ESMO: Genentech Shares Data from Phase III Triple-Negative Breast Cancer Trials
Genentech, a Roche company, presented data from three Phase III trials of Tecentriq (atezolizumab) in triple-negative breast cancer (TNBC) at the European Society for Medical Oncology (ESMO) Virtual Congress 2020 this weekend. They are IMpassion031, IMpassion130 and IMpassion131.
First, they presented data from the Phase III IMpassion031 trial of Tecentriq in combination with chemotherapy (Abraxane [albumin-bound paclitaxel; nab-paclitaxel]; followed by doxorubicin and cyclophosphamide) compared to placebo plus chemotherapy. The trial demonstrated a statistically significant and clinically meaningful improvement in pathological complete response (pCR) for people with early TNBC, regardless of PD-L1 expression. pCR was seen in 57.6% of patients receiving the combination, an increase of 16.5% compared to 41.1% in patients treated with placebo plus chemotherapy.
Second was final overall survival (OS) analysis of the Phase III IMpassion130 study of Tecentric with nab-paclitaxel compared to placebo plus nab-paclitaxel as a first-line treatment for mTNBC. This data was consistent with the first and second interim analyses. The difference in OS between the treatment groups in the intent-to-treat (ITT) populations was not significant. Clinically meaningful improvements in OS were observed with the Tecentriq and nab-paclitaxel group in PD-L1-positive patients. They also indicated that the magnitude of OS improvements with the Tecentriq patients in PD-L1-positive patients was clinically meaningful, with an increase of 7.5 months in median OS with Tecentriq plus nab-paclitaxel compared to placebo plus nab-paclitaxel. But, they noted, the results could not be formally tested because of prespecified statistical testing hierarchy.
And third, data from the Phase III Impassion131 trial of Tecentriq in combination with paclitaxel versus placebo plus paclitaxel as a first-line treatment for patients with metastatic TNBC, did not demonstrate significant improvement for progression-free survival (PFS) in the PD-L1-positive population. The OS data demonstrated a negative trend, but the trial wasn’t powered for the secondary endpoint of OS, plus the OS data were immature at the time of analysis in the PD-L1-positive population, based on 21% of patients with an event.
“While we made great progress in the treatment of many forms of breast cancer, TNBC remains an aggressive and difficult-to-treat disease,” said Levi Garraway, Genentech’s chief medical officer and head of Global Product Development.
He went on to say, “We are proud of our work to address challenges and advance scientific understanding of cancer immunotherapy in the context of distinct chemotherapy regimens and in various TNBC treatment settings. Although the IMpassion131 study did not reach its endpoint, we are pleased to bring new treatment options for some TNBC patients, and remain committed to improving the lives of all women with early and advanced stages of this disease.”
The IMpassion 031 trial is a Phase III trial of Tecentriq in combination with chemotherapy (Abraxane followed by doxorubicin and cyclophosphamide) compared to placebo plus chemotherapy in previously untreated, early TNBC.
The IMpassion130 trial is a Phase III trial of Tecentriq plus nab-paclitaxel compared to placebo plus nab-paclitaxel in unresectable locally advanced or metastatic TNBC who have not received prior systemic therapy for metastatic breast cancer.
The IMpassion131 study evaluated Tecentriq in combination with paclitaxel versus in placebo and paclitaxel in patients previously untreated, inoperable, locally advanced or metastatic TNBC.
Triple-negative breast cancer cells lack hormone receptors and do not have excess HER2 protein. About 15% of breast cancers are triple-negative. It is an aggressive type of cancer with limited treatment options.
Tecentriq is a checkpoint inhibitor, a monoclonal antibody designed to bind with the PD-L1 protein.