O6-benzylguanine

A guanine analogue with antineoplastic activity. O(6)-benzylguanine binds the DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase (AGT), transferring the benzyl moiety to the active-site cysteine and resulting in inhibition of AGT-mediated DNA repair. Co-administration of this agent potentiates the effects of other chemotherapeutic agents that damage DNA.

Octreoscan

(Other name for: indium In 111 pentetreotide)

octreotide acetate

The acetate salt of a synthetic long-acting cyclic octapeptide with pharmacologic properties mimicking those of the natural hormone somatostatin. Octreotide is a more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin. Similar to somatostatin, this agent also suppresses the luteinizing hormone response to gonadotropin-releasing hormone, decreases splanchnic blood flow, and inhibits the release of serotonin, gastrin, vasoactive intestinal peptide (VIP), secretin, motilin, pancreatic polypeptide, and thyroid stimulating hormone.

octreotide pamoate

A synthetic long-acting octapeptide analogue of endogenous somatostatin. Octreotide pamoate binds to somatostatin receptors expressed by some neuroendocrine and non-neuroendocrine tumor cells, thereby initiating somatostatin receptor-mediated apoptosis. Other possible antineoplastic activities of this agent include suppression of tumor angiogenesis and tumor growth-promoting insulin-like growth factor 1 (IGF-1).

odanacatib

An inhibitor of cathepsin K with potential anti-osteoporotic activity. Odanacatib selectively binds to and inhibits the activity of cathepsin K, which may result in a reduction in bone resorption, improvement of bone mineral density, and a reversal in osteoporotic changes. Cathepsin K, a tissue-specific cysteine protease that catalyzes degradation of bone matrix proteins such as collagen I/II, elastin, and osteonectin plays an important role in osteoclast function and bone resorption.

Oestrogenine

(Other name for: diethylstilbestrol)

Oestromenin

(Other name for: diethylstilbestrol)

Oestromon

(Other name for: diethylstilbestrol)

oglufanide disodium

The disodium salt of a synthetic form of a naturally-occurring dipeptide consisting of L-glutamic acid and L-tryptophan with potential antiangiogenic and potential immunomodulating activities. Oglufanide inhibits vascular endothelial growth factor (VEGF), which may inhibit angiogenesis. This agent has also been reported to stimulate the immune response to hepatitic C virus and intracellular bacterial infections.

olaratumab

A fully human IgG1 monoclonal antibody directed against the platelet-derived growth factor receptor alpha (PDGFR alpha) with potential antineoplastic activity. Olaratumab selectively binds to PDGFR alpha, .blocking the binding of its ligand, PDGF; signal transduction downstream of PDGFR through the MAPK and PI3K pathways is inhibited, which may result in inhibition of angiogenesis and tumor cell proliferation. Overexpressed by various cancer cell types, PDGFR is a transmembrane protein tyrosine kinase receptor, consisting of isoforms A and B, that is important in regulating cellular growth and differentiation and angiogenesis.

oleandrin

A lipid soluble cardiac glycoside with potential antineoplastic activity. Upon administration, oleandrin specifically binds to and inhibits the alpha3 subunit of the Na/K-ATPase pump in human cancer cells. This may inhibit the phosphorylation of Akt, upregulate MAPK, inhibit NF-kb activation and inhibit FGF-2 export and may downregulate mTOR thereby inhibiting p70S6K and S6 protein expression. All of this may lead to an induction of apoptosis. As cancer cells with relatively higher expression of the alpha3 subunit and with limited expression of the alpha1 subunit are more sensitive to oleandrin, one may predict the tumor response to treatment with lipid-soluble cardiac glycosides such as oleandrin based on the tumors Na/K-ATPase pump protein subunit expression. Overexpression of the alpha3 subunit in tumor cells correlates with tumor proliferation.

oligonucleotide SPC2996

A synthetic antisense oligonucleotide against Bcl-2 messenger RNA with potential antitumor activity. Oligonucleotide SPC2996 binds to and inactivates Bcl-2 mRNA, thereby inhibiting the expression of Bcl-2 protein, promoting tumor cell apoptosis, and potentially enhancing the efficacy of standard cytotoxic chemotherapy. Linked to tumor drug resistance, the antiapoptotic protein Bcl-2 is upregulated in several types of cancers.

omacetaxine mepesuccinate

A semisynthetic formulation of the cytotoxic plant alkaloid homoharringtonine isolated from the evergreen tree Cephalotaxus with potential antineoplastic activity. Omacetaxine mepesuccinate binds to the 80S ribosome in eukaryotic cells and inhibits protein synthesis by interfering with chain elongation. This agent also induces differentiation and apoptosis in some cancer cell types.

omalizumab

A humanized monoclonal antibody directed against the C-epsilon 3 domain of immunoglobulin E. Olizumab binds to this IgE domain, thereby preventing IgE from binding to its high-affinity mast-cell receptor.

ombrabulin

A synthetic water-soluble analogue of combretastatin A4, derived from the South African willow bush (Combretum caffrum), with potential vascular-disrupting and antineoplastic activities. Ombrabulin binds to the colchicine binding site of endothelial cell tubulin, inhibiting tubulin polymerization and inducing mitotic arrest and apoptosis in endothelial cells. As apoptotic endothelial cells detach from their substrata, tumor blood vessels collapse; the acute disruption of tumor blood flow may result in tumor necrosis.

Omnitarg

(Other name for: pertuzumab)

onartuzumab

A humanized monovalent monoclonal antibody directed against the hepatocyte growth factor receptor (c-Met) with potential antineoplastic activity. Onartuzumab binds to the extracellular domain of c-Met, preventing the binding of its ligand, hepatocyte growth factor (HGF); the activation of the c-Met signaling pathway is thus inhibited, which may result in cell death in c-Met-expressing tumor cells. c-Met, a receptor tyrosine kinase, is overexpressed on the cell surfaces of a variety of cancer cell types and may play a key role in their proliferation, invasion and survival.

OncoGel

(Other name for: PGLA/PEG copolymer-based paclitaxel)

OncoLAR

(Other name for: octreotide pamoate)

oncolytic adenovirus Ad5-Delta 24RGD

An adenovirus serotype 5 strain, selectively replication competent in cells defective in the Rb/p16 tumor suppressor pathway, with potential oncolytic activity. Oncolytic adenovirus Ad5-Delta 24RGD contains an integrin binding RGD-4C motif, allowing Coxsackie adenovirus receptor-independent infection of tumor cells, which are often deficient for Coxsackie and adenovirus receptors (CARs). Selectively replication competent in cells that are defective in retinoblastoma gene (Rb) or cyclin-dependent kinase inhibitor-2A (p16), active replication of oncolytic adenovirus Ad5-Delta 24RGD in tumor cells may induce oncolysis or cell lysis. As integral components of the late G1 restriction point, the Rb gene product and p16 are negative regulators of the cell cycle; ovarian cancer cells and non-small cell lung cancer cells may be defective in the Rb/p16 pathway.

oncolytic adenovirus encoding GM-CSF

A recombinant oncolytic adenovirus encoding the immunohematopoietic cytokine granulocyte-macrophage colony stimulating factor (GM-CSF) with potential antineoplastic activity. Upon administration, the oncolytic adenovirus selectively infects and replicates in tumor cells, which may result in tumor cells lysis. Synergistically, GM-CSF (sargramostim) expressed by the oncolytic adenovirus may promote a cytotoxic T cell response against tumor cells harboring the oncolytic adenovirus, resulting in an immune-mediated tumor cell death.

oncolytic HSV-1 rRp450

A gene therapy agent containing an attenuated, replication-competent, genetically engineered mutant form of the Herpes simplex virus 1 (HSV-1) strain KOS with potential antineoplastic activity. Upon infusion into the hepatic artery, oncolytic HSV-1 rRp450 replicates in hepatocellular carcinoma (HCC) cells and exerts direct cytotoxic effects eventually disrupting cancer cell membranes and liberating progeny virions thereby infecting adjacent tumor cells. In addition, rRp450 expresses the cytochrome P450 transgene that activates oxazaphosphorines, such as cyclophosphamide (CPA). Therefore, CPA can become activated in the presence of rRp450 and exert its antineoplastic effect. rRp450 is deleted for the HSV-1 gene UL39, encoding the viral ribonucleotide reductase large subunit infected cell protein 6 (ICP6), thereby disrupting the activity of viral ribonucleotide reductase and resulting in the inhibition of nucleotide metabolism and viral DNA synthesis in nondividing cells but not in dividing cells. UL39 is replaced by the rat CYP2B1 gene, encoding a cytochrome P450 enzyme that activates oxazaphosphorines. rRp450 also expresses viral thymidine kinase, which activates the cancer prodrug ganciclovir.

oncolytic HSV-1716

A neuroattenuated, replication-restricted, ICP34.5 deleted (RL1 gene)-mutant herpes simplex virus (HSV) type I, constructed from wild-type strain 17, with potential oncolytic activity. Upon intratumoral injection, oncolytic HSV1716 transfects, replicates in, and lyses rapidly dividing cells such as tumor cells. Because the RL1 gene is deleted , HSV1716 is unable to replicate in non-dividing cells.

oncolytic measles virus encoding thyroidal sodium iodide symporter

An attenuated oncolytic Edmonston (Ed) strain of measles virus encoding the human thyroidal sodium iodide symporter (MV-NIS) with potential gene expression and antineoplastic activities. After attachment to and fusion with host tumor cell membranes, MV-NIS may induce tumor cell syncytia and tumor cell lysis. When combined with iodine 123 (I-123), expressed NIS facilitates uptake of I-123 by MV-NIS-infected tumor cells, allowing noninvasive imaging of these cells. MV-NIS may also enhance the oncolytic activity of MV against radiosensitive tumor cells by facilitating the uptake of iodine 131 (I-131) by MV-NIS-infected cells. The cellular receptor for MV is the human CD46 antigen, a type 1 integral membrane glycoprotein found on nearly all human tissues and overexpressed on many cancer cell types.

oncolytic Newcastle disease virus

An oncolytic viral agent containing the oncolytic, live-attenuated strain of the paramyxovirus Newcastle disease virus (NDV), with potential antineoplastic activity. Upon administration, NDV specifically infects and replicates in cancer cells. This may result in a direct cytotoxic effect involving the lysis of tumor cells via apoptotic mechanisms and may eventually lead to an inhibition of cancer cell proliferation.

OncoVax-PR

(Other name for: PSA prostate cancer vaccine)

OncoVEX GM-CSF

(Other name for: talminogene laherparepvec)

Onsolis

(Other name for: fentanyl buccal soluble film)

Opana

(Other name for: oxymorphone hydrochloride)

OPCs/green tea,/spirullina/curcumin/antrodia camphorate/fermented soymilk extract capsule

A capsule containing a fermented soymilk extract and oligomeric proanthocyanidins (OPCs), green tea, spirullina, curcumin and antrodia camphorate powder, with potential antioxidant, immunomodulating, anti-infective and anti-cancer activities. OPCs/green tea/spirullina/curcumin/antrodia camphorate/fermented soymilk extract capsule may boost the immune system and may alleviate fatigue and poor appetite in cancer chemotherapy patients.

opium tincture

Also known as laudanum and formulated for oral administration, opium tincture is made of air-dried poppy (Papaver somniferum) latex and contains alkaloids such as morphine and codeine. As an antidiarrheal agent, it slows transit of intestinal contents by increasing intestinal smooth muscle tone and inhibiting motility; water is absorbed from fecal contents, decreasing diarrhea.

Optison

(Other name for: perflutren protein-type A microspheres)

Ora-Testryl

(Other name for: fluoxymesterone)

Oracit

(Other name for: sodium citrate)

oral fludarabine phosphate

An oral formulation of the phosphate salt of fludarabine, a synthetic purine nucleoside analogue antimetabolite with antineoplastic activity. Fudarabine is preferentially transported into malignant cells and metabolized by deoxycytidine kinase to its active form, 2-fluoro-ara-ATP; 2-fluoro-ara-ATP competes directly with deoxyadenosine triphosphate (dATP) and inhibits alpha DNA polymerase, RNA reductase, and DNA primase, which may result in inhibition of DNA synthesis and cell death.

oral Hsp90 inhibitor IPI-493

An orally bioavailable formulation of the ansamycin derivative 17-amino-17-demethoxygeldanamycin (17-AG) with potential antineoplastic activity. Oral Hsp90 inhibitor IPI-493 binds to and inhibits Hsp90, which may result the in growth inhibition in sensitive tumor cell populations. Hsp90, a 90 kDa molecular chaperone, may be highly expressed in tumor cells, playing a key role in the conformational maturation, stability and function of other substrate or "client" proteins within the cell; many of these client proteins are involved in signal transduction, cell cycle regulation and apoptosis, and may include kinases, transcription factors and hormone receptors.

oral JAK inhibitor INCB18424

An orally bioavailable Janus-associated kinase (JAK) inhibitor with potential antineoplastic and immunomodulating activities. Oral JAK inhibitor INCB18424 specifically binds to and inhibits protein tyrosine kinases JAK 1 and 2, which may lead to a reduction in inflammation and an inhibition of cellular proliferation. The JAK-STAT (signal transducer and activator of transcription) pathway plays a key role in the signaling of many cytokines and growth factors and is involved in cellular proliferation, growth, hematopoiesis, and the immune response; JAK kinases may be upregulated in inflammatory diseases, myeloproliferative disorders, and various malignancies.

oral JAK2 inhibitor SB1518

An orally bioavailable inhibitor of Janus kinase 2 (JAK2) and the JAK2 mutant JAK2V617F with potential antineoplastic activity. Oral JAK2 inhibitor SB1518 competes with JAK2 for ATP binding, which may result in inhibition of JAK2 activation, inhibition of the JAK-STAT signaling pathway, and so caspase-dependent apoptosis. JAK2 is the most common mutated gene in bcr-abl-negative myeloproliferative disorders; the JAK2V617F gain-of-function mutation involves a valine-to-phenylalanine modification at position 617. The JAK-STAT signaling pathway is a major mediator of cytokine activity.

oral microencapsulated diindolylmethane

An orally bioavailable microencapsulated formulation of diindolylmethane, an indole phytonutrient found in cruciferous vegetables, with estrogen-modulating, antiandrogenic, and potential antineoplastic activities. As a dimer of indole-3-carbinol, diindolylmethane (DIM) modulates estrogen balance by reducing the levels of 16-hydroxy estrogen metabolites and increasing the formation of beneficial 2-hydroxy estrogen metabolites. DIM also antagonizes androgen receptor activity, which may result in diminished cell proliferation and apoptosis in susceptible tumor cell populations. Pure DIM, which is relatively hydrophobic, is poorly absorbed after oral administration. This oral formulation, which consists of DIM, d-alpha-tocopheryl acid succinate, phosphatidylcholine, and silica microencapsulated in starch, significantly improves the gastrointestinal absorption of DIM.

oral milataxel

An orally bioavailable taxane with potential antineoplastic activity. Upon oral administration, milataxel and its major active metabolite M-10 bind to and stabilize tubulin, resulting in the inhibition of microtubule depolymerization and cell division, cell cycle arrest in the G2/M phase, and the inhibition of tumor cell proliferation. Unlike other taxane compounds, milataxel appears to be a poor substrate for the multidrug resistance (MDR) membrane-associated P-glycoprotein (P-gp) efflux pump and may be useful for treating multidrug-resistant tumors.

oral picoplatin

An oral preparation of picoplatin, a third generation platinum compound with antineoplastic activity. Designed to overcome platinum drug resistance, picoplatin alkylates DNA, forming both inter- and intra-strand cross-linkages, resulting in inhibition of DNA replication and RNA transcription and the induction of apoptosis. Because of the increase in steric bulk around the platinum center, there is a relative reduction in the inactivation of picoplatin by thiol-containing species such as glutathione and metallothionein in comparison to cisplatin.

oral sodium phenylbutyrate

An orally active derivative of the short-chain fatty acid butyrate with potential antineoplastic activity. 4-Phenylbutyrate inhibits histone deacetylase, resulting in cell cycle gene expression modulation, reduced cell proliferation, increased cell differentiation, and apoptosis. This agent also initiates fragmentation of genomic DNA, resulting in decreased DNA synthesis and the inhibition of tumor cell migration and invasion.

oral topotecan hydrochloride

An oral formulation of the hydrochloride salt of topotecan, a semisynthetic derivative of the quinoline alkaloid camptothecin, with potential antineoplastic activity. Topotecan selectively inhibits topoisomerase I activity by stabilizing topoisomerase I-DNA covalent complexes during the S phase of the cell cycle, thereby inhibiting religation of topoisomerase I-mediated single-strand DNA breaks and producing potentially lethal double-strand DNA breaks when encountered by the DNA replication machinery.

Oralet

(Other name for: fentanyl citrate)

Oramorph

(Other name for: morphine sulfate)

Oramorph SR

(Other name for: morphine sulfate)

Orathecin

(Other name for: rubitecan)

Orazol

(Other name for: enteric-coated zoledronic acid tablet MER-101)

Orencia

(Other name for: abatacept)

Orestralyn

(Other name for: ethinyl estradiol)

ormaplatin

A platinum(IV) analogue with antineoplastic activity. Ormaplatin alkylates DNA, forming both inter- and intra-strand platinum-DNA crosslinks, which result in inhibition of DNA replication and transcription and cell-cycle nonspecific cytotoxicity.

Orplatna

(Other name for: satraplatin)

Orthoclone OKT3

(Other name for: muromonab-CD3)

Osmitrol

(Other name for: mannitol)

Ossirene

(Other name for: ammonium trichlorotellurate)

Ostarine

(Other name for: selective androgen receptor modulator GTx-024)

Ovaban

(Other name for: megestrol acetate)

ovarian cancer peptide vaccine

A cancer vaccine comprised of synthetic peptides corresponding to naturally-occurring peptides derived from ovarian cancer cell antigens. Ovarian cancer peptide vaccine may elicit a cytotoxic T-cell response against tumor cells expressing the related ovarian cancer cell antigens.

ovarian cancer stem cell/hTERT/survivin mRNAs-loaded autologous dendritic cell vaccine

A cancer vaccine containing autologous dendritic cells (DCs) that are transfected with mRNAs extracted from amplified ovarian cancer stem cells, and mRNAs of the universal tumor antigens human telomerase reverse transcriptase (hTERT) and survivin with potential immunostimulatory and antineoplastic activities. Upon administration, ovarian cancer stem cell/hTERT/survivin mRNAs-loaded autologous DC-006 vaccine may elicit a highly specific cytotoxic T-cell (CTL) response against ovarian cancer cells expressing hTERT, survivin, and specific ovarian cancer stem cell antigens. hTERT, the catalytic subunit of human telomerase, and survivin, a member of the inhibitor of apoptosis (IAP) family of proteins, may be upregulated in certain tumor cell types, playing key roles in tumor cell growth and survival. Ovarian cancer stem cells contain a specific range of antigens that are essential for the neoplastic growth and survival of ovarian cancer cells.

OVax

(Other name for: autologous dinitrophenyl-modified ovarian cancer vaccine)

Ovrette

(Other name for: norgestrel)

oxaliplatin-encapsulated transferrin-conjugated N-glutaryl phosphatidylethanolamine liposome

A nanoparticle formulation containing N-glutaryl phosphatidylethanolamine (NGPE)-liposomes encapsulating oxaliplatin and conjugated to the human transferrin (Tf) ligand, with potential antineoplastic activity. Upon infusion of oxaliplatin-encapsulated transferrin-conjugated NGPE liposomes, the transferrin moiety targets and binds to the Tf receptor, which is overexpressed on a variety of human cancer cells. Upon binding and internalization, oxaliplatin is released and its active derivatives alkylate macromolecules, forming both inter- and intra-strand platinum-DNA crosslinks, resulting in an inhibition of DNA replication and transcription. By extending the circulation time and specifically targeting transferrin receptors, this formulation may improve the efficacy and safety of oxaliplatin therapy, compared to administration of oxaliplatin alone. NGPE, a reactive phospholipid, is used as a linker to attach the Tf ligand, to the liposome.

Oxandrin

(Other name for: oxandrolone)

oxitriptan

An aromatic amino acid with antidepressant activity. In vivo, oxitriptan is converted into 5-hydroxytryptamine (5-HT or serotonin) as well as other neurotransmitters. Oxitriptan may exert its antidepressant activity via conversion to serotonin or directly by binding to serotonin (5-HT) receptors within the central nervous system (CNS). Endogenous 5-hydroxytryptophan (5-HTP) is produced from the essential amino acid L-tryptophan. Exogenous therapeutic 5-HTP is isolated from the seeds of the African plant Griffonia simplicifolia.

Oxsoralen

(Other name for: methoxsalen)

Oxsoralen-Ultra

(Other name for: methoxsalen)

OxyContin

(Other name for: oxycodone hydrochloride)

oxymorphone hydrochloride

The hydrochloride salt form of oxymorphone, a semisynthetic opioid with a potent analgesic property. Oxymorphone hydrochloride binds to and activates opiate receptors, specifically mu-receptors, in the central nervous system (CNS). This results in sedation, analgesia, decreased gastrointestinal motility, and respiratory depression.

ozarelix

A highly modified, fourth generation linear decapeptide with gonadotropin-releasing hormone (GnRH or LHRH) antagonizing properties. Ozarelix competitively binds to and blocks the gonadotropin releasing hormone receptor in the anterior pituitary gland, thereby inhibiting the secretion and release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). In males, the inhibition of LH secretion prevents the release of testosterone. As a result, this may relieve symptoms associated with hormonally dependent disease states such as hormone-dependent prostate cancer.