New cancer drug targets mutations
The Food and Drug Administration has approved a new cancer drug that is the first to be designed from the start to fight a specific genetic mutation, not a cancer type.
The new drug, named Vitrakvi, is not approved to fight breast cancer or lung cancer or colon cancer. Instead, it's designed and approved to treat cancers that arise anywhere in the body that carry a certain genetic characteristic.
"Traditionally in cancer therapy, we've treated patients based on where their cancer came from, what part of the body. What makes Vitrakvi unique is that it works regardless of where the cancer came from as long as it has the specific mutation," said Dr. David Hyman, chief of early drug development at Memorial Sloan Kettering Cancer Center in New York.
While several drugs are approved to treat a variety of different cancers based on genetic mutations, Vitrakvi, known generically as larotrectinib, is the first that is approved from the beginning to treat cancers solely based on the mutation.
"Today's approval marks another step in an important shift toward treating cancers based on their tumor genetics rather than their site of origin in the body," FDA Commissioner Dr. Scott Gottlieb said in a statement.
"We now have the ability to make sure that the right patients get the right treatment at the right time. This type of drug development program, which enrolled patients with different tumors but a common gene mutation, wouldn't have been possible a decade ago because we knew a lot less about such cancer mutations."
Keytruda was the first example of a drug approved to treat a genetic mutation. Originally FDA approved in 2014 to treat melanoma that had spread, the makers of Keytruda showed it could treat other tumor types, if they had the same mutation that drives some cases of melanoma. Now it's used against a range of tumors, including breast cancer.
Vitrakvi treats a different genetic mutation involving genes called NTRK genes. Rarely, they can fuse together and cause the out-of-control growth that results in tumors.
"Prior to today's approval, there had been no treatment for cancers that frequently express this mutation, like mammary analogue secretory carcinoma, cellular or mixed congenital mesoblastic nephroma and infantile fibrosarcoma," the FDA said.
Anna Plaza says her daughter, Rihanna, is living proof of how well the drug can work if given to the right patient. When Rihanna was born in Bridgeport, Connecticut last year, she had an enormous mass on her arm.
"They didn't know what was wrong. They just knew it was a mass and they covered it up with a Pamper and we needed to get transferred to another hospital because nobody knew what to do with us," Plaza told NBC News.
"I was like, 'oh my God, what am I going to do? What are we going to do?" she added. "It was horrible."
Biopsies showed Rihanna had a rare tumor known as infantile fibrosarcoma, a malignant soft tissue tumor typically found in children under one year of age.
Chemotherapy did little to help the tiny baby. The family eventually was referred to the clinical trials being done to test the drug at Memorial Sloan-Kettering.
"It was a syrup. She would take it once in the morning, once at night." Surprisingly, the baby liked it.
Three days later, the tumor was already shrinking.
"When we went back to Memorial Sloan-Kettering, they were even more shocked," said Anna Plaza's husband Enrique. "They were like 'Whoa, we've never seen this process go fast. We've seen it in months, but so fast, within a week?'" he added.
"We were happy because they didn't have to cut her arm off."
Surgeons could much more easily remove the tumor afterwards. "If we hadn't shrunk it first, she could had ended up with a forearm and a hand that didn't work the way they should for the rest of her life," said Dr. Todd Heaton, a pediatric oncologist who helped treat her.
Rihanna still goes for follow-up treatments and, as with so many targeted cancer therapies, only a small percentage of cancer patients are helped.
"For patients that have this mutation — it is a revolution for these patients," Hyman said.
"But what we really have recognized about cancer is that it's not a one-size-fits-all approach, and we need to apply the best therapy for every patient."
Another roadblock — health insurance companies don't always pay for the genetic tests needed to guide doctors to the targeted drugs. Hyman hopes having a specific FDA approval can help change that.
And these drugs are not cheap. Bayer, which owns the company that makes Vitrakvi, says it will cost $393,600 a year, while the pediatric syrup formulation will cost $11,000 a month.