Enhertu’s breast cancer drug has achieved an “unknown” survival rate

The patient had metastatic breast cancer, which was progressing despite severe chemotherapy. But the treatment of a drug that targeted cancer cells with laser-like accuracy was a resounding success, slowing tumor growth and prolonging life to the extent rarely seen with advanced cancers.

The new research, presented at the annual meeting of the American Society of Clinical Oncology and published in the New England Journal of Medicine on Sunday, would change the way medicine is practiced, cancer experts said.

“This is a new standard of care,” Dr. Eric Winer, breast cancer specialist, director of the Yale Cancer Center and ASCO Dr. Winer was not involved in the investigation. “It affects a large number of patients,” he added.

The trial focused on a specific mutant protein, HER2, which is a common malignancy in breast and other cancers. HER2-blocking drugs have been shown to be extremely effective in treating breast cancers that are almost entirely populated with protein, and HER2-positive breast cancers have become one of the worst prognostications in patients who adapt very well.

But HER2-positive cases are only about 15 to 20 percent of breast cancer patients, said Dr. Halle Moore, director of breast cancer oncology at Cleveland Clinic. These drugs did not help patients with low HER2 cells — a condition known as HER2-low. Only a small proportion of their cancer cells had HER2, and other mutations mainly boosted cancer growth. And this caused a problem because the cancer cells avoided chemotherapy treatments.

Clinical trial, driven by pharmaceutical companies Daiichi Sankyo and AstraZeneca and Dr. Shanu Modik of Memorial Sloan Kettering Cancer Center was attended by 557 patients with HER2-low breast cancer metastasis. Two-thirds took the experimental drug trastuzumab deruxtecan sold as Enhertu; the rest of the standard chemotherapy.

In patients taking Trastuzumab deruxteca, the tumor stopped growing for about 10 months, compared to those with standard chemotherapy for more than 5 months. Patients with the experimental drug survived for 23.9 months, compared with 16.8 months for those receiving standard chemotherapy.

“It is unheard of for chemotherapy trials of metastatic breast cancer to improve the survival of patients for six months,” said Dr. Moore, who enrolled some patients in the study. Usually, he says, success in a clinical trial is a few weeks of life or no benefit to survival, but it is an improvement in quality of life.

The results were so impressive that researchers received a standing ovation at their oncology conference in Chicago on Sunday when they presented their data.

Trastuzumab deruxtecan was already approved for patients with HER2-positive breast cancer, but few expected it to work because other drugs for these cancers failed in patients with low HER2.

The drug is composed of an antibody that seeks the HER2 protein on the surface of cells. The antibody is linked to a chemotherapy drug. When Trastuzumab deruxtecan finds a cell with HER2 on its surface, it enters the cell, and the chemotherapy drug is separated from the antibody and kills the cell.

But about trastuzumab deruxtecan, which is “unique and distinctive,” Dr. Modi added that chemotherapy is a drug that penetrates the cell membrane. From there, it can move to nearby cancer cells and kill them as well.

Like all chemotherapies, trastuzumab deruxtecan has side effects such as nausea, vomiting, blood disorders and, most importantly, lung injuries that resulted in the deaths of three patients in trials.

But, Dr. Winer said, “If I were a patient with breast cancer metastasis and would get a drug that had side effects from chemotherapy, I would prefer this drug.”

Doctors say they plan to try treatment in breast cancer patients with HER2-low cancer metastasis.

“We’re all going backwards and looking at our patients right now,” Dr. Susan Domch, a breast cancer specialist at the Abramson Cancer Center in Pennsylvania. He says that before the Food and Drug Administration approves trastuzumab deruxtecan for patients with low HER2, it will see that the data from the new study will be enough to convince insurers to accept the drug. weeks.

Dr. Winer points out that trastuzumab deruxtecan is not a cure for pre-stage breast cancer; it still needs to be tested in that group of patients. But it’s likely the next step, as the drug is being tested in other cancers and its strategy is expanding beyond HER2.

“This strategy is a real breakthrough,” he said, and would allow researchers to increase molecular targets in tumor cells that were rarely found.

“This is more than just this drug or breast cancer,” Dr. said Winer. “Its real advantage is that it allows powerful therapies to be delivered directly to cancer cells.”

A patient in the current study, Mary Smrekar, 55, of Medina, Ohio, said she felt she had taken a temporary break from certain death.

She was diagnosed with breast cancer in 2010 and has undergone surgery, chemotherapy and radiation. Her cancer went into remission.

“I thought I was free and clear,” he said.

But in 2019, the cancer came back. It spread to the pelvis. He underwent chemotherapy, but this time there was little improvement.

Two years ago, he entered the test site at the Cleveland Clinic. Her cancer has not gone away, but the tumor has stopped growing.

“I’m so glad I had another two years,” she said. said Smrekar. “My daughter is getting married next month. I didn’t think I’d get married. ‘

Leave a Comment