Targeted treatment and immunotherapy for lung cancer
Chemotherapy, radiotherapy and surgery are the main treatment options for lung cancer patients. However, there are now two new categories of treatment: targeted treatments and immunotherapy.
Targeted treatments work by targeting the difference between cancer cells and normal cells. Cancer growth inhibitor drugs can be used in patients with lung cancer to block the signals to cells and prevent cancer cells from growing.
The treatment can be used with patients with a detectable molecular target picked up in their tumour sample. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) can be used to treat lung cancer that has spread outside the lung, or to another part of the body. The names of the oral TKI drugs all end in ‘inib’, so can easily be recognised.
Gefitinib, erlotinib, afatinib and osimertinib have undergone Phase 3 randomised controlled trials. They have shown improvements in progression-free survival and overall survival.
Targeted treatments are generally given as tablets. The side effects include skin rash, diarrhoea, abnormal liver function, nausea and fatigue.
Immunotherapy is treatment which removes the brakes or checkpoints of T lymphocytes and reactivates the immune system. These treatments are very active in patients who have lung cancer tumours which express the PDL1 and PD1 marker.
Pembrolizumab is one of these immunotherapy drugs; others include nivolumab and atezolizumab. They are all monoclonal antibodies. It has robust, durable anti-tumour activity, and has been shown to be well tolerated both as monotherapy and in combination with chemotherapy.
Studies have shown that immunotherapy gets rid of more cancer, and keeps it away. Pembrolizumab has been shown to increase overall survival to 30 months, compared to 14 months with chemotherapy in advanced lung cancer patients.
The National Institute for Health and Care Excellence (NICE) has approved the use of immunotherapy agents for up to two years.
The main side effects of immunotherapy are similar to autoimmune reactions, and can affect every organ. Possible side effects include headache, sore throat, joint pain and fatigue. However, side effects are very unpredictable and it is important to listen to patients when they describe any side effects, and to grade their severity accordingly.
Steroids can reverse most of the side effects, but early recognition is vital.