By Kim Coghill

Washington Editor

The FDA gave Amgen Inc. clearance Wednesday to market Kineret (anakinra), an interleukin-1 receptor antagonist, for rheumatoid arthritis.

Amgen began its launch immediately following the announcement, Bob Baltera, Amgen¿s senior director of clinical development, told BioWorld Today.

¿This is our first venture into a field outside oncology or anemia,¿ Baltera said of Kineret. ¿This is a landmark for the company. We are moving into a new area, a new business unit that we believe is the third leg of the stool and will provide a lot of opportunity in the future. We have a strong pipeline in this area of inflammation and RA, and I¿m very excited to be a part of it ¿ it¿s like being a pioneer.¿

Baltera explained that Kineret works by blocking the effects of IL-1, which can lead to inflammation and damage to joints. RA patients produce too much IL-1. ¿There are two key proteins that play a role in the effects of RA. They are TNF-alpha [tumor necrosis factor] and interleukin-1. Up until today, physicians have only been able specifically to block the effects of TNF-alpha. Today, with the approval of Kineret, physicians can specifically block the effects of IL-1.¿

Kineret is indicated for the reduction in signs and symptoms of moderately to severely active RA in patients who have failed one or more disease modifying anti-rheumatic drugs (DMARDs). Kineret can be used alone or in combination with DMARDs, other than TNF-blocking agents.

Even though about 2 million people in the U.S. suffer from some level of RA, Elise Wang, biotechnology analyst with Salomon Smith Barney Inc. in New York, estimated Kineret would generate only $30 million in sales next year and upwards of $250 million worldwide at its peak.

¿We are predicting this will be somewhat of an incremental product for them, not a blockbuster,¿ she said. ¿It¿s an alternative product, a real niche product.¿

She said 20 percent to 30 percent of patients (about 300,000 in the U.S.) who do not respond to TNF blockers might have success with Kineret.

¿It does something different, but the efficacy levels are not as potent as a TNF blockers like Enbrel [Immunex Corp.] and Remicade [Johnson & Johnson],¿ Wang said. ¿And this is a daily injection and some patients aren¿t comfortable giving themselves shots.¿

Baltera disagreed with Wang¿s latter statement, saying patients suffering with moderate to severe RA are highly motivated. ¿We¿ve seen high compliance in our studies. Once they start feeling relief, a once-daily injection is a minor nuisance ¿ it¿s like diabetes.¿

In terms of efficacy, members of the FDA¿s Arthritis Advisory Committee raised questions about modest efficacy data, but in the end voted 6-2 in favor of approval. (See BioWorld Today, Aug. 17, 2001.)

Comparing Kineret to other drugs on the market, Baltera said it is impossible to say one drug is better than the other. ¿Every RA patient is different, so they respond differently to different drugs. Because of the nature of this disease, there is no one cure. Naturally, what we need to keep in mind is, there is still an unmet need in the marketplace, in that even the best therapies have been measured by 20 percent improvement on these clinical signs and symptoms. In the future, Amgen will continue research and efforts in this area to really get to a place where we can give physicians all the tools to safely and effectively come as close as possible, if not one day, to cure this disease.¿

Amgen¿s package for FDA approval included Phase III data from a 500-patient efficacy study and a 1,300-patient safety study.

Amgen¿s stock (NASDAQ:AMGN) closed Wednesday at $57.33, down 66 cents.