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By Nancy Lapid

June 2 (Reuters) - Hello Health Rounds readers! Today we revisit the American Society of Clinical Oncology scientific meeting in Chicago, which concludes on Tuesday, to report on three more potentially practice-changing studies.

Radiating brain tumor sites from the inside

A small radiation-emitting tile implanted where a brain tumor had been achieves better outcomes than traditional radiation treatments, researchers reported at ASCO.

Cancer patients with brain metastases who received GT Medical Technology’s cesium-131 GammaTile during surgery to remove a tumor survived longer without recurrence, compared to patients who received standard care, the researchers said.

Ordinarily, surgery for brain tumors is followed by up to six weeks of recovery before radiation treatments begin. In the interim, cancer cells left behind in the brain can grow and replicate.

The thin collagen GammaTile infused with radiation is placed in the cavity left by the surgically removed tumor, where it immediately begins to kill any residual tumor cells, the researchers said. The radiation gradually fades, and the tile is absorbed by the body.

In a late-stage trial, 230 patients with operable brain metastases received either GammaTile implantation or standard radiotherapy following surgery.

One year later, the incidence of tumor regrowth in the surgical area was 1% with GammaTile versus 11.9% with standard therapy.

Patients who received GammaTile had a greater than 50% reduction in risk of either tumor recurrence or death compared to standard care.

Estimated overall survival at 24 months was 61.7% with GammaTile compared with 35.7% for standard radiation.

Quality-of-life and side effect rates were similar in the two groups, the researchers said.

"These patients have faced important challenges with existing treatment approaches," said GT Medical Chief Medical Officer Dr. Michael Garcia in a statement.

Data from this study "delivers the high level of evidence to support GammaTile as a new up-front treatment option," he said.

J&J myeloma drug improves remission odds after relapse

Patients with relapsed multiple myeloma treated with Johnson & Johnson's JNJ.N teclistamab lived significantly longer and remained in remission far longer than those receiving standard therapies in a late-stage trial.

Nearly 70% of patients receiving teclistamab, sold under the brand name Tecvayli, had no disease progression after 18 months, compared with about 27% of patients receiving standard treatments, researchers reported at ASCO and in The New England Journal of Medicine.

Nearly two-thirds of patients treated with Tecvayli in the trial achieved complete remission, compared to roughly 17% of patients in the standard treatment group, the researchers said.

The control group received standard myeloma combination regimens of either Bristol Myers' BMY.N Pomalyst (pomalidomide), Velcade (bortezomib) and the steroid dexamethasone, or Amgen's Kyprolis (carfilzomib) and dexamethasone.

Tecvayli belongs to a newer class of dual-action drugs known as bispecific antibodies. They work by linking immune T cells to a protein found on myeloma cells, allowing the immune system to recognize and attack the cancer directly.

“We are seeing very deep responses and long clinical benefit from these therapies. This is part of a much bigger transformation happening in myeloma care,” study investigator Dr. C. Ola Landgren of the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine said in a statement.

The nearly 600 trial participants from 24 countries had multiple myeloma that recurred after one to three prior treatments.

“Patients with relapsed or refractory multiple myeloma... face poor outcomes and limited effective treatment options," said study leader Dr. Roberto Mina of the Winship Cancer Institute of Emory University in Atlanta.

"These results established teclistamab-based therapy as a new standard of care for (these) patients,” Mina said.

Researchers are now studying whether bispecific antibodies should be given even earlier in the disease course.

An NEJM editorial published with the study said it represents “a pivotal step forward.”

Still, it noted, “an increasingly crowded therapeutic landscape” of myeloma treatments means “treatment selection will probably depend more on patient characteristics, access, and sequencing than on intrinsic differences in efficacy."

Moderna cancer vaccine halves melanoma recurrence

Patients who received an experimental Moderna MRNA.O mRNA-based vaccine along with Merck's MRK.N immunotherapy Keytruda following surgery for melanoma had a dramatically lower risk of recurrence five years later compared to patients who got the drug alone, researchers reported at ASCO.

They tested the vaccine, called intismeran, in a mid-stage trial in combination with Keytruda in 107 patients. Another 50 patients received only Keytruda, the world's biggest-selling prescription medicine.

Intismeran is a personalized immunotherapy formulated with information from individual patients' tumors that aims to trigger an immune response to abnormal proteins, called neoantigens, made by the cancer cells.

After five years, there were no signs of cancer in 68.8% of patients who took the combination therapy, compared with 49.1% of those who only received Keytruda, known chemically as pembrolizumab, according to a report of the study also published in Journal of Clinical Oncology.

Overall survival was 92.2% with the vaccine and 71.3% without it.

The combination therapy reduced the risk of recurrence by 49% and the risk of distant metastasis by 59%, researchers reported.

“Our study offers strong evidence to melanoma patients that intismeran vaccine therapy, when used in combination with immunotherapy, can demonstrably reduce their risk of having their cancer return and improve clinical outcomes,” study leader Dr. Janice Mehnert of NYU Grossman School of Medicine said in a statement.

“Our findings also serve as encouragement to cancer researchers globally that mRNA vaccines like intismeran could work well in combination with immunotherapy for other cancers whose high rates of mutations have proven difficult to target,” Mehnert said.