HER2+ BC: A Year in Review and Updates from SABCS - Episode 11

SABCS 2020 Wrap-Up

Final analysis of data on HER2-positive disease presented at the 2020 San Antonio Breast Cancer Symposium from experts in the field of breast oncology.

Hatem Soliman, MD: In regard to the HER2CLIMB data, let’s discuss the outcomes.

Andrew Seidman, MD: There were 2 reports, one from Erika Hamilton, [MD,] from the Sarah Cannon [Research Institute]. There was no differential efficacy for trastuzumab, capecitabine, and tucatinib based on hormone receptor status, so ER-positive and ER-negative patients benefitted to a similar degree. The same was true for those patients with baseline CNS [central nervous system] involvement. Andrew Wardley, [MBChB, MD,] from the United Kingdom, reported on a health-related quality of life study using a validated quality of life instrument and a visual analog scale. It showed that the tucatinib-treated patients did enjoy a lower risk of deterioration of quality of life on a tool that assessed mobility and activities of daily living, pain, self-care, anxiety, and depression. That was a nice supplement to the overall HER2CLIMB report.

Hatem Soliman, MD: To conclude with some of the data, there were also some interesting data from Japan that were presented regarding the PRECIOUS study, this came from the Japan Breast Cancer Research Group. The main crux of the question was looking at what would be the clinical benefit of retreating patients with pertuzumab in the metastatic setting who had seen prior treatment with pertuzumab in the earlier-line setting. Patients were randomized to either get the pertuzumab/trastuzumab and chemotherapy of physician’s choice versus just trastuzumab plus chemotherapy of the physician’s choice, as we would typically do in normal practice. They randomly assigned 219 patients to either arm.

When you look at the PFS [progression-free survival] as assessed by the investigators, it looked like there was a little bit of a signal there for a slight improvement in the progression-free survival of 5.3 months, versus 4.2 months for the retreatment arm with pertuzumab. It was statistically significant, albeit a very modest difference. It didn’t appear that that difference was significant in those patients who had seen T-DM1 [trastuzumab emtansine] as their immediately preceding regimen. There wasn’t a statistically significant difference in overall survival. There may have been a slight trend there, but it didn’t appear to be statistically significant in that regard.

Andrew Seidman, MD: We did a similar study, using gemcitabine specifically as the chemotherapy foundation when we reintroduced pertuzumab despite prior progression, and again, a saw very similar, weak signal for efficacy. It’s not part of my standard practice to continue pertuzumab through multiple lines of therapy, and these data will not make me feel differently about it.

Hatem Soliman, MD: The NCCN [National Comprehensive Cancer Network] still says if [patients] haven’t seen pertuzumab previously, in later lines obviously we want to try to expose them to it. But we’re not necessarily advocating a lot of retreatment with pertuzumab at this juncture.

Transcript edited for clarity.