp (the second generation of Epogen) and Neulasta (a sustained formulation of Neupogen), and the trio is enough to "drive top- and bottom-line growth of 20 percent annually with little associated clinical, regulatory or patent risk," SG Cowen said.
Amgen isn't the only company vying for the nearly 7 million psoriasis sufferers in the U.S. Competitors include Genentech Inc., of South San Francisco, and XOMA Ltd., of Berkeley, Calif., which in late December submitted their biologics license application for Raptiva as a treatment for moderate to severe psoriasis. Biogen Inc., of Cambridge, Mass., has its BLA for Amevive in psoriasis in the FDA's hands. Malvern, Pa.-based Centocor Inc.'s Remicade (infliximab), which is approved for Crohn's disease and rheumatoid arthritis, is being developed for psoriasis and is being used off label for that indication. But Enbrel's 50 percent and 60 percent achievements in the desired PASA scores compare favorably to its potential competitors.
Amgen's stock (NASDAQ:AMGN) rose 14 cents Friday to close at $51.32. Biogen's stock (NASDAQ:BGEN) fell $3.80, or 9.1 percent, to close at $37.93
Amgen recently received FDA approval of its Enbrel manufacturing facility in Rhode Island, helping to relieve the production stress it had felt in the past trying to supply enough Enbrel to meet demand. With that behind it, there is even more reason for investors to get behind Enbrel, said Leerink Swann & Co. analyst William Tanner.
"With expectations reset to a more attainable level and manufacturing shortfalls resolved, we believe Enbrel could realize its long-awaited breakout potential," he said in a research note.
Enbrel has been administered to more than 130,000 patients with a tolerability that "has been well sustained" and with "no surprises" cropping up in the scores of trials, Hamm said. Now with one psoriasis trial to go, Enbrel is a step closer to another approval.
"I think Enbrel has the potential to reclaim itself as the preferred biologic treatment in rheumatic diseases," Hamm said.