INSIGHT-HER2BC: Real-world evidence of TCHP regimen to describe the best patient profile and open up questions—The interim results.

Abstract

e12607 Background: Neoadjuvant therapy (NAT) of TCHP regimen is approved for standard therapy for early and locally advanced HER2-positive breast cancer (eHER2+ BC) based on encourage TRYPHAENA and KRISTINE trials results. There are limited data regarding patients (pts) treatment outcomes after NAT TCHP in the routine clinical practice. Here we presented the 1st results of ambispective observational program to assess the efficacy and safety of cancer therapy in patients with solid tumors. Early HER2+ breast cancer group: INSIGHT-HER2BC. Methods: We ambispectively reviewed medical records of pts with eHER2+ BC who underwent NAT 6xTCHP (6 docetaxel/carboplatin + trastuzumab/pertuzumab) at three Moscow oncology centers since Jan’2017. This ongoing trial has launched in Feb’22. Here is presented descriptive analyses of pCR (ypT0/is, ypN0) rate for pts who completed NAT and 1-3 yrs. disease-free survival (DFS). Results: At the data cut-off (Jan’2023) 934 pts with HER2+ eBC underwent ≥ 1 cycle of NAТ. The median age is 54.3 y.o. (range: 22-78) where 36% pts were older 60 y.o.; 14% pts - younger than 40 y.o. 75% (571) pts had surgery results. pCR rate is related to KRISTINE trial: 58% (330) pts in the ITT (intention-to-treat) population vs 56% pts, respectively. pCR rate for pts with locally advanced BC is 55% vs 59% for operable BC (114/208 and 215/363 pts, respectively). There is difference in pCR rate achievement according to hormone status (HR+ vs HR-) and HER2 status (3+ vs 2+/ISH +). 1-yr. DFS for pCR group is 97% vs 94% for non-pCR; 2-yr. DFS is 83% vs 83%, respectively, and 3-yr. DFS 64% for pCR group vs 58% for non-pCR. In HR-HER2+ BC the biggest drop between pCR and non-pCR is registered at the 3-yr. DFS: 56% vs 22% while in HR+HER2+ there is almost equal decrease was observed every yr.: 97% vs 93% - 1st yr.; 90% vs 85% - 2nd yr.; 72% vs 68% - 3d yr. Conclusions: NAT TCHP is the effective regimen for HER2+ eBC in the real-world population. The efficiency is observed regardless of disease stage and age. However, there is clear unmet need to find new therapeutic options for HER2 (2+/ISH+) BC. Preliminary results of DFS is markedly lower than in TRYPHAENA and KRISTINE trials but in conjunction with another real-world evidence data. DFS in HR+HER2+ and HR-HER2+ pts likely reflects distinct tumor biology. The mature data for long-term outcomes are awaited. [Table: see text]