Neoadjuvant Pyrotinib plus Trastuzumab and Chemotherapy for Stage I-III HER2-Positive Breast Cancer: A Phase II Clinical Trial

Clinical efficacy of pyrotinib combined with chemotherapy for neoadjuvant treatment in HER2-positive breast cancer: a single-center study

This study aimed to evaluate the efficacy of pyrotinib, an orally administered small molecule tyrosine kinase inhibitor, combined with neoadjuvant chemotherapy in treating patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Pyrotinib works by inhibiting the HER2 signaling pathway, thereby preventing tumor cell growth. This single-arm clinical trial aimed to assess the total pathological complete response (tpCR; ypT0/is and ypN0) rate as the primary endpoint. A total of 27 patients were enrolled, each receiving 4-8 cycles of pyrotinib in combination with neoadjuvant chemotherapy. Pyrotinib combined with neoadjuvant chemotherapy demonstrated notable antitumor activity in patients with HER2-positive breast cancer. Among 26 patients, the tpCR rate was 26% (7/26), while the breast pathological complete response rate was 30% (8/26), indicating complete inhibition of the primary tumor in some cases. Notably, patients with HR-negative breast cancer demonstrated a higher tpCR rate compared with those with HR-positive breast cancer. The treatment regimen was well-tolerated. Diarrhea was the most common adverse event, occurring in 92.3% of patients, with 46.2% experiencing grade 3 or higher diarrhea. No severe adverse events or treatment-related fatalities were reported.

An exploration of the optimal combination chemotherapy regimen based on neoadjuvant therapy containing pyrotinib for HER2-positive breast cancer: A multicenter real-world study

BACKGROUND

The combination of pyrotinib (Py) with cytotoxic agents proved to be effective in early human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). However, the optimal chemotherapy regimen is unknown. This study attempts to explore it from real-world research data.

METHODS

Information was collected from patients with early-stage HER2-positive BC from 23 centers across the country. They were categorized into the anthracycline group (A group) and non-anthracycline group (non-A group). Patients in the non-A group were further categorized into the platinum group and non-platinum group and the short-cycle (≤4 cycles) taxane group and long-cycle (>4 cycles) taxane group. Total pathological complete response (tpCR, ypT0/is ypN0) and breast pathological complete response (bpCR, ypT0/is) rates were assessed.

RESULTS

A total of 107 patients were enrolled. Postoperative pathology indicated a tpCR rate of 36.8 %, a bpCR rate of 42.1 % in the A group, the non-A group had a tpCR rate of 47.8 %, and a bpCR rate of 53.6 %, with P-values of 0.273 and 0.254, respectively. In the long-cycle taxane group, the tpCR and bpCR rates were 60.8 % and 66.7 %, respectively. In the short-cycle taxane group, the tpCR and bpCR rates were 11.1 % and 16.7 %, respectively (both P<0.001). The platinum group had higher tpCR rate (62.9 % vs. 32.4 %, respectively; P = 0.011) and bpCR rate (65.7 % vs. 41.2 %, respectively; P = 0.041).

CONCLUSION

As for a neoadjuvant therapy regimen with Py, an anthracycline-free regimen is feasible. Besides, platinum-containing, long-cycle taxane regimens appear to achieve superior efficacy under anthracycline-removed conditions.

Targeted multimodal synergistic therapy of drug-resistant HER2-positive breast cancer by pyrotinib-ICG self-assembled nanoparticles

Neoadjuvant targeted therapy combining targeted agents with chemotherapy significantly improve survival rates of patients suffering from human epidermal receptor (HER2)-positive breast cancer (BC) in early or locally advanced stages. However, approximately 50% of patients fail to achieve a pathological complete response. In response, targeted photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as effective strategies to bolster primary tumors treatment. In this context, we developed a novel nanodrug, referred to as "P/ICG", which comprised of a tyrosine-kinase inhibitor pyrotinib and the photosensitizer indocyanine green (ICG). This formulation was created for the targeted and multimodal synergistic therapy of HER2-positive BC. Upon irradiation with near-infrared light, ICG generates high levels of intracellular reactive oxygen species and elevated temperature, enhancing chemotherapy effects of pyrotinib. This synergistic action boosts a highly effective anticancer effect promoting the ferroptosis pathway, providing an efficient therapeutic strategy for treating HER2-positive BC.

Trastuzumab-functionalized bionic pyrotinib liposomes for targeted therapy of HER2-positive breast cancer

In this study, we prepared a bionic nanosystem of trastuzumab-functionalized SK-BR-3 cell membrane hybrid liposome-coated pyrotinib (Ptb-M-Lip-Her) for the treatment of HER2-positive breast cancer. Transmission electron microscopy, dynamic light scattering, polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting were used to verify the successful preparation of Ptb-M-Lip-Her. In vitro drug release experiments proved that Ptb-M-Lip-Her had a sustained release effect. Cell uptake experiments and in vivo imaging experiments proved that Ptb-M-Lip-Her had good targeting ability to homologous tumor cells (SK-BR-3). The results of cell experiments such as MTT, flow cytometry, immunofluorescence staining and in vivo antitumor experiments showed that Ptb-M-Lip-Her could significantly promote apoptosis and inhibit the proliferation of SK-BR-3 cells. These results clearly indicated that Ptb-M-Lip-Her may be a promising biomimetic nanosystem for targeted therapy of HER2-positive breast cancer.

Safety and efficacy of pyrotinib for HER‑2‑positive breast cancer in the neoadjuvant setting: A systematic review and meta‑analysis

As a novel tyrosine kinase inhibitor (TKI), pyrotinib can irreversibly block dual pan-ErbB receptors and has been used in the treatment of advanced or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, there are limited data on the use of pyrotinib in early breast cancer. Therefore, the present meta-analysis was conducted to evaluate the safety and efficacy of pyrotinib in the neoadjuvant setting for patients with early-stage or locally advanced HER2-positive breast cancer. Online databases (Pubmed, Web of Science, Embase and Cochrane Library) were comprehensively searched for eligible prospective clinical trials on August 17, 2023. The primary endpoint was the treatment-related adverse events (TRAEs), and the secondary endpoint was pathological complete response (pCR) rate. In total, seven trials with a total enrolment of 407 patients were included. A total of seven studies evaluated pyrotinib in combination with trastuzumab and chemotherapy in the neoadjuvant setting. The median age ranged from 47-50 years. The most common TRAEs were diarrhea [98% of patients; 95% confidence interval (CI): 92-100%], followed by anemia (71%; 95% CI: 55-89%), vomiting (69%; 95% CI: 55-82%), and leucopenia (66%; 95% CI: 35-91%). No treatment-related deaths occurred. The pooled pCR rate was 57% (95% CI: 47-68%). It was concluded that pyrotinib-containing neoadjuvant therapy could be an effective treatment strategy in patients with early-stage or locally advanced HER2-positive breast cancer; however, the management of adverse events should be a key consideration. The management of adverse events should be paid great attention to, during pyrotinib therapy, although pyrotinib-contained neoadjuvant therapy could be an effective treatment for patients with early-stage or locally advanced HER2-positive breast cancer. Head-to-head randomized clinical trials are warranted to further confirm the benefits and risks associated with pyrotinib therapy in patients with breast cancer.

Exploring the effectiveness of molecular subtypes, biomarkers, and genetic variations as first-line treatment predictors in Asian breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Breast cancer incidence has been on the rise significantly in the Asian population, occurring at an earlier age and a later stage. The potential predictive value of molecular subtypes, biomarkers, and genetic variations has not been deeply explored in the Asian population. This study evaluated the effect of molecular subtype classification and the presence or absence of biomarkers and genetic variations on pathological complete response (pCR) after neoadjuvant treatment in Asian breast cancer patients.

METHODS

A systematic search was conducted in MEDLINE (PubMed), Science Direct, Scopus, and Cochrane Library databases. Studies were selected if they included Asian breast cancer patients treated with neoadjuvant chemotherapy and contained data for qualitative or quantitative analyses. The quality of the included studies was assessed using the Newcastle Ottawa Scale. Following the random effects model, pooled odds ratios or hazard ratios with 95% confidence intervals for pCR were analysed using Review Manager Software. Heterogeneity between studies was assessed using Cochran's Q-test and I2 test statistics.

RESULTS

In total, 19,708 Asian breast cancer patients were pooled from 101 studies. In the neoadjuvant setting, taxane-anthracycline (TA) chemotherapy showed better pCR outcomes in triple-negative breast cancer (TNBC) (p<0.0001) and human epidermal growth factor receptor 2 enriched (HER2E) (p<0.0001) than luminal breast cancer patients. Similarly, taxane-platinum (TP) chemotherapy also showed better pCR outcomes in TNBC (p<0.0001) and HER2E (p<0.0001). Oestrogen receptor (ER)-negative, progesterone receptor (PR)-negative, HER2-positive and high Ki-67 were significantly associated with better pCR outcomes when treated with either TA or TP. Asian breast cancer patients harbouring wildtype PIK3CA were significantly associated with better pCR outcomes when treated with TA in the neoadjuvant setting (p=0.001).

CONCLUSIONS

In the neoadjuvant setting, molecular subtypes (HER2E and TNBC), biomarkers (ER, PR, HER2, HR, Ki-67, nm23-H1, CK5/6, and Tau), and gene (PIK3CA) are associated with increased pCR rates in Asian breast cancer patients. Hence, they could be further explored for their possible role in first-line treatment response, which can be utilised to treat breast cancer more efficiently in the Asian population. However, it needs to be further validated with additional powered studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021246295.

Short-term efficacy and safety of neoadjuvant pyrotinib plus taxanes for early HER2-positive breast cancer: a single-arm exploratory phase II trial

Background

The effectiveness and safety of pyrotinib have been substantiated in human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (BC). However, the role of pyrotinib as a single HER2 blockade in neoadjuvant setting among BC patients has not been studied. The objective of this study was to evaluate the efficacy and tolerability of pyrotinib plus taxanes as a novel neoadjuvant regimen in patients with HER2-positive early or locally advanced BC.

Methods

In this single-arm exploratory phase II trial, patients with treatment-naïve HER2-positive BC (stage IIA-IIIC) received pyrotinib 400 mg once daily and taxanes [docetaxel 75 mg/m2 or nanoparticle albumin-bound (nab)-paclitaxel 260 mg/m2 every 3 weeks, or paclitaxel 80 mg/m2 weekly] for a total of four 21-day cycles before surgery. Efficacy assessment was based on pathological and clinical measurements. The primary endpoint of this study was the total pathological complete response (tpCR) rate. The secondary endpoints included breast pCR (bpCR) rate, investigator-assessed objective response rate (ORR) and adverse events (AEs) profiles.

Results

From 1 September 2021 to 30 December 2022, a total of 31 patients were enrolled. One patient was withdrawn due to unbearable skin rash after the second cycle of neoadjuvant therapy. The majority of the intention-to-treat (ITT) population was premenopausal (54.8%), had large tumors (90.3%) and metastatic nodes (58.1%) at diagnosis and hormone-receptor positive tumors (64.5%). Most participants used nab-paclitaxel (74.2%) and received mastectomy (67.7%) after neoadjuvant treatment. The tpCR and bpCR rates were 48.4% [95% confidence interval (CI): 30.8-66%] and 51.6% (95% CI: 34-69.2%), respectively. Grade ≥3 treatment-related AEs were observed in 16.1% (5/31) of the ITT population, including diarrhea (n=2, 6.5%), hand and foot numbness (n=1, 3.2%), loss of appetite (n=1, 3.2%), and skin rash (n=1, 3.2%). AE related dose reduction or pyrotinib interruption was not required.

Conclusions

In female patients with HER2-positive non-metastatic BC, neoadjuvant pyrotinib monotherapy plus taxanes appears to show promising clinical benefit and controllable AEs [Chinese Clinical Trial Registry (ChiCTR2100050870)]. The long-term efficacy and safety of this regime warrant further verification.

Neoadjuvant pyrotinib plus trastuzumab and chemotherapy for HER2-positive breast cancer: a prospective cohort study

BACKGROUND

This prospective study aims to investigate the efficacy and safety of pyrotinib (P) combined with 4 cycles of epirubicin and cyclophosphamide followed by 4 cycles of taxane and trastuzumab (P + EC-TH) regimen as neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2) positive breast cancer and to investigate the predictive value of p53, p63, and epidermal growth factor receptor (EGFR) status for neoadjuvant efficacy.

METHODS

A total of 138 HER2-positive breast cancer patients who received neoadjuvant therapy and underwent surgery were included. Case group: 55 patients received P + EC-TH regimen.

CONTROL GROUP

83 patients received EC-TH regimen. The chi-square test, Fisher's exact test, and logistic regression analysis were applied. The primary endpoint was total pathologic complete response (tpCR), and the secondary endpoints were breast pathologic complete response (bpCR), overall response rate (ORR), and adverse events (AEs).

RESULTS

In the case group, the tpCR rate was 63.64% (35/55), the bpCR rate was 69.09% (38/55), and the ORR was 100.00% (55/55). In the control group, the tpCR rate was 39.76% (33/83), the bpCR rate was 44.58% (37/83), and the ORR was 95.18% (79/83). The case group had significantly higher tpCR and bpCR rates than those of the control group (P < 0.05), but there was no significant difference in ORR (P > 0.05). The tpCR was associated with the status of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), and the patients with any negative ER, PR, AR, or combined, were more likely to achieve tpCR than those with positive results (P < 0.05). The p53-positive patients were more likely to achieve tpCR and bpCR than p53-negative patients (P < 0.05). The incidence of hypokalemia and diarrhea in the case group was higher than that in the control group (P < 0.05). The AEs developed were all manageable, and no treatment-related death occurred.

CONCLUSION

The efficacy and safety of the P + EC-TH regimen were verified by this study. The HER2-positive breast cancer patients treated with the EC-TH neoadjuvant regimen were more likely to achieve tpCR or bpCR if pyrotinib was administered simultaneously.

Exploring the clinical outcomes and safety profile of inetetamab treatment in metastatic breast cancer patients: A multicenter assessment of a Chinese-origin recombinant Anti-HER2 monoclonal antibody

BACKGROUND

Inetetamab is a novel recombinant humanized anti-HER2 monoclonal antibody. This study aimed to evaluate the efficacy and safety of inetetamab and predictive factors for response in HER2-positive metastatic breast cancer (MBC) patients.

METHODS

A cohort of HER2-positive MBC patients who received inetetamab-based therapy between June 2020 and August 2021 was evaluated. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR) and disease control rate (DCR). Adverse events (AEs) were graded according to the National Cancer Institute Common Toxicity Criteria.

RESULTS

A total of 141 patients were included in the final analysis. The median PFS of the entire cohort was 7.1 months. The median number of treatment lines administered was three. The ORR was 36.9 %, and the DCR was 80.9 %. The most frequently employed treatment strategy was inetetamab + chemotherapy (49/141, 34.8 %), followed by inetetamab + HER2-tyrosine kinase inhibitors (HER2-TKIs) + chemotherapy, inetetamab + pertuzumab + chemotherapy, inetetamab + endocrine treatment and inetetamab + HER2-TKIs. Cox multivariate analysis revealed that PFS was associated with liver metastasis (hazard ratio [HR] 2.112, 95 % confidence interval [CI] 1.334-3.343, p = 0.001), previous HER2-TKI treatment (HR 2.019, 95 % CI 1.133-3.597, p = 0.017) and estrogen receptor positivity (HR 0.587, 95 % CI 0.370-0.934, p = 0.024). The toxicity was tolerable, with neutropenia being the most common treatment-related grade 3/4 AE (14.9 %).

CONCLUSION

Inetetamab demonstrates effectiveness with a manageable safety profile, offering a promising therapeutic option for HER2-positive breast cancer patients who have shown resistance to prior anti-HER2 treatments.

Safety and efficacy study of oral metronomic capecitabine combined with pyrotinib in HER2-positive metastatic breast cancer: A phase II trial

PURPOSE

To analyze the safety and efficacy of orally administered metronomic capecitabine plus pyrotinib in HER2 positive metastatic breast cancer (MBC) patients, we conducted a prospective phase II study with a single-arm design.

METHODS

HER2 positive patients received oral metronomic capecitabine 500 mg three times a day and pyrotinib 400 mg per day. The primary endpoint was progression-free survival (PFS). Other endpoints included objective response rate (ORR), overall survival (OS), clinical benefit rate (CBR) and safety.

RESULTS

The study included 50 patients with MBC that was HER2-positive, while 1 patient was excluded due to nonstandard medication. The median PFS and OS was 11.9 months (95%CI 8.8-14.6) and 29.3 months (95%CI 24.4-34.8) respectively. ORR was 34.7%, and CBR was 81.6% with 2 CR (4.1%), 15 PR (30.6%) and 23 SD (46.9%). The mPFS in first- or second-line treatment was 12.2 months. The most frequent treatment-related adverse events included hand-foot syndrome, diarrhea, vomiting and nausea. Grade 3 adverse events occurred in 15(30.6%) patients, including hand-foot syndrome (12.2%), diarrhea (12.2%), vomiting (4.1%), and nausea (2.0%). 1 grade 4 adverse event of diarrhea (2.0%) was observed.

CONCLUSION

The combination of metronomic capecitabine and pyrotinib is a promising regimen with competitive efficacy and improved tolerability in HER2 positive metastatic breast cancer patients.

Imaging-proteomic analysis for prediction of neoadjuvant chemotherapy responses in patients with breast cancer

BACKGROUND

Optimizing patient selection for neoadjuvant chemotherapy in patients with breast cancer remains an unmet clinical need. Quantitative features from medical imaging were reported to be predictive of treatment responses. However, the biologic meaning of these latent features is poorly understood, preventing the clinical use of such noninvasive imaging markers. The study aimed to develop a deep learning signature (DLS) from pretreatment magnetic resonance imaging (MRI) for predicting responses to neoadjuvant chemotherapy in patients with breast cancer and to further investigate the biologic meaning of the DLS by identifying its underlying pathways using paired MRI and proteomic sequencing data.

METHODS

MRI-based DLS was constructed (radiogenomic training dataset, n = 105) and validated (radiogenomic validation dataset, n = 26) for the prediction of pathologic complete response (pCR) to neoadjuvant chemotherapy. Proteomic sequencing revealed biological functions facilitating pCR (n = 139). Their associations with DLS were uncovered by radiogenomic analysis.

RESULTS

The DLS achieved a prediction accuracy of 0.923 with an AUC of 0.958, higher than the performance of the model trained by transfer learning. Cellular membrane formation, endocytosis, insulin-like growth factor binding, protein localization to membranes, and cytoskeleton-dependent trafficking were differentially regulated in patients showing pCR. Oncogenic signaling pathways, features correlated with human phenotypes, and features correlated with general biological processes were significantly correlated with DLS in both training and validation dataset (p.adj < 0.05).

CONCLUSIONS

Our study offers a biologically interpretable DLS for the prediction of pCR to neoadjuvant chemotherapy in patients with breast cancer, which may guide personalized medication.

A multicenter single-arm trial of neoadjuvant pyrotinib and trastuzumab plus chemotherapy for HER2-positive breast cancer

The objective of this multicenter, single-arm trial (ChiCTR1900022293) was to explore the efficacy and safety of neoadjuvant therapy with epirubicin, cyclophosphamide, and pyrotinib followed by docetaxel, trastuzumab, and pyrotinib (ECPy-THPy) in the treatment of patients with stage II-III HER2-positive breast cancer. The present study enrolled patients with stage II-III HER2-positive breast cancer. Epirubicin and cyclophosphamide were administrated for four 21-day cycles, followed by four cycles of docetaxel and trastuzumab. Pyrotinib was taken orally once per day throughout the treatment period. The primary endpoint was total pathological complete response (tpCR, ypT0/is ypN0) rate in the modified intention-to-treat (mITT) population. In total, 175 patients were included. The tpCR rate was 68.6% (95% CI, 60.7-75.8%), while the objective response rate was 89.1%. In the post-hoc subgroup analysis, no association between clinical characteristics and the tpCR rate was observed. The most common grade ≥3 adverse events were diarrhea (54.3%), followed by white blood cell count decreased (5.1%), and neutrophil count decreased (4.6%). In conclusion, the neoadjuvant regimen with ECPy-THPy showed promising pathological response and clinical benefits with an acceptable safety profile in patients with stage II-III HER2-positive breast cancer.

Pyrotinib-based therapeutic approaches for HER2-positive breast cancer: the time is now

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) is a highly aggressive subtype associated with poor prognosis. The advent of HER2-targeted drugs, including monoclonal antibodies, tyrosine-kinase inhibitors (TKIs) and antibody-drug conjugates, has yielded improved prognosis for patients. Compared with widely used monoclonal antibodies, small-molecule TKIs have unique advantages including oral administration and favorable penetration of blood-brain barrier for brain metastatic BC, and reduced cardiotoxicity. Pyrotinib is an irreversible TKI of the pan-ErbB receptor, and has recently been shown to be clinically effective for the treatment of HER2-positive BC in metastatic and neoadjuvant settings. This review highlights the development on the application of pyrotinib-based therapeutic approaches in the clinical settings of HER2-positive BC.

Appraisal of Systemic Treatment Strategies in Early HER2-Positive Breast Cancer-A Literature Review

BACKGROUND

The overexpression of the human epidermal growth factor receptor 2 (HER2+) accounts for 15-20% of all breast cancer phenotypes. Even after the completion of the standard combination of chemotherapy and trastuzumab, relapse events occur in approximately 15% of cases. The neoadjuvant approach has multiple benefits that include the potential to downgrade staging and convert previously unresectable tumors to operable tumors. In addition, achieving a pathologic complete response (pCR) following preoperative systemic treatment is prognostic of enhanced survival outcomes. Thus, optimal evaluation among the suitable strategies is crucial in deciding which patients should be selected for the neoadjuvant approach.

METHODS

A literature search was conducted in the Embase, Medline, and Cochrane electronic libraries.

CONCLUSION

The evaluation of tumor and LN staging and, hence, stratifying BC recurrence risk are decisive factors in guiding clinicians to optimize treatment decisions between the neoadjuvant versus adjuvant approaches. For each individual case, it is important to consider the most likely postsurgical outcome, since, if the patient does not obtain pCR following neoadjuvant treatment, they are eligible for adjuvant T-DM1 in the case of residual disease. This review of HER2-positive female BC outlines suitable neoadjuvant and adjuvant systemic treatment strategies for guiding clinical decision making around the selection of an appropriate therapy.

Efficacy, toxicity and prognostic factors of pyrotinib‑involved neoadjuvant therapy in HER2‑positive breast cancer: A retrospective study

Pyrotinib is a novel irreversible tyrosine kinase inhibitor targeting the human epidermal growth factor receptor (HER), whose efficacy in treating metastatic HER2-positive (HER2⁺) breast cancer has been confirmed. The present study aimed to explore the efficacy, safety and prognostic factors of pyrogenic-involved neoadjuvant therapy in patients with HER2⁺ breast cancer. A total of 49 patients with HER2⁺ breast cancer who received pyrotinib-neoadjuvant therapy were recruited. All patients received pyrotinib plus chemotherapy with or without trastuzumab neoadjuvant treatment for six cycles (21 days/cycle). Concerning the clinical response, 4 (8.2%), 36 (73.4%) and 9 (18.4%) patients achieved complete response, partial response and stable disease after 6-cycle pyrotinib-neoadjuvant treatment, respectively; the objective response rate and disease control rate reached 81.6 and 100.0%, respectively. Concerning the pathological response, 23 (46.9%), 12 (24.5%), 12 (24.5%) and 2 (4.1%) patients were evaluated as Miller-Payne grade 5, 4, 3 and 2, respectively. In addition, 23 (46.9%) patients achieved pathological complete response (pCR) in the breast tissue, 40 (81.6%) patients achieved pCR in lymph nodes, while 22 (44.9%) patients obtained total pCR (tpCR). Further multivariate logistic regression analysis demonstrated that pyrotinib plus trastuzumab and chemotherapy (vs. pyrotinib plus chemotherapy) was independently correlated with increased tpCR (P=0.048). The most frequent adverse events included diarrhea (81.6%), anemia (69.4%), nausea and vomiting (63.3%), and fatigue (51.0%). The majority of the adverse events were mild and controllable. In conclusion, pyrotinib-neoadjuvant therapy presented optimal efficacy and mild toxicity in patients with HER2⁺ breast cancer, whose efficacy was affected by the combination treatment with trastuzumab.

Dual targeted therapy with pyrotinib and trastuzumab for HER2-positive advanced colorectal cancer: A phase 2 trial

This trial was initiated to evaluate the efficacy and safety of pyrotinib in combination with trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive recurrent/metastatic colorectal cancer (CRC). In this single-arm, open-label, multicenter, phase 2 trial patients with HER2-positive recurrent/metastatic CRC were enrolled and received oral pyrotinib 400 mg once a day plus intravenous trastuzumab 8 mg/kg loading dose followed by 6 mg/kg once every 3 weeks. The primary endpoint was the objective response rate (ORR). Disease control rate (DCR), progression-free survival (PFS), duration of response, and safety were assessed as secondary endpoints. From December 2019 to October 2021, a total of 20 patients were enrolled and 18 of them were evaluable for response. All patients were B-rapidly accelerated fibrosarcoma (BRAF) wild type. Four patients achieved partial response, with an ORR of 22.2% (4/18, 95% confidence interval [CI] 6.4-47.6) and DCR of 61.1% (11/18, 95% CI 35.8-82.7), while the ORR and DCR were 33.3% (4/12, 95% CI 13.8-60.9) and 83.3% (10/12, 95% CI 51.6-97.9), respectively, in RAS wild-type patients. At the time of cut-off day, median follow-up was 10.7 months (range 3.8-13.8). The median PFS was 3.4 months (95% CI 1.8-4.3) in the overall population and 4.3 months (95% CI 3.2-8.5) in the RAS wild-type group. The most common adverse event of grade ≥3 was diarrhea (13/20, 65.0%). Pyrotinib combined with trastuzumab showed promising antitumor activity and a manageable safety profile in patients with RAS/BRAF wild-type HER2-positive advanced CRC.

Neoadjuvant pyrotinib plus trastuzumab and vinorelbine for HER2-positive locally advanced breast cancer patient who was initially resistant to HP therapy: a case report and literature review

Background

Trastuzumab (H) and pertuzumab (P) plus chemotherapy is the standard guideline-recommended neoadjuvant therapy recommended for patients with human epidermal growth factor receptor 2 (HER2)-positive locally advanced breast cancer (BC), which has dramatically improved patient prognosis. However, over 10% of patients develop primary drug resistance to HP and did not respond to treatment. There is no standard second-line neoadjuvant therapy approach for these individuals at the present. Pyrotinib and vinorelbine have shown promising efficacy in HER2-positive metastatic breast cancer, but their usage in neoadjuvant therapy has not been reported so far.

Case Description

Here, we present a case of a 58-year-old female patient with locally advanced HER2-positive BC who was initially resistant to HP neoadjuvant therapy. Following the failure of the treatment, this patient was given pyrotinib plus trastuzumab and vinorelbine as second-line neoadjuvant therapy. The patient tolerated this treatment well, with mild symptoms of diarrhea. After 6 cycles of neoadjuvant therapy, the efficacy was assessed to be partial remission (PR), and a modified radical mastectomy was finally conducted. This patient remained disease-free for 23 months after surgery.

Conclusions

This is the first report to present a case of neoadjuvant pyrotinib plus trastuzumab and vinorelbine in a patient with HER2-positive locally advanced BC, suggesting that the combination could be a new option for patients who have developed resistance to HP neoadjuvant treatment.

Pyrotinib for HER2-positive metastatic breast cancer: a systematic review and meta-analysis

Background

Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer patients continue to progress despite multiple anti-HER2-targeted treatments. A number of studies have found that Pyrotinib, a small-molecule pan-ErbB receptor tyrosine kinase inhibitor (TKI), is effective in treating patients with HER2-positive metastatic breast cancer. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of Pyrotinib in the treatment of HER2-positive metastatic breast cancer.

Methods

PubMed, Embase, Web of Science, and Cochrane Library databases were searched until February 2022. Research on HER2-positive metastatic breast cancer being treated with Pyrotinib in any line of therapy was included, both prospective and retrospective. Statistical pooling and meta-analysis of data from the included studies were performed to explore the efficacy and safety of Pyrotinib in HER2-positive metastatic breast cancer.

Results

In this meta-analysis, 23 studies were included. The overall objective response rate was 0.49 (95% CI: 0.40, 0.58) for Pyrotinib in HER2-positive metastatic breast cancer and 0.52 (95% CI: 0.32, 0.71) in those with brain metastases. The objective response rate of Pyrotinib was superior to that of other second-line therapeutics in comparison (RR =1.38, 95% CI: 1.25, 1.52), but was relatively inferior to trastuzumab emtansine (T-DM1) (RR =0.82, 95% CI: 0.36, 1.85). The combined median progression-free survivals (PFSs) for Pyrotinib in metastatic breast cancer and those with brain metastases were 8.2 (95% CI: 6.8, 9.5) months and 8.9 (95% CI: 6.2, 11.7) months, respectively. The most common adverse reaction was diarrhea with an all-grade incidence of 0.84 (95% CI: 0.74, 0.92), followed by nausea and vomiting of 0.52 (95% CI: 0.36, 0.68).

Conclusions

In any line of treatment for HER2-positive metastatic breast cancer, the Pyrotinib-containing regimens demonstrated considerable tumor response, disease control, and survival with manageable adverse effects.

The efficacy and safety of epirubicin and cyclophosphamide combined with pyrotinib in neoadjuvant treatment for HER2-positive breast cancer: A real-world study

Purpose

Long-term survival benefit of anthracyclines for human epidermal growth factor receptor 2 (HER2)-positive breast cancer is clear. In the neoadjuvant treatment, compared with the monoclonal antibody such as trastuzumab and pertuzumab, the clinical benefit of pyrotinib, a new small-molecule tyrosine kinase inhibitor (TKI), as the main anti-HER2 strategy currently requires more research to determine. Our real-world study is the first prospective observational study in China to evaluate the efficacy and safety of epirubicin (E) and cyclophosphamide (C) with pyrotinib as anti-HER2 therapy in the neoadjuvant setting of patients with stage II-III HER2-positive breast cancer.

Methods

From May 2019 to December 2021, 44 untreated patients with HER2-positive nonspecific invasive breast cancer who received 4 cycles of neoadjuvant EC with pyrotinib. The primary endpoint was pathological complete response (pCR) rate. Secondary endpoints included the overall clinical response, breast pathological complete response rate (bpCR), the rate of axillary lymph nodes pathological negativity and adverse events (AEs). Other objective indicators were the rate of surgical breast-conserving, the negative conversion ratios of tumor markers.

Results

Thirty-seven (84.1%) of 44 patients completed this neoadjuvant therapy, and 35 (79.5%) had surgery and were included in the primary endpoint assessment. The objective response rate (ORR) of 37 patients was 97.3%. Two patients reached clinical complete response, 34 obtained clinical partial response, 1 sustained stable disease, and no one had progressive disease. Eleven (31.4%) of 35 patients who had surgery achieved bpCR and the rate of axillary lymph nodes pathological negativity was 61.3%. The tpCR rate was 28.6% (95% CI: 12.8-44.3%). Safety was evaluated in all 44 patients. Thirty-nine (88.6%) had diarrhea, and 2 developed grade 3 diarrhea. Four (9.1%) patients had grade 4 leukopenia. All grade 3-4 AEs could be improved after symptomatic treatment.

Conclusion

The regimen of 4 cycles of EC combined with pyrotinib presented some feasibility in the neoadjuvant setting for HER2-positive breast cancer with manageable safety. New regimens with pyrotinib should be evaluated for higher pCR in future.

Trial registration

chictr.org Identifier: ChiCTR1900026061.

PIK3CA mutations are associated with pathologic complete response rate to neoadjuvant pyrotinib and trastuzumab plus chemotherapy for HER2-positive breast cancer

BACKGROUND

Neoadjuvant treatment with a dual anti-human epidermal growth factor receptor 2 (HER2) blockade with pyrotinib and trastuzumab has been shown to be effective for HER2-positive breast cancer.

METHODS

The genomic characteristics of 425 cancer-related genes from the archived tumour blocks of 50 patients enrolled in a prospective neoadjuvant pyrotinib and trastuzumab plus chemotherapy clinical trial (ChiCTR1900022293) were assessed by next-generation sequencing (NGS). The relationship between tumour biomarkers and the postoperative pathological complete response (pCR) were explored.

RESULTS

Forty-five patients completed neoadjuvant chemotherapy and final surgery, of which 26 (58%) achieved a pCR. Among all driver gene mutations, PIK3CA mutation was screened out for having a significant relationship with the treatment response. The pCR rate of patients with wild-type PIK3CA was significantly higher than patients with mutated PIK3CA (80.8% vs. 26.3%; P = 0.00057), and remained significant after a multiple comparison adjustment (P_adjusted = 0.024). We further evaluated the predictive value with logistic regression model of clinical features, genetic biomarkers or both, an AUC of 0.912 (95% CI: 0.827-0.997) was achieved in the integrated model.

CONCLUSIONS

Our data suggest that HER2-positive breast cancers with activating mutations in PIK3CA are less likely to benefit from pyrotinib combined with trastuzumab neoadjuvant therapy.

Axillary Downstaging and the Impact of Clinical Axillary Status on Efficacy of Neoadjuvant Therapy for HER2-Positive Breast Cancer: A Network Meta-Analysis

Background: Lymph node downstaging and the achievement of total-pCR (ypT0/is ypN0) after neoadjuvant therapy are of great importance in HER-2 positive breast cancer. We aim to provide an overall review of neoadjuvant regimens for lymph node downstaging and to indirectly compare the total-pCR by various neoadjuvant regimens with network meta-analysis in HER2-positive patients according to their clinical lymph node status. Methods: Five English databases were searched comprehensively and systematically for relevant RCTs and case-control studies. The data extracted from the included studies were analyzed with the use of Review Manager 5.3 or STATA 15.0 software. Results: A total of 1508 published manuscripts were identified, and 17 studies including 4747 patients were finally included in our analysis. The network meta-analysis of total-pCR showed that dual-target therapy is significantly better than single-target therapy in clinically node-positive patients, and carboplatin performed significantly better than anthracycline in single-target condition. Lapatinib performed poorly in clinically node-positive patients. However, lapatinib in combination with trastuzumab was ranked at the top in the clinically node-negative group, and pertuzumab showed dissatisfied performance in contrast to the primacy of pertuzumab in clinically node-positive groups. Conclusion: In summary, different lymph node statuses led to the diverse first choice of neoadjuvant regimen. We highly recommended TCbHP as the first choice for the neoadjuvant treatment in clinically node-positive HER-2 positive breast cancer. Since lapatinib with trastuzumab ranked top in the clinically node-negative group, we looked forward to discovering the potential value of TKI in clinically node-negative patients, which needs further analysis in the future.

Advances in neoadjuvant therapy for HER2-positive breast cancers: a narrative review

Background and Objective

Breast cancer (BC) is currently the most frequently diagnosed cancer and the primary cause of cancer-related death among women worldwide. Human epidermal growth factor receptor type 2 (HER2)-positive BC accounts for 14.5-15% of all BCs, with a relatively poor prognosis. Neoadjuvant therapy (NAT) has become a preferred treatment option for HER2+ BCs. With the continuous emergence of various clinical trials and new treatment concepts in BC, the NAT model has changed from chemotherapy alone to the neoadjuvant combination of anti-HER2-targeted therapy with chemotherapy, neoadjuvant endocrine therapy, and so on. Therefore, an up-to-date review is needed to inform the selection of NAT strategies for HER2+ BCs.

Methods

This review was administrated with literature from the PubMed database. Manuscripts were searched using the following keywords: "neoadjuvant" or "preoperative", "breast cancer" or "breast neoplasm", "HER2+" or "HER2-positive", titles and abstracts were screened and evaluated independently by two authors. Information relating to the efficacy and safety profile of NAT for patients with HER2+ BCs were included and analyzed qualitatively. Only English-language articles were included.

Key Content and Findings

This review discusses the neoadjuvant situation for the surgical management of HER2-positive BCs around the world. In this paper, we describe the efficacy assessment of NAT, analyze clinical effect and toxicity of chemotherapy, and targeted therapy, including monoclonal antibody, tyrosine kinase inhibitors (TKIs) and antibody-drug conjugates (ADCs), and other neoadjuvant treatments in HER2+ BC. The data shows while overall survival is the standard endpoint for efficacy, pathological complete response have been implemented more and more frequently in clinical trials for its convenience. Dual-targeted therapy plus chemotherapy exhibited favorable efficacy in most cases, meanwhile other treatment strategies such as combinations without chemotherapy or including CDK4/6 agents may be applicable in specific situation.

Conclusions

As an important part of BC treatment, NAT is lingering in the stage of continuous development, especially for patients with HER2-positive BC. The challenges we are facing today in this field are dose de-escalation without reducing efficacy and choose suitable combination of agents in clinical practice. Moreover, new biomarkers are warrant for individualize treatment.

Neoadjuvant Trastuzumab and Pyrotinib for Locally Advanced HER2-Positive Breast Cancer (NeoATP): Primary Analysis of a Phase II Study

PURPOSE

Despite accumulating evidence on dual blockade of human epidermal growth factor receptor 2 (HER2) for locally advanced HER2-positive breast cancer, no robust evidence supports the addition of pyrotinib to trastuzumab in the neoadjuvant setting. The NeoATP trial aimed to evaluate the efficacy and safety of pyrotinib with neoadjuvant trastuzumab and chemotherapy.

METHODS

The phase II NeoATP trial included female patients with histologically confirmed stage IIA-IIIC and HER2-positive primary invasive breast cancer. Eligible patients received pyrotinib and trastuzumab with weekly paclitaxel-cisplatin neoadjuvant chemotherapy for four cycles. The primary endpoint was pathological complete response (pCR; ypT0 ypN0) rate. Key secondary endpoints included locoregional pCR (ypT0/is ypN0) rate, biomarker analysis and safety.

RESULTS

Among 53 enrolled patients (median age, 47 years; 73.58% stage III), 52 completed the study treatment and surgery. Overall, 37 patients (69.81%) achieved pCR. For women with hormone receptor negative and positive tumors, the pCR rates were 85.71% and 59.38% (P = 0.041), while the corresponding rates were 69.23% and 70.00% respectively for those with and without PIK3CA mutation (P = 0.958). The most frequently reported grade 3 to 4 adverse events were diarrhea (45.28%), leukopenia (39.62%) and neutropenia (32.08%). No deaths occurred, and no left ventricular ejection fraction <50% or >10 points drop from baseline to before surgery was reported.

CONCLUSIONS

The addition of pyrotinib to trastuzumab plus chemotherapy is an efficacious and safe regimen for patients with HER2-positive locally advanced breast cancer in the neoadjuvant setting. The randomized controlled clinical trial is warranted to validate our results.

Pyrotinib-Containing Neoadjuvant Therapy in Patients With HER2-Positive Breast Cancer: A Multicenter Retrospective Analysis

Background

Pyrotinib, a small-molecule tyrosine kinase inhibitor, has been investigated as a component of neoadjuvant therapy in phase 2 trials of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This study aimed to evaluate the effectiveness and safety of pyrotinib-containing neoadjuvant therapy for patients with HER2-positive early or locally advanced breast cancer in the real-world setting.

Methods

Data of 97 patients with HER2-positive breast cancer from 21 centers across China treated with pyrotinib-containing neoadjuvant therapy were reviewed. Neoadjuvant therapy consisted of taxane/carboplatin/trastuzumab plus pyrotinib (TCbH+Py, 30 [30.9%]), anthracycline/cyclophosphamide followed by taxane/trastuzumab plus pyrotinib (AC-TH+Py) or taxane followed by anthracycline/cyclophosphamide/trastuzumab plus pyrotinib (T-ACH+Py, 29 [29.9%]), taxane/trastuzumab plus pyrotinib (TH+Py, 23 [23.7%]), and other pyrotinib-containing neoadjuvant treatment (15 [15.5%]). The primary outcome was breast pathological complete response (bpCR, ypT0/is) rate. Secondary outcomes included total pathological complete response (tpCR, ypT0/is ypN0) rate, objective response rate (ORR), and the incidence of preoperative adverse events.

Results

The ORR of pyrotinib-containing neoadjuvant therapy was 87.6% (85/97). The bpCR and tpCR rates were 54.6% (95% confidence interval [CI], 44.2%-64.7%) and 48.5% [95% CI, 38.2%-58.8%], respectively. The most common grade 3 or 4 treatment-related adverse events included diarrhea (15 [15.5%]), decreased hemoglobin (nine [9.3%]), and decreased neutrophil count (eight [8.2%]). No treatment-related deaths occurred.

Conclusion

Pyrotinib-containing neoadjuvant therapy for patients with HER2-positive early or locally advanced breast cancer shows favorable effectiveness with manageable toxicity in the real-world setting. Trastuzumab plus pyrotinib may be a novel option of dual HER2-targeted blockade.

Rationale and design of a phase II trial of pyrotinib in combination with nab-paclitaxel as adjuvant therapy for N0/N1mi, HER2 + early breast cancer (PHAEDRA)

Background

The de-escalation treatment in patients with low-risk HER2-positive early breast cancer (eBC) is an attractive strategy to avoid unnecessary treatment and improve the quality of life of patients. Pyrotinib, a novel irreversible pan-HER2 tyrosine kinase inhibitor (TKI), has shown efficacy in patients with advanced HER2-positive breast cancer. Meanwhile, nanoparticle albumin-bound (nab)-paclitaxel reveals survival benefit over solvent-based paclitaxel and eliminates the toxicities associated with the solvent. However, the efficacy and safety of pyrotinib in combination with nab-paclitaxel as adjuvant therapy for low-risk HER2 + eBC patients have not been evaluated.

Methods

This is a multicenter, open-label, single-arm phase II study. A sample size of 261 patients with tumor ≤ 3 cm, lymph node-negative (N0) or micrometastatic (N1mi), HER2 + breast cancer will be recruited. Eligible patients will receive nab-paclitaxel 260 mg/m² once every 3 weeks for 12 weeks and pyrotinib 400 mg once daily for one year. The primary endpoint is invasive disease-free survival. A sub-study will be conducted to investigate different prophylactic strategies for diarrhea, which is the most common adverse event of pan-HER TKIs. One hundred and twenty patients from the main study will be randomly (1:1) allocated to receive loperamide either during the first cycle (4 mg tid on days 1–7, then 4 mg bid on days 8–21) or the first 2 cycles (4 mg tid on days 1–7, then 4 mg bid on days 8–42). The primary endpoint of the sub-study is the incidence of grade ≥ 3 diarrhea.

Discussion

This is the first prospective study of pyrotinib in combination with nab-paclitaxel as adjuvant therapy for patients with low-risk HER2-positive eBC. It would probably provide robust evidence for de-escalating strategy of HER2-positive eBC and appropriate management for pyrotinib-related diarrhea.

Trial registration

ClinicalTrials.gov Identifier: NCT04659499. Registered on December 9, 2020.

Neoadjuvant pyrotinib plus trastuzumab and nab-paclitaxel for HER2-positive early or locally advanced breast cancer: an exploratory phase II trial

BACKGROUND

The anti-tumor activity and acceptable tolerability of pyrotinib plus chemotherapy have been demonstrated in phase III trials in human epidermal growth factor receptor 2-positive metastatic breast cancer (BC). In this study, we assessed the efficacy and safety of neoadjuvant pyrotinib plus trastuzumab and albumin-bound paclitaxel in women with human epidermal growth factor receptor 2-positive early or locally advanced BC.

METHODS

In this single-arm exploratory phase II trial, patients with untreated human epidermal growth factor receptor 2-positive BC (stage IIA-IIIC) received pyrotinib 400 mg once daily, trastuzumab 4 mg/kg loading dose, followed by 2 mg/kg once a week, and albumin-bound paclitaxel 125 mg/m2 once a week for four 21-day cycles before surgery. The primary endpoint of the study was total pathological complete response (pCR) rate, defined as no microscopic invasive tumor remnants in the breast and axillary lymph nodes. The secondary endpoints were investigator-assessed objective response rate (ORR) and adverse event profiles.

RESULTS

Between May 17, 2019 and November 26, 2019, a total of 21 patients were enrolled. The total pCR rate was 57.1% (12/21), whereas 23.8% (5/21) and 19.0% (4/21) of patients had minimal and moderate residual disease (RD), respectively. The ORR reached 100% (21/21) at the end of the neoadjuvant therapy. Grade ≥3 treatment-related adverse events were observed in 42.9% (9/21) of patients, including decreased neutrophil count [7 (33.3%)], diarrhoea [6 (28.6%)], decreased white blood cell count [5 (23.8%)], and vomiting [2 (9.5%)]. Adverse event-related dose reduction and interruption of pyrotinib occurred in 6 (28.6%) and 11 (52.4%) patients, respectively.

CONCLUSIONS

In women with human epidermal growth factor receptor 2-positive early or locally advanced BC, neoadjuvant pyrotinib plus trastuzumab and albumin-bound paclitaxel effectively promoted total pCR rate with an acceptable safety profile (ClinicalTrials.gov, NCT04152057).

Clinical observation of neoadjuvant chemotherapy with pyrotinib plus trastuzumab in HER2-positive breast cancer: a cohort study

BACKGROUND

Pyrotinib is a new small-molecule tyrosine kinase inhibitor (TKI). However, the efficacy of pyrotinib in neoadjuvant therapy for HER2-positive breast cancer is unknown. This paper is a population-based cohort study, and the purpose is to evaluate the efficacy and safety of pyrotinib plus trastuzumab in a neoadjuvant setting for HER2-positive early or locally advanced breast cancers, and to compare it with that of pertuzumab plus trastuzumab.

METHODS

This cohort study included 166 patients with HER2-positive breast cancer who received neoadjuvant therapy and underwent surgery. Case groups: Group I: 63 patients received pyrotinib + trastuzumab; Group II: 50 patients received pertuzumab + trastuzumab. The control group consisted of 53 patients treated with trastuzumab alone in combination with neoadjuvant chemotherapy. Univariate logistic regression analysis was applied. Enumeration data were processed by Fisher's exact test.

RESULTS

The total pathological complete response (tpCR) rate of Group I was 63.49% (40/63); the breast pathological complete response (bpCR) rate was 76.19% (48/63); and the objective response rate (ORR) was 100% (63/63). Compared with the tpCR rate of 54.00% (27/50), bpCR rate of 58.00% (29/50), and ORR 100% (50/50) of Group II, there was no statistical difference. Regarding adverse events (AEs), diarrhea (n=56, 88.89%) was the most frequent in the group I, including 7 participants who developed grade 3 diarrhea (11.11%), followed by leukopenia (n=48, 76.19%). In the meantime, there was only 1 patient experienced grade IV thrombocytopenia. Hormone receptor (HR)-negative patients were more likely to reach tpCR as compared to HR-positive patients (61.54% vs. 37.50%, P=0.002, 95% CI: 1.423 to 4.997), and the tpCR rate of tumor, node, metastasis (TNM) stage III 37.04% (20/54) was significantly lower than that of stage II 54.46% (61/112), which was statistically significant (P=0.048, 95% CI: 1.064 to 4.041). No recurrence or metastasis was found during short-term follow-up.

CONCLUSIONS

Pyrotinib plus trastuzumab combined with neoadjuvant chemotherapy showed good short-term efficacy in HER2-positive breast cancer, and the AEs developed were all manageable. More sample data is required to further support the comparison with pertuzumab plus trastuzumab.

Neoadjuvant pyrotinib plus nab-paclitaxel, doxorubicin, and cyclophosphamide for HER2-positive locally advanced breast cancer: a retrospective case-series study

BACKGROUND

The anti-tumor activity of pyrotinib has been confirmed in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. This study investigated the effect of pyrotinib plus nab-paclitaxel, doxorubicin, and cyclophosphamide as neoadjuvant therapy in patients with HER2-positive locally advanced breast cancer.

METHODS

In this single-center retrospective study, female patients with HER2-positive locally advanced breast cancer received pyrotinib 320 mg orally once a day and the TAC regimen (nab-paclitaxel 260 mg/m2, liposomal doxorubicin 20 mg/m2, and cyclophosphamide 600 mg/m2) on day 1 of each 21-day cycle. Surgery was performed after 4-6 cycles of neoadjuvant therapy. The outcomes included total pathological complete response (tpCR, ypT0/Tis ypN0) rate, objective response rate (ORR) after neoadjuvant therapy, progression-free survival, overall survival, and the incidence of adverse events (AEs).

RESULTS

Between March 2019 and January 2020, a total of 22 patients were included. The median age was 48 years (range, 32-60). The ORR was 100% after the completion of neoadjuvant therapy. Ten (45.5%) patients achieved tpCR, including four of ten (40.0%) patients with positive hormone receptor, and six of 12 (50.0%) patients with negative hormone receptor. As at December 2020, no disease recurrence, progression, or death occurred. All patients suffered AEs after neoadjuvant therapy, most of which were grade 1-2. Grade ≥3 AEs included diarrhea [4 (18.2%)], rash [2 (9.1%)], and hand-foot syndrome [1 (4.5%)].

CONCLUSIONS

Neoadjuvant pyrotinib combined with the TAC regimen showed promising clinical benefit in patients with HER2-positive locally advanced breast cancer, with an acceptable safety profile.

The Efficacy of Pyrotinib as a Third- or Higher-Line Treatment in HER2-Positive Metastatic Breast Cancer Patients Exposed to Lapatinib Compared to Lapatinib-Naive Patients: A Real-World Study

Background: Pyrotinib is a novel irreversible pan-ErbB receptor tyrosine kinase inhibitor. Evidence of the efficacy of pyrotinib-based treatments for HER2-positive metastatic breast cancer (MBC) in patients exposed to lapatinib is limited.

Methods: Ninety-four patients who received pyrotinib as a third- or higher-line treatment for HER2-positive MBC were included in this retrospective study. The primary and secondary endpoints were overall survival (OS) and progression‐free survival (PFS). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were implemented to balance important patient characteristics between groups.

Results: Thirty (31.9%) patients were pretreated with lapatinib and subsequently received pyrotinib as an anti-HER2 treatment, and 64 (68.1%) patients did not receive this treatment. The OS and PFS indicated a beneficial trend in lapatinib-naive group compared to lapatinib-treated group in either the original cohort (PFS: 9.02 vs 6.36 months, p = 0.05; OS: 20.73 vs 14.35 months, p = 0.08) or the PSM (PFS: 9.02 vs 6.08 months, p = 0.07; OS: 19.07 vs 18.00 months, p = 0.61) or IPTW (PFS: 9.90 vs 6.17 months, p = 0.05; OS: 19.53 vs 15.10 months, p = 0.08) cohorts. Subgroup analyses demonstrated lapatinib treatment-related differences in PFS in the premenopausal subgroup and the no prior trastuzumab treatment subgroup, but no significant differences were observed in OS.

Conclusion: Pyrotinib-based therapy demonstrated promising effects in HER2-positive MBC patients in a real-world study, especially in lapatinib-naive patients, and also some activity in lapatinib-treated patients.