Relugolix (TAK-385) is an orally active nonpeptide gonadotropin-releasing hormone (GnRH) that binds to human GnRH receptors with subnanomolar affinity. Relugolix was demonstrated to act as a classic competitive antagonist of GnRH binding, but the exact molecular mechanism of that antagonism remains unknown. This drug is being developed as a treatment for various sex hormone related disorders. Based on the phase III HERO trial results, relugolix (Orgovyx) received Food and Drug Administration approval for adult patients with advanced prostate cancer. An oral fixed-dose combination of relugolix/estradiol/norethisterone (also known as norethindrone) acetate (Ryeqo®; Myfembree®) has been approved for the management of heavy menstrual bleeding associated with uterine fibroids in the USA and management of moderate to severe symptoms of uterine fibroids in the EU.

Opicapone (Ongentys®), a potent, oral, third-generation, long-acting, peripheral catechol-O-methyltransferase (COMT) inhibitor, is approved as the adjunctive treatment to levodopa (L-Dopa)/dopa-decarboxylase inhibitor (DDCI) therapy in adults with Parkinson's disease (PD) and end-of-dose motor fluctuations who cannot be stabilized on those combinations. Opicapone is a hydrophilic 1,2,4-oxadiazole analog with a pyridine N-oxide at position 3, with these modifications enhancing its potency and extending its duration of action, whilst avoiding cell toxicity. In preclinical animal studies, Opicapone-induced inhibition of peripheral (but not central) COMT activity was associated with a prolonged increase in systemic and central exposure to L-Dopa, with a corresponding reduction in 3-OMD exposure. Following single or multiple doses of Opicapone (5–1200 mg) in healthy adult volunteers or patients with PD, Opicapone inhibited COMT activity in ex vivo erythrocyte assays in a reversible dose-dependent manner, with the duration of Opicapone-induced COMT inhibition independent of dose. Adjunctive Opicapone was generally well tolerated during more than a year of treatment in BIPARK I and BIPARK II (double-blind plus extension phases). The recommended dosage is 50 mg once daily, which should be taken at bedtime at least 1 h before or after L-Dopa combinations.

Istradefylline is a first-in-class adenosine A2A receptor antagonist antiparkinsonian agent and has been marketed as the brand name NOURIAST® in Japan since May 30, 2013. NOURIAST is indicated for the improvement of wearing-off phenomena in patients with Parkinson’s disease on concomitant treatment with levodopa-containing products.

Tafamidis meglumine (Vyndaqel®, Pfizer) is a novel, first-in-class drug for the treatment of transthyretin familial amyloid polyneuropathy (TTR-FAP), a rare neurodegenerative disorder characterized by progressive sensory, motor and autonomic impairment that is ultimately fatal. Pathogenic mutations in the transthyretin (TTR) protein lead to destabilization of its tetrameric structure and subsequent formation of amyloid aggregates. Tafamidis is a small-molecule inhibitor that binds selectively to TTR in human plasma and kinetically stabilizes the tetrameric structure of both wild-type TTR and a number of different mutants. Clinical trials indicate that tafamidis slows disease progression in patients with TTR-FAP and reduces the burden of disease, demonstrating improvement in small and large nerve fiber function, modified body mass index and lower extremity neurological examination. Tafamidis meglumine has been launched for TTR FAP in the EU, Japan, Argentina, Malta and Mexico, and is preregistration in the US for this indication.

Elexacaftor (VX-445) is a next-generation cystic fibrosis transmembrane conductance regulator (CFTR) corrector. It received FDA approval in October 2019 in combination with tezacaftor and ivacaftor as the combination product Trikafta for the treatment of cystic fibrosis in patients aged ≥ 12 years who have ≥ 1 F508del mutation in the CFTR gene. Trikafta™ has been developed by Vertex Pharmaceuticals Inc. to treat patients with the most common cystic fibrosis mutation (F508del). Its use has been associated with statistically significant and/or clinically meaningful improvements in lung function and respiratory-related quality of life compared with comparator regimens (placebo or ivacaftor/tezacaftor) in multinational phase II and III studies. Elexacaftor and tezacaftor bind to different sites on the CFTR protein and have an additive effect in facilitating the cellular processing and trafficking of select mutant forms of CFTR (including F508del-CFTR) to increase the amount of CFTR protein delivered to the cell surface compared to either molecule alone. Ivacaftor potentiates the channel open probability (or gating) of the CFTR protein at the cell surface.

Upadacitinib (ABT-494) is a Janus kinase 1 (JAK1) inhibitor currently being developed by AbbVie for the treatment of rheumatoid arthritis (RA), Crohn’s disease, ulcerative colitis, atopic dermatitis, and psoriatic arthritis. It is also being investigated as a potential treatment for people with active ankylosing spondylitis (AS). Currently, upadacitinib is being evaluatedin six global phase III studies in RA and twophase III studies in psoriatic arthritis (PsA), inaddition to phase II studies in Crohn’s disease and atopicdermatitis and a combined phase II/III study inulcerative colitis. Upadacitinib is a potent and selective Janus kinase (JAK) 1 inhibitor with an IC50 of 43 nM.

Zanubrutinib (formerly known as BGB-3111) was developed by BeiGene as a small-molecule inhibitor of Bruton's tyrosine kinase (BTK). The drug forms a covalent bond with a cysteine residue in the BTK active site, leading to inhibition of BTK activity. BTK signaling results in activation of pathways necessary for B-cell proliferation, trafficking, chemotaxis, and adhesion, thus Zanubrutinib inhibits malignant B-cell proliferation and reduces tumor growth. Zanubrutinib was granted accelerated approval by the FDA in November 2019 based on clinical trial results that demonstrated an 84% overall response rate from zanubrutinib therapy in patients with mantle cell lymphoma (MCL). On August 31, 2021, the Food and Drug Administration approved zanubrutinib for adult patients with Waldenström’s macroglobulinemia (WM).

Cantharidin is a toxic compound, isolated from the Spanish fly or blistering beetle (Lytta (Cantharis) vesicatoria) and other insects. It is a potent and specific inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A). Cantharidin is a medication used to remove warts and a viral skin infection called molluscum contagiosum. It is made from the secretions that come from the green blister beetle in combination with salicylic acid. It works by creating a blister just below the wart, which pushes the wart up and away from the underlying tissue, cutting of the blood supply to the wart. As the blister and the wart dry out, they both slough off, leaving fresh, unmarred skin behind. It is also used as an experimental anti-tumor agent. Several studies also show potential novel applications of cantharidin in acquired perforating dermatosis, acute herpes zoster, and leishmaniasis. In 1962, cantharidin lost Food and Drug Administration (FDA) approval owing to the failure of its manufacturers to submit data attesting to cantharidin's efficacy. However, in 1999, the FDA included cantharidin on its “Bulk Substances List” of drugs which although not available as commercial products, were approved for compounding on a customized basis for individual patients.

Pitolisant (INN) or tiprolisant (USAN) is a histamine receptor inverse agonist/antagonist selective for the H3 subtype. It has stimulant and nootropic effects in animal studies and may have several medical applications, having been researched for the treatment of narcolepsy, for which it has been granted orphan drug status in the EU and US. It is currently in clinical trials for schizophrenia and Parkinson’s disease. Pitolisant hydrochloride was approved by European Medicine Agency (EMA) on Mar 31, 2016. It was developed and marketed as Wakix® by Bioprojet in EU. Wakix® is available as the tablet for oral use, containing 4.5 mg and 18 mg of Pitolisant hydrochloride. The initial dose of 9 mg (two 4.5 mg, tablets) per day, and it should be used at the lowest effective dose, depending on individual patient response and tolerance, according to an up-titration scheme, without exceeding the dose of 36 mg/day. Pitolisant was the first clinically used H3 receptor inverse agonist.

Triclabendazole, (brand name Avomec, Egaten, etc) is a member of the benzimidazole family of anthelmintics used to treat liver flukes, specifically fascioliasis and paragonimiasis. Triclabendazole used routinely since 1983 in veterinary practice for the treatment of fascioliasis. It was not used in humans until the 1989 epidemic of fascioliasis near the Caspian Sea when Iranian authorities approved the use of the veterinary formulation to treat the infection. Fasciolicidal not only against the adult worms present in the biliary ducts, but also against the immature larval stages of Fasciola migrating through the hepatic parenchyma. Triclabendazole is shown to penetrate into liver flukes by transtegumentary absorption followed by inhibition of the parasite's motility, probably related to the destruction of the microtubular structure, resulting in the death of the parasite; the immobilizing effect is paralleled by changes in the parasite's resting tegumental membrane potential, strongly inhibiting the release of proteolytic enzymes, a process that appears critical to the survival of the parasite. Side effects are generally few, but can include abdominal pain and headaches. Biliary colic may occur due to dying worms. While no harms have been found with use during pregnancy, triclabendazole has not been well studied in this population. Triclabendazole is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. It is not commercially available in the United States.