Paclitaxel is a mitotic inhibitor used in cancer chemotherapy. It was discovered in a US National Cancer Institute program at the Research Triangle Institute in 1967 when Monroe E. Wall and Mansukh C. Wani isolated it from the bark of the Pacific yew tree, Taxus brevifolia and named it taxol. Later it was discovered that endophytic fungi in the bark synthesize paclitaxel. When it was developed commercially by Bristol-Myers Squibb (BMS), the generic name was changed to paclitaxel and the BMS compound is sold under the trademark Taxol. In this formulation, paclitaxel is dissolved in Kolliphor EL and ethanol, as a delivery agent. Taxol is marketed for the treatment of Breast cancer; Gastric cancer; Kaposi's sarcoma; Non-small cell lung cancer; Ovarian cancer. A newer formulation, in which paclitaxel is bound to albumin, is sold under the trademark Abraxane. Paclitaxel is a taxoid antineoplastic agent indicated as first-line and subsequent therapy for the treatment of advanced carcinoma of the ovary, and other various cancers including breast cancer. Paclitaxel is a novel antimicrotubule agent that promotes the assembly of microtubules from tubulin dimers and stabilizes microtubules by preventing depolymerization. This stability results in the inhibition of the normal dynamic reorganization of the microtubule network that is essential for vital interphase and mitotic cellular functions. In addition, paclitaxel induces abnormal arrays or "bundles" of microtubules throughout the cell cycle and multiple asters of microtubules during mitosis. Used in the treatment of Kaposi's sarcoma and cancer of the lung, ovarian, and breast. Abraxane® is specfically indicated for the treatment of metastatic breast cancer and locally advanced or metastatic non-small cell lung cancer. Paclitaxel interferes with the normal function of microtubule growth. Whereas drugs like colchicine cause the depolymerization of microtubules in vivo, paclitaxel arrests their function by having the opposite effect; it hyper-stabilizes their structure. This destroys the cell's ability to use its cytoskeleton in a flexible manner. Specifically, paclitaxel binds to the β subunit of tubulin. Tubulin is the "building block" of mictotubules, and the binding of paclitaxel locks these building blocks in place. The resulting microtubule/paclitaxel complex does not have the ability to disassemble. This adversely affects cell function because the shortening and lengthening of microtubules (termed dynamic instability) is necessary for their function as a transportation highway for the cell. Chromosomes, for example, rely upon this property of microtubules during mitosis. Further research has indicated that paclitaxel induces programmed cell death (apoptosis) in cancer cells by binding to an apoptosis stopping protein called Bcl-2 (B-cell leukemia 2) and thus arresting its function.

Cabazitaxel (JEVTANA®) is an antineoplastic agent belonging to the taxane class and is used to treat people with prostate cancer that has progressed despite treatment with docetaxel. It is prepared by semi-synthesis with a precursor extracted from yew needles (10-deacetylbaccatin III). Cabazitaxel (JEVTANA®) is a microtubule inhibitor. It binds to tubulin and promotes its assembly into microtubules while simultaneously inhibiting disassembly. This leads to the stabilization of microtubules, which results in the inhibition of mitotic and interphase cellular functions. The cell is then unable to progress further into the cell cycle, being stalled at metaphase, thus triggering apoptosis of the cancer cell.

Gefitinib is an anilinoquinazoline with antineoplastic activity. Gefitinib inhibits the epidermal growth factor receptor (EGFR) tyrosine kinase by binding to the adenosine triphosphate (ATP)-binding site of the enzyme. Thus the function of the EGFR tyrosine kinase in activating the Ras signal transduction cascade is inhibited; and malignant cells are inhibited. Gefitinib is the first selective inhibitor of the EGFR tyrosine kinase which is also referred to as Her1 or ErbB-1. EGFR is overexpressed in the cells of certain types of human carcinomas - for example in lung and breast cancers. Overexpression leads to inappropriate activation of the apoptotic Ras signal transduction cascade, eventually leading to uncontrolled cell proliferation. Gefitinib is used for the continued treatment of patients with locally advanced or metastatic non-small cell lung cancer after failure of either platinum-based or docetaxel chemotherapies.

Sirolimus is the USAN-assigned generic name for the natural product rapamycin. Sirolimus is produced by a strain of Streptomyces hygroscopicus, isolated from a soil sample collected from Rapa Nui commonly known as Easter Island. Although sirolimus was isolated as an antifungal agent with potent anticandida activity, subsequent studies revealed impressive antitumor and immunosuppressive activities. Sirolimus demonstrates activity against several murine tumors, such as B16 43 melanocarcinoma, Colon 26 tumor, EM ependymoblastoma, and mammary and colon 38 solid tumors. Demonstration of the potent immunosuppressive activity of sirolimus in animal models of organ transplantation led to clinical trials and subsequent approval by regulatory authorities for prophylaxis of renal graft rejection. Interest in sirolimus as an immunosuppressive therapy in organ transplantation derives from its unique mechanism of action, its unique side-effect profile, and its ability to synergize with other immunosuppressive agents. It is used in medicine to prevent organ transplant rejection and to treat lymphangioleiomyomatosis. Sirolimus inhibits T-lymphocyte activation and proliferation that occurs in response to antigenic and cytokine (Interleukin [IL]-2, IL-4, and IL-15) stimulation by a mechanism that is distinct from that of other immunosuppressants. Sirolimus also inhibits antibody production. In cells, sirolimus binds to the immunophilin, FK Binding Protein-12 (FKBP-12), to generate an immunosuppressive complex. This complex blocks the activation of the cell-cycle-specific kinase, TOR. The downstream events that follow the inactivation of TOR result in the blockage of cell-cycle progression at the juncture of G1 and S phase. Rapamycin/FKBP12 efficiently inhibit some, but not all, functions of mTOR and hence much interest has been placed in the development of drugs that target the kinase activity of mTOR directly. Studies in experimental models show that sirolimus prolongs allograft (kidney, heart, skin, islet, small bowel, pancreatico-duodenal, and bone marrow) survival in mice, rats, pigs, and/or primates. Sirolimus reverses acute rejection of heart and kidney allografts in rats and prolongs the graft survival in presensitized rats. In some studies, the immunosuppressive effect of sirolimus lasts up to 6 months after discontinuation of therapy. This tolerization effect is alloantigen-specific. In rodent models of autoimmune disease, sirolimus suppresses immune-mediated events associated with systemic lupus erythematosus, collagen-induced arthritis, autoimmune type I diabetes, autoimmune myocarditis, experimental allergic encephalomyelitis, graft-versus-host disease, and autoimmune uveoretinitis. Lymphangioleiomyomatosis involves lung tissue infiltration with smooth muscle-like cells that harbor inactivating mutations of the tuberous sclerosis complex (TSC) gene (LAM cells). Loss of TSC gene function activates the mTOR signaling pathway, resulting in cellular proliferation and release of lymphangiogenic growth factors. Sirolimus inhibits the activated mTOR pathway and thus the proliferation of LAM cells.

Docetaxel was protected by patents (U.S. patent and European patent) which were owned by Sanofi-Aventis, and so was available only under the Taxotere brand name internationally. The European patent expired in 2010. Docetaxel is a clinically well-established anti-mitotic chemotherapy medication used for the treatment of patients with locally advanced or metastatic breast cancer after failure of prior chemotherapy. Also used as a single agent in the treatment of patients with locally advanced or metastatic non-small cell lung cancer after failure of prior platinum-based chemotherapy. It is also used in combination with prednisone, in the treatment of patients with androgen independent (hormone refractory) metastatic prostate cancer. Furthermore, docetaxel has uses in the treatment of gastric adenocarcinoma and head and neck cancer. Docetaxel interferes with the normal function of microtubule growth. Whereas drugs like colchicine cause the depolymerization of microtubules in vivo, docetaxel arrests their function by having the opposite effect; it hyper-stabilizes their structure. This destroys the cell's ability to use its cytoskeleton in a flexible manner. Specifically, docetaxel binds to the β-subunit of tubulin. Tubulin is the "building block" of mictotubules, and the binding of docetaxel locks these building blocks in place. The resulting microtubule/docetaxel complex does not have the ability to disassemble. This adversely affects cell function because the shortening and lengthening of microtubules (termed dynamic instability) is necessary for their function as a transportation highway for the cell. Chromosomes, for example, rely upon this property of microtubules during mitosis. Further research has indicated that docetaxel induces programmed cell death (apoptosis) in cancer cells by binding to an apoptosis stopping protein called Bcl-2 (B-cell leukemia 2) and thus arresting its function.

Poziotinib is an inhibitor of EGFR tyrosine kinase family. The drug is being tested in phase II of clinical trials for different cancers: breast cancer, lung adenocarcinoma, head and neck squamous cell carcinoma, HER-2 positive advanced gastric cancer (in combination with Paclitaxel and Trastuzumab).

HM-30181 is a highly selective and potent inhibitor of Multi-drug resistance 1 (MDR1, ABCB1), also known as P-glycoprotein (P-gp). Co-administration of HM30181 greatly increased oral bioavailability of tubulin-stabilizing chemotherapeutic agent paclitaxel. Oraxol is an oral dosage form of paclitaxel administered orally with the HM30181A molecule. Oraxol offers patients with paclitaxel-responsive tumors the possibility of oral therapy without the requirement for premedication to prevent infusion-related hypersensitivity-type reactions. Current clinical data suggests the promising potential of a better clinical response and tolerability profile, which can likely to be attributed to the better pharmacokinetic profile achieved. Oraxol is presently in a Phase 3 trial in metastatic breast cancer and poised to enter into a combination study for treatment of advanced gastric cancer with ramucirumab through a clinical trial collaboration with Eli Lilly and Company.

Bristol-Myers Squibb developed BMS-184476 for the potential treatment of solid tumors. BMS-184476 participated in phase II clinical trials for patients with non-small-cell lung cancer, breast, and ovarian cancers. However, that development has been discontinued.

Bryostatin 1 is a macrocyclic lactone which can be isolated from the marine bryozoan, Bugula neritina. The effects of bryostatin 1 are attributed to its ability to selectively modulate the activity of two of the three subgroups of protein kinase C (PKC) isozymes. PKC isozymes are divided into three subgroups which differ in their molecular structures and co-factor requirements: classical PKC (cPKC), novel PKC (nPKC), and atypical PKC (aPKC). Bryostatin-1 modulates nPKC activity independent of a Ca2+ signaling. It activates cPKC only when associated with Ca2+ signaling. And, aPKC activity is not sensitive to bryostatin-1 administration. Ca2+ signals play an important role in synaptic transmission and information processing which creates a biological environment where Bryostatin-1 possesses a unique action profile. Bryostatin-1 will not affect cPKC activity in neurons which are not functioning as an active part of the signaling processing circuit with significant Ca2+influx and intracellular Ca2+ release. Bryostatin 1 is in phase II clinical trials for investigation as an anticancer agent; specifically for treatment of metastatic or recurrent head and neck cancer, ovarian epithelial cancer that has not responded to previous chemotherapy, and myelodysplastic syndrome. Bryostatin 1 has also generated interest as an investigational compound for the treatment of Alzheimer's disease.

Elesclomol (also known as STA-4783), originally identified in a cell-based phenotypic screen for pro-apoptotic activity, is a novel small-molecule that potently induces apoptosis of cancer cells through the rapid generation of reactive oxygen species (ROS) and the induction of unmanageable levels of oxidative stress. Elesclomol exhibits antitumor activity against a broad spectrum of types of cancer cell in human tumour xenograft models due to its excessive ROS production and elevated levels of oxidative stress leading to the death of cancer cells. Elesclomol is currently being studied as novel cancer therapeutic, in which it has demonstrated the ability to prolong progression-free survival in study subjects. Elesclomol induces oxidative stress by provoking a buildup of reactive oxygen species within cancer cells. Elesclomol requires a redox-active metal ion to function; the Cu(II) complex is 34 times more potent than the Ni(II) complex and 1040-fold more potent than the Pt(II) complex. Elesclomol is an HSP-90 Inhibitor with pro-apoptotic and potential antineoplastic activities. Elesclomol induces oxidative stress and triggers mitochondrial-induced apoptosis in cancer cells. Elesclomol is being developed by Synta Pharmaceuticals and GlaxoSmithKline as a chemotherapy adjuvant and has received both fast track and orphan drug status from the U.S. Food and Drug Administration for the treatment of metastatic melanoma. Synta Pharmaceuticals announced on February 26, 2009, the suspension of all clinical trials involving Elesclomol due to safety concerns. In March 2010, Synta announced that the FDA had approved resuming clinical development of elesclomol, and that they expected to initiate one or more clinical trials for elesclomol in the second half of the year. In a small, randomized phase II study, elesclomol was shown to significantly increase progression-free survival in people with metastatic melanoma when given in addition to paclitaxel (Taxol).