Ritlecitinib is an orally administered, covalent small-molecule selective dual inhibitor of JAK3 and the TEC kinase family. In vitro studies showed ritlecitinib covalently binds to JAK3 and is more than 10 000 times more potent against JAK3 than against JAK1, JAK2, and tyrosine kinase. Ritlecitinib also inhibits the five members of the TEC kinase family. Ritlecitinib irreversibly inhibits Janus kinase 3 (JAK3) and TEC kinase family by blocking the adenosine triphosphate (ATP) binding site. In cellular settings, ritlecitinib inhibits cytokine induced STAT phosphorylation mediated by JAK3-dependent receptors. Additionally, ritlecitinib inhibits signaling of immune receptors dependent on TEC kinase family members.The FDA has approved ritlecitinib (LITFULO; Pfizer Inc), a once daily oral treatment, for individuals aged 12 years and older with severe alopecia areata. This makes ritlecitinib, in the 50 mg dosage, the first and only treatment approved by the FDA for adolescents with severe alopecia areata. The approval was based on the results of the ALLEGRO phase 2b/3 trial (NCT03732807), which included 718 individuals who had 50% or more scalp hair loss measured by the Severity of Alopecia Tool. Investigators of the study evaluated the safety and efficacy of ritlecitinib at 118 different sites in 18 different countries. Regulatory applications for LITFULO in alopecia areata have been submitted to countries around the world for review, including China, the European Union, Japan, and the United Kingdom. The European Medicines Agency (EMA) has accepted the Marketing Authorization Application (MAA) for ritlecitinib with a decision anticipated in the third quarter of 2023. LITFULO is also being evaluated for vitiligo, Crohn’s disease, and ulcerative colitis.

Trofinetide (NNZ 2566), a proprietary small molecule analogue of glycine-proline-glutamate [Glypromate®], is being developed by Neuren Pharmaceuticals and Acadia Pharmaceuticals for the treatment of brain injuries, fragile X syndrome, Rett syndrome. Trofinetide is a synthetic analogue of a naturally occurring neurotrophic peptide derived from IGF-1, a growth factor produced by brain cells. In animal models, trofinetide exhibits a wide range of important effects including inhibiting neuroinflammation, normalizing the role of microglia and correcting deficits in synaptic function. Trofinetide was approved in March 2023 in the USA for the treatment of Rett syndrome in adult and pediatric patients 2 years of age and older.

Difelikefalin (Korsuva™) is a synthetic peptide agonist of the kappa opioid receptor being developed by Cara Therapeutics for the treatment of pruritus. In August 2021, intravenous difelikefalin was approved in the USA for the treatment of moderate-to-severe pruritus associated with chronic kidney disease (CKD) in adults undergoing haemodialysis. Difelikefalin selectively acts on kappa opioid receptors in peripheral tissues, which contribute to pruritis and nociception. The activation of opioid receptors in peripheral neurons and keratinocytes reduces afferent (sensory) impulses towards the central nervous system, decreasing pain signals. Activating kappa opioid receptors on immune cells, including monocytes and T lymphocytes, decreases the release of pro-inflammatory chemicals such as prostaglandins.

Ibrexafungerp (BREXAFEMME®) is an orally active triterpenoid antifungal drug being developed by SCYNEXIS, Inc. for the treatment of fungal infections. The inhibition of β-1,3-D glucan synthetase by ibrexafungerp compromises the integrity of fungal cell walls. Ibrexafungerp has been recently approved for the treatment of vulvovaginal candidiasis (VVC), and it is the first novel antifungal drug class to be approved in more than 20 years. Food and Drug Administration's decision was based on positive results from two pivotal phase III studies in which oral ibrexafungerp proved both safe and effective in patients with vulvovaginal candidiasis. Development for the treatment of recurrent VVC and invasive fungal infections is ongoing.

Finerenone (Kerendia®), a first-in-class, orally administered, selective, nonsteroidal mineralocorticoid receptor antagonist (MRA), is being developed by Bayer HealthCare Pharmaceuticals for the treatment of diabetic kidney disease (DKD) and heart failure (HF), including chronic HF (CHF). Finerenone blocks MR mediated sodium reabsorption and MR overactivation in both epithelial (e.g., kidney) and nonepithelial (e.g., heart, and blood vessels) tissues. MR overactivation is thought to contribute to fibrosis and inflammation. Finerenone has a high potency and selectivity for the MR and has no relevant affinity for androgen, progesterone, estrogen, and glucocorticoid receptors. Finerenone has been approved in the USA to reduce the risk of sustained estimated glomerular filtration rate (eGFR) decline, end stage renal disease (ESRD), cardiovascular death, nonfatal myocardial infarction (MI), and hospitalization for HF in adults with chronic kidney disease (CKD) associated with type 2 diabetes (T2D). Finerenone is undergoing regulatory assessment in the EU and in China. A phase III trial is investigating finerenone in patients who have HF with preserved ejection fraction.

Cabotegravir is an investigational drug that is being studied for the treatment and prevention of HIV infection. Cabotegravir belongs to a class (group) of HIV drugs called integrase inhibitors. Integrase inhibitors block an HIV enzyme called integrase. (An enzyme is a protein that starts or increases the speed of a chemical reaction.) By blocking integrase, integrase inhibitors prevent HIV from multiplying and can reduce the amount of HIV in the body. Cabotegravir does not require boosting with an additional drug. Two forms of cabotegravir are being studied: tablets that are taken by mouth (known as oral cabotegravir or oral CAB) and a long-acting injectable form that is injected into the muscle (known as cabotegravir LA or CAB LA; LA stands for "long-acting"). (A long-acting drug formulation works over a long period of time. Using this type of drug might mean that the drug could be taken less often, making a treatment or prevention regimen simpler to take.) Cabotegravir is in Phase-III clinical trials for HIV infections.

Fostemsavir (BMS-663068) is an investigational attachment inhibitor with a unique mechanism of action. It is a prodrug of temsavir, which binds to HIV envelope glycoprotein 120 (gp120), thereby preventing viral attachment to the host CD4 cell surface receptor. In the absence of effective binding of HIV gp120 with the host CD4 receptor, HIV does not enter the host cell. Because fostemsavir has a novel mechanism of action, the drug should have full activity against HIV strains that have developed resistance to other classes of antiretroviral medications. In a phase 2b study of treatment-experienced individuals, fostemsavir appeared to be well tolerated. Phase 3 studies are ongoing.

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.

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.

Cannabidiol is the major nonpsychoactive ingredient in cannabis. Cannabidiol demonstrates a range of effects that may be therapeutically useful, including anti-seizure, antioxidant, neuroprotective, anti-inflammatory, analgesic, anti-tumor, anti-psychotic, and anti-anxiety properties. Exact mechanism of action of cannabidiol is not known, but may include effects on the orphan G-protein-coupled receptor GPR55; the transient receptor potential of vanilloid type-1 channel; the 5-HT1a receptor; and the α3 glycine receptors. GW Pharmaceuticals successfully developed the world’s first prescription medicine derived from the cannabis plant, Sativex® (buccal spray containing delta-9-tetrahydrocannabinol and cannabidiol) now approved in over 29 countries outside of the United States for the treatment of spasticity due to Multiple Sclerosis. GW Pharmaceuticals is developing Epidiolex® (a liquid formulation of pure plant-derived cannabidiol) for certain rare and severe early-onset, drug-resistant epilepsy syndromes.