A new drug being developed by Sanofi and Regeneron Pharmaceuticals Inc. has successfully passed a clinical trial proving its effectiveness in easing the pain and damage caused by rheumatoid arthritis.

The clinical trial involves 1,200 patients who reported insufficient treatment from methotrexate which is the most commonly used drug to treat several forms of arthritis and other rheumatic conditions. The new study combined it with another drug “sarilumab.”

They divided the patients into three groups: methotrexate with 200 mg sarilumab, methotrexate with 150 mg sarilumab, and placebo.

The researchers found that combining the two drugs have doubled the benefits of the patients. The mixed treatment eased the pain and stiffness twice than if they take the methotrexate alone. Joint damage also decreased by 90 percent.

In a Wall Street Journal report, the American College of Rheumatology measured a 20 percent improvement on the conditions of the patients after 24 weeks of the treatment. There was also improvement on the movement at week 16 and less joint damage at week 52.

However, 14 percent of those in the first group who has 200 mg of sarilumab showed side effects and infections. This percentage is higher than the five percent withdrawal rate of methoxerate alone.

"Irreversible joint damage can be a consequence for patients suffering from rheumatoid arthritis, and this is accompanied by reduced physical function in these patients," said Tanya M. Momtahen, M.S., Sarilumab Global Project Head, Sanofi. "This remains a major concern for rheumatoid arthritis patients. We are encouraged by these Phase 3 results and the impact sarilumab demonstrated on inhibition of progression of structural damage assessed radiographically in this study."

According to Bloomberg, this clinical trial is just one of the two trials needed for Sanofi to receive approval for sarilumab. The company can get as much as $780 million worth of revenue by 2020 once approved.