Why Is Dyne Therapeutics Stock Soaring On Monday?

Monday, Dyne Therapeutics Inc DYN released clinical data from its ongoing Phase 1/2 ACHIEVE trial of DYNE-101 in patients with myotonic dystrophy type 1 (DM1) and its ongoing Phase 1/2 DELIVER trial of DYNE-251 in patients with Duchenne muscular dystrophy (DMD) who are amenable to exon 51 skipping. 

Earlier this year, Dyne Therapeutics released initial clinical data from both trials.

In the ACHIEVE trial, patients in the 5.4 mg/kg Q8W cohort had a 27% mean splicing correction from baseline across a broad, 22-gene panel at 3 months, with all participants demonstrating splicing correction.

DYNE-101 demonstrated an improvement in myotonia as measured by video hand opening time (vHOT) in all reported cohorts. 

The 1.8 mg/kg Q4W group had a mean 3.1-second benefit in myotonia at 3 months, increasing to 4.4 seconds at 12 months. 

In addition, the 5.4 mg/kg Q8W cohort had a mean 4.5-second improvement in myotonia at 3 months.

DYNE-101 demonstrated an improvement in muscle strength and early and sustained potential benefit in the 10-meter Walk/Run Test and 5-times to Stand Test.

Dyne reported efficacy data from 8 male patients with DMD amenable to exon 51 skipping enrolled in the 10 mg/kg (approximate PMO dose) cohort of the randomized, placebo-controlled MAD portion of the DYNE-251 DELIVER trial.

10 mg/kg of DYNE-251 Q4W demonstrated dose-dependent exon skipping and dystrophin expression. 

DYNE-251 reached levels of dystrophin expression that exceeded levels reported in a clinical trial for the current weekly standard of care for DMD exon 51, eteplirsen, at 6 months1 with a 12-fold lower PMO dose. 

DYNE-251 also demonstrated encouraging trends in multiple functional endpoints.

Patients treated with 10 mg/kg of DYNE-251 Q4W had a mean absolute dystrophin level of 3.22% of normal and a 2.97% change (unadjusted for muscle content) from baseline at 6 months. 

Eteplirsen reached a mean absolute unadjusted dystrophin level of 0.30% of normal and a 0.06% change from baseline at 6 months.

When adjusting for muscle content, the DYNE-251 treated group reached 7.64% mean absolute dystrophin, greater than levels reported by peptide conjugate PMOs in clinical development.

Trends in improvement were observed in multiple functional endpoints in the 10 mg/kg DYNE-251 Q4W group at 6 months.

Price Action: DYN shares are up 27.80% at $35.36 at the last check Monday.