According to various sites, a woman suffering from an advanced stage of breast cancer that had spread throughout her body was completely cleared off the disease.
The study used a gene test done on tumors to help decide whether a woman would benefit from chemo or if they could receive hormone therapy. That comprises about 85 percent of women with breast cancer in this age group, the researchers noted.
Nina Barough, the founder and chief executive of Walk the Walk - the breast cancer charity behind the coming Moonwalk Scotland event - said: "I had my cancer 20 years ago and, at that time, scientists knew chemotherapy wasn't suitable for everybody, but what they couldn't tell is who it was suited for and who it wasn't".
Certain women 50 or younger did benefit from chemo; slightly fewer cases of cancer spreading far beyond the breast occurred among some of them given chemo, depending on their risk scores on the gene test.
"Part of the excitement is because all cancers contain mutations, it's a technique that could potentially be applied to any tumor type", Rosenberg said. The 67 percent of women who were at intermediate risk all had surgery and hormone therapy.
While the USA doctors who developed the therapy can not be sure how much the infused immune cells contributed to her recovery, the use of pembrolizumab alone has not been very effective for advanced breast cancer in the past. "The case with other TIL therapies in the past is that they've not been able to expand enough T cells in many patients, there aren't enough to start with".
"We have been waiting for these results for years", said Allison Kurian, an oncologist at Stanford University who wasn't involved in the trial.
The study is thought to be the largest breast cancer treatment trial ever conducted.
About 17 percent of the women tested had high-risk scores and were advised to have chemotherapy. There is no published evidence for Keytruda having any effect on HR-positive breast cancer, and the researchers say the short course of the drug is unlikely to have been able to confer such a protracted benefit on its own.
Researchers at the National Cancer Institute have put a patient with metastatic breast cancer into complete remission by using a new approach to immunotherapy. After that, a Phase 3 trial will need to broaden the volume of patients treated to verify any positive results, .
The immunotherapy field has seen major breakthroughs in the past year, including the approval of two so-called CAR-T treatments from Gilead and Novartis AG that extract T-cells from a patient's blood and re-engineer them to recognize malignancies.
Gilead shares gained as much as 3.7 percent on Monday, and were up 1.9 percent to $69.60 at 11:16 a.m.in NY.
Rachel Rawson, from the charity Breast Cancer Care, said: "Every day, women with certain types of breast cancer face the awful dilemma of whether or not to have the treatment, without hard facts about the benefit for them". While unequal access to high-quality screening and cancer treatment likely contributes to the higher mortality rate among African-Americans, the reasons for this racial disparity in breast cancer go beyond access to care. Since its establishment in 1996, over 15,000 people have participated in more than 350 cancer trials. "If we are going to take a step back" from chemotherapy, he said, "we really had to be sure".