|The following article features coverage from the San Antonio Breast Cancer Symposium (SABCS) 2018 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Patients with HER2-positive early breast cancer with residual disease who received adjuvant trastuzumab emtansine (T-DM1) had improved invasive disease-free survival (IDFS) compared to patients who received adjuvant trastuzumab, according to the results from the phase 3 KATHERINE trial (ClinicalTrials.gov Identifier: NCT01772472). Trials results were presented at the 2018 San Antonio Breast Cancer Symposium (SABCS) and published in the New England Journal of Medicine.1,2
The KATHERINE trial enrolled nearly 1500 patients with HER2-positive early breast cancer and residual tumor present in the breast or axillary lymph nodes following preoperative therapy. Patients were randomly selected to receive either adjuvant T-DM1 or trastuzumab.
The 3-year IDFS was 77% for patients who received trastuzumab and 88.3% for patients who received T-DM1 (hazard ratio [HR] = 0.50; 95% confidence interval [CI], 0.39–0.64; P < .0001). This translates into an absolute increase in IDFS of 11% for patients who received T-DM1. A subgroup analysis further revealed that IDFS favored T-DM1 consistently across all subgroups.
Adverse events for patients who received T-DM1 included decreased platelet count, increased liver enzymes, headache, and sensory neuropathy, with the most common being fatigue and nausea. Most of the adverse event toxicities were grade 1 or grade 2 and were reversible.
“Overall, this does appear to be a tolerable, manageable regimen,” said study presenter Charles E. Geyer, Jr., MD, professor of medicine at Virginia Commonwealth University School of Medicine and associate director for clinical research and Harrigan, Haw, Luck Families Chair in Cancer Research at Massey Cancer Center in Richmond, Virginia.
“KATHERINE demonstrated that adjuvant T-DM1 has both a statistically significant and clinically meaningful improvement in IDFS compared with trastuzumab,” Dr Geyer concluded.
Disclosure: This trial was supported by F. Hoffmann La Roche/Genentech. For a full list of disclosures, please see the study abstract.
Read more of Cancer Therapy Advisor‘s coverage of the SABCS 2018 meeting by visiting the conference page.
- Geyer CE, Huang CS, Mano MS, et al. Phase III study of trastuzumab emtansine (T-DM1) vs trastuzumab as adjuvant therapy in patients with HER2-positive early breast cancer with residual invasive disease after neoadjuvant chemotherapy and HER2-targeted therapy including trastuzumab: Primary results from KATHERINE. Oral presentation at: 2018 San Antonio Breast Cancer Symposium; December 4-8, 2018; San Antonio, TX.
- Minckwitz GV, Huang CS, Mano MS, et al. Trastuzumab emtansine for residual invasive HER2-positive breast cancer [published online December 5, 2018]. N Engl J Med. doi: 10.1056/NEJMoa1814017