Optimizing Therapy in HER2+ MBC Across the Globe

Volkmar Müller, MD, PhD: I’d like to know about the availability of drugs in your country. What’s available? Reimbursement is not the same in every country, so please comment on that briefly.

Giuseppe Curigliano, MD, PhD: In Italy, we don’t have a reimbursement for tucatinib or trastuzumab deruxtecan, but we have expanded access. We can access both trastuzumab deruxtecan and tucatinib.

Carmen Criscitiello, MD, PhD: Regarding the sequencing issue, trastuzumab deruxtecan will likely become the new standard of care for second-line treatment. I’d prefer tucatinib as third line, but there will be differences across countries if regulatory agencies adopt different positions. In some countries, tucatinib will remain available after 2 prior lines of anti–HER2 [human epidermal growth factor receptor 2] agents; in others, after prior T-DM1 [trastuzumab emtansine]. We have to consider access to drugs across the world, especially in low-income countries. These are matters that should be considered when discussing sequencing. It will affect the choice of treatment sequencing on what patients will receive as part of the adjuvant treatments because these drugs are moving earlier in the course of the disease.

Tiffany A. Traina, MD: If we’re sequencing these agents with monoclonal antibody or antibody-drug conjugate, as a mechanism of resistance you begin to see the extra-cellular domain of HER2 downregulated? Could there be a rationale for sequencing your tyrosine kinase inhibitor between these agents to mix up the strategy with which we’re targeting the cancer cell? That would be interesting to see, and we need help sequencing these agents and data to guide us.

Volkmar Müller, MD, PhD: That’s an important point. One reason I prefer third-line treatment with tucatinib for sequencing is because most patients also receive a fourth-line treatment.

Transcript edited for clarity.