Researchers have just announced that they have completed enrollment for a new Phase 3 trial for patients with transthyretin-mediated (ATTR) amyloidosis who have heart disease. This trial is examining a therapy called Onpattro to evaluate its safety and its efficacy in this patient population. The trial is called APOLLO-B and the researchers expect to release the results by the middle of next year.

This trial is based on the Phase 3 APOLLO trial with demonstrated that this therapy was able to reduce heart strain and the thickness of the left lower chamber of the heart.

ATTR Amyloidosis

ATTR amyloidosis is a name encompassing a few conditions, all characterized by abnormal transthyretin deposits. This protein can build up in the tissues and various organs, causing damage.

Familial amyloid polyneuropathy (FAP) is just one type of this condition. FAP is specifically caused by a gene mutation in the gene responsible for creating the protein transthyretin. In this form of the condition, the deposits typically accumulate within the nerves causing damage, and ultimately, polyneuropathy.

Onpattro has been shown to lessen the accumulation of this protein by using a form of technology called RNAi (RNA interference). This therapy has already been approved within the US, Japan, Canada, Brazil, Switzerland, and Europe for adults diagnosed with FAP.

The accumulation of transthyretin in both FAP and other forms of ATTR amyloidosis also has the potential to impact the heart. This damage can ultimately lead to cardiomyopathy. As such, the heart is unable to properly function, and heart failure is possible. In fact, cardiomyopathy is the primary reason of death for individuals diagnosed with ATTR amyloidosis.

APOLLO-B

The APOLLO-B study is taking place across 20 countries at 90 trial sites. Over 300 participants have been enrolled, all of whom are between the ages 18 and 85 and are diagnosed with cardiomyopathy as a result of ATTR amyloidosis.

All participants will be given .3mg/kg of either Onpattro or placebo by infusion. This infusion will occur once every 3 weeks for a total of one year. The primary endpoint of the trial is changes in the 6 minute walk test, which provides an understanding of patient’s physical fitness. Additionally, the researchers will evaluate the patient’s quality of life and measures of the heart’s performance.

After the year period, all patients will be able to join an open-label extension study to continue to receive the treatment.

You can read more about this clinical trial here.