Repurposed Drugs

Repurposing drugs refers to the process of finding uses for existing drugs that aren't approved for their new intended use. Many patients are using these agents as an alternative to standard of care, and many are using these drugs as adjuncts to the standard of care treatments.

Having been involved in the use of repurposed drugs for over 20 years, I have come to the following conclusion: in general, repurposed drugs are not sufficiently efficacious on their own to stabilize or reverse advanced-stage cancers. Having said that, it is certainly possible that some repurposed drugs may be additive or even synergistic with therapies such as chemotherapy, radiation, immunotherapy, and surgical resection. The following represents some, but not all of the repurposed drugs used for cancer at Advanced Medical Therapeutics.

Repurposed Drugs utilized at Advanced Medical Therapeutics

1. Hydroxychloroquine (HCQ); many studies have shown that HCQ can be synergistic with chemotherapy. The primary mechanism of action is thought to be inhibition of autophagy. Autophagy is a process in which cells consume or degrade themselves. This process can aid in the renewal of cellular proteins and other molecules that help cancer cells survive under stressful conditions such as hypoxia and nutrient deprivation. In advanced-stage cancers, autophagy promotes the survival of tumor cells by ameliorating stress in the microenvironment. Therefore, autophagy inhibition with drugs such as HCQ may be a useful adjunct in the treatment of cancer.
2. Ivermectin; this antiparasitic drug has recently received a lot of publicity regarding its use for Covid-19 and cancer. Ivermectin inhibits cancer and cancer stem cells through a myriad of mechanisms. On the surface, it appears to be a miracle for cancer. In addition to its ability Having said that, what is the optimal dose for humans with cancer? Unfortunately, we do not know that at this time. A phase 2 doses escalation trial in triple negative breast cancer is currently under way combining ivermectin with a PD-1 inhibitor (immunotherapy). Not only has ivermectin shown to inhibit cancer proliferation, metastasis, and angiogenic activity, but it also targets cancer stem cells. There are anectdotal cases of advanced-stage cancer patients having a good response to 2 mg/kg daily, but this high dose is generally not tolerated, as it causes uncomfortable visual disturbances.
3. Statins; while many of us are not pleased with the overuse of statins, multiple publications with many different types of cancer have shown that individuals on lipophilic statins live longer than those not on a lipophilic statin. Statins work through many mechanisms in inhibiting cancer, including the ability to reduce cell proliferation and angiogenesis as well as decrease invasion.
4. 2-deoxy-d-glucose (2DG); this is a glucose derivative that stops glycolysis so the cancer cannot produce ATP (energy) via this mechanism. 2DG if given in adequate doses, outcompetes glucose for uptake in the cell. Many cancer cells, especially the more aggressive cells, prefer to utilize glucose for energy. Unfortunately, studies have revealed that this drug, when used as a single agent, is not effective against cancer. However, when this drug is combined with metformin and/or hydroxychloroquine (HCQ), it may be much more effective. In response to the stress on the cancer cells caused by 2DG, many of these cells escape death by undergoing autophagy, as mentioned above. In preclinical studies blocking the uptake of glucose with 2DG, while simultaneously inhibiting autophagy with HCQ, proved to be synergistic
5. Metformin; while the anti-diabetic drug metformin inhibits cancer through multiple mechanisms, prospective studies using metformin as an adjunct to standard of care have been disappointing. Metformin’s effects on cancer cells are multifaceted, but one mechanism may be its ability to inhibit mitochondrial oxidative phosphorylation, which is an important process for the production of energy for the cell. Based on this mechanism, metformin may cause the cancer cells to rely more heavily on glycolysis for the production of energy. Preclinical data shows that combining the mitochondrial inhibitor (metformin) with the glycolysis inhibitor (2DG), was synergistic in inhibiting cancer growth.
6. Mebendazole (MBZ); this antiparasitic drug inhibits a wide range of factors involved in tumor progression such as tubulin polymerization, angiogenesis, pro-survival pathways, matrix metalloproteinases, and multi-drug resistance protein transporters. MBZ not only exhibits direct cytotoxic activity, but also synergizes with ionizing radiations and different chemotherapeutic agents and stimulates antitumoral immune response. MBZ treatment has dual use as a chemotherapeutic agent as well as blocking the hypoxia-induced phenotype that promotes chemoresistance. In my opinion, most individuals are using doses too low to have efficacy against cancer. Studies are ongoing in several different types of cancers, especially brain tumors, using up to 200 mg/kg per day; that equals 14,000 mg daily in a 70 kg individual. For most adults, I am starting at 1500 mg/day.