This was a multicenter, open-label, Phase II study in subjects with Human epidermal growth factor receptor (HER2)-positive metastatic breast cancer who received at least 2 prior lines of anti-HER2-targeted therapies of which at least one included a Trastuzumab-containing regimen. This study was a post-approval commitment with regulatory authorities. It was designed to evaluate whether treatment with Dual blockade promoted changes to biomarkers associated with immunomodulation.
This study was designed to address the post-authorization measures as agreed with the Committee for Medicinal Products for Human Use (CHMP). Recruitment of subjects into this study was challenging, and following agreement with the European Medicines Agency (EMA) enrollment into this study was halted after the enrollment of 42 of the 225 planned subjects. The primary endpoint of the study evaluated changes in expression of biomarkers associated with immunomodulation between a pre-treatment biopsy and the disease progression biopsy. Secondary efficacy endpoints included overall response rate, clinical benefit rate and progression-free survival (PFS), as well as safety/tolerability. All subjects received study treatment until disease progression, death, unacceptable toxicity, or subject withdrawal. In case of disease progression during the treatment period, the subject was followed-up for 30 days for safety evaluation. In case of study treatment discontinuation for any reasons other than disease progression, the subject was followed-up for safety and efficacy assessments until disease progression, new anticancer therapy, death, withdrawal of consent or end of study, whichever came first. This study supported a better understanding of the rapidly accumulating evidence for the importance of the immune microenvironment in HER2-positive breast cancer and the observed immunomodulation in the neoadjuvant setting could be confirmed in the advanced setting and supported the putative mechanism of action of HER2 dual blockade and its potential function on the tumor microenvironment. No formal comparisons between treatment arms were undertaken.
Lapatinib is available as 250-mg orange tablets. Subjects randomized to the Lapatinib plus Trastuzumab arm received 1000 mg per day of Lapatinib, so wre instructed to take 4 x 250 mg tablets per day. Lapatinib was to be taken either 1 hour (or more) before a meal or 1 hour (or more) after a meal
Trastuzumab is a sterile, white to pale yellow, preservative-free lyophilized powder for IV administration. Trastuzumab was administered on Day 1 of the start of Lapatinib or in conjunction with the first cycle of chemotherapy, as an 8 mg/kg loading dose. Subsequently, Trastuzumab was administered q3weekly as a 6 mg/kg maintenance dose. At the discretion of the investigator, weekly Trastuzumab could be given in either of the three treatment arms (loading dose 4mg/kg followed by weekly administration of 2mg/kg).
Subjects who were hormone receptor-positive were required to receive an aromatase inhibitor as combination treatment; however the choice of the aromatase inhibitor selected for each patient was determined by the patients' investigator. The AIs the Investigator could choose from were anastrozole, exemestane, and letrozole and dosing was per product information.
Berazategui, Buenos Aires, Argentina
Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina
Viedma, Río Negro Province, Argentina
Rosario, Santa Fe Province, Argentina
Buenos Aires, Argentina
Córdoba, Argentina
La Rioja, Argentina
San Miguel de Tucumán, Argentina