TD beat chemotherapy after failure of hormonal therapy in HER-2 low and ultra low. Wait for the indication.
Outcomes in patients with hormone receptor–positive metastatic breast cancer worsen after one or more lines of endocrine-based therapy. Trastuzumab deruxtecan has shown efficacy in patients with metastatic breast cancer with low expression of human epidermal growth factor receptor 2 (HER2) after previous chemotherapy.
We conducted a phase 3, multicenter, open-label trial involving patients with hormone receptor–positive metastatic breast cancer with low HER2 expression (a score of 1+ or 2+ on immunohistochemical [IHC] analysis and negative results on in situ hybridization) or ultralow HER2 expression (IHC 0 with membrane staining) who had received one or more lines of endocrine-based therapy and no previous chemotherapy for metastatic breast cancer. Patients were randomly assigned in a 1:1 ratio to receive trastuzumab deruxtecan or the physician’s choice of chemotherapy. The primary end point was progression-free survival (according to blinded independent central review) among the patients with HER2-low disease. Secondary end points included progression-free survival among all the patients who had undergone randomization, overall survival, and safety.
Of the 866 patients who underwent randomization, 713 had HER2-low disease, and 153 had HER2-ultralow disease. Among the patients with HER2-low disease, the median progression-free survival was 13.2 months (95% confidence interval [CI], 11.4 to 15.2) in the trastuzumab deruxtecan group and 8.1 months (95% CI, 7.0 to 9.0) in the chemotherapy group (hazard ratio for disease progression or death, 0.62; 95% CI, 0.52 to 0.75; P<0.001); the results were consistent in the exploratory HER2-ultralow population. Data for overall survival were immature. Adverse events of grade 3 or higher occurred in 52.8% of the patients in the trastuzumab deruxtecan group and in 44.4% of those in the chemotherapy group. Adjudicated interstitial lung disease or pneumonitis occurred in 49 patients (11.3%; three events were grade 5 in severity) and in 1 patient (0.2%; grade 2), respectively.
Among patients with hormone receptor–positive, HER2-low or HER2-ultralow metastatic breast cancer who had received one or more lines of endocrine-based therapy, treatment with trastuzumab deruxtecan resulted in longer progression-free survival than chemotherapy. No new safety signals were identified. (Funded by AstraZeneca and Daiichi Sankyo; DESTINY-Breast06 ClinicalTrials.gov number, NCT04494425.)
MammaPrint did not predict distant recurrence, but it did predict patients who may benefit from extended hormonal therapy. We do have breast index, so now we have options. Breast index can predict the possibility of recurrence though by helping to determine the level of risk.
This study confirms what we saw in initial reports showing the addition of pembro increasing the rate of ypathological complete response (ypCR’s) in the neoadjuvant setting for triple-negative breast cancer (TNBC). New data shows a 5% improvement (87 vs 82%) in overall survival (OS) with the quadruplet. Higher gains but at higher cost of toxicity. The fact that adjuvant intraosseous (IO) does not seem to improve outcomes, but neoadjuvant chemo+IO does show intact tumor-immune interactions to create maximum treatment effectiveness is most likely real. Of note, this seems mostly independent of programmed death-ligand 1 (PDL1) status.
Adding Inavolisib to CKD4/6 inhibitor and AI improved progression-free survival (almost doubled 15 vs 7m) but toxicity was higher still in the single digits (hyperglycemia, diarrhea, stomatitis… all less than 6% G3/4).
Well done study showing a 20% decrease in recurrence risk when using dose dense therapy [EC]/D compared to conventional dose [FEC]/D. Sometimes it is worth it to push.
Myth busted. In aggressive breast cancer, no need to start chemotherapy now, ET and CKD4/6 inhibitors are better tolerated with significant progression-free survival (PFS) benefit and same response rate.
FCS Hematology Oncology Review creates a platform for our physician network to observe the most recent articles and studies available in the oncology and hematology world. By sharing these articles we are building our wealth of knowledge of new observations and treatments as they come available.
