The following article features coverage from the 2019 San Antonio Breast Cancer Symposium. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

In combination with neoadjuvant chemotherapy, a fixed-dose combination of pertuzumab and trastuzumab administered subcutaneously appeared to be noninferior to intravenous administration of these drugs in patients with HER2-positive breast cancer, potentially offering patients a more convenient administration option. 

The findings were based on the results of the FeDeriCa trial (ClinicalTrials.gov identifier: NCT03493854), which were presented during a poster discussion session at the 2019 San Antonio Breast Cancer Symposium (SABCS) in San Antonio, Texas.

The trial enrolled patients with HER2-positive, invasive breast cancer; 252 patients were randomly assigned to receive neoadjuvant chemotherapy plus pertuzumab and trastuzumab intravenously and 248 patients were assigned to receive neoadjuvant chemotherapy plus a fixed-dose combination of pertuzumab and trastuzumab administered subcutaneously into the thigh. 

The completion rates were similar for patients who received pertuzumab and trastuzumab intravenously versus subcutaneously (96.0% vs 94.4%).


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The fixed-dose combination of pertuzumab and trastuzumab administered subcutaneously after chemotherapy led to a noninferior serum trough concentration of pertuzumab compared with intravenous administration, meaning the study met its primary endpoint. The serum trough concentration of trastuzumab after subcutaneous administration was also found to be noninferior.

The total pathologic complete response rates were similar for patients who received pertuzumab and trastuzumab intravenously compared with patients who received the combination subcutaneously (59.5%; 95% CI, 53.2-65.6 vs 59.7%; 95% CI, 53.3-65.8). 

The safety profile also appeared similar for patients who received pertuzumab and trastuzumab intravenously versus subcutaneously, with similar rates of any grade adverse events (99.6% vs 100.0%), alopecia (70.2 vs 77.0%), nausea (60.3% vs 58.9%), diarrhea (55.2% vs 58.5%), primary cardiac events (0.0% vs 0.8%), secondary cardiac events (3.6% vs 1.6%), serious adverse events (17.9% vs 16.1%), and grade 3 or higher adverse events (52.8% vs 48.8%).

Poster discussant Antonio Wolff, MD, professor of oncology, Johns Hopkins School of Medicine in Baltimore, Maryland, said what he was “most excited” about was not these 2 drugs as a subcutaneous injection but the technology behind it.

The fixed-dose combination of pertuzumab and trastuzumab uses recombinant human hyaluronidase PH20 enzyme (rHuPH20), which is proprietary technology from Halozyme, to degrade hyaluronan in human tissue.

In addition, this technology is not limited to pertuzumab and trastuzumab. According to Dr Wolff, Roche is developing a subcutaneous injection for atezolizumab, as is Bristol-Myers Squibb for nivolumab.

“I tip my hat to Halozyme for having developed this,” he said. 

Disclosure: Authors of this study disclosed financial relationships with the pharmaceutical industry. For a full list of disclosures, please refer to the original abstract.

Read more of Cancer Therapy Advisor‘s coverage of SABCS by visiting the conference page.

Reference

  1. Tan AR, Im S-A, Mattar A, et al. Subcutaneous administration of the fixed-dose combination of trastuzumab and pertuzumab in combination with chemotherapy in HER2-positive early breast cancer: Primary analysis of the phase III, multicenter, randomized, open-label, two-arm FeDeriCa study. Poster presentation at: 2019 San Antonio Breast Cancer Symposium; December 10-14, 2019; San Antonio, TX. Abstract PD4-07.