Hope rises for cancer cure
A GLIMMER of light may have appeared at the end of the tunnel in the search for cancer cure with new immunotherapy drug, Keytruda, being linked to former United States (U.S.) President Jimmy Carter’s brain tumour shrinkage.
Pembrolizumab (formerly MK-3475 and Lambrolizumab (trade name Keytruda) is a human antibody used in cancer immunotherapy marketed by Merck which targets the programmed cell death 1 (PD-1) receptor. The drug was initially used in treating metastatic melanoma.
Merck said Keytruda (pembrolizumab), the latest in a string of breakthrough cancer therapies helping push the overall market for oncology drugs to $100 billion a year, would cost $12,500 (N3.1 million) per patient per month, or $150,000 (N37.35 million) per year.
It was learnt that the drug is not one of the Merck drugs registered by the National Agency for Food Drug Administration and Control (NAFDAC). However, this could not be confirmed at press time because The Guardian was not able to reach the Director General of NAFDAC, Dr. Paul Orhii.
It was also learnt that Merck and Co. is already well established in Nigeria. It was also found that most Nigerians who need it access it when they travel abroad for medical treatment or order it through the help of their doctors or treatment centres.
The Guardian’s investigation also revealed that most Nigerian doctors and pharmacists do not know about the drug.
On September 4, 2014 the U.S. Food and Drug Administration (FDA) approved pembrolizumab under the FDA Fast Track Development Programme. It is approved for use following treatment with ipilimumab, or after treatment with ipilimumab and a BRAF inhibitor in advanced melanoma patients who carry a BRAF mutation.
On October 2, 2015, the US FDA approved pembrolizumab for the treatment of metastatic non-small cell lung cancer in patients whose tumors express PD-L1 and who have failed treatment with other chemotherapeutic agents.
Indeed, Carter credits the new cancer drug Keytruda for shrinking his brain tumors completely. It is one more possible victory for the newest class of cancer drugs that empower the immune system to fight off tumors.
Carter shared the happy news on Sunday when he told his Sunday School class that recent brain scans showed he was clear of cancer.
“My most recent MRI brain scan did not reveal any signs of the original cancer spots nor any new ones,” the former president said to his class at Maranatha Baptist Church in his hometown of Plains, Georgia. Carter, now 91, was diagnosed over the summer with melanoma that had spread to his liver and brain.
Whether Carter’s cancer is gone for good, no one knows for sure, but experts say the fact that the metastatic melanoma is no longer detectable and that no new tumors have appeared are good signs, and may offer hope for others who may benefit from new immunotherapy treatments like the one used to fight Carter’s cancer.
“It is fantastic news. This really illustrates the importance of multidisciplinary care,” Cleveland Clinic cancer specialist Dr. Dale Shepard, told CBS News.
Carter was first diagnosed in August after a mass was removed from his liver. Then doctors discovered that the cancer had also spread to his brain as four small spots.
Most cases of melanoma begin as a skin cancer, but Carter said this past summer that his doctors had not determined where his cancer originated.
He underwent liver surgery, received radiation therapy on his brain and then began immunotherapy, said Shepard, a medical oncologist.
According to Shepard, there are about 200,000 cases of metastatic melanoma in the U.S. every year and that it is the most dangerous type of skin cancer. Approximately 10,000 deaths occur from it annually.
“Not uncommonly, it can spread to organs like the liver and the brain,” said Shepard.
In a statement, Carter talked about his ongoing medical plan, “I will continue to receive regular three-week immunotherapy treatments of pembrolizumab.” The drug goes by the name Keytruda commercially.
According to Shepard, the recently-approved drug and others like it are important.
“Prior to these immunotherapies, we didn’t have good treatment options for melanoma that was metastatic, that had spread to other organs,” Shepard said.
Normally, the immune system can recognise things that shouldn’t be there, like bacteria or virus, Shepard explained. “But you can have a very large tumor that the immune system seemingly ignores, even though it’s an abnormal collection of cells,” he said.
These tumours can express proteins on their surfaces that essentially can hide the mass from the immune system so that it can’t attack it and get rid of it.
Newer immunotherapy drugs are engineered to “unmask” the tumors by interacting with those proteins to make them visible to the immune system so it can fight the offending cancer.
Now, several months since beginning immunotherapy, Carter’s treatments appear to have worked.
“While giving this therapy, they were able to prevent regrowth of existing tumors and growth of new tumors,” said Shepard.
Carter’s family is no stranger to cancer; three siblings and his father died from pancreatic cancer.
Is it a cure? While Carter’s clean bill of health is very good news, Shepard said it was too early to call it ‘a cure.’
“The way we think about this is that the drug has kept the disease under control and it has been well-tolerated,” he said.
“For someone who is 90 years old, getting these sorts of therapies and doing so well, it is pretty amazing,” said Shepard.
Shepard is not involved in Carter’s treatment, but he said his doctors would probably continue with his treatment another two or three months and then scan again to see if it was still controlling his disease.
Carter, the 39th president of the United States, served between 1977 and 1981 and is now the nation’s second-oldest living president.
After leaving the White House, he established the Carter Centre and has travelled the world working on issues like health care and global democracy. He recently finished a book tour promoting his latest book, A Full Life: Reflections at 90.
The medication Carter is taking is currently FDA-approved for use in certain lung cancers. There are ongoing trials in a number of other diseases, too.
“This is good science — realising that the therapies we have available are not optimal and creatively looking for new ways to treat cancers,” said Shepard.
According to him, Carter’s news underlies the importance of the need for continued basic scientific research and clinical trials.
“You can actually see that it can have benefits- this particular case with the former president puts a face to this- and how people can really benefit from this,” Shepard said
Making the drugs affordable needs to be addressed, too, he added. “This therapy costs tens of thousands of dollars a month.”
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