There is a lot of noise about the use of immunotherapy for lung cancer, which was combined with chemotherapy. https://www.npr.org/2018/04/16/602980973/merck-immunotherapy-drug-shines-in-lung-cancer-study
So far there were only a small percentage of patients who qualified for treatment with Keytruda (pembrolizumab) as a second-line therapy. https://en.wikipedia.org/wiki/Pembrolizumab But a new publication in the New England Journal of Medicine (NEJM) tested whether a combination of chemotherapy with Keytruda would be better than chemotherapy together with a placebo.
Results of the NEJM trial with Keytruda
In this trial there were 616 patients with metastatic non-small cell lung cancers (NSCLC). The patients received all treatments intravenously. Half of them received treatment with chemotherapy and Keytruda. The other half received chemotherapy and placebo (normal saline). After 10.5 months of treatments the researchers determined the 12 months follow-up rates. The chemotherapy/Keytruda group survived 69.2%. The chemotherapy/placebo group survived only 49.4%. The 20% difference in survival was due to the effect of the immunotherapy with Keytruda. Keytruda works by targeting a protein on the surface of NSCLC cells, which prevents an attack by the immune cells on the lung cancer cells. Keytruda is an antibody, which stops the surface protein PD-1 on T immune cells. PD-1 stands for “programmed cell death 1”. The end effect is that the immune response against the lung cancer can no longer be stopped.
Discussion
Immunotherapy is the latest cancer therapy, but unfortunately it is still fairly toxic. In this trial 99.8% of the treatment group experienced toxic side effects, the control group 99.0%. The cost per patient is 150,000.00 USD per year. But the result is only a survival advantage of 20% over the control. 75% of patients had a lung cancer recurrence within the next 1.5 years. This is not a good deal for lung cancer patients who had hoped that their cancer would become manageable. Instead they experienced horrendous costs, only a fleeting improvement of 20% more survival, but the cancer came back! All of these patients had to suffer terrible side effects. It looks to me like Big Pharma is trying to increase their profit by vigorously advertising Keytruda to patients with lung cancer. But what is really necessary is the development of more effective drugs that have fewer side effects!
Overall lung cancer survival
As this link shows, there is only less than 5% survival over 5 years (the 5-year survival rates) for stage IV lung cancer. https://nethealthbook.com/cancer-overview/lung-cancer/staging-lung-cancer/ The earlier stage IIIA can expect a 15-35% 5-year survival. But the later stage IIIB has less than 5% survival within 5 years. It is in this group of patients that new immune stimulatory methods are urgently necessary.
Immunotherapy For Lung Cancer
Conclusion
There is a lot of discussion about new immunotherapies for lung cancer. Lung cancer is still a deadly disease, particularly in the more advanced cases. The study regarding immunotherapy using Keytruda showed a lot of toxicity and only 20% temporary survival benefit, which was lost 1.5 years later, when the cancer came back. The costs of 15,000.00 USD per patient per year are also prohibitive. I see this as a good start. But the scientists at Merck need to go back to the lab and produce an improved immune stimulant with fewer side effects and less costs. Only then will there be real progress.
Comparison to Gleevec
I see a certain parallel with Gleevec (imatinib) for chronic myelogenous leukemia (CML) where the 5-year survival rate was 31% in 1993. In 2003 to 2009 the 5-year survival increased to 59%. https://en.wikipedia.org/wiki/Imatinib This is an astounding 28% increase regarding the 5-year survival. Unlike Keytruda the side effects with Gleevec are not as extensive. We need immunostimulants drugs with less side effects and better survival rates.
