Duravalumab plus chemotherapy for patients with triple negative breast cancer

This study evaluated the effectiveness of durvalumab (Imfinzi) combined with chemotherapy for patients with triple-negative breast cancer (TNBC). This study found that more patients treated with durvalumab had a complete disappearance of all signs of cancer (complete response) compared to placebo.

TNBC is breast cancer that does not have receptors for certain hormones called estrogen, progesterone, or HER2. Because of this, it can be slightly harder to treat. Immunotherapy is becoming a more common treatment option for these patients. Durvalumab is a new immunotherapy under investigation for the treatment of TNBC.

Durvalumab binds to cancer cells and helps the body's immune system attack them. This leads to cancer cell death. Previous studies have shown that other medications similar to durvalumab used together with chemotherapy are effective. Whether durvalumab plus chemotherapy works better than chemotherapy alone for treating TNBC remains unclear.

This study had 174 patients with breast cancer. More than half (65%) had disease that was stage 2A or higher. Almost all patients (99%) had surgery to remove the tumor. Then, 117 patients received either durvalumab or placebo (a substance with no active effect) before chemotherapy. 57 patients received one of these treatments at the same time as chemotherapy.

88 patients received durvalumab and 86 patients received a placebo (a substance with no active effect). Overall, more patients treated with durvalumab and chemotherapy had a complete response compared to the placebo group (53.4% vs. 44.2%). Treatment with durvalumab plus chemotherapy was associated with a 1.45-fold higher likelihood of completely responding to treatment compared to placebo.

Significantly more patients who started treatment before chemotherapy achieved a complete response compared to the 57 patients who started treatment with chemotherapy (50.0% vs. 37.9%). In the durvalumab group, this rate was 61.0% compared to 41.1% in the placebo group.

Overall, 59 patients had at least one side effect. Slightly more patients in the durvalumab group reported side effects compared to placebo (30 patients vs. 29 patients). The most common ones were low red blood cell count (94.6% vs. 96.3%) and low white blood cell count (77.2% vs. 81.7%). Tiredness (76.1% vs. 82.9%) and nausea (58.7% vs. 64.6%) were also reported. 

Only thyroid dysfunction was more common in the durvalumab group than placebo (50% vs. 43.9%). Overall, more patients in the durvalumab group stopped treatment compared to placebo (20 patients vs. 17 patients). Of these, 9 versus 5 patients stopped treatment due to side effects.

The study concluded that patients with TNBC who were treated with duravalumab had more complete responses after chemotherapy compared to placebo.

This is a small phase 2 study. More studies are needed to determine the best timing of durvalumab treatment for patients with TNBC.