Disease-modifying Therapies Found to Extend Patient Survival
Treatment with disease-modifying therapies can extend survival in people with familial amyloid polyneuropathy (FAP), a new study indicates.
The study, “Use of Drugs for ATTRv Amyloidosis in the Real World: How Therapy Is Changing Survival in a Non-Endemic Area,” was published in the journal Brain Sciences.
FAP is caused by mutations in the TTR gene. As a result, the protein called transthyretin, encoded by this gene, forms misfolded clumps in the body that are toxic to several tissues and organs.
Over the past few decades, there have been substantial advances in how FAP is treated, with several medications gaining regulatory approvals. While studies have broadly demonstrated the benefits of these treatments in the short term, there is a lack of data on how these therapies might affect patient survival.
“The aim of this work was to analyze whether current therapies have prolonged survival in Sicilian patients affected by [FAP],” the researchers wrote.
The team of researchers from Italy analyzed data from 105 FAP patients who had been followed at two Sicilian referral centers from 1991 to 2020. Seven of the nine researchers declared that they had received speaker fees and/or consulting honoraria from pharmaceutical companies.
Among these patients, 71 had been treated with disease-modifying therapies, meaning treatments that have been proven to alter the course of the disease, while the remaining 34 had not received any treatment specifically for FAP. These disease-modifying therapies included Onpattro (patisiran), tafamidis (sold as Vyndaqel, among other brand names), Tegsedi (inotersen), and liver transplantation.
These two groups were similar in terms of demographic and clinical characteristics, including age at disease onset, type of symptoms experienced, and specific TTR gene mutations.
Statistical analyses demonstrated that patients who received these treatments lived longer than those who did not (median of 12 vs. eight years). Additional analyses that included only individuals who were already deceased also showed a significant benefit associated with the use of disease-modifying therapies.
Further analyses indicated that the beneficial effect of treatment on patient survival was not affected by heart involvement and weight loss at diagnosis, or by specific TTR mutations.
However, the investigators found that treatment provided a greater benefit in terms of survival to patients who had a polyneuropathy disability (PND) score of one at diagnosis — meaning those who had no walking impairments — compared with those who had more substantial walking difficulties.
“Disease-modifying therapies … have significantly improved the survival of patients,” the researchers concluded. “When patients are diagnosed with a PND score of 1, their overall survival is longer.”