Immunotherapy Drugs for Mesothelioma: A Promising Avenue for Treatment

Mesothelioma is a rare but aggressive form of cancer, often related to asbestos exposure, which predominantly affects the pleura lining the lungs. Traditional treatment options have included chemotherapy, radiation, and surgical procedures. However, these options generally offer limited success, given the late-stage diagnosis and aggressive nature of the disease. The emergence of immunotherapy in the treatment landscape for mesothelioma offers renewed hope for patients. This article will explore the role of immunotherapy drugs in treating mesothelioma, their efficacy, and ongoing research in this area.

What is Immunotherapy?

Immunotherapy harnesses the body's immune system to recognize and attack cancer cells. It functions by either stimulating the immune system to work harder or smarter against cancer cells or by introducing man-made immune system proteins to attack cancer. Immunotherapies have been successful in treating other forms of cancer and are now being studied extensively for mesothelioma.

Types of Immunotherapy Drugs

Checkpoint Inhibitors

Checkpoint inhibitors like pembrolizumab (Keytruda) and nivolumab (Opdivo) have shown promise. They work by blocking the PD-1 pathway, which cancer cells often exploit to suppress the immune response. A study published in the Lancet Respiratory Medicine found that nivolumab demonstrated anti-tumor activity in about 30% of mesothelioma patients, showing it to be a viable second-line treatment option (Scherpereel et al., 2019).

Monoclonal Antibodies and Immune Modulators

Monoclonal antibodies like bevacizumab (Avastin) are designed to target specific molecules expressed by cancer cells. The MAPS trial demonstrated that adding bevacizumab to standard chemotherapy regimens could extend the life expectancy of mesothelioma patients by approximately three months (Zalcman et al., 2016).

Drugs like interferon and interleukin-2 are being studied for their ability to modify or boost the immune system. However, their efficacy as standalone treatments remains less established.

Efficacy and Ongoing Research

Immunotherapy drugs have shown a varying range of efficacy. For example, a study in the Journal of Clinical Oncology revealed that pembrolizumab led to a partial response in approximately 20% of mesothelioma patients (Alley et al., 2017). Moreover, the combination of immunotherapy drugs is also being explored. A study combining nivolumab and ipilimumab (Yervoy) demonstrated an impressive 40% disease control rate (Disselhorst et al., 2019).

Side Effects and Limitations

While immunotherapy offers a new avenue for mesothelioma treatment, it is not without its downsides. Side effects may include fatigue, skin rashes, and gastrointestinal issues. More seriously, these drugs can sometimes cause the immune system to attack healthy cells, leading to autoimmune diseases. Also, not all mesothelioma patients are candidates for immunotherapy, and its high cost remains a significant barrier.

Conclusion

Immunotherapy is increasingly seen as a promising addition to the arsenal against mesothelioma. Ongoing trials are assessing various immunotherapies, alone or in combination with other treatments, aiming to improve patient outcomes and reduce side effects. While not devoid of challenges, the future of immunotherapy in mesothelioma treatment looks promising, offering a glimmer of hope to patients and their families.

Sources

- Scherpereel, A., et al. (2019). "Nivolumab or nivolumab plus ipilimumab in patients with relapsed malignant pleural mesothelioma (IFCT-1501 MAPS2): a multicentre, open-label, randomised, non-comparative, phase 2 trial." *Lancet Respiratory Medicine*, 7(6), 487-498.

- Zalcman, G., et al. (2016). "Bevacizumab for newly diagnosed pleural mesothelioma in the Mesothelioma Avastin Cisplatin Pemetrexed Study (MAPS): a randomised, controlled, open-label, phase 3 trial." *The Lancet*, 387(10026), 1405-1414.

- Alley, E. W., et al. (2017). "Clinical safety and activity of pembrolizumab in patients with malignant pleural mesothelioma (KEYNOTE-028): preliminary results from a non-randomised, open-label, phase 1b trial." *Journal of Clinical Oncology*, 35(15), 1542-1549.

- Disselhorst, M. J., et al. (2019). "Ipilimumab and Nivolumab in the Treatment of Recurrent Malignant Pleural Mesothelioma (INITIATE): Results of a Prospective, Single-Arm, Phase 2 Trial." *Journal of Clinical Oncology*, 37(8), 633-639.