Ipilimumab is a new treatment for advanced melanoma that has generated a lot of excitement. While a step in the right direction, it has limited efficacy and still has to be determined as to its best use.
Considering that only 5-10% of people are alive in 5 years when they have stage IV melanoma, any advance is welcome.
Melanoma is the most dangerous type of skin cancer and can be very serious. It is often noticed as a weird discoloration on the skin and can be caused by exposure to ultraviolet light from the sun. If caught early and able to be removed by surgery, survival rates of melanoma are almost 100%.
But when it advances and is not stopped initially, melanoma quickly becomes very dangerous.
Mechanism of action
Ipilimumab is a monoclonal antibody that targets cytotoxic T lymphocyte associated antigen 4 (CTLA-4). This marker is associated with promoting a regulatory response by the immune system, slowing it down. By knocking it out, ipilimumab may shift the body’s immune response from inaction into action.
On the other hand, this modification of the immune system can lead to serious side effects. Severe enterocolitis and hypophysitis, a type of autoimmunity, among other reactions are possible.
How well does Ipilimumab work?
Decently. Let’s look at some of the data.
One study looked at 676 patients with a specific type of melanoma that was advanced and not able to be properly treated by surgery. That study gave Ipilimumab alone, with gp100, or just gp100.
The median objective survival for Ipilimumab and gp100: 10 months
Ipilimumab alone: 10.1 months
Gp100 alone: 6.4 months
Another much smaller study looked at 53 patients and had similar results. There, however, there was a significant correlation between absolute lymphocyte count (ALC) and response. There, a higher ALC count meant a 11.9 median objective survival compared to just 1.4 months in those with much lower ALC.
It seems like ipilimumab increases duration and quality of life but might not act to knock the cancer out entirely itself.
The response to ipilimumab might not follow the typical response to cancer therapies. It may take longer than usual. It is even possible to have an initial increase in tumor load and spread of melanoma and still have a significant response to ipilimumab later.
Ipilimumab may work best in combination with other chemotherapeutic treatments.
It also has a high rate of side effects. 10-15% of people on Ipilimumab had a serious, grade 3 or 4 adverse side effect in one study.
If you want to learn about other new drugs, see here.
1) Improved Survival with Ipilimumab in Patients with Metastatic Melanoma
2) Novel immunotherapies as potential therapeutic partners for traditional or targeted agents: cytotoxic T-lymphocyte antigen-4 blockade in advanced melanoma