X-396 (Ensartinib) is a novel, potent anaplastic lymphoma kinase (ALK) small molecule tyrosine kinase inhibitor (TKI) with additional activity against MET, ABL, Axl, EPHA2, LTK, ROS1 and SLK. Ensartinib has demonstrated activity in ALK treatment naïve and previously treated patients and has a generally well tolerated safety profile. Ensartinib is currently in a global phase 3 trial in ALK positive non-small cell lung cancer (NSCLC) patients. The phase 1/2 clinical findings support the preclinical results that the use of ensartinib may result in favorable therapeutic outcomes in patients with ALK NSCLC, including patients with CNS metastases. In this study, ensartinib was generally well tolerated with the most common adverse event being a rash.

Momelotinib (CYT387) is an ATP-competitive small molecule that potently inhibits JAK1/JAK2 kinases. Momelotinib is developing by Gilead Sciences for the oral treatment of pancreatic and non-small cell lung cancers, and myeloproliferative disorders (including myelofibrosis, essential thrombocythaemia and polycythaemia vera).

Nirmatrelvir (PF-07321332) is a new oral antiviral drug developed by Pfizer. Nirmatrelvir is a major bioavailable oral SARS-CoV-2 protease inhibitor with in vitro human coronavirus antiviral activity, and excellent selection of off-target and in vivo immune profiles. The combination of ritonavir and nirmatrelvir under the brand name Paxlovid was approved by the FDA on May 25, 2023, for the treatment of mild-to-moderate COVID-19 in adults who are at high risk for progression to severe COVID-19, including hospitalization or death. Nirmatrelvir is a peptidomimetic inhibitor of the SARS-CoV-2 main protease (Mpro), also referred to as 3C-like protease (3CLpro) or nonstructural protein 5 (nsp5) protease. Inhibition of SARS-CoV-2 Mpro renders it incapable of processing the viral polyproteins pp1a and pp1ab, preventing viral replication. Nirmatrelvir inhibited the activity of recombinant SARS-CoV-2 Mpro in a biochemical assay with a Ki value of 3.1 nM and an IC50 value of 19.2 nM. Nirmatrelvir was found to bind directly to the SARS-CoV-2 Mpro active site by X-ray crystallography.

Zavegepant is a third generation, small-molecule, calcitonin gene-related peptide (CGRP) receptor antagonist being developed by Pfizer, under a license from Bristol-Myers Squibb, for the prevention and treatment of chronic and episodic migraine. In March 2023, zavegepant nasal spray (ZAVZPRET™) received its first approval in the USA for the acute treatment of migraine with or without aura in adults, based on two randomized, double-blind, placebo-controlled studies. Clinical development of an oral formulation of zavegepant is currently underway.

Pirtobrutinib is a small molecule, noncovalent inhibitor of BTK. BTK is a signaling protein of the B-cell antigen receptor (BCR) and cytokine receptor pathways. In B-cells, BTK signaling results in activation of pathways necessary for B-cell proliferation, trafficking, chemotaxis, and adhesion. Pirtobrutinib binds to wild type BTK and BTK harboring C481 mutations, leading to inhibition of BTK kinase activity. In nonclinical studies, pirtobrutinib inhibited BTK-mediated B-cell CD69 expression and inhibited malignant B-cell proliferation. Pirtobrutinib showed dose-dependent anti-tumor activities in BTK wild type and BTK C481S mutant mouse xenograft models. On January 27, 2023, the Food and Drug Administration (FDA) granted accelerated approval to pirtobrutinib (Jaypirca, Eli Lilly and Company) for relapsed or refractory mantle cell lymphoma (MCL) after at least two lines of systemic therapy, including a BTK inhibitor.

Quizartinib (AC220) is an orally bioavailable, small molecule receptor tyrosine kinase inhibitor that is being developed by Daiichi Sankyo Company (previously Ambit Biosciences) and Astellas Pharma as a treatment for acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) and advanced solid tumours. The highest affinity target identified for Quizartinib was FLT3. The only other kinases with binding constants within 10-fold that for FLT3 were the closely related receptor tyrosine kinases KIT, PDGFRA, PDGFRB, RET, and CSF1R. Kinase inhibition of (mutant) KIT, PDGFR and FLT3 isoforms by quizartinib leads to potent inhibition of cellular proliferation and induction of apoptosis in in vitro leukemia models as well as in native leukemia blasts treated ex vivo.

Sparsentan (RE-021; BMS-346567; PS433540; DARA-a) is a novel candidate in development by Retrophin for the treatment of focal segmental glomerulosclerosis (FSGS), a serious kidney disorder that often leads to end-stage renal disease (ESRD). Sparsentan is a single molecule with antagonism of the endothelin type A receptor (ETAR) and the angiotensin II type 1 receptor (AT1R). Sparsentan has high affinity for both the ETAR (Ki= 12.8 nM) and the AT1R (Ki=0.36 nM), and greater than 500-fold selectivity for these receptors over the endothelin type B and angiotensin II subtype 2 receptors. Endothelin-1 and angiotensin II are thought to contribute to the pathogenesis of IgAN via the ETAR and AT1R, respectively. The US Food and Drug Administration gave accelerated approval on February 17 2023 to sparsentan (Filspari), the first non-immunosuppressive therapy labeled for treating adults with primary immunoglobulin A (IgA) nephropathy.

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.

Fezolinetant (VEOZAH™) is an oral, small molecule, neurokinin 3 receptor (NK3R) antagonist, which is being developed by Astellas Pharma Inc. for the treatment of moderate to severe vasomotor symptoms (VMS) or hot flashes due to menopause. Inhibiting NK3R-mediated signaling in the central nervous system is a non-hormonal strategy to modulate the activity of neurons that are associated with thermoregulation, thereby reducing the frequency and severity of VMS. VEOZAH is a neurokinin 3 (NK3) receptor antagonist that blocks neurokinin B (NKB) binding on the kisspeptin/neurokinin B/dynorphin (KNDy) neuron to modulate neuronal activity in the thermoregulatory center. Fezolinetant has a high affinity for the NK3 receptor (Ki value of 19.9 to 22.1 nmol/L), which is more than 450-fold higher than the binding affinity to NK1 or NK2 receptors. Fezolinetant received its first approval in the USA in May 2023 for the treatment of moderate to severe VMS due to menopause.

Pacritinib (SB1518), discovered in Singapore at the labs of S*BIO Pte Ltd., is an oral tyrosine kinase inhibitor (TKI) with activity against two important activating mutations: Janus Associated Kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3). The JAK family of enzymes is a central component in signal transduction pathways, which are critical to normal blood cell growth and development as well as inflammatory cytokine expression and immune responses. Activating mutations of JAK2 are implicated in certain blood-related cancers, including myeloproliferative neoplasms (MPNs), leukemia and certain solid tumors. FLT3 is a gene commonly found mutated in patients with acute myeloid leukemia (AML). Pacritinib has demonstrated encouraging results in Phase 1 and 2 studies for patients with myelofibrosis and may offer an advantage over other JAK inhibitors through effective treatment of symptoms while having less treatment-emergent thrombocytopenia and anemia than has been seen in currently approved and in-development JAK inhibitors. Pacritinib is acquired by Cell Therapeutics, Inc. (CTI) and Baxter international and could effectively address an unmet medical need for patients living with myelofibrosis who face treatment-emergent thrombocytopenia on marketed JAK inhibitors. Currently Pacritinib is undergoing preregistration for myelofibrosis.