Roche has reported positive results from the Phase Ib clinical trial of its ipatasertib in combination with Tecentriq (atezolizumab) and chemotherapy as first line therapy for advanced triple-negative breast cancer (TNBC).

Initial findings showed that the combination led to a 73% confirmed objective response rate (ORR), regardless of tumour biomarker status. Out of the first 26 subjects, 19 had confirmed responses.

The most common all-grade adverse events observed during the trial were diarrhoea and rash.

Roche chief medical officer and Global Product Development head Sandra Horning said: “These early results support the contribution of ipatasertib to our combination treatment approach in TNBC and reinforce our vision to develop medicines that may benefit patients with this challenging disease.”

“These early results support the contribution of ipatasertib to our combination treatment approach in TNBC.”

Ipatasertib is an investigational, oral drug being develop to selectively bind to all three isoforms of AKT, which blocks the PI3K/AKT signalling pathway and may help in preventing cancer growth and survival.

Inhibition of the PI3K/AKT pathway is expected to reverse T-cell-mediated immunotherapy resistance.

The drug was discovered by Roche subsidiary Genentech in alliance with Array BioPharma.

During the open-label, multi-centre Phase Ib trial, the safety and efficacy of the ipatasertib combination was evaluated in subjects who did not receive prior chemotherapy in advanced setting.

The trial consists of two arms, namely ipatasertib in combination with atezolizumab and paclitaxel, and ipatasertib plus atezolizumab and nab-paclitaxel.

In addition, a separate cohort is now enrolling TNBC patients who have progressed following at least one line of chemotherapy in the advanced setting.

This cohort will see a collection of tumour biopsies to evaluate treatment-related biomarker changes.

Roche is also planning to launch a pivotal randomised, multi-centre, double-blind Phase III trial to assess the ipatasertib, atezolizumab and paclitaxel combination as a first-line treatment for locally advanced / metastatic triple-negative breast cancer.