Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): survival outcomes of a randomised, open-label, multicentre, phase 3 trial and their association with pathological complete response

Combined Estrogen Receptor and Progesterone Receptor Level Can Predict Survival Outcome in Human Epidermal Growth Factor Receptor 2-positive Early Breast Cancer

BACKGROUND

In human epidermal growth factor receptor 2 (HER2)-positive breast cancer, emerging evidence imply that clinical behaviors differ according to hormone receptor (HR) status. However, there is no conclusion about the relevance between estrogen receptor (ER) or progesterone receptor (PR) expression and clinical outcome of HER2+ breast cancer. Our study aimed to determine the influence of different ER/PR levels on survival outcome of HER2+ early breast cancer.

PATIENTS AND METHODS

Nine hundred and nineteen early HER2+ breast cancer patients treated between 2009 and 2016 were retrospectively reviewed and HR+/HER2+ patients were further divided based on ER level (Low/L: 1%-9%; Median/M: 10%-79%; High/H: 80%-100%) and PR level (Low/L: 0%-19%; High/H: 20%-100%) according to restricted cubic spline (RCS) smoothing curve. Disease-free survival (DFS) and overall survival (OS) were estimated by Kaplan-Meier method and log rank test.

RESULTS

Four hundred and forty two HR+/HER2+ and 477 HR-/HER2+ breast cancer patients were included in our study and 73.2% received target therapy (HR+ 69.7%, HR- 76.5%). While HR+/HER2+ breast cancer showed better survival than HR-/HER2+ subtype in 5-year disease free survival (DFS, 93.0% vs. 86.8%, P < .001), no significant difference was observed between DFS in ER+/PR+ and ER+/PR- subgroup (94.4% vs. 90.4%, P = .22). However, a potential correlation was found between ER/PR levels and DFS in HR+/HER2+ (P = .074) tumors. In HR+/HER2+ breast cancer, all subgroups showed DFS improvement trend versus M-ER/L-PR. In all HER2+ patients, hazard ratio of H-ER/H-PR compared with HR- subtype was 0.10 (95%CI 0.01-0.74, P = .024) in all patients and 0.14 (95%CI, 0.02-1.02, P = .053) in patients receiving anti-HER2 therapy.

CONCLUSION

ER/PR expression may become a predictor of survival benefit in HER2+ early breast cancer and a higher ER/PR level might be associated with better DFS.

Locally Advanced Breast Cancer: Treatment Patterns and Predictors of Survival in a Saudi Tertiary Center

Background  Breast cancer (BC) is the most common cancer in the Kingdom of Saudi Arabia (KSA) and the second leading cause of cancer-related mortality. About 40% of BC in KSA is locally advanced BC (LABC), which has been associated with poorer survival compared with early diagnosed BC. Objective To review the presentation and outcomes of LABC, including the characteristics of the disease, different treatment modalities, overall survival (OS), disease-free survival (DFS), and local recurrence in relation to different radiotherapy (RT) techniques. Methods  We retrospectively reviewed the medical records of 153 female patients with pathologically proven LABC diagnosed at King Abdulaziz University Hospital, Jeddah, KSA, between 2009 and 2017. We obtained data on patient demographics, stage of cancer at diagnosis, tumor characteristics (subtype and receptor status), type of surgery, systemic treatments received (hormonal, targeted therapy, and chemotherapy), RT variables, and recurrence and death dates. Data were analyzed to assess OS and DFS by using Kaplan-Meier analyses and the log-rank test. Univariate and multivariate Cox proportional hazard regression analyses were used to explore and identify factors associated with survival. Results  The median survival time in the study population was 9.16 years. Older age (65+ years) was associated with worse OS and DFS than was younger age (<65 years) (hazard ratio (HR) 3.20, 95% CI 1.48-6.90, P = 0.003 and HR 2.21, 95% CI 1.12-4.36, P = 0.022, respectively). Regarding the type of surgery, having a mastectomy was associated with worse OS and DFS than was having a lumpectomy (HR 2.44, 95% CI 0.97-6.12, P = 0.05 and HR 2.41, 95% CI 1.13-5.14, P = 0.023, respectively). Positive estrogen and progesterone receptor status was associated with better OS and DFS than was a negative estrogen or progesterone receptor status (HR 0.13, 95% CI 0.05-0.30, P < 0.001 and HR 0.21, 95% CI 0.11-0.41, P < 0.001, respectively). Patients who received RT had a lower risk of recurrence than did those who did not receive RT (P = 0.011). Moreover, three-dimensional conformal RT was associated with lower local recurrence than intensity-modulated RT or volumetric-modulated arc therapy (P = 0.003). Conclusion  Multiple factors can affect the OS and DFS in LABC. Younger patients, having hormone-positive disease, and undergoing lumpectomy were associated with better outcomes. Adjuvant RT may improve local control and the use of three-dimensional conformal RT was superior for local control. Prospective studies with larger sample sizes are needed to further highlight these findings and to assess the role of chemotherapy and targeted therapy in patients with LABC.

Independent Validation of the PAM50-Based Chemo-Endocrine Score (CES) in Hormone Receptor-Positive HER2-Positive Breast Cancer Treated with Neoadjuvant Anti-HER2-Based Therapy

PURPOSE

We do not yet have validated biomarkers to predict response and outcome within hormone receptor-positive/HER2-positive (HR+/HER2+) breast cancer. The PAM50-based chemo-endocrine score (CES) predicts chemo-endocrine sensitivity in hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer. Here, we evaluate the relationship of CES with response and survival in HR+/HER2+ breast cancer.

EXPERIMENTAL DESIGN

Intrinsic subtype and clinicopathologic data were obtained from seven studies in which patients were treated with HER2-targeted therapy either with endocrine therapy (ET) or with chemotherapy (CTX). CES was evaluated as a continuous variable and categorically from low to high scores [CES-C (chemo-sensitive), CES-U (uncertain), and CES-E (endocrine-sensitive)]. We first analyzed each dataset individually, and then all combined. Multivariable analyses were used to test CES association with pathologic complete response (pCR) and disease-free survival (DFS).

RESULTS

A total of 457 patients were included (112 with ET and 345 with CTX). In the combined cohort, CES-C, CES-U, and CES-E were identified in 60%, 23%, and 17% of the patients, respectively. High CES (i.e., CES-E) was associated with a lower probability of achieving pCR independently of clinical characteristics, therapy, intrinsic subtype, and study (adjusted OR = 0.42; P = 0.016). A total of 295 patients were analyzed for DFS with a median follow-up of 66 months. High CES was also associated with better DFS (adjusted HR, 0.174; P = 0.003) independently of pCR, clinical characteristics and intrinsic subtype. In patients with residual disease, the adjusted DFS HR of CES was 0.160 (P = 0.012).

CONCLUSIONS

In HER2+/HR+ breast cancer, CES is useful for predicting chemo-endocrine sensitivity and provides additional prognostication beyond intrinsic subtype and clinicopathologic characteristics.

An Evaluation of Clinicopathological Correlation and Outcome of Human Epidermal Growth Factor Receptor 2 Subgroups Reclassified According to the Latest ASCO/CAP Guideline

BACKGROUND

The latest American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline has updated the interpretation of uncommon human epidermal growth factor receptor 2 (HER2) in situ hybridization (ISH) patterns (groups 2-4) with concomitant HER2 immunohistochemistry, leading to changes in the diagnosis of these subgroups. We sought to assess the clinicopathological features and outcomes in these subgroups in detail with our local cohort.

PATIENTS AND METHODS

Clinicopathologic features of groups 2 to 4 were compared to the typical amplified group (group 1: HER2/CEP17 ≥ 2, HER2 ≥ 4) and non-amplified group (group 5: HER2/CEP17 < 2, HER2 < 4).

RESULTS

Group 2 (HER2/CEP17 ≥ 2, HER2 < 4) cases showed lower Ki67 expression and grade (P ≤ .002) than group 1 but no differences compared with group 5. Group 4 (HER2/CEP17 < 2, HER2 = 4-6) cases were associated with less necrosis, more estrogen receptor positivity, lower grade, more nodal metastases, and more special histotypes (P ≤ .037) than group 1, but higher grade and more nodal metastases (P ≤ .021) than group 5. Except for presenting as a larger tumor and of special histotypes, group 3 (HER2/CEP17 < 2, HER2 ≥ 6) cases showed no other significant differences from group 1, but were of higher grade and Ki67 level than groups 2, 4, and 5. Group 4, similar to group 5, showed worse survival than group 1 (disease-free survival: log-rank = 5.547, P = .019; overall survival: log-rank = 4.678, P = .031). The rate of relapse was similar in group 4 with and without anti-HER2 therapy, albeit with limited cases.

CONCLUSION

Our findings indicate more similarities among groups 2, 4, and 5 than between groups 1 and 3, supporting the HER2 categorization in the latest guideline. Additional studies may be warranted to assess the outcomes of these patients with different management approaches.

The role of infiltrating lymphocytes in the neo-adjuvant treatment of women with HER2-positive breast cancer

Background

Pre-treatment tumour-associated lymphocytes (TILs) and stromal lymphocytes (SLs) are independent predictive markers of future pathological complete response (pCR) in HER2-positive breast cancer. Whilst studies have correlated baseline lymphocyte levels with subsequent pCR, few have studied the impact of neoadjuvant therapy on the immune environment.

Methods

We performed TIL analysis and T-cell analysis by IHC on the pretreatment and ‘On-treatment’ samples from patients recruited on the Phase-II TCHL (NCT01485926) clinical trial. Data were analysed using the Wilcoxon signed-rank test and the Spearman rank correlation.

Results

In our sample cohort (n = 66), patients who achieved a pCR at surgery, post-chemotherapy, had significantly higher counts of TILs (p = 0.05) but not SLs (p = 0.08) in their pre-treatment tumour samples. Patients who achieved a subsequent pCR after completing neo-adjuvant chemotherapy had significantly higher SLs (p = 9.09 × 10^–3) but not TILs (p = 0.1) in their ‘On-treatment’ tumour biopsies. In a small cohort of samples (n = 16), infiltrating lymphocyte counts increased after 1 cycle of neo-adjuvant chemotherapy only in those tumours of patients who did not achieve a subsequent pCR. Finally, reduced CD3 + (p = 0.04, rho = 0.60) and CD4 + (p = 0.01, rho = 0.72) T-cell counts in 'On-treatment' biopsies were associated with decreased residual tumour content post-1 cycle of treatment; the latter being significantly associated with increased likelihood of subsequent pCR (p < 0.01).

Conclusions

The immune system may be ‘primed’ prior to neoadjuvant treatment in those patients who subsequently achieve a pCR. In those patients who achieve a pCR, their immune response may return to baseline after only 1 cycle of treatment. However, in those who did not achieve a pCR, neo-adjuvant treatment may stimulate lymphocyte influx into the tumour.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06244-1.

TrkA Interacts with and Phosphorylates STAT3 to Enhance Gene Transcription and Promote Breast Cancer Stem Cells in Triple-Negative and HER2-Enriched Breast Cancers

JAK2-STAT3 and TrkA signaling pathways have been separately implicated in aggressive breast cancers; however, whether they are co-activated or undergo functional interaction has not been thoroughly investigated. Herein we report, for the first time that STAT3 and TrkA are significantly co-overexpressed and co-activated in triple-negative breast cancer (TNBC) and HER2-enriched breast cancer, as shown by immunohistochemical staining and data mining. Through immunofluorescence staining-confocal microscopy and immunoprecipitation-Western blotting, we found that TrkA and STAT3 co-localize and physically interact in the cytoplasm, and the interaction is dependent on STAT3-Y705 phosphorylation. TrkA-STAT3 interaction leads to STAT3 phosphorylation at Y705 by TrkA in breast cancer cells and cell-free kinase assays, indicating that STAT3 is a novel substrate of TrkA. β-NGF-mediated TrkA activation induces TrkA-STAT3 interaction, STAT3 nuclear transport and transcriptional activity, and the expression of STAT3 target genes, SOX2 and MYC. The co-activation of both pathways promotes breast cancer stem cells. Finally, we found that TNBC and HER2-enriched breast cancer with JAK2-STAT3 and TrkA co-activation are positively associated with poor overall metastasis-free and organ-specific metastasis-free survival. Collectively, our study uncovered that TrkA is a novel activating kinase of STAT3, and their co-activation enhances gene transcription and promotes breast cancer stem cells in TNBC and HER2-enriched breast cancer.

Neoadjuvant approach as a platform for treatment personalization: focus on HER2-positive and triple-negative breast cancer

The neoadjuvant setting provides unquestionable clinical benefits for high-risk breast cancer (BC) patients, mainly in terms of expansion of locoregional treatment options and prognostic stratification. Additionally, it is also emerging as a strategical tool in the research field. In the present review, by focusing on HER2-positive and triple-negative subtypes, we examined the role of the neoadjuvant setting as a research platform to facilitate and rationalize the placement of escalation strategies, promote the adoption of biomarker-driven approaches for the investigation of de-escalated treatments, and foster the conduction of comprehensive translational analyses, thus ultimately aiming at pursuing treatment personalization. The solid prognostic role of pathologic complete response after neoadjuvant therapy, and its use as a surrogate endpoint to accelerate the drug approval process were discussed. In this context, available data on escalated treatment strategies capable of enhancing pathologic complete response (pCR) rate or improving prognosis of patients with residual disease (RD) after neoadjuvant treatment, were comprehensively reviewed. We also summarized evidence regarding the possibility of obtaining pCR with de-escalated strategies, with particular emphasis on the role of biomarker-driven approaches for patient selection. Pitfalls of the dichotomy of pCR/RD were also deepened, and data on alternative/complementary biomarkers with a possible clinical relevance in this regard were reviewed.

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE

To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options.

RESULTS

A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.

Adjuvant T-DM1 versus trastuzumab in patients with residual invasive disease after neoadjuvant therapy for HER2-positive breast cancer: subgroup analyses from KATHERINE

BACKGROUND

In the KATHERINE study (NCT01772472), patients with residual invasive early breast cancer (EBC) after neoadjuvant chemotherapy (NACT) plus human epidermal growth factor receptor 2 (HER2)-targeted therapy had a 50% reduction in risk of recurrence or death with adjuvant trastuzumab emtansine (T-DM1) versus trastuzumab. Here, we present additional exploratory safety and efficacy analyses.

PATIENTS AND METHODS

KATHERINE enrolled HER2-positive EBC patients with residual invasive disease in the breast/axilla at surgery after NACT containing a taxane (± anthracycline, ± platinum) and trastuzumab (± pertuzumab). Patients were randomized to adjuvant T-DM1 (n = 743) or trastuzumab (n = 743) for 14 cycles. The primary endpoint was invasive disease-free survival (IDFS).

RESULTS

The incidence of peripheral neuropathy (PN) was similar regardless of neoadjuvant taxane type. Irrespective of treatment arm, baseline PN was associated with longer PN duration (median, 105-109 days longer) and lower resolution rate (∼65% versus ∼82%). Prior platinum therapy was associated with more grade 3-4 thrombocytopenia in the T-DM1 arm (13.5% versus 3.8%), but there was no grade ≥3 hemorrhage in these patients. Risk of recurrence or death was decreased with T-DM1 versus trastuzumab in patients who received anthracycline-based NACT [hazard ratio (HR) = 0.51; 95% confidence interval (CI): 0.38-0.67], non-anthracycline-based NACT (HR = 0.43; 95% CI: 0.22-0.82), presented with cT1, cN0 tumors (0 versus 6 IDFS events), or had particularly high-risk tumors (HRs ranged from 0.43 to 0.72). The central nervous system (CNS) was more often the site of first recurrence in the T-DM1 arm (5.9% versus 4.3%), but T-DM1 was not associated with a difference in overall risk of CNS recurrence.

CONCLUSIONS

T-DM1 provides clinical benefit across patient subgroups, including small tumors and particularly high-risk tumors and does not increase the overall risk of CNS recurrence. NACT type had a minimal impact on safety.

Trastuzumab emtansine (T-DM1) versus trastuzumab in Chinese patients with residual invasive disease after neoadjuvant chemotherapy and HER2-targeted therapy for HER2-positive breast cancer in the phase 3 KATHERINE study

PURPOSE

In the KATHERINE study (NCT01772472), patients with HER2-positive early breast cancer (EBC) and residual invasive disease after neoadjuvant chemotherapy plus HER2-targeted therapy who were treated with adjuvant trastuzumab emtansine (T-DM1) had a 50% reduction in the risk of an invasive disease-free survival (IDFS) event compared to patients treated with adjuvant trastuzumab. In metastatic disease, T-DM1 has resulted in higher rates of thrombocytopenia in Asian versus non-Asian patients. Here, we report safety and efficacy in Chinese patients from KATHERINE.

METHODS

Patients with HER2-positive EBC and residual invasive disease after taxane- and trastuzumab-containing neoadjuvant chemotherapy followed by surgery were randomized 1:1 to 14 cycles of adjuvant T-DM1 or trastuzumab. The primary endpoint was time to an IDFS event.

RESULTS

Among Chinese patients (T-DM1 n = 51, trastuzumab n = 50), T-DM1 treatment resulted in a 43% reduction in risk of an IDFS event compared to trastuzumab (HR = 0.57; 95% CI 0.25-1.31), with similar results for secondary endpoints. As in the global population, Chinese patients receiving T-DM1 versus trastuzumab had more grade ≥ 3 adverse events (AEs; 39.2% versus 4.1%) and AEs leading to treatment discontinuation (27.5% versus 0%). The most common grade ≥ 3 AE with T-DM1 was thrombocytopenia (21.6%), a frequency higher than the frequency in the global population (5.7%). Grade ≥ 3 hemorrhage was reported in 1 patient (T-DM1 arm).

CONCLUSIONS

In the KATHERINE study, T-DM1 demonstrated increased efficacy compared to trastuzumab in Chinese patients. Consistent with previous data in Asian patients, T-DM1 was associated with more grade ≥ 3 AEs, and AEs leading to discontinuation, which was driven by an increase in thrombocytopenia.

Efficacy and safety of neoadjuvant therapy for HER2-positive early breast cancer: a network meta-analysis

Aims:

Currently, there are many approaches available for neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2)-positive breast cancer that improve therapeutic efficacy but are also controversial. We conducted a two-step Bayesian network meta-analysis (NMA) to compare odds ratios (ORs) for pathologic complete response (PCR) and safety endpoints.

Methods:

The Cochrane Central Register of Controlled Trials, PubMed, Embase, and online abstracts from the American Society of Clinical Oncology and San Antonio Breast Cancer Symposium were searched comprehensively and systematically. Phase II/III randomised clinical trials for targeted therapy in at least one arm were included.

Results:

A total of 9779 published manuscripts were identified, and 36 studies including 10,379 patients were finally included in our analysis. The NMA of PCR showed that dual-target therapy is better than single-target therapy and combination chemotherapy is better than monochemotherapy. However, anthracycline did not bring extra benefits, whether combined with dual-target therapy or single-target therapy. On the other hand, the addition of endocrine therapy in the HER2-positive, hormone receptor (HR)-positive subgroup might have additional beneficial effects but without significant statistical difference. By performing a conjoint analysis of the PCR rate and safety endpoints, we found that ‘trastuzumab plus pertuzumab’ and ‘T-DM1 containing regimens’ were well balanced in terms of efficacy and toxicity in all target regimens.

Conclusion:

In summary, trastuzumab plus pertuzumab-based dual-target therapy with combination chemotherapy regimens showed the highest efficacy of all optional regimens. They also achieved the best balance between efficacy and toxicity. As our study showed that anthracycline could be replaced by carboplatin, we strongly recommended TCbHP as the preferred choice for neoadjuvant treatment of HER2-positive breast cancer. We also look forward to the potential value of T-DM1 in improving outcomes, which needs further study in future trials.

Optimum adjuvant trastuzumab duration for human epidermal growth factor receptor-2 positive breast cancer: a network meta-analysis of randomized trials

BACKGROUND

Adjuvant trastuzumab treatment for 12 months is the standard-of-care for early HER2-positive breast cancer; however, the optimal duration is unclear. We performed a network meta-analysis (NMA) to determine the optimal treatment duration.

METHODS

We identified 16 randomized controlled trials involving 29,837 patients that assessed trastuzumab treatment in HER2-positive early breast cancer. Our NMA compared six trastuzumab durations: observation, T-9 weeks, T-12 weeks, T-6 months, T-12 months, and T-24 months. We assessed overall survival (OS), disease-free survival (DFS), acceptability, and cardiotoxicities and grade 3-4 nonhematologic toxicities, and ranked the durations in terms of efficacy and safety by surface under the cumulative ranking (SUCRA).

RESULTS

Pairwise meta-analysis showed that while T-6 months was associated with a significant reduction in DFS compared to T-12 months. In our NMA, increasing or decreasing durations showed a significant benefit in DFS compared to observation; however, decreasing durations was not associated with a significant reduction in DFS compared with T-12 months, regardless of the lymph node and hormone receptor statuses. SUCRA ordered the optimum durations of trastuzumab treatment based on PFS as T-12 months (95.6%), T-24 months (69.6%), T-6 months (53.2%), T-9 weeks (41.2%), T-12 weeks (34.3%) and observation (6.1%).

CONCLUSIONS

Escalating trastuzumab treatment beyond T-12 months confers no additional survival benefit but increased risk of cardiotoxicities. Furthermore, de-escalating treatment confers no improvement on OS compared to T-12 months. These data suggest that T-12 months is the most appropriate treatment schedule for HER2-positive early breast cancer.

Spatial proteomic characterization of HER2-positive breast tumors through neoadjuvant therapy predicts response

The addition of HER2-targeted agents to neoadjuvant chemotherapy has dramatically improved pathological complete response (pCR) rates in early-stage, HER2-positive breast cancer. Nonetheless, up to 50% of patients have residual disease after treatment, while others are likely overtreated. Here, we performed multiplex spatial proteomic characterization of 122 samples from 57 HER2-positive breast tumors from the neoadjuvant TRIO-US B07 clinical trial sampled pre-treatment, after 14-21 d of HER2-targeted therapy and at surgery. We demonstrated that proteomic changes after a single cycle of HER2-targeted therapy aids the identification of tumors that ultimately undergo pCR, outperforming pre-treatment measures or transcriptomic changes. We further developed and validated a classifier that robustly predicted pCR using a single marker, CD45, measured on treatment, and showed that CD45-positive cell counts measured via conventional immunohistochemistry perform comparably. These results demonstrate robust biomarkers that can be used to enable the stratification of sensitive tumors early during neoadjuvant HER2-targeted therapy, with implications for tailoring subsequent therapy.

Dual HER2 blockade with lapatinib and trastuzumab in combination with chemotherapy in metastatic gastroesophageal adenocarcinoma

The development of resistance to trastuzumab in HER2-positive gastroesophageal cancer remains a problem. The use of dual HER2 blockade to overcome this is a therapeutic strategy that should be researched more extensively.

Prognostic factors of ado-trastuzumab emtansine treatment in patients with metastatic HER-2 positive breast cancer

BACKGROUND

Ado-trastuzumab emtansine is an antibody-drug conjugate that combines the cytotoxic activity of emtansine with human epidermal growth factor receptor 2-targeted antitumor features of trastuzumab.

OBJECTIVE

We conducted a study of metastatic breast cancer patients treated with trastuzumab emtansine. By evaluating progression-free survival, overall survival, and response rates, we aimed to find prognostic factors of trastuzumab emtansine treatment.

METHODS

Our study is a single-center, retrospective, observational study. We have clinical data from 78 patients treated with trastuzumab emtansine for metastatic breast cancer, from May 2016 through May 2019, at Kartal Dr Lutfi Kirdar Education and Research Hospital, Medical Oncology Department. Our objective is to assess the survival and response rates in trastuzumab emtansine-treated individuals and the factors associated with survival. The factors we analyzed were cancer antigen 15-3 sensitivity, Eastern Cooperative Oncology Group-Performance Status, presence or absence of visceral metastases, presence or absence of cranial metastases, and treatment-associated thrombocytopenia.

RESULTS

Among 78 patients, median progression-free survival was 7.8 months, and overall survival was 21.1 months. Twenty of the patients had an objective tumor response. The results showed that trastuzumab emtansine was tolerable with a manageable safety profile and consistent with the results of the previous literature. Mostly seen adverse events were anemia, thrombocytopenia, fatigue, and increased levels of alkaline phosphatase. Patients with Eastern Cooperative Oncology Group-Performance Status = 2 had worse progression-free survival and overall survival compared to ones with Eastern Cooperative Oncology Group-Performance Status < 2; progression-free survival and overall survival are worse in cancer antigen 15-3-sensitive breast cancer patients. According to our findings, treatment-associated thrombocytopenia was a significant prognostic factor for survival. Patients with thrombocytopenia had 12 months progression-free survival, whereas patients without thrombocytopenia had only 4.1 months progression-free survival. In like manner, overall survival was much better in the thrombocytopenia-experienced patients as 29.5 versus 11.8 months.

CONCLUSIONS

Trastuzumab emtansine prolongs progression-free survival and overall survival with a manageable safety profile. Thrombocytopenia, Eastern Cooperative Oncology Group-Performance Status, and cancer antigen 15-3 are correlated with progression-free survival and/or overall survival.

Concurrent Radiation and Modern Systemic Therapies for Breast Cancer: An Ever-Expanding Frontier

Radiotherapy is a critical tool for reducing locoregional recurrence, extending survival, and palliating symptoms in patients with breast cancer. With an ever-expanding armamentarium of systemic agents available, and an increasing trend toward the use of hypofractionated radiation regimens, it can be difficult to determine the safety of concurrent therapy. In particular, new targeted agents in both the adjuvant and metastatic setting have limited prospective or long-term data demonstrating safety when delivered concurrently with radiotherapy. Other systemic agents, including chemotherapy and endocrine therapy, are also important components of the overall treatment strategy for localized and metastatic breast cancer, and are often delivered concurrently with radiation in certain clinical scenarios. This review explores the safety, efficacy, and pitfalls of delivering radiation in conjunction with systemic therapies for breast cancer.

Tumor Cellularity and Infiltrating Lymphocytes (CelTIL) as a Survival Surrogate in HER2-Positive Breast Cancer

In early-stage HER2-positive breast cancer, biomarkers that guide de-escalation and/or escalation of systemic therapy are needed. CelTIL score is a novel, combined biomarker based on stromal tumor-infiltrating lymphocytes and tumor cellularity and determined in tumor biopsies at week 2 of anti-HER2 therapy only. We evaluated the prognostic value of CelTIL in 196 patients with early-stage HER2-positive disease treated with standard trastuzumab-based chemotherapy in the NeoALTTO phase III trial. Using a pre-specified CelTIL cutoff, a better 5-year event-free survival and overall survival was observed between CelTIL-high and CelTIL-low score with a 76.4% (95% confidence interval [CI] = 68.0%-85.0%) versus 59.7% (95% CI = 50.0%-72.0%) (hazard ratio = 0.40; 95% CI = 0.17 to 0.94), and 86.4% (95% CI = 80.0%-94.0%) vs 73.5% (95% CI = 64.0%-84.0%) (hazard ratio = 0.43; 95% CI = 0.20 to 0.92), respectively. Statistical significance was maintained after adjusting for baseline TILs, hormone receptor status, pre-treatment tumor size and nodal status, type of surgery, treatment arm, and pathological complete response. Further studies to support CelTIL as an early read-out biomarker to help de-escalate/escalate systemic therapy in HER2-positive breast cancer seem warranted.

Updated results from the international phase III ALTTO trial (BIG 2-06/Alliance N063D)

AIM

To present the pre-specified analyses of >5-years follow-up of the Phase III ALTTO trial.

PATIENTS AND METHODS

8381 patients with stage I-III HER2 positive breast cancer randomised to chemotherapy plus 1-year of trastuzumab (T), oral lapatinib (L; no longer evaluated), trastuzumab followed by lapatinib (T→L), and lapatinib + trastuzumab (L+T). The primary endpoint was disease-free survival (DFS). A secondary analysis examined DFS treatment effects by hormone receptor status, nodal status and chemotherapy timing; time to recurrence; overall survival (OS) and safety (overall and cardiac).

RESULTS

At a median follow-up of 6.9 years, 705 DFS events for L+T versus T were observed. Hazard Ratio (HR) for DFS was 0.86 (95% CI, 0.74-1.00) for L+T versus T and 0.93 (95% CI, 0.81-1.08) for T→L versus T. The 6-year DFS were 85%, 84%, and 82% for L+T, T→L, and T, respectively. HR for OS was 0.86 (95% CI, 0.70-1.06) for L+T versus T and 0.88 (95% CI, 0.71-1.08) for T→L versus T. The 6-year OS were 93%, 92%, and 91% for L+T, T→L, and T, respectively. Subset analyses showed a numerically better HR for DFS in favour of L+T versus T for the hormone-receptor-negative [HR 0.80 (95% CI, 0.64-1.00; 6-yr DFS% = 84% versus 80%)] and the sequential chemotherapy [HR 0.83 (95% CI, 0.69-1.00; 6-yr DFS% = 83% versus79%)] subgroups.

CONCLUSION

T+L did not significantly improve DFS and OS over T alone, both with chemotherapy, and, therefore, cannot be recommended for adjuvant treatment of early-stage HER2-positive breast cancer.

TRIAL REGISTRATION

clinicaltrials.gov Identifier NCT00490139.

Real-world data of subcutaneous trastuzumab and intravenous pertuzumab as neoadjuvant therapy for localized HER2+ breast cancer in Panama

The aim of this study is to determine the effectiveness of subcutaneous trastuzumab in combination with intravenous pertuzumab and chemotherapy for patients with HER2-overexpressing localized breast cancer treated in our center. Methods: This was a descriptive, retrospective, real-world study. Results: Of 156 patients, pathological complete response (pCR) was achieved in 64.1%. A multivariate analysis showed a relationship with a negative hormone receptor (HR) expression and a HER2 score of 3+ by immunohistochemistry. Relapse-free survival (RFS) was higher in patients with pCR. Conclusion: Neoadjuvant therapy with dual blockade using intravenous pertuzumab and subcutaneous trastuzumab for HER2+ localized breast cancer in routine clinical practice resulted in a 64.1% pCR rate. Additionally, this outcome was related to a negative HR expression and HER2 overexpression, and correlated with higher relapse-free survival.

Clinicopathological Characteristics and Prognosis of Breast Cancer in Young Women - A Single Center Study in a Developing Country

Objective

Breast cancer (BC) in young women tends to be more aggressive. This study highlights the clinicopathological features and outcomes of young breast cancer (YBC) patients in a developing country.

Methods

Consecutive patients aged 35 years or younger with a pathologically confirmed diagnosis of breast cancer treated and followed up at our department were included. Medical records and follow-up databases were reviewed and documented.

Results

The rate of breast conservation and reconstruction surgery is higher in YBC patients. YBC patients are more likely to have tumors over 5cm, high-grade, hormone receptor negative, triple negative and stage III than old patients. There was no statistically significant difference in the pathological type, lymph node metastasis, and HER2 status. The median follow-up time was 96 months. The disease-free survival (DFS) was significantly worse in the YBC group. However, the overall survival (OS) had no difference between the two groups.

Conclusion

YBC patients had more aggressive pathological features, such as hormone receptor negative, triple negative, high-grade and advanced stage, and poorer DFS than the old counterparts.

Survival Advantage With Adjuvant Chemotherapy for Locoregionally Advanced Rectal Cancer: A Veterans Health Administration Analysis

BACKGROUND

Adjuvant chemotherapy (AC) after chemoradiation (CRT) and surgery for locoregionally advanced rectal cancer (LARC) is a standard of care in the United States. This study examined the role, optimal regimen, and duration of AC using data from the largest integrated health system in the United States.

PATIENTS AND METHODS

Using the Veterans Affairs Central Cancer Registry, patients with stage II-III rectal cancer diagnosed in 2001 through 2011 who received neoadjuvant CRT and surgery with or without AC were identified. Kaplan-Meier analysis, log-rank tests, and propensity score (PS) adjustment analysis were used to assess survival.

RESULTS

A total of 866 patients were identified; 417 received AC and 449 did not (observation [OBS] group). Median follow-up was 109 months. Median disease-specific survival (DSS) was not reached. Six-year DSS was 73.7%; 79.5% for the AC group versus 68.0% for the OBS group. PS-matched analysis for DSS favored AC (P=.0002). Median overall survival (OS) was 90.8 months. Six-year OS was 56.7%; 64.3% for AC versus 49.6% for OBS. In PS-matched analysis, median OS was 117.4 months for AC and 74.3 months for OBS (P<.0001). A DSS advantage was seen when comparing ≥4 months with <4 months of AC (P=.023). No difference in DSS or OS was seen with single-agent versus multiagent AC.

CONCLUSIONS

In this population of patients with LARC treated with neoadjuvant CRT and surgery, OS and DSS were improved among those treated with AC versus OBS. DSS benefits were seen with ≥4 months of AC. No additional benefit was observed with multiagent therapy. In the absence of phase III data, these findings support the use of AC for LARC.

A correlation analysis to assess event-free survival as a trial-level surrogate for overall survival in early breast cancer

BACKGROUND

Event-free survival (EFS) has been listed on the FDA Table of Surrogate Endpoints as a surrogate measure that can be considered for accelerated or traditional approval in breast cancer. However, no studies have evaluated the correlation between the treatment effects on EFS and treatment effects on overall survival (OS).

METHODS

We performed a systematic search of the literature until May 2020 according to the PRISMA guideline for all published randomized controlled trials (RCTs) in early breast cancer in the neoadjuvant setting. Data on EFS and OS, including the hazard ratio (HR) and 95% confidence intervals (CI), were extracted from each study and the association between the trial-level EFS HR and the trial-level OS HR was estimated using a linear mixed-effects model on the log scale.

FINDINGS

Of the 7 RCTs (N = 2211) included in the analysis, 5 included patients with HER2 positive tumor type. The estimated linear association between log HR EFS and log HR OS indicated a positive slope ( β  = 0.58 [95% CI: -0.32-1.48]) and the coefficient of determination confirmed a moderate trial-level association between log HRs for OS and EFS (R² 0.76 [95% CI 0.34-1.00], but with wide confidence intervals.

INTERPRETATION

Treatment effects in EFS are moderately correlated with treatment effects in OS in early breast cancer in the neoadjuvant setting, but the association was not significant. Thus, there is currently insufficient evidence to support EFS for use as a surrogate endpoint for traditional approval, although it may be considered for accelerated approval.

FUNDING

Arnold Ventures.

Recent advances in neoadjuvant therapy for breast cancer

Neoadjuvant trials for early breast cancer have accelerated the identification of novel active agents, enabling streamlined conduct of registration trials with fewer subjects. Measurement of neoadjuvant drug effects has also enabled the identification of patients with high risk of distant recurrence and has justified development of additional adjuvant approaches to improve outcomes. Neoadjuvant evaluation of new drugs was significantly improved by the introduction of pathologic complete response (pCR) rate as a quantitative surrogate endpoint for distant disease-free survival (DDFS) and event free survival (EFS). The neoadjuvant phase 2 platform trial I-SPY 2 simultaneously tests multiple drugs across multiple breast cancer subtypes using Bayesian methods of adaptive randomization for assessment of drug efficacy. In addition to the pCR endpoint, the I-SPY 2 trial has demonstrated that the residual cancer burden (RCB) score measures gradations of tumor response that correlate with DDFS and EFS across treatments and subtypes. For HER2-positive and triple-negative breast cancers that have failed to attain pCR with neoadjuvant chemotherapy (NAC), effective modifications of adjuvant treatment have improved outcomes and changed the standard of care for these subtypes. Neoadjuvant therapy is therefore preferred for stage II and III, as well as some stage I, HER2-positive and triple-negative tumors. Neoadjuvant endocrine therapy (NET) strategies have also emerged from innovative trials for stage II and III estrogen receptor (ER)-positive/HER2-negative tumors, as in the ALTERNATE trial. From neoadjuvant trials, opportunities have emerged to de-escalate therapy on the basis of metrics of response to chemotherapy or hormonal therapy. Neoadjuvant therapy for early breast cancer is therefore emerging as a promising approach to accelerate new drug development, optimize treatment strategies, and (where appropriate) de-escalate neoadjuvant therapy.

Early HER2-Positive Breast Cancer: Current Treatment and Novel Approaches

BACKGROUND

Trastuzumab significantly improves outcomes in early HER2-positive breast cancer, irrespectively of any prognostic or predictive factors. Unfortunately, about a quarter of patients receiving neoadjuvant trastuzumab experience disease recurrence, revealing the unquestionable need for further improvement of treatment outcomes.

SUMMARY

Adding HER2 blockade to adjuvant trastuzumab with pertuzumab and neratinib improves invasive disease-free survival (IDFS), particularly for those at highest risk of recurrence. A shift toward a neoadjuvant strategy for patients with a higher risk of recurrence could result in further treatment optimization. For patients without a pathological complete response (pCR) after the neoadjuvant part of the therapy, a switch to adjuvant trastuzumab emtansine significantly improves IDFS and distant recurrence-free survival and shows a trend towards improved overall survival (OS). On the other hand, for low-risk patients, chemotherapy deescalation should be strongly considered with the use of trastuzumab monotherapy as an anti-HER2 backbone.

KEY MESSAGES

Neoadjuvant therapy should be offered for a significant proportion of HER2-positive early breast cancer patients with a higher risk of recurrence. Postneoadjuvant treatment should be tailored according to the initial stage of disease and the response to neoadjuvant treatment.

Circulating tumor DNA-based predictive biomarkers in breast cancer clinical trials: a narrative review

Breast carcinoma is the most frequent and the second leading cause of cancer mortality in women worldwide. Current treatment decisions are based on tumor profiling of the initial tissue biopsy. Cancer though evolves both spatially and temporarily in a significant percentage of patients during treatment. However, sequential biopsies from the primary tumor or its metastatic sites are not either convenient or feasible in the majority of cases. In the era of precision medicine, analysis of circulating blood-based biomarkers in the field of liquid biopsies provides an insight into the dynamic molecular profiling of the primary tumor and its metastases, in a relatively non-invasive way. The latter permits not only patient stratification but also longitudinal evaluation of treatment response, when incorporated into clinical trials. This review summarizes the results from recent and ongoing circulating tumor DNA (ctDNA)-based biomarker-driven clinical trials, with respect to ctDNA analysis' predictive role, both in adjuvant, neo-adjuvant, and metastatic setting. Furthermore, current challenges in ctDNA analysis applications are critically discussed, including pre-analytical and analytical issues, and future perspectives in this field, through the conduct of well-designed, multicenter, randomized, large-scale, biomarker-stratified trials, with robust statistical methods. Despite in its infancy, ctDNA analysis holds great promise as a minimally invasive tool regarding tailored, personalized treatment guidance for breast cancer patients.

Escalating and De-escalating Therapy for Early-Stage HER2-Positive Breast Cancer

Untreated, HER2+ disease is the most aggressive breast cancer phenotype; however, the development of multiple highly effective HER2-targeting drugs has transformed treatment and survival. These drugs include the anti-HER2 monoclonal antibodies trastuzumab and pertuzumab; small molecule inhibitors lapatinib, neratinib, and tucatinib; and antibody-drug conjugates trastuzumab emtansine (T-DM1) and now trastuzumab deroxtecan. More complex regimens using these drugs continue to improve outcomes, but the incremental benefits of these advances are often modest. Improved outcomes came from the addition of HER2-targeted therapies to conventional chemotherapy, beginning with trastuzumab, then pertuzumab added to trastuzumab, or with neratinib given for the year after trastuzumab. Neoadjuvant, or preoperative, administration of chemotherapy plus HER2-targeting allows surgical deescalation and tailoring treatment by pathologic complete response (pCR) to therapy. Patients with pCR after conventional therapy have excellent outcomes; what we now know is that the poorer outcomes associated with residual disease can be ameliorated with adjuvant T-DM1. However, as we have developed more complex, effective, and expensive therapy to maximize outcomes, it is also true that we are overtreating many patients. In stage I HER2+ breast cancer, there are excellent outcomes with paclitaxel plus trastuzumab or T-DM1 alone. Higher clinical stage HER2+ disease is still treated aggressively, although intrinsic subtype or activated immune tumor microenvironment may identify those with augmented treatment response or better outcome. It is likely that future strategies to escalate and de-escalate treatment with less chemotherapy, fewer anti-HER2 drugs, or shorter duration will depend upon integrated clinical and genomic modeling.

Lapatinib Plus Local Radiation Therapy for Brain Metastases From HER-2 Positive Breast Cancer Patients and Role of Trastuzumab: A Systematic Review and Meta-Analysis

Background

Intracranial activity of lapatinib has been demonstrated in several studies in patients with human epidermal growth factor receptor-2 positive breast cancers (HER-2+ BC). Stereotactic radiosurgery (SRS) has been increasingly used as the local therapy for brain metastases in breast cancer patients. Increased objective response rate was observed for lapatinib plus whole brain radiotherapy (WBRT) is such patients with high toxicity.

Objective

We seek to obtain clinical evidence of synergistic efficacy of lapatinib in combination with radiation therapy, in particular, SRS.

Materials and methods

We carried out a comprehensive research using the following databases: PubMed; Medline; EMBASE; Cochrane library. These databases were searched until 10 June 2020. PRISMA guidelines were followed step by step for carrying out this systematic review and meta-analysis. Review Manager v 5.4 software was used for statistical evaluation of data.

Results

Overall 6 studies with 843 HER-2 positive breast cancer patients (442 HER-2 amplified disease, 399 luminal B disease) were included in this systematic review and meta-analysis. A total 279 patients had received lapatinib in addition to HER-2 antibody (trastuzumab) plus/minus chemoradiotherapy, while 610 patients had received trastuzumab-based management or only chemoradiotherapy. Lapatinib-based management of BM was associated with significant increase in overall survival (HR 0.63 [0.52, 0.77], p < 0.00001). Combination of the two (trastuzumab plus lapatinib) was associated with increased survival advantage compared to each agent alone (0.55 [0.32, 0.92], p = 0.02). SRS in combination with lapatinib was associated with increased local control (HR 0.47 [0.33, 0.66], p = 0.0001). Ever use of lapatinib with SRS was associated an increased survival as reported in two studies (Shireen et al.: 27.3 vs. 19.5 months, p = 0.03; Kim et al.: 33.3 vs. 23.6 months, p = 0.009). Kim et al. also revealed significant increase in intracranial activity with concurrent lapatinib reporting 57% complete response compared to 38% (p < 0.001) and lower progressive disease rate of 11 vs. 19% (p < 0.001). Risk of radiation necrosis was decreased with lapatinib use.

Conclusions

Lapatinib has shown intracranial activity and yielded better survival for HER-2+ BC patients with BMs. SRS in combination with ever use of lapatinib had better local control and were associated with better survival. Radiation necrosis risk was reduced with the use of lapatinib.

Trastuzumab emtansine: a game changer in HER2-positive early breast cancer

Trastuzumab emtansine (T-DM1), given postoperatively for 14 cycles to patients with human epidermal growth factor receptor 2-positive (HER2-positive) early breast cancer (EBC) who failed to achieve a pathological complete response after standard chemotherapy and HER2 blockade, represents probably the greatest progress in the management of this aggressive form of breast cancer since the adjuvant trastuzumab pivotal trials. This article addresses the rationale behind the conception of the KATHERINE trial, T-DM1's structure and pharmacokinetics data, clinical efficacy data of the KATHERINE trial and of other EBC trials with T-DM1, safety aspects, implications of the KATHERINE trial results to clinical practice and future perspectives in the management of HER2-positive EBC.

Survival, Pathologic Response, and Genomics in CALGB 40601 (Alliance), a Neoadjuvant Phase III Trial of Paclitaxel-Trastuzumab With or Without Lapatinib in HER2-Positive Breast Cancer

PURPOSE

CALGB 40601 assessed whether dual versus single human epidermal growth factor receptor 2 (HER2) -targeting drugs added to neoadjuvant chemotherapy increased pathologic complete response (pCR). Here, we report relapse-free survival (RFS), overall survival (OS), and gene expression signatures that predict pCR and survival.

PATIENTS AND METHODS

Three hundred five women with untreated stage II and III HER2-positive breast cancer were randomly assigned to receive weekly paclitaxel combined with trastuzumab plus lapatinib (THL), trastuzumab (TH), or lapatinib (TL). The primary end point was pCR, and secondary end points included RFS, OS, and gene expression analyses. mRNA sequencing was performed on 264 pretreatment samples.

RESULTS

One hundred eighteen patients were randomly allocated to THL, 120 to TH, and 67 to TL. At more than 7 years of follow-up, THL had significantly better RFS and OS than did TH (RFS hazard ratio, 0.32; 95% CI, 0.14 to 0.71; P = .005; OS hazard ratio, 0.34; 95% CI, 0.12 to 0.94; P = .037), with no difference between TH and TL. Of 688 previously described gene expression signatures, significant associations were found in 215 with pCR, 45 with RFS, and only 22 with both pCR and RFS (3.2%). Specifically, eight immune signatures were significantly correlated with a higher pCR rate and better RFS. Among patients with residual disease, the immunoglobulin G signature was an independent, good prognostic factor, whereas the HER2-enriched signature, which was associated with a higher pCR rate, showed a significantly shorter RFS.

CONCLUSION

In CALGB 40601, dual HER2-targeting resulted in significant RFS and OS benefits. Integration of intrinsic subtype and immune signatures allowed for the prediction of pCR and RFS, both overall and within the residual disease group. These approaches may provide means for rational escalation and de-escalation treatment strategies in HER2-positive breast cancer.

Early response and pathological complete remission in Breast Cancer with different molecular subtypes: a retrospective single center analysis

Purpose: To evaluate the association of clinical early response and pathological complete remission (pCR) in breast cancer patients with different molecular subtypes.

Materials and methods: Breast cancer patients who received neoadjuvant treatment (NAT) with clinical early response assessment from October 2008 to October 2018 were retrospectively analyzed. Clinical early response was defined as tumor size decreasing ≥30% evaluated by ultrasound after two cycles of NAT. Chi-square test was used to compare the pCR rates between the responder and non-responder groups with different molecular subtypes. Multivariate logistic regression was used to identify independent factors associated with the pCR.

Results: A total of 328 patients were included: 100 responders and 228 non-responders. The progesterone receptor (PR) expression was an independent factor associated with clinical early response (OR=2.39, 95%CI=1.41-4.05, P=0.001). The pCR rate of breast was 50.0% for responders and 18.0% for non-responders (P<0.001). Regarding different molecular subtypes, responders had higher pCR rates than non-responders for patients with HER2 overexpression (OR=10.66, 95%CI=2.18-52.15, P=0.001), triple negative (OR=3.29, 95%CI=1.23-8.84, P=0.016) and Luminal (HER2-) subtypes (OR=8.58, 95%CI=3.05-24.10, P<0.001) respectively. Moreover, pCR rate can be achieved as high as 88.2% in HER2 overexpression patients with early clinical response, which was significantly higher than patients without early response (41.3%, P=0.001). Multivariate analysis showed that clinical early response was an independent factor associated with the pCR rate (OR=4.87, 95%CI=2.72-8.72, P<0.001).

Conclusions: Early response was significantly associated with a higher pCR rate in breast cancer patients receiving NAT, especially for patients with HER2 overexpression subtype, which warrants further clinical evaluation.

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

LESSONS LEARNED

This is the first trial to explore the neoadjuvant therapy of pyrotinib in HER2-positive operable and locally advanced breast cancer, in combination with epirubicin plus cyclophosphamide followed by docetaxel plus trastuzumab. Results primarily showed that pyrotinib in combination with epirubicin plus cyclophosphamide followed by docetaxel plus trastuzumab was effective and safe in HER2-positive operable and locally advanced breast cancer. A subsequent randomized controlled trial is still warranted to confirm these results.

BACKGROUND

The efficacy and safety of neoadjuvant therapy of pyrotinib, a new irreversible tyrosine kinase inhibitor (TKI), was first estimated in patients with HER2-positive breast cancer in this phase II study, in combination with trastuzumab and chemotherapy.

METHODS

Between February 19, 2019, and November 20, 2019, 20 female Chinese patients with stage I-III HER2-positive breast cancer were assigned to receive eight cycles of neoadjuvant pyrotinib (P) in combination with four cycles of epirubicin (E) and cyclophosphamide (C) followed by four cycles of docetaxel (T) and trastuzumab (H), once every 3 weeks, referred to as P + EC-TH.

RESULTS

A total of 19 patients completed the therapy and final surgery. The total pathological complete response (tpCR) rate was 73.7% (95% confidence interval [CI], 48.8-90.9), and no recurrence or metastasis occurred during the short-term follow-up period. The objective response rate (ORR) was 100% (95% CI, 82.4-100). The most common adverse events (AEs) were diarrhea and leukopenia in 18 of 20 patients (90%), but no grade 5 AEs were reported.

CONCLUSION

This study showed that in HER2-positive operable or locally advanced breast cancer, the tpCR rate of P + EC-TH neoadjuvant therapy was about twice as high as that of EC-TH neoadjuvant therapy reported in other trials, with tolerable side effects.

Landmark trials in the medical oncology management of early stage breast cancer

With the advent of breast cancer screening programs, the majorities of patients with newly diagnosed breast cancer are diagnosed with early stage disease and are likely to experience cure with proper treatment. Significant advances have been made in the management of early-stage breast cancer to personalize treatment according to disease biology. This progress has led to improvement in survival outcomes and quality of life for our patients. In this review, we discuss landmark clinical trials in medical oncology that have shaped the current standard of care for early stage ER-positive, HER2-positive, and triple negative breast cancer.

Dual HER2 Blockade in Neoadjuvant Treatment of HER2+ Breast Cancer: A Meta-Analysis and Review

Background:

To investigate the pathologic complete response (pCR) rates of dual human epidermal growth factor receptor 2 (HER2) blockade in a neoadjuvant setting for HER2+ breast cancer.

Methods:

We searched randomized clinical trials (RCTs) using dual HER2 blockade in a neoadjuvant setting for HER2+ breast cancer in PubMed, the Cochrane Library, Embase and ClinicalTrials.gov up to July 5, 2020, and all included studies were assessed according to the Cochrane Collaboration tool for assessing the risk of bias of RCTs, and the statistical analyses were performed using STATA 14.0 software.

Results:

A total of 9 RCTs involving 2758 patients were included. Meta-analysis indicated that the pCR rates of lapatinib/pertuzumab/neratinib plus trastuzumab versus trastuzumab [relative risk (RR) = 1.31; 95% confidence interval (CI): 1.21-1.43; p < 0.001)] and lapatinib plus trastuzumab versus lapatinib (RR = 1.39; 95%CI: 1.25-1.53; p < 0.001) showed a significant statistical difference between dual HER2-blockade treatment and single-agent treatment in a neoadjuvant setting for HER2+ breast cancer. Additionally, there was no statistically significant difference in disease-free survival (HR = 0.72; 95% CI: 0.47-1.09; p = 0.123), incidence of serious adverse events (SAEs) (RR = 1.04; 95%CI: 0.81-1.33; p = 0.778) and cardiotoxicity(RR = 1.30; 95%CI: 0.81-2.08; p = 0.280), and the pCR rate was unaffected by hormone receptor status.

Conclusions:

The pCR rate of neoadjuvant dual-target therapy for HER2+ breast cancer was significantly higher than that of single-target therapy. Furthermore, the results indicated that the safety of dual-target therapy is similar to that of single-target therapy.

The use of a second core needle biopsy to predict response to neoadjuvant chemotherapy in breast cancer patients, especially in the HER2-positive population

BACKGROUND

Early and accurate assessment of the response to neoadjuvant chemotherapy offers the potential to optimize treatment to obtain improved responses. We aimed to predict the response to neoadjuvant chemotherapy using a second breast core needle biopsy after a median of 2 cycles of neoadjuvant chemotherapy.

METHODS

We evaluated 805 consecutive patients undergoing neoadjuvant chemotherapy who had a second core needle biopsy between 2013 and 2017. The second core needle biopsy was performed after a median of 2 cycles of neoadjuvant chemotherapy. Pathologic response was evaluated after completion of all the chemotherapy cycles. Diagnostic values were compared and evaluated between the second core needle biopsy and contrast-enhanced magnetic resonance imaging in both the whole and the human epidermal growth factor receptor 2-positive populations.

RESULTS

Overall, 653 patients were eligible and underwent a median of 6 chemotherapy cycles. The second core needle biopsy predicted residual breast cancer earlier than the final contrast-enhanced magnetic resonance imaging, with a greater positive predictive value (positive predictive value: 0.856 vs 0.802, P = .028). Multivariate analysis revealed that a estrogen receptor status, human epidermal growth factor receptor 2 positivity, findings on the final contrast-enhanced magnetic resonance imaging and the pathologic findings of the second core needle biopsy pathology were independent predictive factors for treatment response. The superiority in diagnostic value of a second core needle biopsy pathology in human epidermal growth factor receptor 2-positive patients was consistent with that in the whole population, with a positive predictive value of 0.785 (95% confidence interval: 0.707-0.847). The second core needle biopsy predicted the response to neoadjuvant chemotherapy as early as after 2 cycles, but the accuracy increased from 0.744 to 0.872 if the procedure was performed after more cycles (P = .002).

CONCLUSION

The second core needle biopsy predicted the response to neoadjuvant chemotherapy after 2 cycles quite well, especially in human epidermal growth factor receptor 2-positive patients. The ability of the prediction of response improved if the second biopsy was performed after 3 or 4 cycles.

Evolving standards of care and new challenges in the management of HER2-positive breast cancer

The management of human epidermal growth factor receptor (HER2)-positive breast cancer (BC) has rapidly evolved over the last 20 years. Major advances have led to US Food and Drug Administration approval of 7 HER2-targeted therapies for the treatment of early-stage and/or advanced-stage disease. Although oncologic outcomes continue to improve, most patients with advanced HER2-positive BC ultimately die of their disease because of primary or acquired resistance to therapy, and patients with HER2-positive early BC who have residual invasive disease after preoperative systemic therapy are at a higher risk of distant recurrence and death. The concept of treatment de-escalation and escalation is increasingly important to optimally tailor therapy for patients with HER2-positive BC and is a major focus of the current review. Research efforts in this regard are discussed as well as updates regarding the evolving standard of care in the (neo)adjuvant and metastatic settings, including the use of novel combination therapies. The authors also briefly discuss ongoing challenges in the management of HER2-positive BC (eg, intrinsic vs acquired drug resistance, the identification of predictive biomarkers, the integration of imaging techniques to guide clinical practice), and the treatment of HER2-positive brain metastases. Research aimed at superseding these challenges will be imperative to ensure continued progress in the management of HER2-positive BC going forward.

Application of the ESMO-Magnitude of Clinical Benefit Scale (V.1.1) to the field of early breast cancer therapies

Click here to listen to the Podcast BACKGROUND: The European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated value scale for solid tumour anticancer treatments. Form 1 of the ESMO-MCBS, used to grade therapies with curative intent including adjuvant therapies, has only been evaluated for a limited number of studies. This is the first large-scale field testing in early breast cancer to assess the applicability of the scale to this data set and the reasonableness of derived scores and to identify any shortcomings to be addressed in future modifications of the scale.

METHOD

Representative key studies and meta-analyses of the major modalities of adjuvant systemic therapy of breast cancer were identified for each of the major clinical scenarios (HER2-positive, HER2-negative, endocrine-responsive) and were graded with form 1 of the ESMO-MCBS. These generated scores were reviewed by a panel of experts for reasonableness. Shortcomings and issues related to the application of the scale and interpretation of results were identified and critically evaluated.

RESULTS

Sixty-five studies were eligible for evaluation: 59 individual studies and 6 meta-analyses. These studies incorporated 101 therapeutic comparisons, 61 of which were scorable. Review of the generated scores indicated that, with few exceptions, they generally reflected contemporary standards of practice. Six shortcomings were identified related to grading based on disease-free survival (DFS), lack of information regarding acute and long-term toxicity and an inability to grade single-arm de-escalation scales.

CONCLUSIONS

Form 1 of the ESMO-MCBS is a robust tool for the evaluation of the magnitude of benefit studies in early breast cancer. The scale can be further improved by addressing issues related to grading based on DFS, annotating grades with information regarding acute and long-term toxicity and developing an approach to grade single-arm de-escalation studies.

Pathological Complete Response from Pyrotinib Combined with Trastuzumab, Paclitaxel and Cisplatin in a Postpartum Woman with HER2-Positive Locally Advanced Breast Cancer: A Case Report

Background

Overexpression of human epidermal growth factor receptor 2 (HER2) is associated with aggressive disease and poor prognosis. Traditional HER2-targeted agents can improve clinical outcome and have played an essential role in therapy. Pyrotinib is a newly irreversible tyrosine kinase inhibitor (TKI) that is well developed for the treatment of HER2-positive advanced breast tumors.

Case Presentation

A 37-year-old postpartum female was presented at a local hospital and was diagnosed with HER2-positive stage IIIB (cT4N1M0) invasive micropapillary adenocarcinoma in the left breast with left axillary metastatic lymph nodes. The patient failed to respond to two cycles of the doxorubicin plus cyclophosphamide (AC) regimen but achieved clinical partial response (cPR) after 4 cycles of the combination of pyrotinib, trastuzumab, paclitaxel and cisplatin (PTPC) regimen according to radiologic assessments. Then, she underwent left-side modified radical mastectomy (MRM) and achieved pathologic complete response (pCR), as confirmed by postoperative pathology. The patient held on receiving 2 cycles of the targeted therapy plus chemotherapy with trastuzumab, paclitaxel plus cisplatin (TPC) and adjuvant radiation therapy but continued to receive targeted therapy with trastuzumab and pertuzumab during the 1-year follow-up period. There has been no clinical evidence of disease progression so far.

Conclusion

Breast cancer overexpressing HER2 is a malignant tumor responsible for many cancer-related deaths. The combination of pyrotinib plus other targeted chemotherapy can dramatically improve the outcome of locally advanced disease.

NSABP B-41, a Randomized Neoadjuvant Trial: Genes and Signatures Associated with Pathologic Complete Response

PURPOSE

In NSABP B-41, pathologic complete response (pCR) was associated with prolonged survival among women with HER2-positive operable breast cancer treated with neoadjuvant chemotherapy and lapatinib, trastuzumab, or the combination. We used a large human breast cancer gene expression panel to select candidate prognostic biomarkers for pCR among women treated with trastuzumab in NSABP B-41.

PATIENTS AND METHODS

Eligible patients had a baseline preadjuvant treatment core biopsy sample, known pCR status, and no withdrawal of consent. We analyzed extracted RNA using the human nCounter Breast Cancer 360 gene expression panel. Gene counts were normalized to housekeeping genes and transformed into logarithmic scale with base 2. To screen for candidate genes and metagene signatures prognostic of pCR, we used univariate logistic regression. Variable selection was done by multivariable logistic regression with lasso regularization.

RESULTS

Analyses of data from 130 patients revealed that a composite of gene expression from 19 genes and one gene signature appeared to predict pCR in women with HER2-positive early-stage breast cancer undergoing neoadjuvant chemotherapy with trastuzumab-containing regimens. The identified genes are involved in important pathways such as epithelial-mesenchymal transition, adhesion and migration, estrogen receptor signaling, DNA damage and repair, apoptosis, and proliferation. The AUC from a 10-fold cross-validation on predicting pCR, with these 20 genomic markers in a logistic regression model, was 0.73.

CONCLUSIONS

The expression level of ERBB2, ESR1, and a few other genomic markers was highly predictive of pCR after trastuzumab-containing regimens. These findings need to be validated and calibrated in future studies.

Prognostic potential of automated Ki67 evaluation in breast cancer: different hot spot definitions versus true global score

PURPOSE

The proliferation-associated biomarker Ki67 has potential utility in breast cancer, including aiding decisions based on prognosis, but has unacceptable inter- and intralaboratory variability. The aim of this study was to compare the prognostic potential for Ki67 hot spot scoring and global scoring using different digital image analysis (DIA) platforms.

METHODS

An ER+/HER2- breast cancer cohort (n = 139) with whole slide images of sequential sections stained for hematoxylin-eosin, pancytokeratin and Ki67, was analyzed using two DIA platforms. For hot spot analysis virtual dual staining was applied, aligning pancytokeratin and Ki67 images and 22 hot spot algorithms with different features were designed. For global Ki67 scoring an automated QuPath algorithm was applied on Ki67-stained whole slide images. Clinicopathological data included overall survival (OS) and recurrence-free survival (RFS) along with PAM50 molecular subtypes.

RESULTS

We show significant variations in Ki67 hot spot scoring depending on number of included tumor cells, hot spot size, shape and location. The higher the number of scored tumor cells, the higher the reproducibility of Ki67 proliferation values. Hot spot scoring had greater prognostic potential for RFS in high versus low Ki67 subgroups (hazard ratio (HR) 6.88, CI 2.07-22.87, p = 0.002), compared to global scoring (HR 3.13, CI 1.41-6.96, p = 0.005). Regarding OS, global scoring (HR 7.46, CI 2.46-22.58, p < 0.001) was slightly better than hot spot scoring (HR 6.93, CI 1.61-29.91, p = 0.009). In adjusted multivariate analysis, only global scoring was an independent prognostic marker for both RFS and OS. In addition, global Ki67-based surrogate subtypes reached higher concordance with PAM50 molecular subtype for luminal A and B tumors (66.3% concordance rate, κ = 0.345), than using hot spot scoring (55.8% concordance rate, κ = 0.250).

CONCLUSIONS

We conclude that the automated global Ki67 scoring is feasible and shows clinical validity, which, however, needs to be confirmed in a larger cohort before clinical implementation.

Working together for the family: determination of HER oncogene co-amplifications in breast cancer

HER2 is a well-studied tyrosine kinase (TK) membrane receptor which functions as a therapeutic target in invasive ductal breast carcinomas (IDC). The standard of care for the treatment of HER2-positive breast is the antibody trastuzumab. Despite specific treatment unfortunately, 20% of primary and 70% of metastatic HER2 tumors develop resistance. HER2 belongs to a gene family, with four members (HER1-4) and these members could be involved in resistance to anti-HER2 therapies. In this study we designed a probemix to detect the amplification of the four HER oncogenes in a single reaction. In addition, we developed a protocol based on the combination of MLPA with ddPCR to detect the tumor proportion of co-amplified HERs. On 111 IDC, the HER2 MLPA results were validated by FISH (Adjusted r ² = 0,91, p < 0,0001), CISH (Adjusted r ² = 0,938, p < 0,0001) and IHC (Adjusted r ² = 0,31, p < 0,0001). HER1-4 MLPA results were validated by RT-qPCR assays (Spearman Rank test p < 0,05). Of the 111 samples, 26% presented at least one HER amplified, of which 23% showed co-amplifications with other HERs. The percentage of cells with HER2 co-amplified varied among the tumors (from 2-72,6%). Independent in-silico findings show that the outcome of HER2+ patients is conditioned by the status of HER3 and HER4. Our results encourage further studies to investigate the relationship with patient's response to single or combined treatment. The approach could serve as proof of principle for other tumors in which the HER oncogenes are involved.

Relative Survival Benefit by Hormonal Receptor Status of Adding Trastuzumab to Neoadjuvant Chemotherapy in Breast Cancer Patients

Purpose

Neoadjuvant chemotherapy (NAC) involving trastuzumab markedly increases pathologic complete response (pCR) rates in patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer. Despite increasing pCR rates, long-term survival gains are controversial owing to distinctive biologic behavior mediated by the presence of hormonal receptors (HRs) that may interact with HER2 receptors. We, therefore, investigated the differences in relative survival gain provided by neoadjuvant trastuzumab-based chemotherapy on HR positive (HR+) status of patients.

Methods

We retrospectively analyzed women with stage II or III HER2+ breast cancer who underwent NAC followed by a breast cancer surgery between 2008 and 2013. The survival benefits of adding trastuzumab to NAC were analyzed by classifying patients into HR+ and HR negative (HR−) groups.

Results

Of 666 patients included in the study, 374 (52.1%) were HR+ and 319 (47.9%) were HR−. In the HR+ group, trastuzumab treatment led to higher pCR rates and significantly better breast cancer specific survival (BCSS) and overall survival (OS) than no trastuzumab treatment. However, among patients with HR− breast cancer, trastuzumab treatment showed no statistically significant difference between BCSS and OS following multivariate analysis.

Conclusion

We found that the addition of trastuzumab to NAC improved relative survival benefit in HER2+/HR+ patients than in HER2+/HR− patients, even though the pCR rate increases were lower. Although pCR has been regarded as a surrogate marker for estimating long-term survival benefits after NAC, it alone may not translate into real long-term oncologic outcomes in particular cancer subtypes after trastuzumab-based NAC. Further longer-term evaluation of the objective survival benefit after NAC driven by a dual HER2 block according to HR status is warranted.

Pathologic Complete Response after Neoadjuvant Chemotherapy and Impact on Breast Cancer Recurrence and Survival: A Comprehensive Meta-analysis

PURPOSE

While various studies have highlighted the prognostic significance of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAT), the impact of additional adjuvant therapy after pCR is not known.

EXPERIMENTAL DESIGN

PubMed was searched for studies with NAT for breast cancer and individual patient-level data was extracted for analysis using plot digitizer software. HRs, with 95% probability intervals (PI), measuring the association between pCR and overall survival (OS) or event-free survival (EFS), were estimated using Bayesian piece-wise exponential proportional hazards hierarchical models including pCR as predictor.

RESULTS

Overall, 52 of 3,209 publications met inclusion criteria, totaling 27,895 patients. Patients with a pCR after NAT had significantly better EFS (HR = 0.31; 95% PI, 0.24-0.39), particularly for triple-negative (HR = 0.18; 95% PI, 0.10-0.31) and HER2+ (HR = 0.32; 95% PI, 0.21-0.47) disease. Similarly, pCR after NAT was also associated with improved survival (HR = 0.22; 95% PI, 0.15-0.30). The association of pCR with improved EFS was similar among patients who received subsequent adjuvant chemotherapy (HR = 0.36; 95% PI, 0.19-0.67) and those without adjuvant chemotherapy (HR = 0.36; 95% PI, 0.27-0.54), with no significant difference between the two groups (P = 0.60).

CONCLUSIONS

Achieving pCR following NAT is associated with significantly better EFS and OS, particularly for triple-negative and HER2+ breast cancer. The similar outcomes with or without adjuvant chemotherapy in patients who attain pCR likely reflects tumor biology and systemic clearance of micrometastatic disease, highlighting the potential of escalation/deescalation strategies in the adjuvant setting based on neoadjuvant response.See related commentary by Esserman, p. 2771.

Anti-HER2 therapy for breast cancer in older patients

Older patients now form between 30 and 40% of breast cancer (BC) patients. Managing older patients with BC is particularly challenging due to the limited availability of high-quality evidence. In this review we discuss the available evidence on the efficacy and safety of anti-HER2 agents in older patients with HER2-positive BC is presented, with a particular look at the latest results of promising new agents such trastuzumab-deruxtecan. The data suggest that older patients can expect similar efficacy when using standard regimens, with higher toxicity, particular cardiac toxicity and diarrhea. Anti-HER2 agents should thus be used in most older patients most as per standard of care as long as adequate follow-up is available to manage toxicities.

Capecitabine + Epirubicin + Cyclophosphamide Combination Therapy (CEX Therapy) as Neoadjuvant Chemotherapy for HER-2-Negative Breast Cancer: A Retrospective, Single-Center Study

BACKGROUND

We modified and administered capecitabine + epirubicin + cyclophosphamide combination therapy (CEX) as neoadjuvant chemotherapy (NAC) for HER-2-negative breast cancer and retrospectively analyzed its effectiveness and tolerability at our center.

METHODS

The inclusion criteria were presence of breast cancer negative for HER-2 and positive lymph node metastasis, or negative lymph node metastasis when tumor diameter was 20 mm or greater without distant metastasis. Additional inclusion criteria were a performance status of 0 or 1, an EF >60%, and an age of 75 years or less. Clinical outcomes were evaluated after 4 courses of epirubicin 80 mg/m2, cyclophosphamide 500 mg/m2 (administered every 3 weeks), and capecitabine 1,500 mg/m2 (administered for 2 weeks and withdrawn for 1 week).

RESULTS

A clinical benefit was noted in all 18 patients who received CEX as neoadjuvant chemotherapy during the period from 2009 through 2013. The clinical response rate was 83.3% (15/18), and the clinical complete response rate was 50%. Aesthetic outcomes of breast-conserving surgery were positive in all patients. Among patients with satisfactory outcomes, 33.3% had a pathologic complete response (triple-negative: 6, luminal: 0) and 68.8% were n0 (triple-negative: 8, luminal: 3). All patients with a pathologic complete response are presently alive, free of recurrence, and currently undergoing follow-up. Adverse events were classified as grade 2 or lower in all patients.

CONCLUSIONS

CEX therapy administered as neoadjuvant chemotherapy could be useful for individualized treatment. In particular, this regimen was effective for triple-negative breast cancer.

The Role of Contrast-Enhanced Ultrasound in the Diagnosis and Pathologic Response Prediction in Breast Cancer: A Meta-analysis and Systematic Review

PURPOSE

To determine the overall performance of contrast-enhanced ultrasound (CEUS) in differentiating between benign and malignant breast lesions and in predicting the pathologic response to neoadjuvant chemotherapy (NAC) in patients with breast cancer (BC).

MATERIALS AND METHODS

Articles published up to April 2019 were systematically searched in Medline, Web of Science, and China National Knowledge Infrastructure. The sensitivities and specificities across studies, the calculations of positive and negative likelihood ratios (LR⁺ and LR^-), diagnostic odds ratio (OR), and constructed summary receiver operating characteristic curves were determined. Methodologic quality was assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) tool. Subgroup analyses and metaregression were performed on prespecified study-level characteristics.

RESULTS

Fifty-one studies involving 4875 patients with 5246 breast lesions and 10 studies involving 462 patients with BC receiving NAC were included. Methodologic quality was relatively high, and no publication bias was detected. The overall sensitivity, specificity, diagnostic OR, LR⁺, and LR^- for CEUS were 0.88 (95% confidence interval [CI], 0.86-0.89), 0.82 (95% CI, 0.80-0.83), 30.55 (95% CI, 21.40-43.62), 4.29 (95% CI, 3.51-5.25), and 0.16 (95% CI, 0.13-0.21), respectively, showing statistical heterogeneity. Multivariable metaregression analysis showed contrast mode to be the most significant source of heterogeneity. The overall sensitivity, specificity, LR⁺, LR, and diagnostic OR of CEUS imaging in predicting the overall pathologic response to NAC in patients with BC were 0.89 (95% CI, 0.83-0.93), 0.83 (95% CI, 0.78-0.88), 4.49 (95% CI, 3.04-6.62), 0.16 (95% CI, 0.10-0.24,), and 32.21 (95% CI, 16.74-62.01), respectively, showing mild heterogeneity.

CONCLUSION

Our data confirmed the excellent performance of breast CEUS in differentiating between benign and malignant breast lesions as well as pathologic response prediction in patients with BC receiving NAC.

Nanobody-targeted photodynamic therapy induces significant tumor regression of trastuzumab-resistant HER2-positive breast cancer, after a single treatment session

Rationale

A substantial number of breast cancer patients with an overexpression of the human epidermal growth factor receptor 2 (HER2) have residual disease after neoadjuvant therapy or become resistant to trastuzumab. Photodynamic therapy (PDT) using nanobodies targeted to HER2 is a promising treatment option for these patients. Here we investigate the in vitro and in vivo antitumor efficacy of HER2-targeted nanobody-photosensitizer (PS) conjugate PDT.

Methods

Nanobodies targeting HER2 were obtained from phage display selections. Monovalent nanobodies were engineered into a biparatopic construct. The specificity of selected nanobodies was tested in immunofluorescence assays and their affinity was evaluated in binding studies, both performed in a panel of breast cancer cells varying in HER2 expression levels. The selected HER2-targeted nanobodies 1D5 and 1D5-18A12 were conjugated to the photosensitizer IRDye700DX and tested in in vitro PDT assays. Mice bearing orthotopic HCC1954 trastuzumab-resistant tumors with high HER2 expression or MCF-7 tumors with low HER2 expression were intravenously injected with nanobody-PS conjugates. Quantitative fluorescence spectroscopy was performed for the determination of the local pharmacokinetics of the fluorescence conjugates. After nanobody-PS administration, tumors were illuminated to a fluence of 100 J∙cm^-2, with a fluence rate of 50 mW∙cm^-2, and thereafter tumor growth was measured with a follow-up until 30 days.

Results

The selected nanobodies remained functional after conjugation to the PS, binding specifically and with high affinity to HER2-positive cells. Both nanobody-PS conjugates potently and selectively induced cell death of HER2 overexpressing cells, either sensitive or resistant to trastuzumab, with low nanomolar LD₅₀ values. In vivo, quantitative fluorescence spectroscopy showed specific accumulation of nanobody-PS conjugates in HCC1954 tumors and indicated 2 h post injection as the most suitable time point to apply light. Nanobody-targeted PDT with 1D5-PS and 1D5-18A12-PS induced significant tumor regression of trastuzumab-resistant high HER2 expressing tumors, whereas in low HER2 expressing tumors only a slight growth delay was observed.

Conclusion

Nanobody-PS conjugates accumulated selectively in vivo and their fluorescence could be detected through optical imaging. Upon illumination, they selectively induced significant tumor regression of HER2 overexpressing tumors with a single treatment session. Nanobody-targeted PDT is therefore suggested as a new additional treatment for HER2-positive breast cancer, particularly of interest for trastuzumab-resistant HER2-positive breast cancer. Further studies are now needed to assess the value of this approach in clinical practice.

Patient-reported outcomes from KATHERINE: A phase 3 study of adjuvant trastuzumab emtansine versus trastuzumab in patients with residual invasive disease after neoadjuvant therapy for human epidermal growth factor receptor 2-positive breast cancer

Background

The phase 3 KATHERINE trial demonstrated significantly improved invasive disease–free survival with adjuvant trastuzumab emtansine (T‐DM1) versus trastuzumab in patients with HER2‐positive early breast cancer and residual invasive disease after neoadjuvant chemotherapy plus HER2‐targeted therapy.

Methods

Patients who received taxane‐ and trastuzumab‐containing neoadjuvant therapy (with/without anthracyclines) and had residual invasive disease (breast and/or axillary nodes) at surgery were randomly assigned to 14 cycles of adjuvant T‐DM1 (3.6 mg/kg intravenously every 3 weeks) or trastuzumab (6 mg/kg intravenously every 3 weeks). The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire–Core 30 (QLQ‐C30) and breast cancer module (QLQ‐BR23) were completed at screening, at day 1 of cycles 5 and 11, within 30 days after study drug completion, and at 6‐ and 12‐month follow‐up visits.

Results

Of patients who were randomly assigned to T‐DM1 (n = 743) and trastuzumab (n = 743), 612 (82%) and 640 (86%), respectively, had valid baseline and ≥1 postbaseline assessments. No clinically meaningful changes (≥10 points) from baseline in mean QLQ‐C30 and QLQ‐BR23 scores occurred in either arm. More patients receiving T‐DM1 reported clinically meaningful deterioration at any assessment point in role functioning (49% vs 41%), appetite loss (38% vs 28%), constipation (47% vs 38%), fatigue (66% vs 60%), nausea/vomiting (39% vs 30%), and systemic therapy side effects (49% vs 36%). These differences were no longer apparent at the 6‐month follow‐up assessment, except for role functioning (23% vs 16%).

Conclusion

These data suggest that health‐related quality of life was generally maintained in both study arms over the course of treatment.

Patient‐reported outcomes are reported from the randomized, phase 3 KATHERINE trial, which demonstrated significantly improved invasive disease–free survival with adjuvant T‐DM1 compared with trastuzumab in patients who had residual invasive disease following neoadjuvant chemotherapy plus HER2‐targeted therapy. Patients who are treated with T‐DM1 have a greater incidence of any grade and grade ≥3 adverse events compared with trastuzumab‐treated patients; however, these adverse events appear to have a minimal impact on patient‐reported quality of life.

Dual HER2 Blockade versus a Single Agent in Trastuzumab-Containing Regimens for HER2-Positive Early Breast Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose

Although trastuzumab is the standard of care for patients with human epidermal growth factor receptor 2 (HER2)- positive early breast cancer (EBC), drug resistance and disease relapse occur. Therefore, we performed a meta-analysis to assess the efficacy and safety of trastuzumab-containing dual anti-HER2 therapy compared to trastuzumab alone.

Methods

A systematic search was performed to identify eligible randomized controlled trials (RCTs). Main outcomes including event-free survival/invasive disease-free survival (EFS/iDFS), overall survival (OS), and safety were considered.

Results

Ten RCTs were included (15,284 patients). Significant improvements were observed in both EFS/iDFS (HR 0.86, p=0.0003) and OS (HR 0.86, p=0.02) with trastuzumab-based dual anti-HER2 therapy, especially in adjuvant treatment, while in the neoadjuvant setting, dual-targeted therapy also achieved a substantial pathological complete response (pCR) benefit (HR 1.34, p=0.0002). Subgroup analysis revealed that the EFS/iDFS benefit was slightly higher with trastuzumab plus pertuzumab or plus neratinib than trastuzumab plus lapatinib, while OS benefit was significant with trastuzumab plus lapatinib, but there were no subgroup differences (interaction test, p=0.80 and 0.24, resp.). In addition, EFS/iDFS benefit was unrelated to hormone receptor status but pronounced in the lymph node-positive (LN+) subgroup, which should be interpreted cautiously for lacking interaction (p=0.18). Besides, patients receiving dual therapy, especially with the lapatinib-containing regimen, experienced more toxicity, but no increase in cardiotoxicity.

Conclusions

Despite being associated with more toxicity, trastuzumab-containing dual anti-HER2 therapy is superior to trastuzumab single agent for HER2-positive EBC independent of hormone receptor status. The correlation between survival and LN status needs further verification. Trastuzumab plus pertuzumab or plus neratinib is the preferred regimen with substantial efficacy and lower toxicity.