– Novel, Potent, Selective NK3 Antagonist in Phase 2 Clinical Development for Menopausal Hot Flashes –
– Statistically Significant Effect on Pharmacodynamic Markers of NK3 Receptor Antagonism and Once-Daily (QD) Pharmacokinetic Profile –
Sojournix, a clinical-stage biopharmaceutical company developing transformative medicines for women’s health and neuroendocrine disorders, announced today the publication of results from a Phase 1 proof-of-mechanism clinical study of SJX-653 in The Journal of Clinical Endocrinology & Metabolism. SJX-653 is a novel, potent, highly-selective neurokinin 3 (NK3) antagonist in clinical development as a non-hormonal once-daily treatment for moderate to severe vasomotor symptoms (VMS) due to menopause, commonly called hot flashes.
“We are delighted to see the first human study with the new neurokinin 3 receptor antagonist, SJX-653, now published,” said Dr. Richard Anderson, MD, PhD, publication author and Professor of Clinical Reproductive Science at the University of Edinburgh. “These data are likely to translate into an effective once-a-day medication for menopausal hot flashes.”
In this study, SJX-653 demonstrated statistically significant and dose-dependent effects on pharmacodynamic markers of NK3 antagonism. SJX-653 exhibited a plasma half-life supporting once-daily (QD) dosing and was well tolerated. Top-line data from this study were previously presented in a scientific poster at ENDO 2019, the Endocrine Society’s 101st Annual Meeting.
The proof-of-mechanism study was a randomized, placebo-controlled, double-blind, single ascending dose study of SJX-653 (0.5 to 90 mg) in 42 healthy adult men. The effect of SJX-653 on luteinizing hormone (LH) and total testosterone (T), established pharmacodynamic markers of central NK3 receptor antagonism, was measured. In addition, the safety, tolerability, and pharmacokinetics of SJX-653 were assessed.
Data highlights from the study include:
- SJX-653 demonstrated statistically significant, dose-dependent and reversible reductions in LH and T in healthy adult men vs. placebo.
- SJX-653 15 mg achieved near maximal effect with 57% reduction in LH and 55% reduction in T vs. 4% and 23% with placebo (p<0.01 for both) at the corresponding timepoints.
- Reductions in T followed reductions in LH by 2-3 hours, consistent with the longer plasma half-life of T and underlying biology.
- Reduction of FSH at higher doses was additional evidence of NK3R antagonism in men.
- SJX-653 exhibited a long plasma half-life of 10-13 hours, consistent with once-daily (QD) dosing, and a low Cmax to C24 ratio predicting a peak to trough ratio of ~3:1 upon repeat dosing.
- SJX-653 was well tolerated and no safety concerns were identified.
SJX-653 is a novel, potent, and selective neurokinin 3 (NK3) antagonist in Phase 2 clinical development as a non-hormonal once-daily (QD) therapy for moderate to severe vasomotor symptoms (VMS) due to menopause. NK3 antagonism is a clinically and genetically validated new approach for treating menopausal hot flashes. During menopause, declining estrogen levels lead to an over-production of neurokinin B (NKB), an endogenous neuropeptide that binds to and activates NK3 receptors. By reducing the excessive signaling of NKB through NK3 receptors in the hypothalamic area of the brain that regulates heat dissipation, SJX-653 is expected to alleviate vasomotor symptoms due to menopause.
About Vasomotor Symptoms (VMS)
Vasomotor symptoms (VMS), or hot flashes, are sudden sensations of intense heat, sweating, and skin reddening that can occur frequently in menopausal women. VMS occur both during the day and night, disrupting daily activities and sleep, and are associated with increased rates of insomnia, depression, and cognitive impairment. More than 2 million women in the United States enter menopause each year and the majority experience VMS, with symptoms typically persisting for many years during and after menopause. Current treatment options are limited to hormone therapy, which patients and physicians often avoid due to safety concerns, or non-hormonal agents known to have limited efficacy. There is a significant unmet medical need for a new non-hormonal approach.
Sojournix is a clinical-stage biopharmaceutical company dedicated to developing and commercializing transformative new medicines for the treatment of women’s health and neuroendocrine disorders. The company is developing SJX-653, a novel, potent, selective neurokinin 3 (NK3) antagonist as a non-hormonal once-daily therapy for moderate to severe vasomotor symptoms (commonly called hot flashes) due to menopause. NK3 antagonism is a clinically and genetically validated new approach to treating menopausal hot flashes that targets the excessive signaling of neurokinin B through NK3 receptors in the hypothalamic area of the brain that regulates heat dissipation. To learn more about Sojournix, please visit www.sojournixpharma.com.
For media or investor inquiries: