In the U.S. approximately 40 million women are at or near menopause, and some 45 million are beyond menopause. Up to 80% of women may experience hot flashes during the perimenopause transition or after menopause.
Currently available therapies to treat hot flashes include hormone replacement therapy (estrogen with or without progesterone, or a synthetic progestin), gabapentin, SSRIs, clonidine, and herbal products. These therapies have well-known side effects (hormonal treatments, SSRIs, gabapentin, clonidine) or have been proven ineffective to treat menopausal hot flashes (herbal products).
Although estrogens have been proven to relieve hot flashes, use in the U.S. became sharply curtailed after 2002 with concerns about breast cancer and cardiovascular events associated with chronic treatment. At present, there is no alternative prescription medication approved by the US Food and Drug Administration for the treatment of menopausal hot flashes.
Nasal Spray Study
Pherin Pharmaceuticals conducted a Phase 2 exploratory randomized study in 40 eligible volunteers age 45-65 years, to compare the effectiveness and tolerability of 1.6 micrograms PH80-HF nasal spray for the acute management of daily menopausal hot flashes. Study medication or a placebo was administered six times daily for two consecutive weeks. The primary outcome measures were the significant improvement in the severity, number of hot flashes, and the following objective parameters: body temperature, electrodermal activity, and skeletal muscle tension. Secondary endpoints included tolerability and safety of Salubrin-HF nasal spray.
The results of this study showed rapid onset of action of PH80 (35-65 sec) after intranasal spray administration of 1.6 micrograms. Physiologic parameters that were increased during the occurrence of hot flashes improved significantly better than placebo after administration of Salubrin-HF: body temperature (p < .02), electrodermal activity (p < .01) and muscle tension (p < .04).
PH80-HF (1.6 micrograms) improved the severity (p < .02) and the number (p < .07) of daily hot flashes along the 14-day in-house treatment period. Intranasal administration of PH80-HF was safe, and there were no reports of local (nasal) or systemic side effects and severe adverse effects during the treatment period and the follow-up period.