A new immunotherapy drug pembrolizumab is pushing up melanoma survival rates, eliminating cancers entirely in 15% of patients and leading 40% of recipients surviving past a 3 year period
Melanoma is a particularly virulent cancer and many patients struggle to respond to treatment. Immunotherapy strategies have had some previous success targeting the disease, and efforts are underway across the board to bring bigger, better immunotherapy drugs to market against many cancers.
What is pembrolizumab?
Pembrolizumab is a humanised antibody against the programmed death receptor 1 (PD-1). It’s part of a range of antibody treatments called ‘checkpoint blockade’ therapy, which essentially re-tunes immune activity – activating it and drawing attention to evading cancerous cells. Many cancer cells express specific receptors on their surface that repress immune activity, enabling them to survive when they would normally be destroyed. Checkpoint blockade antibodies lock onto these receptors, blocking their activity and revealing them to the immune system.
Improving survival rates
Data from a recent pembrolizumab trial involving 655 patients has now been released. 4 in 10 patients were still alive after 3 years, which might not sound like a success but considering past survival rates this is a definite improvement. 15% of recipients’ cancers were also undetectable by the conclusion of the study.
“Before 2011 advanced melanoma had a median overall survival of less than one year and things have changed a lot. What is really exciting is to see at three years the estimated survival rate is 40% and this is regardless of previous treatment”
The drug is already being used around the globe and has been approved for use by the NHS in the UK, but the latest data suggests there may be greater long term benefits than previously believed. Unfortunately immunotherapy isn’t suitable for everyone, and future cancer therapy may involve multiple targets and treatment types. There are also risks of autoimmune complications, which have caused fatalities in some patients in past immunotherapy trials. This is still promising news however, and highly encouraging for the growing field.
“This has been a bad disease, it’s hard to treat, it’s a sneaky disease and the mortality rates have been enormous so to see 40% of patients alive at three years is really a step forward. We’re even wondering if we could use the word cure here, but it’s going to take longer follow up”
Read more at BBC News