Medical science is incessantly looking for new treatments and selective therapies to combat cancer.

However, it has become increasingly clear that conventional therapeutics such as chemotherapy and radiation therapy have limitations in their effectiveness and can cause significant side effects in patients. This has resulted in a growing interest in the study of repurposing old drugs for the treatment of cancer.

What is Drug Repurposing?

Drug repurposing is a process of identifying new uses for existing drugs. This can be done by restoring the drug to a new indication or by modifying the drug into a new molecule with different applications.

Drug repurposing has been largely successful for treating diseases such as HIV, diabetes, and hypertension. The idea of old drugs can also be extended to the treatment of cancer.

Why Revive Old Drugs?

The primary reason for repurposing old drugs is that it can reduce the cost and time required to develop new drugs.

It is estimated that the average cost of bringing a new oncology drug to market is approximately $2.6 billion, and the time required for the development of new drugs from discovery to clinical use averages around 14 years. By using already available drugs, the process can be cut short, and the existing pharmaceutical industry can provide the necessary infrastructure for immediate production and distribution of these drugs.

Factors that affect the Use of Repurposed Drugs

Several factors can determine the success of repurposing old drugs, including compounds that have already passed through clinical trials, favorable safety profiles, knowledge of pharmacokinetics and pharmacodynamics, and the availability of patents.

Patents are an important consideration since manufacturing drugs can be labor-intensive work, and the pharmaceutical companies must be guaranteed a return on their investments.

Examples of repurposed drugs and their effectiveness against cancer

: Aspirin

Aspirin has been known as an effective painkiller and has been used for reducing inflammation for many years. It has also shown some promising results in fighting cancer.

Studies have shown that aspirin has anti-tumor properties and the ability to prevent the formation of blood vessels that can support the growth of tumors. In a study conducted in China, Aspirin significantly reduced the risk of pancreatic cancer by 48%.

Another study by researchers at the University of Oxford, UK, found that taking a low dose of aspirin also had a significant impact on reducing the number of cancer-related deaths.

: Cimetidine

Cimetidine is a medication typically used to treat acid reflux, stomach ulcers, and heartburn. Still, it has also shown promising results in the treatment of cancer.

It is believed that cimetidine works by blocking histamine receptors, which are involved in cell growth and division. It has been found to improve the outcome of chemotherapy in stomach cancer patients. A study published in the Journal of Clinical Oncology showed that cimetidine may also reduce the risk of metastasis in breast cancer patients.

: Metformin

Metformin is typically used to treat type 2 diabetes, but it has shown to be effective in treating cancer as well. Research has shown that metformin can reduce the risk of developing various types of cancer, including breast, liver, and lung cancer.

It works by reducing insulin-like growth factor-1, a hormone that is present in high levels in cancer patients. It also helps activate the immune system, which can combat cancer cells, and promotes autophagy, the process through which cells break down and recycle old, damaged cellular components.

: Thalidomide

Best known for its infamous side effects on pregnant women, Thalidomide has emerged as a promising anti-cancer drug.

In recent years, the drug has successfully been repurposed in the treatment of multiple myeloma, a blood cancer that affects plasma cells. It works by preventing the growth of blood vessels that can nourish cancer cells and also indirectly activates the immune system. It has shown promising results in clinical trials, and it is used in combination with other therapies to fight cancer.

: Propranolol

Propranolol is a medication typically used to treat high blood pressure and anxiety disorders, but it is also being studied for its potential use in cancer treatment.

It is known to calm the sympathetic nervous system, which controls the fight or flight response, and plays a role in the spread of cancer. Propranolol has been found to help reduce the risk of cancer development in patients with melanoma, breast cancer, and hepatocellular carcinoma.

It is believed that propranolol can help to reduce the risk of recurrence and improve the survival rate of cancer patients.

Conclusion

The repurposing of old drugs offers an exciting new avenue for the treatment of cancer. The potential benefits of using existing drugs include reduced costs, quicker development times, and a ready infrastructure for manufacturing and distribution.

While there is no guarantee that repurposed old drugs will be effective in combatting cancer, the fact that they have already been through rigorous testing and analysis makes them promising candidates.