For years treatment of most cancers has come in two forms. One is chemotherapy and the other is surgery. While they have led to many patients recovering from the dreaded disease, both can take a heavy physical toll.
And they don't always work. The American Cancer Society estimates a total of 1,665,540 new cancer cases in the U.S. in 2014 with 585,720 cancer deaths.
But is it possible that cancer treatment in the near future will be carried out with a new generation of drugs that are more effective and less toxic? New research suggests that it might.
One of the most promising new drugs to come along in the fight against cancer is a compound known as OTS964, which was used in a small recent animal trial.
Researchers developed aggressive human lung cancers – the type that are typically fatal – and transplanted them into mice. The mice were then given OTS964. The scientists wanted to see how the drug was tolerated but also whether it worked. They were pleased on both counts.
Writing about their findings in the journal Science Translational Medicine, the scientists said the drug, when taken orally, had limited toxicity. When it was given by injection there were even fewer side effects.
Best of all, it led to complete regression of the transplanted tumors.
How it works
OTS964 works by inhibiting a protein called TOPK that is produced in the body by several types of malignant tumors. The protein is almost never produced by healthy tissue.
Cancerous tumors need this protein in order to multiply and spread. Without it, the cell-division process comes to a screeching halt and the cancer cells die.
"We identified the molecular target for this drug ten years ago, but it took us nearly a decade to find an effective way to inhibit it," said study author Yusuke Nakamura, professor of medicine at the University of Chicago. "We initially screened 300,000 compounds and then synthesized more than 1,000 of them, and found a few that were likely to work in humans. We focused on the most effective. We think we now have something very promising."
In previous research on this drug, researchers kept running into the same problem; yes, it could kill cancer cells but it could also interfere with the production of new red and white blood cells in the body.
The patient could face side effects ranging from mild anemia to very serious infections. The drug could also produce an over abundance of blood platelets.
No dangerous side effects
The latest version of the drug does not disrupt blood cell production. This approach "completely eliminated the hematopoietic toxicity," the researchers wrote.
The tumors transplanted to the mice are known as LU-99, among the most aggressive human tumors. The researchers allowed the tumors to grow to about the size of a raisin – a significant size in a mouse – and then administered the OTS964 intravenously to 6 mice, twice a week for three weeks.
The tumors quickly got smaller and continued to shrink even after treatment stopped. In 5 of the 6 mice, the tumors completely disappeared — 3 within 25 days of the first treatment and 2 within 29 days. If this sounds like a big deal, Nakamura says it is.
"It is rare to see complete regression of tumors in a mouse model," he said. "Many drugs can repress the growth, but it is uncommon to see them eradicated. This has rarely been reported."
What happens next
The next step will be Phase I clinical trials. The drug will be administered to human volunteers to make sure the drug is as safe for people as it is for mice.
Assuming that it is, Phase II trials will follow, with people seriously ill with cancer receiving the drug. If those results also duplicate the results in mice, the drug will be submitted for approval by the U.S. Food and Drug Administration.
The researchers say they are working with oncologists at the University of Chicago to begin a Phase I clinical trial as soon as the fall of 2015.