Combination Therapy for lung cancer: a game-changing treatment

Dr. Kenneth O’Byrne, Professor of Medical Oncology and Queensland Senior Clinical Research Fellow, presented the results of the Keynote-021 study combining immunotherapy and chemotherapy which showed high response rates that will greatly benefit patients with advanced non-small cell lung cancer

Lung cancer is inevitably fatal. The Global Cancer Observatory (GLOBOCAN) Project by the World Health Organization showed that, in 2018, more than 2 million people1 were diagnosed with the disease. Dr. Ted Hamilton of the Florida Hospital Central Care estimated that only 250,000 of these patients will be alive five years later. The Philippine Society of Medical Oncology (PSMO) cited lung cancer as one of the top cancers leading to death. Given the grim reality, doctors look at combination therapy as a bright glimmer of hope for the treatment of lung cancer.

Lung cancer treatment prior to combination therapy

For decades, doctors have administered chemotherapy for cancer treatment as the only available option for patients. Dr. Kenneth O’Byrne, Professor of Medical Oncology and Queensland Senior Clinical Research Fellow, has studied cancer for over 30 years and has seen both positive and negative effects of chemotherapy.

Chemotherapy targets cancer cells but also kills healthy cells along the way. Doctors acknowledge the fact that cancer cells can go undetected by the body’s immune system, thrive even under hostile environment, and manifest in its later stages.

Speaking at a PSMO symposium on the topic of “A New Standard-of-Care (SOC) for the treatment of First Line Advanced Non-Small Cell Lung Cancer (NSCLC)”, Dr. O’Byrne explained the ability of cancer cells to evade the immune system. This probably arises because tumors are mutations and they develop the capacity to evolve, and as a natural selection process, some tumor cells survive in hostile environment and this includes switching off processes in the immune system.

Lung cancer is just as evasive. Smoking, air pollution, asbestos, radiation, chromates and coke-oven emissions have been linked to lung cancer development. However, medical researchers have not come to one single cause of the disease.

The glimmer of hope brought by immunotherapy

Immunotherapy held great promises in the treatment of lung cancer and other malignancies. With this therapy, patients receive drug treatment to activate the immune system and enable it to fight cancer. In other countries, immunotherapy is used as first line treatment for lung cancer, meaning once the patient is diagnosed with cancer, there is no need to undergo chemotherapy – the patient can receive immunotherapy immediately. How can a breakthrough regimen like immunotherapy achieve this phenomenal result?

According to O’Byrne, scientific breakthroughs now allow doctors to identify which cancer cells switch off the immune system. The next step is to convert this discovery into a therapeutic agent.

The first of these “therapeutic agents” include pembrolizumab. Pembrolizumab interacts with PD-1 which is a checkpoint protein on immune cells called T-cells, to stop it from binding with PD-L1, which is a protein on some normal (and cancer) cells. Some cancer cells have large amounts of PD-L1, which helps them evade immune attack when bound with PD-1. In immunotherapy, this binding is prevented and immune response against cancer cells is boosted.

An immunotherapy drug reactivates the patient’s immune response, fights cancer, and causes cancer cells to shrink. Observations show that the agent may be more effective as first line of treatment.

Thus, early screening and diagnosis become a necessity in order to identify whether a particular lung cancer is due to a gene mutation or a protein proliferation, like the PD-L1. Dr. O’Byrne noted that clinical trials showed that immunotherapy as first line treatment yielded almost 20% survival rate.

Immunotherapy is already good news to cancer patients and their family. But, a more game-changing approach is getting medical attention.

How combination therapy is changing the face of lung cancer treatment

Lung cancer patients get more benefits when they undergo a combination of immunotherapy and chemotherapy. This type of combination therapy is more capable of killing cancer cells and achieves remission, as clinical studies show.

The purpose of the PD-L1 test is to determine the patient compatibility to the benefits of immunotherapy. Combination therapy is especially suitable for patients with lower PD-L1 expression. With combined antibody treatment (immunotherapy) and chemotherapy, the response rate showed positive results.

In his keynote, O’Byrne cited a clinical trial which showed a response rate of around 50 percent and remission of 18 months – proving that the medical field has taken a massive step forward in lung cancer treatment.

Any kind of treatment will have side effects. It is important to remember that chemotherapy and immunotherapy express different toxicity profiles. When used in combination, O’Byrne emphasized the importance of patient education as well as a strong support team which includes the patient’s medical team and family.