RESEARCH RESULTS

TNBC lacks the hormone and HER2 receptors that many targeted therapies attack. It often grows faster, spreads sooner, and strikes younger women more severely, leaving few treatment options. While standard chemotherapy can shrink tumours, its high doses and long schedules can lead to fatigue, nerve damage, and even heart problems years later.

In Neo-N, 108 women at 14 hospitals in Australia, New Zealand, and Italy received 12 weeks of pre‑surgery treatment combining nivolumab – a therapy that awakens the immune system – with two common chemotherapy drugs. The trial deliberately omitted a class of medicines called anthracyclines, which are linked to lasting heart risks and other side effects.

To test timing, participants were split into two groups. One began nivolumab alone for two weeks, then added chemotherapy. The other started all drugs together. After 12 weeks, each woman had surgery to remove the treated tumour and nearby lymph nodes.

The results were striking. 57 of 108 women (53%) had no detectable cancer at surgery – a ‘complete response’ matching rates seen with much longer, more intensive regimens. “This 12‑week chemo‑immunotherapy treatment combination is a promising new treatment option that has been very effective at eradicating the cancer in those patients,” says Professor Sherene Loi, medical oncologist at the Peter MacCallum Cancer Centre, who led the study.

Neo-N also highlighted two simple lab tests that predicted who would benefit most. Women whose tumours contained at least 30% immune cells saw a 67% complete-response rate, while those whose tumours displayed the PD‑L1 protein reached 71%. These markers could help doctors tailor treatment to each patient’s tumour biology.

Importantly, the shorter plan proved generally well tolerated. Serious side effects affected 65% of women – mainly low white-blood cells, anaemia and mild liver changes – but these were managed promptly with standard supportive medications, and did not force most participants to stop treatment. No one died from therapy, and the vast majority completed the full course.

Researchers stress that larger phase 3 trials are now needed – and Neo-N participants will remain under observation for up to three years to track any recurrence, long‑term survival, and late effects.

By pairing immunotherapy with a shorter, heart-safer chemotherapy regimen, Neo-N points toward a future where some people can beat early-stage TNBC with fewer treatments, less toxicity, and a better quality of life.

Publication

Zdenkowski N, Kuper‑Hommel MJJ, Niman SM, et al. Timing of nivolumab with neoadjuvant carboplatin and paclitaxel for early triple-negative breast cancer (BCT1902/IBCSG 61–20; Neo-N). Lancet Oncol. 2025;26(3):367–77. doi:10.1016/S1470-2045(24)00092-4