Leniolisib (JOENJA®) is an oral selective phosphoinositide 3-kinase-delta (PI3Kdelta) inhibitor being developed by Pharming Group NV in-licensed from Novartis for the treatment of immunodeficiency disorders. Leniolisib inhibits PI3K-delta by blocking the active binding site of PI3K-delta. In cell-free isolated enzyme assays, leniolisib was selective for PI3K-delta over PI3K-alpha (28-fold), PI3K-beta (43-fold), and PI3K-gamma (257-fold), as well as the broader kinome. In cell-based assays, leniolisib reduced pAKT pathway activity and inhibited proliferation and activation of B and T cell subsets. Gain-of-function variants in the gene encoding the p110-delta catalytic subunit or loss of function variants in the gene encoding the p85-alpha regulatory subunit each cause hyperactivity of PI3K-delta. Leniolisib inhibits the signalling pathways that lead to increased production of PIP3, hyperactivity of the downstream mTOR/AKT pathway, and to the dysregulation of B and T cells. In March 2023, leniolisib received its first approval for the treatment of activated PI3Kdelta syndrome (APDS) in adult and paediatric patients 12 years of age and older. Leniolisib is also under regulatory review in European Union for the treatment of APDS. Development of leniolisib for the treatment of Sjögren's syndrome has been discontinued.

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.

Osilodrostat (INN, USAN) (developmental code name LCI-699) is an orally active, non-steroidal corticosteroid biosynthesis inhibitor which is under development by Novartis for the treatment of Cushing's syndrome and pituitary ACTH hypersecretion (a specific subtype of Cushing's syndrome). Osilodrostat specifically acts as a potent and selective inhibitor of aldosterone synthase (CYP11B2) and at higher dosages of 11β-hydroxylase (CYP11B1). Osilodrostat decreases plasma and urinary aldosterone levels and rapidly corrects hypokalemia, in patients with primary aldosteronism and hypertension. At doses ≥1 mg o.d. Osilodrostat markedly increases 11-deoxycortisol plasma levels and blunts ACTH-stimulated cortisol release in ≈20% of patients, consistent with the inhibition of CYP11B1. In patients with resistant hypertension, Osilodrostat produces a non-significant reduction in blood pressure, possibly due to the increase in 11-deoxycortisol levels and the stimulation of the hypothalamic-pituitary-adrenal feedback axis. Because of the lack of selectivity, poor antihypertensive effect, and short half-life, the development of Osilodrostat as antihypertensive was halted. As of 2017, Osilodrostat is in phase III and phase II clinical trials for the treatment of pituitary ACTH hypersecretion and Cushing's syndrome, respectively.

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.

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.

Baricitinib (trade name Olumiant) is an investigational drug for rheumatoid arthritis (RA), being developed by Incyte and Eli Lilly. Baricitinib is a selective JAK1 and JAK2 inhibitor with IC50 of 5.9 nM and 5.7 nM in cell-free assays. In February 2017 Baricitinib was approved for use in the European Union as a second-line therapy for moderate to severe active rheumatoid arthritis in adults, either alone or in combination with methotrexate. On 31 May 2018 FDA approved Barictinib for the treatment of adult patients with moderately to severely active rheumatoid arthritis who have had an inadequate response to one or more TNF antagonist therapies.

Amifampridine (Firdapse), currently approved in the European Union, is the first and only approved drug for the symptomatic treatment of Lambert-Eaton Myasthenic Syndrome (LEMS) in adults, a rare autoimmune disease with the primary symptoms of muscle weakness. In LEMS, the body’s own immune system attacks connections between nerves and muscles and disrupts the ability of nerve cells to send signals to muscle cells. Amifampridine blocks voltage-dependent potassium channels, thereby prolonging pre-synaptic cell membrane depolarization. Prolonging the action potential enhances the transport of calcium into the nerve ending. The resulting increase in intracellular calcium concentrations facilitates exocytosis of acetylcholine containing vesicles, which in turn enhances neuromuscular transmission. Amifampridine phosphate has been granted Orphan Drug Designation and Breakthrough Therapy designation by the FDA for the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS).

Fostamatinib is a pro-drug of a Syk inhibitor R406 initially developed by Rigel Pharmaceuticals, but then in-licensed by AstraZeneca. It reached phase III of clinical trials for such diseases as Rheumatoid Arthritis and Immune Thrombocytopenic Purpura, however, AstraZeneca decided not to proceed with regulatory filings and return the rights to the compound to Rigel Pharmaceuticals. In 2018 the drug was approved by the FDA for treatment of chronic immune thrombocytopenia. Fostamatinib is being developed for Autoimmune Hemolytic Anemia (phase II), graft versus host disease (phase I) and ovarian cancer (phase I).

Fostamatinib is a pro-drug of a Syk inhibitor R406 initially developed by Rigel Pharmaceuticals, but then in-licensed by AstraZeneca. It reached phase III of clinical trials for such diseases as Rheumatoid Arthritis and Immune Thrombocytopenic Purpura, however, AstraZeneca decided not to proceed with regulatory filings and return the rights to the compound to Rigel Pharmaceuticals. In 2018 the drug was approved by the FDA for treatment of chronic immune thrombocytopenia. Fostamatinib is being developed for Autoimmune Hemolytic Anemia (phase II), graft versus host disease (phase I) and ovarian cancer (phase I).

Rucaparib is a poly (ADP-ribose) polymerase (PARP) inhibitor indicated for the treatment of advanced mutant BRCA ovarian cancer. Rucaparib is being investigated in clinical trials against prostate cancer, breast cancer and other neoplasms.