Amvuttra Approved in Europe as Polyneuropathy Treatment for FAP
European Commission OKs under-the-skin therapy 3 months after FDA
The European Commission has approved Amvuttra (vutrisiran) as a treatment for familial amyloid polyneuropathy (FAP) — also known as hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy — for people in the EU with stage 1 or stage 2 polyneuropathy.
The decision was announced by the medication’s developer, Alnylam Pharmaceuticals, which noted in a company press release that more than 50% of patients given the under-the-skin (subcutaneous) treatment in a Phase 3 clinical trial saw their polyneuropathy symptoms halted or reversed.
“On behalf of patients across Europe, we could not be prouder to announce the approval of Amvuttra … for hATTR amyloidosis,” said Kasha Witkos, senior vice president and international region head at Alnylam.
The approval in Europe comes just a few months after Amvuttra was approved to treat FAP in the U.S. The therapy is under review in Japan and Brazil.
“Today’s decision now means we can progress working with health authorities across Europe to achieve responsible and sustainable access arrangements that allow us to bring Amvuttra to patients as quickly as possible,” Witkos said, adding, “Our thanks go to the patients, families, investigators and study staff who have enabled us to reach this significant milestone.”
In FAP, mutations in the TTR gene lead to production of an abnormal form of a protein called transthyretin, which forms toxic clumps in body tissues, ultimately causing disease symptoms.
Amvuttra is an RNA interference (RNAi) therapy that is designed to lower transthyretin production by targeting and silencing its messenger RNA, an intermediate molecule that cells normally use as a template to make proteins.
Its mechanisms of action is virtually identical to that of Onpattro (patisiran), a previously approved FAP treatment also developed by Alnylam. Amvuttra was designed to be more stable in the body than Onpattro, which could allow for a more powerful and longer-lasting therapeutic effect.
“Although the considerable research into hATTR amyloidosis over the past few years has resulted in a more positive outlook for those diagnosed with the condition, there remain unmet needs in treatment for patients living with this rapidly progressive, multi-system disease” said David Adams, MD, PhD, head of the neurology department at Bicêtre Hospital AP-HP, University of Paris-Saclay.
“RNAi therapeutics are changing the future of medicine,” Adams said.
Amvuttra in trial
Amvuttra’s approval in Europe was supported by data from the Phase 3 HELIOS-A trial (NCT03759379).
In the study, 164 adults with FAP were randomly assigned to receive either Amvuttra or Onpattro. Amvuttra was given via under-the-skin injection every three months, while Onpattro was administered via infusion directly into the bloodstream (intravenously) every three weeks.
All participants in HELIOS-A had either stage 1 or 2 polyneuropathy, meaning symptoms of numbness and pain were present, but there was not debilitating pain or a complete loss of sensation.
Data from the ongoing study showed that treatment with Amvuttra significantly reduced polyneuropathy symptoms after 18 months, as indicated by a mean decrease of 0.46 points on the modified Neuropathy Impairment Score (mNIS+7), as compared with an external placebo group.
The therapy also improved measures of life quality and physical disability, and exploratory analyses suggested it also could lessen heart damage.
The most common side effects associated with Amvuttra in HELIOS-A were joint stiffness and pain in the arms and legs. Less common side effects included injection site reactions, shortness of breath, and increases in blood levels of a liver enzyme called alkaline phosphatase.
“Results from the HELIOS-A study have shown the potential Amvuttra has to benefit patients with hATTR amyloidosis with stage 1 or stage 2 polyneuropathy, whilst also helping reduce treatment burden through subcutaneous dosing once every three months,” said Adams, the lead investigator of HELIOS-A.
“I am honored to have contributed to these research efforts that have enabled us to bring an innovative new medicine to patients,” Adams added.
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