Study shows promising treatment of knee osteoarthritis

Injections of the drug sprifermin, either once or twice a year, slightly improved cartilage thickness

The knee is the largest and strongest joint in your body. If it deteriorates, it causes mobility problems and pain.

More than 10 percent of Americans older than 60 experience knee pain related to osteoarthritis, the most common disease of the knee joint. In osteoarthritis, the cartilage in the knee joint gradually wears away.

Researchers at the University of Maryland School of Medicine may have found a way to alleviate deterioration, however.

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Their study involved 549 volunteers who were randomly assigned to receive injections of either 30 micrograms of sprifermin, recombinant human fibroblast growth factor 18; 100 micrograms of sprifermin; or a placebo.

MRIs revealed the group that received the 100 microgram dose, either once or twice a year, had a slight gain in joint cartilage thickness even after two years. The group given the smaller dosage showed smaller gains. The placebo group lost cartilage during the same period.

None of the study participants experienced any significant improvement in their arthritis symptoms, however.

When the researchers went back and analyzed a small group of the participants — osteoarthritis patients with severe pain and narrow joint space in their knee who were at higher risk of disease progression — that received 100 micrograms of sprifermin every six months showed significant improvement in their symptoms 18 months after their last shot.

"These results support further investigation of sprifermin as a potential osteoarthritis treatment for both structure modification and symptom relief for higher-risk patient populations," said Marc Hochberg, lead investigator and a professor of medicine at UMSOM.

The study was published Tuesday in the Journal of the American Medical Association.