Despite this setback in the SMA context, branaplam has demonstrated promise in reducing huntingtin mRNA levels, the mutated protein in Huntington's disease (HD), earning the US FDA Orphan Drug Designation for HD, with a phase IIb trial started in 2021 but soon terminated in 2022, due to the observed peripheral neuropathy and other side effects [120]. Here, HTT is linked to Huntington disease.