Long-term Vyndaqel Improves Survival in FAP, Study Suggests

Long-term treatment with Vyndaqel (tafamidis) may reduce the risk of death in people with familial amyloid polyneuropathy (FAP), a study shows.

The study, “Evaluation of Mortality During Long-Term Treatment with Tafamidis for Transthyretin Amyloidosis with Polyneuropathy: Clinical Trial Results up to 8.5 Years,” were published in the journal Neurology and Therapy.

FAP is caused by the buildup of a mutated version of the protein transthyretin (TTR), particularly in nerves and the heart. Vyndaqel, developed by Pfizer, works by stabilizing the altered TTR, which may halt the formation of disease-causing protein deposits.

This therapy is approved for FAP in Europe. In the U.S., it is approved for the treatment of a TTR-associated heart disease called TTR cardiac amyloidosis, but not for FAP.

Previous research has shown that long-term Vyndaqel treatment can delay the progression of neurologic disease in FAP. However, the effect of this treatment on survival has not been thoroughly assessed.

The Pfizer-funded study assessed data from three clinical trials (NCT00409175, NCT00791492 and NCT00630864), whose participants joined an ongoing, 10-year, Phase 3 study (NCT00925002). Overall, this included data from 93 people with FAP who had received long-term treatment with Vyndaqel of up to 8.5 years.

Most of the trial participants (75) had the Val30Met mutation in the TTR gene, the most common cause of FAP. Participants without this mutation were older, had a longer duration of symptoms, and showed more advanced disease at study enrollment than those who did have the mutation.

As of the study’s cut-off date (Jan. 3, 2017), 11 patients had died. None of these deaths were considered related to Vyndaqel treatment.

“There were very few deaths observed during tafamidis treatment,” the researchers wrote.

They then conducted an analysis data to predict long-term survival rates based on Val30Met mutation status. For people with this mutation, the survival rate was approximately 85% at nine years. For those without, the survival rate was about 75% at eight years.

Based on when participants started treatment, eight or nine years on Vyndaqel corresponds to around 11 to 14 years since the onset of FAP symptoms.

Given data indicating approximately 10-year survival in untreated FAP patients, these findings reveal a high survival rate in those treated with Vyndaqel, the investigators said.

“Long-term tafamidis [Vyndaqel] treatment may confer survival benefit in patients with [FAP],” the scientists wrote. Adding that these findings warrant longer-term data, the investigators added that the results “underscore the importance of early treatment intervention with tafamidis.”

Notably, three of the study’s authors are employees of Pfizer while two others received funding from the company.