The landscape for breast cancer therapies is set to become more dynamic, as newer targeted agents and drug combinations launch over the next few years, according to new research from Decision Resources.
A US survey conducted for the study also finds that, more than any other factor, efficacy drives oncologists’ prescribing of targeted therapies for breast cancer, and that for most of the doctors polled, the escalating overall cost of drug treatment for breast cancer has little or no impact on their treatment decisions.
Reimbursement and restrictions by managed care organisations (MCOs) have only a limited influence on prescribing of approved agents, adds the study, which also polled medical directors and pharmacy directors of MCOs to examine how receptive US physicians and payers are to the integration of novel premium-priced therapies in highly generic market segments.
Treatment of first-line HER2-positive breast cancer will become increasingly fragmented, it forecasts. First-line treatment is currently dominated by Roche/Genentech/Chugai’s Herceptin (trastuzumab) and, to a lesser extent, by Roche/Genentech/Chugai’s Perjeta (everolimus)/Herceptin, but the approval of Novartis’ Afinitor (everolimus)/Herceptin and Roche/Genentech/Chugai’s Kadcyla (ado-trastuzumab emtansine)/Perjeta will recast patient share within the first line, it says.
Also, dual HER2-targeted therapies - GlaxoSmithKline’s Tykerb (lapatinib)/Herceptin and Perjeta/Herceptin - could obtain significant patient share in the adjuvant setting. If the US Food and Drug Administration (FDA) approves Perjeta/Herceptin in 2016, office- and hospital-based oncologists surveyed for the study estimate that they would prescribe this therapy to over half of their adjuvant HER2+ breast cancer patients one year after launch.
And surveyed oncologists who do not currently prescribe Afinitor/exemestane to their eligible patients most commonly cited, as their reasons for not doing so, the treatment’s high cost compared with generically-available alternatives, plus their lack of familiarity with Afinitor/exemestane.
The survey also finds that more than one half of hospital-based oncologists and almost a third of office-based oncologists consider the P13/Akt/mTOR signalling pathway to be a validated target in hormone-resistant breast cancer, following the approval of Afinitor in this population, notes Decision Resources group senior director. Niamh Buckley, who describes this finding as “encouraging” for Novartis’ emerging pan-class I P13K inhibitor buparlisib.
Moreover, if approved, Poly-ADP ribose polymerase (PARP) inhibitors will be mostly prescribed to triple-negative patients in the first-line setting, says Dr Buckley. However, she adds that many oncologists anticipate reserving the PARP inhibitors for later lines of treatment, because they believe that currently-available chemotherapy options are more efficacious.
