ESMO 2026 | HER2CLIMB-05: quality of life with tucatinib maintenance in HER2+ breast cancer

So just to remind the HER2CLIMB-05study, this phase 3 randomized study assesses the impact of adding tucatinib to maintenance therapy pertuzumab, trastuzumab after induction with taxaen, pertuzumab and trastuzumabs with patients with no progression. And the first results are already published. The primary endpoint was met as improvement more than 8 months with tucatinib in progression-free survival. As we know about tucatinib, the tucatanib addition led to increase in adverse events, mainly diarrhea, fatigue, also liver enzymes, some nausea. So it’s very important. In this very long treatment to ASSESS the quality of life. That was the aim of the secondary endpoint we presented last Saturday. So the health-related quality of live in this study. We use the well-validated URTCQ30 scales and ASSESS the whole functioning and the physical functioning. When we made three analyses, the pre-specified was the time to first deterioration of quality of life, defined as a decline of 10 points compared to baseline, excluding disease progression or death. The second one was a postdoc analysis looking to time to the first deteriorations, but including disease progression and death. And the third one, I think was very important, is a post-doc analysis, a time to 1st confirm deterioration. Because the patient may be resolved with medication, with adaptation of the dosage. So considering the first endpoint pre-specified, in fact, the addition of tucatinib was associated with a shorter time to deterioration compared to the placebo arm, with increased risk of 29%. However, when we include disease progression and death, in fact, the results are very similar. So it’s, I think, a good point. Considering the time to CONFIRM deterioration, in fact the addition of tucatinib and including disease progression was much better than in the control arm. So this is very important because the main message that we should advise the patient about adverse events, how to detect, how to manage and PREVENT these adverse events. And in our primary analysis of the safety, we saw that even if the adverse events were much higher than in a control arm, in fact, very few patients discontinued tucatinib due to adverse events . But these patient-reported outcomes are very important to have some fair discussion with the patient because we have other treatment options for maintenance today.