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).

Entrectinib (previously known as RXDX-101, NMS-E628) is an investigational drug, potent inhibitor of ALK, ROS1, and, importantly, of TRK family kinases, which shows promise for therapy of tumors bearing oncogenic forms of these proteins. Entrectinib (RXDX-101) is a selective inhibitor for all three Trk receptor tyrosine kinases encoded by the three NTRK genes, as well as the ROS1 and ALKreceptor tyrosine kinases.This investigational drug is active at low nanomolar concentrations, allowing for once-daily oral administration to patients whose tumors have been shown to have gene rearrangements in NTRK, ROS1, or ALK. Nerviano Medical Sciences, the original sponsor for entrectinib (formerly referred to as NMS-1191372), initiated the first-in-human Phase 1 study ALKA-372-001 in Italy in October 2012. The study is currently ongoing in Italy. Entrectinib is currently being tested in a global phase 2 basket clinical trial called STARTRK-2. In the U.S., entrectinib has orphan drug designation and rare pediatric disease designation for the treatment of neuroblastoma and orphan drug designation for treatment of TrkA-, TrkB-, TrkC-, ROS1- and ALK-positive non-small cell lung cancer (NSCLC) and metastatic colorectal cancer (mCRC).

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.

Fedratinib (SAR-302503, TG-101348) is a selective small-molecule inhibitor of Janus kinase-2. Fedratinib demonstrated therapeutic efficacy in a murine model of myeloproliferative disease. Sanofi was developing Fedratinib for the treatment of myeloproliferative diseases and solid tumors. The clinical development of fedratinib was terminated after reports of Wernicke's encephalopathy in myelofibrosis patients.

Pexidartinib (PLX3397) is a small-molecule receptor tyrosine kinase (RTK) inhibitor with potential antineoplastic activity. Pexidartinib binds to and inhibits phosphorylation of stem cell factor receptor (KIT), colony-stimulating factor-1 receptor (CSF1R) and FMS-like tyrosine kinase 3 (FLT3), which may result in the inhibition of tumor cell proliferation and down-modulation of macrophages, osteoclasts and mast cells involved in the osteolytic metastatic disease. FDA has granted Breakthrough Therapy Designation to pexidartinib (PLX3397) for the treatment of tenosynovial giant cell tumor (TGCT) where surgical removal of the tumor would be associated with potentially worsening functional limitation or severe morbidity. In addition to Breakthrough Therapy Designation, pexidartinib (PLX3397) has been granted Orphan Drug Designation by FDA for the treatment of pigmented villonodular synovitis (PVNS) and giant cell tumor of the tendon sheath (GCT-TS). It also has received Orphan Designation from the European Commission for the treatment of TGCT.

Gilteritinib, also known as ASP2215, is a potent FLT3/AXL inhibitor, which showed potent antileukemic activity against AML with either or both FLT3-ITD and FLT3-D835 mutations. In in vitro, among the 78 tyrosine kinases tested, Gilteritinib inhibited FLT3, LTK, ALK, and AXL kinases by over 50% at 1 nM with an IC50 value of 0.29 nM for FLT3, approximately 800-fold more potent than for c-KIT, the inhibition of which is linked to a potential risk of myelosuppression. Gilteritinib inhibited the growth of MV4-11 cells, which harbor FLT3-ITD, with an IC50 value of 0.92 nM, accompanied with inhibition of pFLT3, pAKT, pSTAT5, pERK, and pS6. Gilteritinib decreased tumor burden in bone marrow and prolonged the survival of mice intravenously transplanted with MV4-11 cells. In previous preclinical studies, gilteritinib has demonstrated superior antitumor effects when given in combination with AraC and either DNR or IDR compared with combination chemotherapy. In November 2018, the FDA approved gilteritinib for treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) with a FLT3 mutation as detected by an FDA-approved test.

Lorlatinib is an investigational medicine that inhibits the anaplastic lymphoma kinase (ALK) and ROS1 proto-oncogene. Lorlatinib was specifically designed to inhibit tumor mutations that drive resistance to other ALK inhibitors. Lorlatinib has in vitro activity against ALK and number of other tyrosine kinase receptor related targets including ROS1, TYK1, FER, FPS, TRKA, TRKB, TRKC, FAK, FAK2, and ACK. Lorlatinib demonstrated in vitro activity against multiple mutant forms of the ALK enzyme, including some mutations detected in tumors at the time of disease progression on crizotinib and other ALK inhibitors. Moreover, lorlatinib possesses the capability to cross the blood-brain barrier, allowing it to reach and treat progressive or worsening brain metastases as well. Lorlatinib is a third-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) indicated for the treatment of patients with ALK-positive metastatic non-small cell lung cancer (NSCLC) whose disease has progressed on a) the prior use of crizotinib and at least one other ALK inhibitor for metastatic disease, or b) the prior use of alectinib as the first ALK inhibitor therapy for metastatic disease, or c) the prior use of certinib as the first ALK inhibitor therapy for metastatic disease.

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.

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).

Acalabrutinib, also known as ACP-196, is a novel irreversible second-generation Bruton’s tyrosine kinase (BTK) inhibitor, which prevents the activation of the B-cell antigen receptor (BCR) signaling pathway and that, was rationally designed to be more potent and selective than ibrutinib. This drug in clinical trials phase III for treatment the treatment of relapsed chronic lymphocytic leukemia. Also in combination with others drugs, Acalabrutinib in phase II of clinical trials for the treatment Glioblastoma Multiforme, Mantle Cell Lymphoma, Squamous Cell Carcinoma of the Head and Neck, Rheumatoid Arthritis and some others.