20 July 2020 - The submission requested a PBS (Section 100) listing for atezolizumab for use in combination with taxane chemotherapy for the first-line treatment of patients with unresectable locally advanced or metastatic triple negative breast cancer whose condition expresses programmed death ligand 1 (PD-L1) of any intensity in tumour-infiltrating immune cells covering ≥1% of the tumour area.

The submission was supported by the results from the IMpassion 130 trial, a Phase III, multi-centre, randomised, placebo-controlled study of atezolizumab in combination with nanoparticle albumin-bound paclitaxel (Abraxane) compared with nanoparticle albumin-bound paclitaxel and placebo for patients with previously untreated metastatic triple negative breast cancer.

Roche nominated nanoparticle albumin-bound paclitaxel as the main comparator. The main argument provided in support of the nomination of nanoparticle albumin-bound paclitaxel as the main comparator was a survey of 30 medical oncologists commissioned by Roche.

Nanoparticle-albumin bound paclitaxel was first listed on the PBS on 1 May 2009 for patients with metastatic breast cancer after the failure of prior treatment which includes an anthracycline.

The ESC noted that the data from the survey showed that the majority (58-65%) of Australian patients with triple negative breast cancer do not receive nanoparticle albumin-bound paclitaxel as first-line treatment for metastatic disease.

Although nanoparticle albumin-bound paclitaxel and placebo was the comparator in the key trial, the PBAC agreed with the ESC and the commentary that nanoparticle albumin-bound paclitaxel  may not represent optimal evidence-based treatment in the majority of the proposed population, including: patients who have received previous taxane therapy; patients who are chemotherapy naïve, including those with de novo metastatic disease or some patients with previously untreated locally advanced disease; and patients with BRCA1/2 deleterious mutations. The PBAC considered the most appropriate comparator for this heterogeneous population would be physician choice, but noted that there are various treatment pathways and the available evidence was limited to the comparison with nanoparticle albumin-bound paclitaxel.

This the first time the PBAC has ever requested a comparison with 'physician's choice.'  What is 'physician's choice?' 

In 2013, The Committee considered a submission where the applicant proposed a comparison with 'physician's choice'; the in the economic evaluation a single agent (vinorelbine tartrate) was used as the comparator. It will be interesting to see how Roche handles this issue in a resubmission.

Read PBAC Public Summary Document for Tecentriq