Abstract 192P
Background
For neoadjuvant treatment of HER2+ BC, earlier use of HER2-targeting drugs may be helpful to shrink tumor as soon as possible. However, the combinational use of traditional anthracyclines and H is generally avoided due to increased cardiotoxicity. PLD, with much less cardiotoxicity than doxorubicin, was shown to be safe when used with H in advanced BC patients (pts). Hence, we conducted this prospective study to evaluate the efficacy and safety of PLD combined with HP in neoadjuvant treatment for HER2+ BC.
Methods
Eligible pts were non-metastatic HER2+ invasive BC with tumour ≥2 cm or positive lymph node (LN). The pts received PLD (30-35mg/m2) plus C and HP (q3w, 4 cycles) followed by taxanes (T) plus HP (q3w, 4 cycles) for neoadjuvant therapy. The primary endpoint was pathological complete response rate (pCR, ypT0/isN0). Secondary endpoints were objective response rate (ORR) after the first four cycles and the safety. The sample size was estimated to be 78 and the recruitment of study is still ongoing.
Results
As of April 21, 2022, 69 pts received neoadjuvant therapy were enrolled, of whom 35 completed the therapy and underwent surgery. Median age was 50 (range 29-72) years old, and other baseline characteristics were shown in the table. The pCR was 51.4% (18/35), and the ORR after the first four cycles was 68.6%. The most common adverse events in grade 3/4 were white blood cell count decrease (40.0%), lymphocyte count decrease (34.3%), neutrophil count decrease (28.6%). 5 of 35 pts had left ventricular ejection fraction declines larger than 10 percentage points from baseline without symptoms of congestive heart failure, but all of them were above 55%. Table: 192P
| no. (%) | Characteristics | pCR |
| All pts | 35 (100.0%) | 18 (51.4%) |
| Age ≤40 years > 40 years | 11 (31.4%) 24 (68.6%) | 3 (27.3%) 15 (62.5%) |
| Hormone receptor (HR) status HR- HR+ | 14 (40.0%) 21 (60.0%) | 8 (57.1%) 10 (47.6%) |
| LN status LN- LN+ | 12 (34.3%) 23 (65.7%) | 8 (66.7%) 10 (43.5%) |
| Clinical stage II III | 27 (77.1%) 8 (22.9%) | 14 (51.9%) 4 (50.0%) |
Conclusions
Preliminary results of the study suggest that the neoadjuvant treatment with PLD + C + HP followed by THP is safe and have promising efficacy for HER2+ BC.
Clinical trial identification
ChiCTR1900028433.
Editorial acknowledgement
Legal entity responsible for the study
Qiang Liu and Yaping Yang.
Funding
CSPC Ouyi Pharmaceutical Co., Ltd.
Disclosure
All authors have declared no conflicts of interest.