Acivicin is a modified amino acid and structural analog of glutamine, that irreversibly inhibits glutamine-dependent amidotransferases involved in nucleotide and amino acid biosynthesis. Acivicin is a potent antitumor agent that induces apoptosis in human lymphoblastoid cells. Phase I dose-escalating studies conducted in cancer patients administered acivicin showed reversible, dose-limiting CNS toxicity, characterized by lethargy, confusion and decreased mental status.

Uracil is a common and naturally occurring pyrimidine derivative, one of the four nucleobases in the nucleic acid of RNA In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by it’s methylated form -- thymine. Originally discovered in 1900 by Alberto Ascoli, it was isolated by hydrolysis of yeast nuclein;[4] it was also found in bovine thymus and spleen, herring sperm, and wheat germ. It is a planar, unsaturated compound that has the ability to absorb light. Uracil readily undergoes regular reactions including oxidation, nitration, and alkylation. While in the presence of phenol (PhOH) and sodium hypochlorite (NaOCl), uracil can be visualized in ultraviolet light. Uracil also has the capability to react with elemental halogens because of the presence of more than one strongly electron donating group. Uracil readily undergoes addition to ribose sugars and phosphates to partake in synthesis and further reactions in the body. Uracil becomes uridine, uridine monophosphate (UMP), uridine diphosphate (UDP), uridine triphosphate (UTP), and uridine diphosphate glucose (UDP-glucose). Each one of these molecules is synthesized in the body and has specific functions. Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates. Uracil serves as allosteric regulator and coenzyme for reactions in the human body and in plants. Uracil can be used for drug delivery and as a pharmaceutical. When elemental fluorine is reacted with uracil, 5-fluorouracil is produced. 5-Fluorouracil is an anticancer drug (antimetabolite) used to masquerade as uracil during the nucleic acid replication process. In combination with Tegafur, uracil used as a chemotherapy drug (called UFT or UFUR) used in the treatment of cancer, primarily bowel cancer. UFT is an anticancer medication composed of a fixed molar ratio (1:4) of tegafur and uracil to be administered with calcium folinate.

Epitiostanol is androgenic antiestrogen developed for the treatment of breast cancer. The drug inhibits estrogen receptor and activates androgen receptor and was shown to be active in vitro on MCF-7, U-2 and U-3 cells. The current marketing status of Epitiostanol is unknown and is supposed to be "discontimued".

3-Aminopropionitrile (Beta-amino-propionitrile, BAPN) is a toxic constituent from lathyrus plants. BAPN found in lathyrus odoratus (our more common garden sweet pea plant) is thought to be responsible for osteolathyrism due to irreversible inhibition of lysyl oxidase (LOX), an enzyme necessary for the covalent cross-linking of tropocollagen molecules during the maturation of mature collagen. BAPN demonstrated in antimetastatic and antimyelofibrotic activity in vivo due to inhibition of LOX.

Paroxypropione (brand names Frenantol, Frenormon, Hypophenon, Paroxon, Possipione, Profenone is a synthetic, non-steroidal estrogen that has been used medically as an antigonadotropin in Spain and Italy. Paroxypropione was first synthesized in 1902. Its antigonadotropic properties were discovered in 1951 and it entered clinical use shortly thereafter. Paroxypropione is a product from the oxidative splitting of stilbestrol, with a low degree of estrogenicity, has been found a valuable drug for checking the growth of lung metastases secondary to certain malignant tumors such as chorionepitheliomas or nephrobiastomas. As the drug possesses relatively low affinity for the estrogen receptor and must be given at high dosages to achieve significant estrogenic and antigonadotropic action.

Trastuzumab emtansine (ado-trastuzumab emtansine, trade name Kadcyla) is a combination between a monoclonal antibody and a small-molecule drug. Each molecule of trastuzumab emtansine consists of a single trastuzumab molecule with several molecules of DM1, a cytotoxic maytansinoid, attached. SMCC, or succinimidyl trans-4-(maleimidylmethyl)cyclohexane-1-carboxylate, is a heterobifunctional crosslinker, a type of chemical reagent that contains two reactive functional groups, a succinimide ester and a maleimide. The succinimide group of SMCC reacts with the free amino group of a lysine residue in the trastuzumab molecule and the maleimide moiety of SMCC links to the free sulfhydryl group of DM1, forming a covalent bond between the antibody and the DM1. Each trastuzumab molecule may be linked to zero to eight DM1 molecules (3.5 on average). Trastuzumab emtansine is an antibody-drug conjugate consisting of the recombinant anti-epidermal growth factor receptor 2 (HER2) monoclonal antibody trastuzumab conjugated to the maytansinoid DM1. The trastuzumab moiety of this ADC binds to HER2 on tumor cell surface surfaces; upon internalization, the DM1 moiety is released and binds to tubulin, thereby disrupting microtubule assembly/disassembly dynamics and inhibiting cell division and the proliferation of cancer cells that overexpress HER2. Linkage of antibody and drug through a nonreducible linker has been reported to contribute to the improved efficacy and reduced toxicity of this ADC compared to similar ADCs constructed with reducible linkers. Trastuzumab emtansine is used for the treatment of patients with HER2-positive, metastatic breast cancer who previously received rastuzumab and a taxane, separately or in combination. Patients should have either: received prior therapy for metastatic disease, or developed disease recurrence during or within six months of completing adjuvant therapy. Ado-trastuzumab emtansine is marketed under the brand name Kadcyla and is indicated for use in HER2-positive, metastatic breast cancer patients who have already used taxane and/or trastuzumab for metastatic disease or had their cancer recur within 6 months of adjuvant treatment. The FDA label has two precautions. First that ado-trastuzumab emtansine and trastuzumab cannot be interchanged. Second that there is a black box warning of serious side effects such as hepatotoxicity, embryo-fetal toxicity, and cardiac toxicity.

Technetium (99mTc) tilmanocept, trade name Lymphoseek, is a radiopharmaceutical diagnostic imaging agent approved for the imaging of lymph nodes. It is used to locate those lymph nodes which may be draining from tumors, and assist doctors in locating those lymph nodes for removal during surgery.

Nirogacestat (PF-3084014) is a tetralin imidazole gamma-secretase inhibitor. Gamma-secretase, a proteolytic enzyme complex, mediates processing of several integral membrane proteins including amyloid precursor protein and Notch. This compound can inhibit both Notch-related pathway in neoplasia and reduces amyloid-β production. Nirogacestat (PF-3084014) is under development by Pfizer for the treatment of cancer.

Estetrol is the natural human fetal selective estrogen receptor modulator. It is synthesized exclusively by the human fetal liver during pregnancy. Estetrol has a moderate affinity for human estrogen A receptor (ERa) and estrogen B receptor (ERb). Estetrol may be suitable as a potential drug for human use in applications such as hormone replacement therapy (vaginal atrophy, hot flushes), contraception and osteoporosis. The most common drug-related adverse events were lower abdominal pain, nausea, headache, dysmenorrhoea, breast enlargement and acne. Estetrol had been in clinical trials for the treatment of breast and prostate cancers.

TUCATINIB (ONT-380 or ARRY-380) is an orally active, reversible and selective small-molecule HER2 inhibitor invented by Array and licensed to Cascadian Therapeutics (previously named Oncothyreon) for development, manufacturing and commercialization. HER2, a growth factor receptor that is over-expressed in multiple cancers, including breast, ovarian, and stomach cancer. HER2 mediates cell growth, differentiation and survival, and tumors that overexpress HER2 are more aggressive and historically have been associated with poorer overall survival compared with HER2-negative cancers. ONT-380 is highly active as a single agent and in combination with both chemotherapy and Herceptin® (trastuzumab) in xenograft models of HER2+ breast cancer, including models of CNS metastases that were refractory to Tykerb® (lapatinib) or neratinib treatment. In a Phase 1 single agent clinical study, ONT-380 administered orally twice a day was well tolerated and demonstrated anti-tumor activity in heavily pre-treated HER2+ breast cancer patients with metastatic disease. Based on the strength of these preclinical and clinical trials, ONT-380 is advancing in one Phase 2 and three Phase 1b combination trials in patients with metastatic breast cancer. A second study reported the CNS activity of ONT-380 in combination with either T-DM1 or trastuzumab or capecitabine. Patients with brain metastases assessable for response were included in the combined analysis. Responses and clinical benefit in the CNS were reported with the three combinations tested, supporting future development of the drug for this particular indication.