Keytruda is a new cancer treatment drug recently making headlines after it appeared to successfully make former US president Jimmy Carter’s tumors vanish. Find out everything you need to know about Keytruda today in our guide.
What is Keytruda?
Jimmy Carter is crediting the new cancer drug Keytruda for completely shrinking his brain tumors. After that ringing endorsement, Keytruda has been making headlines across America.
Keytruda is one member of an exciting new class of cancer treatment drugs that works by boosting the immune system, allowing it to fight off tumors. These immunotherapy drugs are showing increasing promise when it comes to tackling tough-to-fight cancers, like stage 4 cancers that have spread throughout the body.
Despite Carter’s exciting cancer-free announcement, cancer experts are warning that it’s not 100% clear that Keytruda shrunk Carter’s tumors. The former president also received radiation treatment on his brain tumor and had a large tumor on his liver removed.
Of course, that hasn’t stopped people from wanting to learn more about Keytruda.
How Does Keytruda Work?
Keytruda is the brand name for a generic drug known as pembrolizumab. That drug targets the activity of two specific genes: PD-1 and PD-L1. Interactions between these two genes allow some tumors to escape destruction and detection by immune system cells, which then lets cancer spread throughout the body.
Basically, PD-1 prevents immune system cells from attacking normal healthy cells accidentally. Cancer cells make PD-L1 turn on PD-1 when immune cells approach.
Keytruda reverses this mechanism by acting as a monoclonal antibody, which is a type of engineered-immune protein. This disrupts the “cloaking” effect used by tumor cells, which then lets your immune system do its job and fight back against the tumor cells.
Carter was recently diagnosed with stage 4 melanoma, which means it had spread throughout his body. Cures for stage 4 cancer are rare – but not unheard of. It is possible that Carter’s cancer has shrunk so small that scans can’t find it. However, as one researcher said, “it almost always comes back”.
The US Food and Drug Administration awarded Keytruda accelerated approval in 2014 for use on cancer patients across America whose cancer had spread. The FDA awarded Keytruda approval after one breakthrough study found that Keytruda could shrink tumors of about one third of all patients by as much as 90%.
Carter appears to be among that lucky one third of patients.
The study was led by Dr. Antoni Ribas of UCLA. Ribas claims that the one third of patients who were positively affected by Keytruda are continuing to see results to this day: between 70 and 80% of the patients who tumors shrank on Keytruda are still continuing to see their tumors shrink to this day.
Former President Carter Isn’t the Only One
Jimmy Carter isn’t the only one who has successfully used immunotherapy drugs like Keytruda to treat cancer.
In the same article NBC News interviewed Kathy Thomas from Torrance, California, who went from being in a wheelchair to walking three miles per day.
Thomas had previously tried other immunotherapy treatments – including interleukin and Yervoy – before starting Keytruda in 2012. She claims to have felt the effects after just two rounds of treatment:
“My hair is back and I am fat and happy.”
Why Doesn’t Keytruda Help All Patients?
In the one major clinical study on Keytruda, it was seen to affect approximately one third of all patients. In other words, one out of three patients involved in the clinical trial were able to successfully shrink their tumors while taking the drug.
The big question surrounding Keytruda is: why didn’t it affect more than one third of all patients?
Researchers have a few different theories about this.
Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, said the following:
“One hopes that by using immunotherapy the body can respond to whatever happens but cancer cells are clever and can develop workarounds for the various treatments.”
Lichtenfeld also cautioned that it was unclear whether or not Keytruda actually cured Jimmy Carter of his cancer. His current cancer-free status may be a genuine remission caused by Keytruda. Or it could be the result of radiation. Or his cancer may simply be too small to notice and could be preparing for a return:
“It's always tough to label someone cancer-free because there may be cells that doctors haven't detected, but it's possible that removing the mass in his liver several months ago allowed his immune system — along with radiation and the drug Keytruda — to fight the four lesions in his brain. The surgery and radiation may have done it. We may not know if he is responding or not.”
In Another Study, 76% of Keytruda Users Saw a Meaningful Reduction in Cancer
In a Phase 1 study on Keytruda, researchers tested the effects of the drug in combination with Celgene’s Revlimid as well as the corticosteroid dexamethasone. Participants in this study were patients whose disease had progressed after they had already received several other treatments – including those whose treatments had not been previously helped with Revlimid.
Among the 17 patients available for evaluation in the ongoing 50-patient trial, the overall response rate was 76%. In other words, 13 of 17 had a “meaningful reduction in cancer”.
Researchers cautioned that this work was preliminary and that the full results from the remaining 33 patients still needed to be evaluated.
Meanwhile, Keytruda is currently being tested on some 30 different tumor types. It’s being tested on its own and used in conjunction with other medicines.
Who Makes Keytruda?
Keytruda is made by pharmaceutical giant Merck & Co (NYSE: MRK).
Merck recently announced the new findings at the 57th American Society of Hematology (ASH) Annual Meeting. The company discussed how Keytruda was being tested on 30 different cancer types in clinical trials.
The company also displayed data across five presentations, including releasing data on the myeloma trials and updated findings on Keytruda’s effectiveness towards Hodgkin lymphoma.
Merck Oncology is a division of Merck & Co. The organization’s goal is “to translate breakthrough science into innovative oncology medicines to help people with cancer worldwide.”
You can stay up to date on the clinical trials for Keytruda here: Merck.com/clinicaltrials
Merck & Co. is headquartered in Kenilworth, New Jersey, and is one of the largest pharmaceutical companies in the world today. The American pharmaceutical giant was founded in 1889.