Treosulfan (l-threitol-1,4-bis-methanesulfonate; dihydroxybusulfan) is a prodrug of a bifunctional alkylating cytotoxic agent that is approved for the treatment of ovarian carcinomas in a number of European countries. The antitumor activity of treosulfan has been shown in a variety of solid tumors. It is used for the treatment of all types of ovarian cancer, either supplementary to surgery or palliatively. Treosulfan is a prodrug that is converted nonenzymatically first to a mono-epoxide – (2S,3S)- 1,2-epoxy-3,4-butanediol-4-methanesulfonate – and then to a diepoxide – l-diepoxybutane, which is also a metabolite of butadiene – under physiological conditions. Such conversions are assumed to account for the alkylating and therapeutic activities of treosulfan.

Selinexor (KPT-330) is a first in class XPO1 antagonist being evaluated in multiple later stage clinical trials in patients with relapsed and/or refractory hematological and solid tumor malignancies.

Ixazomib (trade name Ninlaro) is a drug for the treatment of multiple myeloma in adults after at least one prior therapy, in combination with lenalidomide and dexamethasone. It is taken by mouth in form of capsules. Common side effects include diarrhea, constipation and low platelet count. Like the older bortezomib (which can only be given by injection), it acts as a proteasome inhibitor, has orphan drug status in the US and Europe. At therapeutic concentrations, ixazomib selectively and reversibly inhibits the protein proteasome subunit beta type-5 (PSMB5) with a dissociation half-life of 18 minutes. This mechanism is the same as of bortezomib, which has a much longer dissociation half-life of 110 minutes; the related drug carfilzomib, by contrast, blocks PSMB5 irreversibly. Proteasome subunits beta type-1 and type-2 are only inhibited at high concentrations reached in cell culture models. PSMB5 is part of the 20S proteasome complex and has enzymatic activity similar to chymotrypsin. It induces apoptosis, a type of programmed cell death, in various cancer cell lines. A synergistic effect of ixazomib and lenalidomide has been found in a large number of myeloma cell lines. The medication is taken orally as a prodrug, ixazomib citrate, which is a boronic ester; this ester rapidly hydrolyzes under physiological conditions to its biologically active form, ixazomib, a boronic acid. Absolute bioavailability is 58%, and highest blood plasma concentrations of ixazomib are reached after one hour. Plasma protein binding is 99%.

Pomalidomide is a derivative of thalidomide marketed by Celgene, an analogue of thalidomide, is an immunomodulatory agent with antineoplastic activity. In in vitro cellular assays, pomalidomide inhibited proliferation and induced apoptosis of hematopoietic tumor cells. Additionally, pomalidomide inhibited the proliferation of lenalidomide-resistant multiple myeloma cell lines and synergized with dexamethasone in both lenalidomide-sensitive and lenalidomide-resistant cell lines to induce tumor cell apoptosis. Pomalidomide enhanced T cell- and natural killer (NK) cell-mediated immunity and inhibited production of pro-inflammatory cytokines (e.g., TNF-α and IL-6) by monocytes. Pomalidomide demonstrated anti-angiogenic activity in a mouse tumor model and in the in vitro umbilical cord model.

Carfilzomib is an epoxomicin derivate with potential antineoplastic activity. Kyprolis (carfilzomib's trade name) is a proteasome inhibitor that is indicated for the treatment of patients with relapsed or refractory multiple myeloma who have received one or more lines of therapy as a single agent or in combination with dexamethasone or with lenalidomide plus dexamethasone. Carfilzomib is made up of four modified peptides. It irreversibly and selectively binds to N-terminal threonine-containing active sites of the 20S proteasome, the proteolytic core particle within the 26S proteasome. This 20S core has 3 catalytic active sites: the chymotrypsin, trypsin, and caspase-like sites. Inhibition of the chymotrypsin-like site by carfilzomib (β5 and β5i subunits) is the most effective target in decreasing cellular proliferation, ultimately resulting in cell cycle arrest and apoptosis of cancerous cells. At higher doses, carfilzomib will inhibit the trypsin-and capase-like sites. Inhibition of proteasome-mediated proteolysis results in an accumulation of polyubiquinated proteins, which may lead to cell cycle arrest, induction of apoptosis, and inhibition of tumor growth.

Plerixafor is a bicyclam molecule, which has been identified as a specific antagonist of CXCR4. It had originally been developed as an inhibitor of T-tropic human immunodeficiency virus, but later demonstrated to be an effective mobilizer of hematopoietic stem cells. Plerixafor was approved by FDA for autologous transplantation (in combination with granulocyte-colony stimulating factor) in patients with non-Hodgkin's lymphoma and multiple myeloma under the name Mozobil.

Lenalidomide (trade name Revlimid) is a derivative of thalidomide introduced in 2004. It is an immunomodulatory agent with anti-angiogenic properties. Revlimid in combination with dexamethasone is indicated for the treatment of patients with multiple myeloma (MM) who have received at least one prior therapy. Also is indicated for the treatment of patients with transfusion-dependent anemia due to low- or intermediate-1-risk myelodysplastic syndromes (MDS) associated with a deletion 5q cytogenetic abnormality with or without additional cytogenetic abnormalities. In addition, Revlimid is indicated for the treatment of patients with mantle cell lymphoma (MCL) whose disease has relapsed or progressed after two prior therapies, one of which included bortezomib. The mechanism of action of lenalidomide remains to be fully characterized. Lenalidomide inhibited the secretion of pro-inflammatory cytokines and increased the secretion of anti-inflammatory cytokines from peripheral blood mononuclear cells. Lenalidomide causes a delay in tumor growth in some in vivo nonclinical hematopoietic tumor models including multiple myeloma. Immunomodulatory properties of lenalidomide include activation of T cells and natural killer (NK) cells, increased numbers of NKT cells, and inhibition of pro-inflammatory cytokines (e.g., TNF-α and IL-6) by monocytes. In multiple myeloma cells, the combination of lenalidomide and dexamethasone synergizes the inhibition of cell proliferation and the induction of apoptosis. Recently was discovered, that protein cereblon (CRBN) is a proximate, therapeutically important molecular target of lenalidomide. Low CRBN expression was found to correlate with drug resistance in multiple myeloma (MM) cell lines and primary MM cells. One of the downstream targets of CRBN identified is interferon regulatory factor 4 (IRF4), which is critical for myeloma cell survival and is down-regulated by (immune-modulatory drugs) treatment. CRBN is also implicated in several effects of immunomodulatory drugs, such as down-regulation of tumor necrosis factor-α (TNF-α) and T cell immunomodulatory activity, demonstrating that the pleotropic actions of the immunomodulatory drugs (IMiDs) are initiated by binding to CRBN. Future dissection of CRBN downstream signaling will help to delineate the underlying mechanisms for IMiD action and eventually lead to development of new drugs with more specific anti-myeloma activities. It may also provide a biomarker to predict IMiD response and resistance. Lenalidomide also inhibited the expression of cyclooxygenase-2 (COX-2) but not COX-1 in vitro.

Bortezomib is the therapeutic proteasome inhibitor. First, which is tested in humans. The boron atom in bortezomib binds the catalytic site of the 26S proteasome with high affinity and specificity. Bortezomib is approved in the U.S. for treating relapsed multiple myeloma and mantle cell lymphoma. The 26S proteasome degrades various proteins critical to cancer cell survival, such as cyclins, tumor suppressors, BCL-2, and cyclin-dependent kinase inhibitors. Inhibition of these degradations sensitizes cells to apoptosis. Bortezomib is a potent inhibitor of 26S proteasome, which sensitizes activity in dividing multiple myeloma and leukemic cells, thus inducing apoptosis. Most commonly reported adverse reactions (incidence ≥30%) in clinical studies include asthenic conditions, diarrhea, nausea, constipation, peripheral neuropathy, vomiting, pyrexia, thrombocytopenia, psychiatric disorders, anorexia and decreased appetite, neutropenia, neuralgia, leukopenia and anemia. Co-administration of ketoconazole, a potent CYP3A inhibitor, increased the exposure of bortezomib. Co-administration of melphalan-prednisone increased the exposure of bortezomib. However, this increase is unlikely to be clinically relevant.

Thalidomide is an immunomodulatory agent with a spectrum of activity that is not fully characterized. Thalidomide is racemic — it contains both left and right-handed isomers in equal amounts: one enantiomer is effective against morning sickness, and the other is teratogenic. The enantiomers are converted to each other in vivo. That is, if a human is given D-thalidomide or L-thalidomide, both isomers can be found in the serum. Hence, administering only one enantiomer will not prevent the teratogenic effect in humans. In patients with erythema nodosum leprosum (ENL) the mechanism of action is not fully understood. Available data from in vitro studies and preliminary clinical trials suggest that the immunologic effects of this compound can vary substantially under different conditions, but may be related to suppression of excessive tumor necrosis factor-alpha (TNF-a) production and down-modulation of selected cell surface adhesion molecules involved in leukocyte migration. For example, administration of thalidomide has been reported to decrease circulating levels of TNF-a in patients with ENL, however, it has also been shown to increase plasma TNF-a levels in HIV-seropositive patients. As a cancer treatment, the drug may act as a VEGF inhibitor. Thalidomide is used for the acute treatment of the cutaneous manifestations of moderate to severe erythema nodosum leprosum (ENL). Also for use as maintenance therapy for prevention and suppression of the cutaneous manifestations of ENL recurrence. Thalidomide is sold under the brand name Immunoprin, among others.

Carmustine is a cancer medication that interferes with the growth and spread of cancer cells in the body. Carmustine is used to treat brain tumors, Hodgkin's disease, multiple myeloma, and non-Hodgkin's lymphoma. Although it is generally agreed that carmustine alkylates DNA and RNA, it is not cross-resistant with other alkylators. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. Pulmonary toxicity characterized by pulmonary infiltrates and/or fibrosis has been reported to occur from 9 days to 43 months after treatment with BiCNU and related nitrosoureas. A frequent and serious toxicity of BiCNU is delayed myelosuppression. Nausea and vomiting after intravenous administration of BiCNU are noted frequently. Greater myelotoxicity (e.g., leukopenia and neutropenia) has been reported when carmustine was combined with cimetidine.