The drug tocilizumab performs better than steroids in treating the most common form of blood vessel inflammation known as giant cell arteritis, a new study has shown.

The phase 3 clinical trial of 251 patients confirmed that tocilizumab (Actemra) reduced symptoms and also the need for high-dose steroid treatment for the condition. Phase 3 clinical trials represent the last phase before approval for general use. They compare the safety and effectiveness of the new treatment against the current standard treatment.

The trial results led to the U.S. Food and Drug Administration's recent approval of tocilizumab to treat giant cell arteritis. It's the first new treatment for arterial inflammation in more than 50 years.

"Giant cell arteritis affects around 250,000 individuals in the U.S. alone, targeting people over the age of 50, and is three times more likely in women," said study lead author Dr. John Stone, a rheumatologist at Massachusetts General Hospital.

"This trial is the first to demonstrate beyond any doubt that an alternative to chronic, unending steroid treatment exists," Stone said in a hospital news release.

"One of the most surprising findings was just how poorly the traditional, steroid-only regimens worked. These results are likely to have an immediate, sustained impact on the lives of hundreds of thousands of patients across the world," he said.

Giant cell arteritis primarily affects arteries in the head, neck and eyes, as well as the aorta and its primary branches. It causes blindness in up to 20 percent of patients. They are also at increased risk for stroke and aortic aneurysms.

Symptoms of giant cell arteritis include headache, pain in the scalp or other areas, and changes in vision, which can be sudden.

Until now, steroids have been the only effective treatment. But most patients require high doses of steroids, which can cause serious side effects such as weight gain, body fat redistribution, osteoporosis, mood changes, high blood pressure, glucose intolerance and increased risk of infection, the researchers said.

Actemra injections are already used to treat rheumatoid arthritis.

The study results were published July 26 in the New England Journal of Medicine.