A novel treatment for a rare genetic disease is getting closer to approval.

Alnylam Pharmaceuticals reported patisiran, an investigational therapy using RNA interference to treat hereditary ATTR (hATTR) amyloidosis with polyneuropathy, met the primary efficacy endpoint and all secondary endpoints in a phase III study called APOLLO.

The primary endpoint was based on how the drug could induce a change from the baseline in the modified neuropathy impairment score (mNIS+7) at 18 months whereas the key secondary endpoint was based on quality of life improvement assessed by the Norfolk Quality of Life Questionnaire-Diabetic Neuropathy (Norfolk QOL-DN).

About 225 patients with this condition, which accounted for 39 genotypes of the condition, enrolled in this randomized trial where investigators intravenously administered 0.3 mg/kg of patisiran once every three weeks for 18 months.

Results had indicated the mean and median changes in mNIS+7 impairment scores for the drug reached negative values, which indicated an improvement overall especially in the majority of patients compared to the baseline.

Patients in the patisiran group also produced an improvement in quality of life compared to placebo based on negative values.

Other notable secondary goals that were achieved included statistically significant favorable differences in the patisiran arm, such as improved muscle strength, gait speed, and reporting of better daily living and disability metrics.

"This is a significant milestone that supports our belief that RNAi therapeutics have the potential to become an innovative new class of medicines for patients with rare genetic diseases," said Elias Zerhouni, M.D., the president of Global R&D at Sanofi, in a statement. Alnylam is handling the development of the drug with plans to commercialize it in the U.S., Canada and Western Europe while Sanofi will handle filings for Japan, Brazil, and other countries.

"The APOLLO data suggest that patisiran could help improve the lives of people living with hATTR amyloidosis with polyneuropathy, a patient population in urgent need of additional treatment options. We look forward to working with Alnylam to make patisiran available around the globe as quickly as possible,” continued Zerhouni.

Patisiran harnesses the body’s natural processes to lower the levels of the TTR protein that produces TTR amyloidosis. It initiates this process by targeting and silencing specific messenger RNA therefore blocking the production of the protein before it is made to helpi clear TTR amyloid deposits in peripheral tissues and possibly restoring function.

This could be a significant improvement over current treatments for hATTR, which are either liver transplantations for early-stage disease or tafamidis, a drug approved in Europe, Japan, and certain Latin America countries, reported Reuters.

Alnylam plans on submitting a New Drug Application to the U.S. Food and Drug Administration in late 2017 and a Marketing Authorization Application in Europe shortly after that. Sanofi will submit regulatory filings in the other countries starting in the first half of 2018.