Trastuzumab DeruxtecanEnhertu

6.1 The PBAC did not recommend trastuzumab deruxtecan (T-DXd) for the treatment of adult patients with hormone receptor positive (HR-positive) human epidermal growth factor receptor 2 (HER2)-low or HER2-ultralow unresectable and/or metastatic breast cancer (mBC) who have received at least one prior line of endocrine therapy (ET) in the metastatic setting and are no longer suitable for further ET.PSD · Mar 2026

6.2 The PBAC considered that the primary reason for this outcome was the economic evaluation.PSD · Mar 2026

5.52 The submission presented a modelled economic evaluation based on the key DB-06 trial, which compared T-DXd with ICC for the treatment of patients with HR-positive, HER2-low or HER2-ultralow mBC who have received at least one prior line of ET in the metastatic setting and are no longer considered suitable for ET.PSD · Mar 2026

5.53 The key components of the economic evaluation are summarised Table 11.PSD · Mar 2026

5.45 The submission described T-DXd as superior in terms of effectiveness compared with chemotherapy and inferior but with a manageable safety profile compared with chemotherapy. The Sub-Committees noted that T-DXd demonstrated a modest increase in effectiveness in terms of PFS, unclear OS benefit, no clear QoL benefit, and a clear increase in associated harms, including life-threatening adverse events.PSD · Mar 2026

5.46 The Sub-Committees agreed with the evaluation that the therapeutic conclusion presented in the submission was partially supported by the evidence from the key DB- 06 trial.PSD · Mar 2026

6.2 The PBAC noted and welcomed the input from health care professionals (1) and organisations (3) via the Consumer Comments facility on the PBS website. The comments from Rare Cancers Australia and the Pancare foundation highlighted the poor prognosis for HER2+ G/GOJ adenocarcinoma and the benefits of increased choice of treatment for the population.PSD · May 2025

Consumer input also noted the potential for significant side effects from T-DXd, and the health professional described the importance of educating clinicians regarding monitoring and early intervention for pneumonitis.PSD · May 2025