pCR Improved With PLD Plus Docetaxel/Trastuzumab in Invasive HER2+ Breast Cancer

Patients with invasive HE2-positive breast cancer who were treated with pegylated liposomal doxorubicin plus docetaxel and trastuzumab experienced an increase in a pathological complete response.

Neoadjuvant pegylated liposomal doxorubicin (PLD) plus docetaxel plus trastuzumab (Herceptin) yielded an improved pathological complete response rate (pCR) in patients with invasive HER2-positive breast cancer, according to results from a phase 2 multicenter copen-label trial (ChiCTR1900021473).

The results, which were presented at the 2021 European Society of Medical Oncology Congress, indicated that the regimen yielded a total pCR of 48% (95% CI, 33.7%-62.6%), and a breast pCR of 60% (95% CI, 45.2%-73.6%). Patients who were hormone receptor (HR) positive had a total pCR of 41.4% (95% CI, 23.5%-61.1%) and a breast pCR of 48.3% (n = 14/29; 95% CI, 29.4%-67.5%).

A total of 54 patients with invasive HER2-positive breast cancer were recruited from March 2019 to February 2021, 50 of whom underwent treatment. Patients were given PDL at a dose of 40 mg/m2, docetaxel at 75 mg/m2, and a loading dose of trastuzumab at 8 mg/kg and a maintenance dose of 6 mg/kg every 3 weeks for 6 cycles of neoadjuvant treatment.

The primary end points of the study were total pCR and breast pCR, with a secondary end point of safety.

Patients had a median age of 51 years and 72.0% had a Karnofsky performance scale score of 100. In total, 68.0% of patients that had T2 disease, and 12.0% had T4 disease. Additionally, 96.0% of patients were a lymph node positive and 4.0% were negative.Half of all patients had either stage II or stage III disease. Forty-siz percent of women were menopausal.

Patients who were HR negative had a total pCR of 57.1% (95% CI, 34.0%-78.2%) and the breast pCR was 76.2% (n = 16/21; 95% CI, 52.8%-91.8%). Patients who were HR negative had a significantly higher breast pCR compared with the HR-positive patients (P = .047). 

The most common grade 3/4 adverse effects were hand-foot syndrome (12.0%), leukopenia (12.0%), interstitial pneumonia (10%), and oral mucositis (8.0%). Notably, 1 patient died due to interstitial pneumonia. Nine patients who experienced a decline in left ventricular ejection fraction, although they did not fall below 50%, and were able to recover. No patients experienced congestive heart failure. 

Reference

Song Z, Wang H, Yang Q, et al. Pegylated liposomal doxorubicin (PLD) combined with docetaxel and trastuzumab in neoadjuvant treatment for HER2-positive breast cancer: a multicenter, randomized, phase II, open-label trial. Annal of Oncol. 2021;32(suppl 5):S407-S446. doi:10.1016/annonc/annonc687