Transthyretin-mediated amyloid cardiomyopathy (ATTR-CM) is a fatal condition caused
by misfolding and aggregation of transthyretin (TTR). Despite the treatment with a
TTR stabilizer, tafamidis, disease progression still occurs. IONIS-TTR-LRx is an antisense
oligonucleotide that inhibits TTR production by the liver. It has the same sequence
as inotersen but is conjugated to a triantennary N-acetyl galactosamine (GalNAc) moiety,
which allows the use of a lower dose to achieve identical pharmacodynamic results.
METHODS AND RESULTS
CARDIO-TTRansform (ClinicalTrials.gov NCT04136171) is a Phase 3 global, double-blind,
randomized, placebo-controlled study assessing the efficacy and safety of IONIS-TTR-LRx
in hereditary and wild-type ATTR-CM patients. Approximately 750 patients will be randomized
1:1 to receive either IONIS-TTR-LRx 45 mg or placebo administered by monthly SC injection.
Key inclusion criteria include ATTR-CM diagnosis by biopsy or positive PYP/DPD/HMDP
scan, interventricular septum thickness >12mm, NT-proBNP >600 pg/mL, NYHA class I-III
and 6-minute walk distance (6MWD) ≥150m. Concomitant treatment with tafamidis is allowed.
Primary efficacy endpoint is the composite of cardiovascular (CV) mortality and recurrent
CV clinical events at the Week 120 study visit using the Andersen-Gill method.
The CARDIO-TTRansform trial is a Phase 3 trial designed to evaluate the clinical efficacy
and safety of IONIS-TTR-LRx for the treatment of ATTR-CM.