Avidity Biosciences (NASDAQ: RNA) announced encouraging initial data from the phase I/II FORTITUDE study evaluating two doses of delpacibart braxlosiran (del-brax, or formerly AOC 1020) in facioscapulohumeral muscular dystrophy (FSHD), a rare genetic disease of the muscles. Data from the study showed that treatment with 2mg/kg dose of del-brax achieved greater than 50% mean reductions in DUX4 regulated genes for 12 patients at the four-month timepoint. The early data also showed trends of improving muscle strength and function in patients treated with this dosage.   Though Aviditydid not reveal the details of patients who received a 4mg/kg dose of del-brax, it stated that all participants who received the drug achieved reductions greater than 20% in DUX4 regulated genes. Treatment with del-brax also exhibited a favorable safety and tolerability profile, with no serious adverse events and no discontinuations. Based on the above results, management now plans to accelerate the initiation of registrational cohorts in the FORTITUDE study. Shares of RNA were up 32.6% on Wednesday as investors cheered the results. The results show the potential of del-brax to address the underlying cause of FHSD, which is the ...