Halofuginone is a low molecular weight quinazolinone alkaloid, and a potent inhibitor of collagen alpha1(I) and matrix metalloproteinase 2 (MMP-2) gene expression. Halofuginone also effectively suppresses tumor progression and metastasis in mice. Halofuginone is a potent inhibitor of collagen a1(I) and matrix metalloproteinase 2 (MMP-2) gene expression. Halofuginone also suppresses extracellular matrix deposition and cell proliferation. Also was shown that halofuginone increased apoptosis in α smooth muscle actin- and prolyl 4-hydroxylase β-expressing cells in mdx diaphragm and in myofibroblasts, the major source of extracellular matrix. The profound antitumoral effect of halofuginone is attributed to its combined inhibition of tumour-stromal support, vascularization, invasiveness, and cell proliferation. HT-100 (delayed-release halofuginone), currently in clinical phase 1b/2a in five U.S. hospitals, is a small molecule drug candidate taken orally for the treatment of Duchenne muscular dystrophy (DMD) patients primarily through its ability to reduce fibrosis and inflammation and promote muscle fiber regeneration. The medicine candidate has been granted orphan drug designation in the U.S. and the EU — meaning it has been commercially undeveloped due to its limited profitability — and fast-track designation in the U.S. — an FDA process that aims to facilitate the development and patients’ reach to novel therapies for unmet medical needs.

Nafoxidine is a nonsteroidal antiestrogen available as an investigational agent from the Investigational Drug Branch of the National Cancer Institute. It has been used effectively in the treatment of breast cancer patients. Nafoxidine competes with endogenous estrogen for binding to specific estrogen receptors. This agent also inhibits angiogenesis in some tissues by blocking the effects of fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF); paradoxically, it may enhance angiogenesis in uterine tissue. Nafoxidine also induces oxidative stress, protein kinase C and calcium signaling.

Umbralisib (Ukoniq, TG Therapeutics) is an orally available PI3K delta inhibitor, targeting the delta isoform with nanomolar potency and several fold selectivity over the alpha, beta, and gamma isoforms of PI3K. The delta isoform of PI3K is strongly expressed in cells of hematopoietic origin and is believed to be important in the proliferation and survival of B-cell lymphocytes. On February 5, 2021, the Food and Drug Administration granted accelerated approval to umbralisib for the following indications: adult patients with relapsed or refractory marginal zone lymphoma (MZL) who have received at least one prior anti-CD20-based regimen; adult patients with relapsed or refractory follicular lymphoma (FL) who have received at least three prior lines of systemic therapy. However, on June 1, 2022, the FDA withdrew its approval for the cancer medicine Ukoniq due to safety concerns.

Copanlisib, developed by Bayer, is a phosphoinositide 3-kinase (PI3K) inhibitor with potential antineoplastic activity. Copanlisib inhibits the activation of the PI3K signaling pathway, which may result in inhibition of tumor cell growth and survival in susceptible tumor cell populations. Activation of the PI3K signaling pathway is frequently associated with tumorigenesis and dysregulated PI3K signaling may contribute to tumor resistance to a variety of antineoplastic agents. Copanlisib is currently under Phase II/III clinical trials for the treatment of non-Hodgkin lymphoma and chronic lymphocytic leukemia.

Suramin is an antiprotozoal and anthelmintic compound. It is indicated for the treatment of African trypanosomiasis (African sleeping sickness; trypanosome fever) and Onchocerciasis (river blindness). Additionally, suramin exhibits antineoplastic action. It was discovered that suramin produced dramatic, but transient, improvement of core symptoms of autism spectrum disorder.

Clomiphene (CLOMID®) is a triphenyl ethylene stilbene derivative which is an estrogen agonist or antagonist depending on the target tissue. It is an orally administered, nonsteroidal, ovulatory stimulant. Clomiphene (CLOMID®) is a mixture of two geometric isomers [cis (zuclomiphene) and trans (enclomiphene)] containing between 30% and 50% of the cis-isomer. Clomiphene (CLOMID®) initiates a series of endocrine events culminating in a preovulatory gonadotropin surge and subsequent follicular rupture. The first endocrine event in response to a course of clomiphene therapy is an increase in the release of pituitary gonadotropins. This initiates steroidogenesis and folliculogenesis, resulting in growth of the ovarian follicle and an increase in the circulating level of estradiol. Following ovulation, plasma progesterone and estradiol rise and fall as they would in a normal ovulatory cycle.