Atezolizumab in combination with chemotherapy has met primary endpoint of improved pCR, regardless of PD-L1 status, as initial treatment for patients with early triple-negative breast cancer
The phase III IMpassion031 study, evaluating Atezolizumab ( Tecentriq ) in combination with chemotherapy ( Abraxane, albumin-bound Paclitaxel; nab-Paclitaxel; followed by Doxorubicin and Cyclophosphamide ) in comparison to placebo plus chemotherapy ( including Abraxane ), met its primary endpoint by demonstrating a statistically significant and clinically meaningful improvement in pathological complete response ( pCR ) for the treatment of people with early triple-negative breast cancer ( TNBC ), regardless of PD-L1 expression.
In the study, fewer patients who received the Atezolizumab combination as a neoadjuvant ( before surgery ) treatment had evidence of tumour tissue detectable at the time of surgery, regardless of PD-L1 expression, in comparison to the control arm.
Safety for the Atezolizumab combination appeared to be consistent with the known safety profiles of the individual medicines and no new safety signals were identified.
The IMpassion031 study is the second positive phase III study demonstrating the benefit of Atezolizumab in triple-negative breast cancer, and the first Atezolizumab study to demonstrate benefit in early TNBC.
Tecentriq in combination with nab-Paclitaxel is currently approved in more than 70 countries worldwide, including the US and across Europe, for the treatment of adults with unresectable locally advanced or metastatic TNBC in people whose tumours express PD-L1 ( IC greater than or equal to 1% ).
The IMpassion031 enrolled 333 people who were randomised in a 1:1 ratio to receive Atezolizumab or placebo plus chemotherapy in the neoadjuvant ( before surgery ) setting.
Treatment with Atezolizumab continued adjuvantly ( after surgery ) for those in the Atezolizumab arm of the study.
The primary endpoint is pCR using the American Joint Committee on Cancer ( AJCC ) staging system in the intention-to-treat ( ITT ) population and in the PD-L1-positive population. Secondary endpoints include overall survival ( OS ), event-free survival ( EFS ), disease-free survival ( DFS ) and quality of life measures.
Breast cancer is the most common cancer among women with more than 2 million diagnosed worldwide each year.
TNBC represents approximately 15% of all breast cancers and is more common in women under the age of 50, compared with other forms of breast cancer.
It is defined by the lack of expression and/or amplification of the targetable receptors for oestrogen, progesterone and HER2 amplification.
Patients with metastatic TNBC generally experience rapid progression and shorter overall survival compared to other subtypes of breast cancer. ( Xagena )
Source: Roche, 2020