Fosaprepitant Dimeglumine

Pruritus, commonly known as itching, is an unpleasant sensation that triggers the urge to scratch, which may provide temporary relief. Pruritus can be intermittent or persistent, localized or widespread, and may be associated with medication use. Chronic pruritus, defined as lasting more than six weeks, can significantly affect sleep and quality of life.
Dermatologic toxicities are among the most common immune-related adverse events (irAEs), reported in 43-45% of patients receiving ipilimumab and approximately 34% of those treated with nivolumab or pembrolizumab. Combination therapies (ipilimumab+ nivolumab or pembrolizumab) tend to elevate the incidence of potential irAEs to 41%. These toxicities typically emerge within the first few weeks of treatment, though delayed-onset cases have been documented. Cutaneous irAEs occur more rapidly in patients receiving combination therapy compared to anti-PD1 monotherapy.
Pruritus is one of the most frequently observed cutaneous irAEs. Current treatments for pruritus are often inadequate, leaving many patients suffering from persistent and debilitating symptoms. Despite available therapies, a significant number of individuals continue to experience chronic itch that negatively impacts their quality of life. Substance P (SP) functions as a neurotransmitter and neuromodulator in the central and peripheral nervous systems of mammals. It is produced by both neuronal and non-neuronal cells and plays a role in various physiological responses, including nausea, depression, vomiting, pain, neurogenic inflammation, and, more recently, pruritus. SP exerts its biological effects primarily through neurokinin receptors (NKRs), also known as tachykinin receptors. When SP binds to NK1R in the skin, it triggers mast cell degranulation, leading to the release of pruritogenic and proinflammatory mediators such as histamine, interferon-γ, leukotriene B4, vascular endothelial growth factor (VEGF), and nerve growth factor (NGF). This results in vasodilation and neurogenic inflammation, manifesting clinically as pruritus, erythema, and edema. NK1R antagonists are a class of drugs with antiemetic, antidepressant, anxiolytic, and antipruritic properties, though they have not been effective as analgesics in humans. These drugs act centrally by crossing the blood-brain barrier and selectively blocking NK1R activation by SP in the central nervous system, particularly in vomiting centers. Aprepitant has also demonstrated efficacy in treating pruritus induced by anticancer therapies.
This study is a pilot, single-center open label study evaluating the safety and efficacy of single course of EMEND® (aprepitant) capsules (80mg +125mg) in treating pruritus (new onset and/or refractory) induced by immune checkpoint inhibitors in patients with solid tumors.

The study team proposes a randomized, double-blind, RCT to address the following goal: to determine the relative efficacy and adverse event profile of fosaprepitant compared to the standard of care antiemetic ondansetron. Fosaprepitant and its active metabolite aprepitant are a relatively new class of antiemetic that exclusively acts in the central nervous system by blocking neurokinin (NK-1) which is a key signaling molecule in the centrally mediated aspects of the vomiting reflex. Currently, fosaprepitant and aprepitant both have only two United Stated Food and Drug Administration (USFDA) approved indications for nausea and vomiting: chemotherapy-induced and postoperative. Neurokinin inhibitors are highly effective and generally well-tolerated. Therefore, this class of medication may be a more appropriate medication for the millions of patients with nausea and vomiting that seek care in EDs. Intravenous fosaprepitant is converted to the active metabolite aprepitant on the order of minutes and is significantly cheaper to procure at this time. The outcome for the efficacy analysis will be no need for additional medication to treat nausea and vomiting within 2 hours of investigational medication administration. The primary outcome for the tolerability analysis will be the development of any new symptom within 2 hours of medication administration.