Proof-of-Concept Trial to Assess the Efficacy and Safety of Fezolinetant in Improving Vasomotor Symptoms in Men With Prostate Cancer Undergoing Androgen Deprivation Therapy

Prostate cancer is the most common type of cancer in men. At the time of initial diagnosis, most men have disease that is confined to the prostate and are typically managed through surveillance or local treatments, such as prostatectomy or radiation therapy. Since the prostate relies on androgens (male hormones), androgen deprivation therapy is the primary treatment for patients with locally advanced, recurrent, or metastatic prostate cancer.

Androgen deprivation therapy involves suppressing the production of androgens in men, which can be achieved through orchiectomy (removal of the testes) or medications like gonadotropin-releasing hormone agonists or antagonists that lower serum testosterone levels to a castrate range (less than 20 ng/dL). In men, 95% of serum estrogen comes from the aromatization of testosterone. Consequently, androgen deprivation not only leads to androgen deficiency but also results in near-absolute estrogen deficiency. The absence of sex hormones in these patients can cause numerous adverse effects, including sexual dysfunction, and loss of muscle and bone. Among these side effects, vasomotor symptoms (such as hot flashes) are particularly debilitating. These symptoms are characterized by sudden feelings of intense heat that spread throughout the body, prompting the activation of heat-dissipation mechanisms to lower body temperature.

Hot flashes are reported by 70-80% of men undergoing androgen deprivation therapy, typically beginning a few weeks after treatment starts, with most men experiencing more than five episodes daily. These vasomotor symptoms significantly affect the patient's quality of life, sleep quality, concentration, and overall productivity. Despite the burden they impose, effective treatments for hot flashes in men undergoing androgen deprivation therapy are still lacking.

The introduction of neurokinin 3 (NK3) receptor antagonists has brought hope to this area. Fezolinetant is a selective NK3 receptor antagonist that has recently been approved for treating moderate to severe vasomotor symptoms in menopausal women. Given that the underlying cause of vasomotor symptoms in both menopausal women and men on androgen deprivation therapy stems from estrogen deficiency, fezolinetant offers an opportunity to assess its efficacy and safety for male patients.

No previous studies have evaluated the effectiveness of NK3 receptor antagonists on vasomotor symptoms in men undergoing androgen deprivation therapy for prostate cancer. Since prostate cancer is the most prevalent solid tumor in men and vasomotor symptoms are common, distressing, and highly burdensome, a trial demonstrating the safety and efficacy of fezolinetant could provide clinicians and patients with a novel, effective, safe, and easy-to-administer treatment that has the potential to transform care for these patients.

• Change in quality-of-life symptoms related to hot flashes, as assessed using the Hot Flash-Related Daily Interference Scale [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in overall quality of life, as assessed using the Short Form-36 questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in sleep quality, as assessed using the Patient-Reported Outcomes Measurement Information System Sleep Disturbance questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in mood, as assessed using the Positive and Negative Affect Schedule questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in sexual function, as assessed using the Sexual Arousal, Interest and Drive questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in inflammatory status, as assessed by measuring high-sensitivity C-reactive protein (hsCRP) levels [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in fatigue, as assessed using the using the Hypogonadism Energy Diary questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in fatigue, as assessed using the using the Functional Assessment of Chronic Illness Therapy - Fatigue questionnaire [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in fasting glucose level [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in glycated hemoglobin (HbA1c) level [Time frame: From baseline to the end of treatment at 4 weeks.]
• Change in fasting lipid levels [Time frame: From baseline to the end of treatment at 4 weeks.]