AEON Biopharma, Inc. announced positive topline results from its Phase 2 clinical study of ABP-450 for the treatment of cervical dystonia (CD), a chronic and debilitating neurologic condition affecting the muscles of the neck. The Phase 2 randomized, double-blind, placebo-controlled study analyzed a total of 57 patients across a total of 20 study sites in the United States. Patients were divided evenly across four cohorts, including a low dose (150 units), mid-dose (250 units) and high dose (350 units) treatment of ABP-450, and placebo.

Each patient received a single treatment cycle of their designated dose of ABP-450 or placebo. Patients were followed up to a total of 20 weeks, and the primary efficacy endpoint was assessed at four weeks after dosing. Due to the nature of the disease, dosing is tailored to the individual patient by the investigator based on the severity of the patient's head and neck position, localization of pain, muscle hypertrophy, patient response, and adverse event history.

The study met its primary safety endpoint with all three doses of ABP-450 appearing to be generally safe and well tolerated with adverse event rates similar to, or lower than, other botulinum toxin products for the treatment of cervical dystonia. All treatment-related adverse events were mild or moderate in severity and transient in nature, with no serious adverse events. Each of the three active arms demonstrated low rates of dysphagia (0.0%, 12.5%, and 20.0%) and muscle weakness (14.3%, 0.0%, and 6.7%), which are common toxin-related adverse events in CD patients.

The main efficacy endpoint assessed the change at week four from baseline in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Total Score, the gold standard in cervical dystonia trials. All three doses demonstrated a clinically meaningful improvement in the signs and symptoms of cervical dystonia, with peak efficacy occurring at week four. Subjects treated with the low and mid doses of ABP-450 showed a statistically significant improvement from baseline at week four, compared with placebo, while the dose narrowly missed statistical significance.

The mean improvement from baseline in TWSTRS was 3.57 for placebo, 14.01 for 150 U (p=0.007), 11.28 for 250 U (p=0.0406), and 9.92 for 350 U (p=0.0864), which compares favorably to clinical trials of other botulinum toxin products.