(This is an excerpt from the Health Rounds newsletter, where we present the latest medical research on Tuesdays and Thursdays.)
Nancy Lapid
June 3 (Reuters) - We return today to the American Society of Clinical Oncology scientific meeting in Chicago, which concluded on Tuesday, to report three more studies that have the potential to change clinical practice.
Radiation of brain tumors from the inside.
Implanting a small radiation paddle into a brain tumor site produces better results than traditional radiation therapy, researchers reported at the ASCO conference.
Researchers said that patients with cancer and brain metastases who were given a gamma tile containing the isotope cesium-131 from GT Medical Technology during tumor removal surgery lived longer without recurrence compared to patients who received standard treatment.
Brain tumor surgery typically involves a recovery period of up to six weeks, after which radiation therapy begins. During this time, any remaining cancer cells in the brain can grow and multiply.
A thin collagen gamma-ray tile, impregnated with radiation, is placed into the cavity left after surgical removal of a tumor, where it immediately begins to destroy any remaining tumor cells, the researchers reported. The radiation gradually wears off, and the tile is absorbed by the body.
In the final stage of the study, 230 patients with operable brain metastases were either implanted with GammaTile or given standard radiation therapy after surgery.
After one year, the tumor recurrence rate at the surgical site was 1% with GammaTile compared with 11.9% with standard therapy.
In patients treated with GammaTile, the risk of tumor recurrence or death was reduced by more than 50% compared with standard treatment.
The estimated overall survival at 24 months was 61.7% with GammaTile compared with 35.7% with standard radiotherapy.
As the researchers noted, quality of life and the incidence of side effects were similar in both groups.
«"These patients have faced significant challenges with existing treatments," GT Medical's chief medical officer, Dr. Michael Garcia, said in a statement.
«"The data from this study provide compelling evidence that GammaTile is a new treatment option in early-stage disease," he said.
J&J's myeloma drug improves chances of remission after relapse.
In clinical trials of late-stage multiple myeloma, patients treated with Johnson & Johnson's teclistamab lived significantly longer and remained in remission for much longer than patients receiving standard therapy.
Nearly 70% patients treated with teclistamab (brand name Tecvayli) had no disease progression after 18 months, compared with about 27% patients receiving standard treatment, according to data from researchers presented at the ASCO conference and published in The New England Journal of Medicine.
Nearly two-thirds of patients treated with Tekwaili in the study achieved complete remission, compared with about 17% patients in the standard treatment group, the researchers said.
The control group received standard combination myeloma treatment regimens, including either Bristol Myers' Pomalyst (pomalidomide), Velcade (bortezomib), and the steroid dexamethasone, or Amgen's Kyprolis (carfilzomib) and dexamethasone.
Tekwayli belongs to a new class of dual-action drugs known as bispecific antibodies. They work by binding immune T cells to a protein found on myeloma cells, allowing the immune system to recognize and attack cancer cells directly.
«"We are seeing very dramatic treatment responses and long-lasting clinical benefits from these therapies. This is part of a much larger transformation taking place in myeloma treatment," said Dr. K. Ola Landgren, study leader at the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, in a statement.
The study involved about 600 people from 24 countries who developed multiple myeloma after one to three previous courses of treatment.
«"Patients with relapsed or refractory multiple myeloma… face poor prognoses and limited effective treatment options," said study leader Dr. Roberto Mina of the Winship Cancer Institute at Emory University in Atlanta.
«"These results set a new standard of care for these patients based on teclistamab therapy," Mina said.
Researchers are currently studying the feasibility of administering bispecific antibodies at earlier stages of the disease.
An NEJM editorial published alongside the study said it represents "an important step forward.".
However, it noted that the "increasingly crowded therapeutic landscape" of myeloma treatments means that "treatment choice is likely to depend more on patient characteristics, availability, and sequencing of treatment than on intrinsic differences in efficacy.".
A vaccine against moderate-grade cancer halves the rate of melanoma recurrence.
Patients who received Moderna's experimental mRNA vaccine in combination with Merck's immunotherapy drug Keytruda after melanoma surgery had a significantly lower risk of recurrence after five years compared with patients who received the drug alone, researchers reported at the ASCO conference.
The vaccine, called Intismeran, was tested in mid-stage clinical trials in combination with Keytruda on 107 patients. Another 50 patients received Keytruda alone, the world's best-selling prescription drug.
Intismeran is a personalized immunotherapy developed using information about individual patients' tumors that aims to trigger an immune response to abnormal proteins, called neoantigens, produced by cancer cells.
According to the study report, also published in the Journal of Clinical Oncology, after five years, 68.8% of patients receiving the combination therapy had no evidence of cancer, compared with 49.1% of those receiving Keytruda (chemically known as pembrolizumab) alone.
Overall survival was 92.2% with the vaccine and 71.3% without it.
The researchers reported that combination therapy reduced the risk of recurrence at 49% and the risk of distant metastases at 59%.
«"Our study provides compelling evidence for melanoma patients that intismeran vaccine therapy, combined with immunotherapy, can significantly reduce the risk of cancer recurrence and improve clinical outcomes," said study leader Dr. Janice Mehnert of the New York University Grossman School of Medicine in a statement.
«"Our results also give cancer researchers worldwide confidence that mRNA vaccines like Intismeran could work well in combination with immunotherapy in other cancers where high mutation rates have proven difficult to target," Mehnert said.
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(Reporting by Nancy Lapid; Editing by Bill Berkrot)