Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer.

BACKGROUND: Among breast cancers without human epidermal growth factor receptor 2 (HER2) amplification, overexpression, or both, a large proportion express low levels of HER2 that may be targetable. Currently available HER2-directed therapies have been ineffective in patients with these "HER2-low" cancers. METHODS: We conducted a phase 3 trial involving patients with HER2-low metastatic breast cancer who had received one or two previous lines of chemotherapy. (Low expression of HER2 was defined as a score of 1+ on immunohistochemical [IHC] analysis or as an IHC score of 2+ and negative results on in situ hybridization.) Patients were randomly assigned in a 2:1 ratio to receive trastuzumab deruxtecan or the physician's choice of chemotherapy. The primary end point was progression-free survival in the hormone receptor-positive cohort. The key secondary end points were progression-free survival among all patients and overall survival in the hormone receptor-positive cohort and among all patients. RESULTS: Of 557 patients who underwent randomization, 494 (88.7%) had hormone receptor-positive disease and 63 (11.3%) had hormone receptor-negative disease. In the hormone receptor-positive cohort, the median progression-free survival was 10.1 months in the trastuzumab deruxtecan group and 5.4 months in the physician's choice group (hazard ratio for disease progression or death, 0.51; P<0.001), and overall survival was 23.9 months and 17.5 months, respectively (hazard ratio for death, 0.64; P = 0.003). Among all patients, the median progression-free survival was 9.9 months in the trastuzumab deruxtecan group and 5.1 months in the physician's choice group (hazard ratio for disease progression or death, 0.50; P<0.001), and overall survival was 23.4 months and 16.8 months, respectively (hazard ratio for death, 0.64; P = 0.001). Adverse events of grade 3 or higher occurred in 52.6% of the patients who received trastuzumab deruxtecan and 67.4% of those who received the physician's choice of chemotherapy. Adjudicated, drug-related interstitial lung disease or pneumonitis occurred in 12.1% of the patients who received trastuzumab deruxtecan; 0.8% had grade 5 events. CONCLUSIONS: In this trial involving patients with HER2-low metastatic breast cancer, trastuzumab deruxtecan resulted in significantly longer progression-free and overall survival than the physician's choice of chemotherapy. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast04 ClinicalTrials.gov number, NCT03734029.).

Clinical Application of Multimodal Sentinel Lymph Node Mapping Method in Patients with Breast Cancer Undergoing Neoadjuvant Chemotherapy: An Interim Analysis.

BACKGROUND: After neoadjuvant chemotherapy (NAC), the SLN identification rate is lower and has a higher false-negative rate than that at upfront surgery. This clinical trial aimed to confirm the effectiveness of sentinel lymph node (SLN) surgery by determining the lymph node identification rate using multimodal SLN marker methods in patients with advanced breast cancer undergoing NAC. PATIENTS AND METHODS: This clinical study is a prospective single-center randomized controlled trial involving patients with breast cancer receiving NAC. Patients are randomized (1:1:1) into arm A that involves the use of radioisotope (RI) plus indocyanine green fluorescence (ICG-F); arm B, RI plus vital dye; and, arm C, ICG-F plus vital dye. A total of 348 patients are needed. An interim analysis was performed on 50% of the patients enrolled. The primary outcome of this trial was the SLN identification rate. RESULTS: Among the 164 total patients (median age 51 years), T2 and N1 were the most common clinical stages. The identification rate of SLN was 95% in arm A, 92% in arm B, and 79% in arm C. To assess superior efficacy, the one-sided endpoint was set at α < 0.0056. Arms A and C showed a difference of 0.1597 in the detection rate (p = 0.0055). CONCLUSIONS: The use of ICG-F plus vital dye for SLNB was the least effective. The results show that the choice of tracer should be radioisotope in combination with one of the other tracers to have the highest SLN identification rate when SLNB cannot be implemented conventionally due to the circumstances of each institution.

TROPION-Breast01: Datopotamab deruxtecan vs chemotherapy in pre-treated inoperable or metastatic HR+/HER2- breast cancer.

Improving the prognosis for patients with metastatic HR+/HER2- breast cancer remains an unmet need. Patients with tumors that have progressed on endocrine therapy and/or are not eligible for endocrine therapy had limited treatment options beyond chemotherapy. Antibody-drug conjugates are a novel and promising treatment class in this setting. Datopotamab deruxtecan (Dato-DXd) consists of a TROP2-directed humanized IgG1 monoclonal antibody attached via a serum-stable cleavable linker to a topoisomerase I inhibitor payload. TROPION-Breast01 is an ongoing phase III study that is evaluating the efficacy and safety of Dato-DXd compared with investigator's choice of standard-of-care chemotherapy in patients with inoperable or metastatic HR+/HER2- breast cancer who have received one or two prior lines of systemic chemotherapy in the inoperable or metastatic setting. Clinical Trial Registration: NCT05104866 (ClinicalTrials.gov).

Antibody-drug conjugates are a type of drug with two parts: an antibody that directs the drug to the cancer cells and a cancer-cell killing toxic payload. By binding to cancer cells before releasing the payload, treatment is directed to the site of action so there are fewer side effects in the rest of the body. Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugates made up of datopotamab (antibody) and DXd (payload) which are joined together via a stable linker. Datopotamab binds to a protein found on cancer cells called TROP2; it then goes inside and releases the DXd payload to kill the tumor cells. DXd may leak out to surrounding cancer cells and kill those as well. The TROPION-Breast01 study is comparing Dato-DXd with standard-of-care chemotherapy. Around 700 patients will take part, who have: Tumors that cannot be surgically removed. Tumors that are hormone receptor-positive and do not have HER2 overexpression. Had one or two lines of previous chemotherapy (after the tumor could not be surgically removed, or had spread). Had tumor growth despite hormonal therapy or are ineligible for hormonal therapy. Patients who meet the entry criteria will be randomly assigned to a treatment group in equal numbers to either Dato-DXd or an appropriate chemotherapy, out of four options chosen by the treating doctor. At the end of the study, researchers will look at whether the patients who receive Dato-DXd live longer without their breast cancer getting worse, compared with patients who receive chemotherapy. This study is also looking at how the treatment affects patients' quality of life.

Trastuzumab Deruxtecan in Previously Treated HER2-Positive Breast Cancer.

BACKGROUND: Trastuzumab deruxtecan (DS-8201) is an antibody-drug conjugate composed of an anti-HER2 (human epidermal growth factor receptor 2) antibody, a cleavable tetrapeptide-based linker, and a cytotoxic topoisomerase I inhibitor. In a phase 1 dose-finding study, a majority of the patients with advanced HER2-positive breast cancer had a response to trastuzumab deruxtecan (median response duration, 20.7 months). The efficacy of trastuzumab deruxtecan in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab emtansine requires confirmation. METHODS: In this two-part, open-label, single-group, multicenter, phase 2 study, we evaluated trastuzumab deruxtecan in adults with pathologically documented HER2-positive metastatic breast cancer who had received previous treatment with trastuzumab emtansine. In the first part of the study, we evaluated three different doses of trastuzumab deruxtecan to establish a recommended dose; in the second part, we evaluated the efficacy and safety of the recommended dose. The primary end point was the objective response, according to independent central review. Key secondary end points were the disease-control rate, clinical-benefit rate, duration of response and progression-free survival, and safety. RESULTS: Overall, 184 patients who had undergone a median of six previous treatments received the recommended dose of trastuzumab deruxtecan (5.4 mg per kilogram of body weight). In the intention-to-treat analysis, a response to therapy was reported in 112 patients (60.9%; 95% confidence interval [CI], 53.4 to 68.0). The median duration of follow-up was 11.1 months (range, 0.7 to 19.9). The median response duration was 14.8 months (95% CI, 13.8 to 16.9), and the median duration of progression-free survival was 16.4 months (95% CI, 12.7 to not reached). During the study, the most common adverse events of grade 3 or higher were a decreased neutrophil count (in 20.7% of the patients), anemia (in 8.7%), and nausea (in 7.6%). On independent adjudication, the trial drug was associated with interstitial lung disease in 13.6% of the patients (grade 1 or 2, 10.9%; grade 3 or 4, 0.5%; and grade 5, 2.2%). CONCLUSIONS: Trastuzumab deruxtecan showed durable antitumor activity in a pretreated patient population with HER2-positive metastatic breast cancer. In addition to nausea and myelosuppression, interstitial lung disease was observed in a subgroup of patients and requires attention to pulmonary symptoms and careful monitoring. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast01 ClinicalTrials.gov number, NCT03248492.).

Overall Survival with Ribociclib plus Endocrine Therapy in Breast Cancer.

BACKGROUND: An earlier analysis of this phase 3 trial showed that the addition of a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor to endocrine therapy provided a greater benefit with regard to progression-free survival than endocrine therapy alone in premenopausal or perimenopausal patients with advanced hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Here we report the results of a protocol-specified interim analysis of the key secondary end point of overall survival. METHODS: We randomly assigned patients to receive either ribociclib or placebo in addition to endocrine therapy (goserelin and either a nonsteroidal aromatase inhibitor or tamoxifen). Overall survival was evaluated with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods. RESULTS: A total of 672 patients were included in the intention-to-treat population. There were 83 deaths among 335 patients (24.8%) in the ribociclib group and 109 deaths among 337 patients (32.3%) in the placebo group. The addition of ribociclib to endocrine therapy resulted in significantly longer overall survival than endocrine therapy alone. The estimated overall survival at 42 months was 70.2% (95% confidence interval [CI], 63.5 to 76.0) in the ribociclib group and 46.0% (95% CI, 32.0 to 58.9) in the placebo group (hazard ratio for death, 0.71; 95% CI, 0.54 to 0.95; P = 0.00973 by log-rank test). The survival benefit seen in the subgroup of 495 patients who received an aromatase inhibitor was consistent with that in the overall intention-to-treat population (hazard ratio for death, 0.70; 95% CI, 0.50 to 0.98). The percentage of patients who received subsequent antineoplastic therapy was balanced between the groups (68.9% in the ribociclib group and 73.2% in the placebo group). The time from randomization to disease progression during receipt of second-line therapy or to death was also longer in the ribociclib group than in the placebo group (hazard ratio for disease progression or death, 0.69; 95% CI, 0.55 to 0.87). CONCLUSIONS: This trial showed significantly longer overall survival with a CDK4/6 inhibitor plus endocrine therapy than with endocrine therapy alone among patients with advanced hormone-receptor-positive, HER2-negative breast cancer. No new concerns regarding toxic effects emerged with longer follow-up. (Funded by Novartis; MONALEESA-7 ClinicalTrials.gov number, NCT02278120.).

Pembrolizumab versus investigator-choice chemotherapy for metastatic triple-negative breast cancer (KEYNOTE-119): a randomised, open-label, phase 3 trial.

BACKGROUND: Pembrolizumab showed durable antitumour activity and manageable safety in metastatic triple-negative breast cancer in the single-arm KEYNOTE-012 and KEYNOTE-086 trials. In this study, we compared pembrolizumab with chemotherapy for second-line or third-line treatment of patients with metastatic triple-negative breast cancer. METHODS: KEYNOTE-119 was a randomised, open-label, phase 3 trial done at 150 medical centres (academic medical centres, community cancer centres, and community hospitals) in 31 countries. Patients aged 18 years or older, with centrally confirmed metastatic triple-negative breast cancer, Eastern Cooperative Oncology Group performance status of 0 or 1, who had received one or two previous systemic treatments for metastatic disease, had progression on their most recent therapy, and had previous treatment with an anthracycline or taxane were eligible. Patients were randomly assigned (1:1) using a block method (block size of four) and an interactive voice-response system with integrated web-response to receive intravenous pembrolizumab 200 mg once every 3 weeks for 35 cycles (pembrolizumab group), or to single-drug chemotherapy per investigator's choice of capecitabine, eribulin, gemcitabine, or vinorelbine (60% enrolment cap for each; chemotherapy group). Randomisation was stratified by PD-L1 tumour status (positive [combined positive score (CPS) ≥1] vs negative [CPS <1]) and history of previous neoadjuvant or adjuvant treatment versus de-novo metastatic disease at initial diagnosis. Primary endpoints were overall survival in participants with a PD-L1 combined positive score (CPS) of 10 or more, those with a CPS of 1 or more, and all participants; superiority of pembrolizumab versus chemotherapy was tested in all participants only if shown in those with a CPS of one or more. The primary endpoint was analysed in the intention-to-treat population; safety was analysed in the all-subjects-as-treated population. This Article describes the final analysis of the trial, which is now completed. This trial is registered with ClinicalTrials.gov, number NCT02555657. FINDINGS: From Nov 25, 2015, to April 11, 2017, 1098 participants were assessed for eligibility and 622 (57%) were randomly assigned to receive either pembrolizumab (312 [50%]) or chemotherapy (310 [50%]). Median study follow-up was 31·4 months (IQR 27·8-34·4) for the pembrolizumab group and 31·5 months (27·8-34·6) for the chemotherapy group. Median overall survival in patients with a PD-L1 CPS of 10 or more was 12·7 months (95% CI 9·9-16·3) for the pembrolizumab group and 11·6 months (8·3-13·7) for the chemotherapy group (hazard ratio [HR] 0·78 [95% CI 0·57-1·06]; log-rank p=0·057). In participants with a CPS of 1 or more, median overall survival was 10·7 months (9·3-12·5) for the pembrolizumab group and 10·2 months (7·9-12·6) for the chemotherapy group (HR 0·86 [95% CI 0·69-1·06]; log-rank p=0·073). In the overall population, median overall survival was 9·9 months (95% CI 8·3-11·4) for the pembrolizumab group and 10·8 months (9·1-12·6) for the chemotherapy group (HR 0·97 [95% CI 0·82-1·15]). The most common grade 3-4 treatment-related adverse events were anaemia (three [1%] patients in the pembrolizumab group vs ten [3%] in the chemotherapy group), decreased white blood cells (one [<1%] vs 14 [5%]), decreased neutrophil count (one [<1%] vs 29 [10%]), and neutropenia (0 vs 39 [13%]). 61 (20%) patients in the pembrolizumab group and 58 (20%) patients in the chemotherapy group had serious adverse events. Three (<1%) of 601 participants had treatment-related adverse events that led to death (one [<1%] in the pembrolizumab group due to circulatory collapse; two [1%] in the chemotherapy group, one [<1%] due to pancytopenia and sepsis and one [<1%] haemothorax). INTERPRETATION: Pembrolizumab did not significantly improve overall survival in patients with previously treated metastatic triple-negative breast cancer versus chemotherapy. These findings might inform future research of pembrolizumab monotherapy for selected subpopulations of patients, specifically those with PD-L1-enriched tumours, and inform a combinatorial approach for the treatment of patients with metastatic triple-negative breast cancer. FUNDING: Merck Sharp & Dohme.

A phase Ib/II study of xentuzumab, an IGF-neutralising antibody, combined with exemestane and everolimus in hormone receptor-positive, HER2-negative locally advanced/metastatic breast cancer.

BACKGROUND: Xentuzumab-a humanised IgG1 monoclonal antibody-binds IGF-1 and IGF-2, inhibiting their growth-promoting signalling and suppressing AKT activation by everolimus. This phase Ib/II exploratory trial evaluated xentuzumab plus everolimus and exemestane in hormone receptor-positive, locally advanced and/or metastatic breast cancer (LA/MBC). METHODS: Patients with hormone receptor-positive/HER2-negative LA/MBC resistant to non-steroidal aromatase inhibitors were enrolled. Maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of xentuzumab/everolimus/exemestane were determined in phase I (single-arm, dose-escalation). In phase II (open-label), patients were randomised 1:1 to the RP2D of xentuzumab/everolimus/exemestane or everolimus/exemestane alone. Randomisation was stratified by the presence of visceral metastases. Primary endpoint was progression-free survival (PFS). RESULTS: MTD was determined as xentuzumab 1000 mg weekly plus everolimus 10 mg/day and exemestane 25 mg/day. A total of 140 patients were enrolled in phase II (70 to each arm). Further recruitment was stopped following an unfavourable benefit-risk assessment by the internal Data Monitoring Committee appointed by the sponsor. Xentuzumab was discontinued; patients could receive everolimus/exemestane if clinically indicated. Median PFS was 7.3 months (95% CI 3.3-not calculable) in the xentuzumab/everolimus/exemestane group and 5.6 months (3.7-9.1) in the everolimus/exemestane group (hazard ratio 0.97, 95% CI 0.57-1.65; P = 0.9057). In a pre-specified subgroup of patients without visceral metastases at screening, xentuzumab/everolimus/exemestane showed evidence of PFS benefit versus everolimus/exemestane (hazard ratio 0.21 [0.05-0.98]; P = 0.0293). Most common any-cause adverse events in phase II were diarrhoea (29 [41.4%] in the xentuzumab/everolimus/exemestane group versus 20 [29.0%] in the everolimus/exemestane group), mucosal inflammation (27 [38.6%] versus 21 [30.4%]), stomatitis (24 [34.3%] versus 24 [34.8%]), and asthenia (21 [30.0%] versus 24 [34.8%]). CONCLUSIONS: Addition of xentuzumab to everolimus/exemestane did not improve PFS in the overall population, leading to early discontinuation of the trial. Evidence of PFS benefit was observed in patients without visceral metastases when treated with xentuzumab/everolimus/exemestane, leading to initiation of the phase II XENERA™-1 trial (NCT03659136). TRIAL REGISTRATION: ClinicalTrials.gov, NCT02123823 . Prospectively registered, 8 March 2013.

Final results of the randomized phase 2 LEO trial and bone protective effects of everolimus for premenopausal hormone receptor-positive, HER2-negative metastatic breast cancer.

The phase 2 LEO study showed that everolimus (EVE) plus letrozole (LET) with ovarian suppression increased progression-free survival (PFS) in tamoxifen-exposed premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer with visceral metastases. Here we report final survival outcomes from the LEO study, and the results of exploratory analyses of bone turnover marker changes and bone-specific progressive disease. Patients who were exposed to or progressed on tamoxifen as adjuvant/palliative treatments were randomly assigned (2:1) to the EVE (leuprorelin + LET + EVE, n = 92) or LET (leuprorelin + LET, n = 45) arm. In a median 51-months of follow-up, the median PFS was 17.5 and 13.8 months in the EVE and LET arms, respectively (P = .245). Patients in the EVE arm with baseline visceral (median PFS 16.4 vs 9.5 months, P = .040) and bone (median PFS 17.1 vs 10.9, P = .003) metastases had greater PFS compared to the LET arm. No differences in overall survival (OS) were observed (median OS, 48.3 vs 50.8 months, P = .948). The 1-year cumulative incidences of bone-specific disease progression were 6.0% and 23.4% in the EVE and LET arms, respectively (hazard ratio 0.26, P < .001). Bone turnover markers at 6 and 12 weeks after treatment decreased in the EVE arm but were increased or stationary in the LET arm. Skeletal-related events occurred in 6.5% and 11.1% of patients in the EVE and LET arms, respectively. EVE + LET with ovarian suppression prolonged PFS in patients with baseline visceral or bone metastases and offered bone-protective effects in the overall study population. However, these clinical benefits did not translate into an OS benefit.

Safety and efficacy of everolimus (EVE) plus exemestane (EXE) in postmenopausal women with locally advanced or metastatic breast cancer: final results from EVEREXES.

BACKGROUND: This study was conducted to collect clinical safety, tolerability, and efficacy data with the use of everolimus (EVE) combined with exemestane (EXE) in patients with advanced breast cancer (ABC). METHODS: The EVEREXES trial initiated in 2012, provided early access to the first dual blockade treatment with EVE + EXE in patients with HR+, HER2 - ABC in Asia and other emerging growth countries. Postmenopausal women with HR+, HER2 - ABC who had documented recurrence or progression, following a nonsteroidal aromatase inhibitor therapy, were treated with EVE (10 mg/day) + EXE (25 mg/day) orally. RESULTS: A total of 235 patients received ≥ 1 dose of study medication. At the end of the study, all patients ceased the treatment. Disease progression (66.0%) was the primary reason of discontinuation. The most common AEs (≥ 20%) were stomatitis, decreased appetite, hyperglycemia, rash, aspartate aminotransferase increased, anemia, alanine aminotransferase increased, cough, and fatigue. No new safety concerns were identified in the current study. Median progression-free survival (PFS) in the Asian subset was similar to that of the overall population (9.3 months in both groups). Confirmed overall response rate (ORR) was achieved for 19.6% of the patients. Efficacy of EVE + EXE across subgroups (prior CT, line of treatment, and presence of visceral metastases) was maintained. CONCLUSION: The safety and efficacy results from EVEREXES trial are consistent to data previously reported in BOLERO-2. These results support that EVE + EXE could be a viable treatment option for the postmenopausal women with HR+, HER2 - ABC in Asian region.

Neratinib + capecitabine sustains health-related quality of life in patients with HER2-positive metastatic breast cancer and ≥ 2 prior HER2-directed regimens.

PURPOSE: To characterize health-related quality of life (HRQoL) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) from the NALA phase 3 study. METHODS: In NALA (NCT01808573), patients were randomized 1:1 to neratinib + capecitabine (N + C) or lapatinib + capecitabine (L + C). HRQoL was assessed using seven prespecified scores from the European Organisation for Research and Treatment of Cancer Quality Of Life Questionnaire core module (QLQ-C30) and breast cancer-specific questionnaire (QLQ-BR23) at baseline and every 6 weeks. Descriptive statistics summarized scores over time, mixed models evaluated differences between treatment arms, and Kaplan-Meier methods were used to assess time to deterioration in HRQoL scores of ≥ 10 points. RESULTS: Of the 621 patients randomized in NALA, patients were included in the HRQoL analysis if they completed baseline and at least one follow-up questionnaire. The summary, global health status, physical functioning, fatigue, constipation, and systemic therapy side effects scores were stable over time with no persistent differences between treatment groups. There were no differences in time to deterioration (TTD) for the QLQ-C30 summary score between treatment arms; the hazard ratio (HR) for N + C vs. L + C was 0.94 (95% CI 0.63-1.40). Only the diarrhea score worsened significantly more in the N + C arm as compared to the L + C arm, and this remained over time (HR for TTD for N + C vs. L + C was 1.71 [95% CI 1.32-2.23]). CONCLUSION: In NALA, patients treated with N + C maintained their global HRQoL over time, despite a worsening of the diarrhea-related scores. These results may help guide optimal treatment selection for HER2-positive MBC.

Analysis of the pan-Asian subgroup of patients in the NALA Trial: a randomized phase III NALA Trial comparing neratinib+capecitabine (N+C) vs lapatinib+capecitabine (L+C) in patients with HER2+metastatic breast cancer (mBC) previously treated with two or more HER2-directed regimens.

PURPOSE: Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has demonstrated systemic efficacy and intracranial activity in various stages of HER2+breast cancer. NALA was a phase III randomized trial that assessed the efficacy and safety of neratinib+capecitabine (N+C) against lapatinib+capecitabine (L+C) in HER2+ metastatic breast cancer (mBC) patients who had received ≥ 2 HER2-directed regimens. Descriptive analysis results of the Asian subgroup in the NALA study are reported herein. METHODS: 621 centrally assessed HER2+ mBC patients were enrolled, 202 of whom were Asian. Those with stable, asymptomatic brain metastases (BM) were eligible for study entry. Patients were randomized 1:1 to N (240 mg qd) + C (750 mg/m2 bid, day 1-14) with loperamide prophylaxis or to L (1250 mg qd) + C (1000 mg/m2 bid, day 1-14) in 21-day cycles. Co-primary endpoints were centrally assessed progression-free survival (PFS) and overall survival (OS). Secondary endpoints included time to intervention for central nervous system (CNS) disease, objective response rate, duration of response (DoR), clinical benefit rate, and safety. RESULTS: 104 and 98 Asian patients were randomly assigned to receive N+C or L+C, respectively. Median PFS of N+C and L+C was 7.0 and 5.4 months (P = 0.0011), respectively. Overall cumulative incidence of intervention for CNS disease was lower with N+C (27.9 versus 33.8%; P = 0.039). Both median OS (23.8 versus 18.7 months; P = 0.185) and DoR (11.1 versus 4.2 months; P < 0.0001) were extended with N+C, compared to L+C. The incidences of grade 3/4 treatment emergent adverse events (TEAEs) and TEAEs leading to treatment discontinuation were mostly comparable between the two arms. Diarrhea and palmar-plantar erythrodysesthesia were the most frequent TEAEs in both arms, similar to the overall population in incidence and severity. CONCLUSION: Consistent with the efficacy profile observed in the overall study population, Asian patients with HER2+ mBC, who had received ≥ 2 HER2-directed regimens, may also benefit from N+C. No new safety signals were noted. CLINICAL TRIAL REGISTRATION: NCT01808573.

Genome-wide association study of genetic variants related to anthracycline-induced cardiotoxicity in early breast cancer.

We performed a genome-wide association study to investigate the association between single nucleotide polymorphisms and anthracycline-induced cardiotoxicity (ACT) in patients diagnosed with early breast cancer. From January 2000 to December 2015, 8490 patients underwent breast surgery at the National Cancer Center in Korea. Patients who received doxorubicin (cumulative dose 240 mg/m2 -300 mg/m2 ) with or without trastuzumab as a neoadjuvant/adjuvant therapy were included in our cohort. Sixty-seven patients in our cohort were diagnosed with ACT. Clinical data, including age, body weight, height, cancer stage, trastuzumab treatment, comorbidities, and concomitant medications, were collected retrospectively. Patients were classified as having either persistent or transient ACT based on their clinical course. In total, 346 946 single nucleotide polymorphisms in 42 cases and 215 controls were tested in this study. Body mass index (BMI) ≥25 kg/m2 [odds ratio (OR) = 2.45, 95% confidence interval (CI), 1.23-4.88, P = .011] and trastuzumab use (OR = 2.40, 95% CI, 1.11-5.17, P = .026) were identified as significant risk factors. We found 7 genetic variants for ACT including rs17530621 (SHISA3, P = 3.10E-06), rs11894115 (MPP4, P = 4.71E-06), rs58328254 (RPL7, P = 6.09E-06), and rs117299725 (PRUNE2, P = 8.53E-06), although none of these variants reached the Bonferroni-corrected significance level when adjusted for BMI and trastuzumab use ( = α1.44E-07 based on 0.05/346 946). rs117299725 was a common variant when only the persistent ACT group was analyzed separately. It is meaningful that our study analyzed comprehensively the influence of genetic variation on ACT, along with some clinical factors in Asian breast cancer patients who received anthracycline with or without trastuzumab. Further research will be needed on candidate genetic variants found in this study.

Cumulative incidence of chemotherapy-induced cardiotoxicity during a 2-year follow-up period in breast cancer patients.

PURPOSE: Cardiotoxicities are adverse effects often reported in chemotherapy-treated breast cancer patients. This study evaluated the potential risk factors and cumulative incidence of doxorubicin-induced cardiotoxicity in Korean breast cancer patients. METHODS: We retrospectively analyzed the data of 613 breast cancer patients who underwent a multigated acquisition (MUGA) scan or echocardiography prior to chemotherapy and at least one post-chemotherapy follow-up MUGA scan/echocardiography between 2007 and 2016 at National Cancer Center, Korea. The Cox proportional hazards models were used to evaluate cardiotoxicity risks. Competing risks analyses were performed to estimate cumulative incidence of cardiotoxicity. RESULTS: Risk factors associated with cardiotoxicity within 2 years of doxorubicin administration included age [adjusted hazard ratio (aHR) = 1.02, 95% confidence interval (CI) 1.00-1.04; p = 0.05], metastasis (aHR = 2.66; 95% CI 1.36-5.20; p < 0.01), and concomitant trastuzumab (aHR = 4.08; 95% CI 2.31-7.21; p < 0.01). The cumulative incidence of patients with cardiotoxicity was 6.1% at 2 years (without substantial change from about 9 months)and 20.2% at 2 years (without substantial change from about 15 months) after initiation of doxorubicin-containing therapy without and with trastuzumab, respectively. CONCLUSIONS: Susceptibility to chemotherapy-induced cardiotoxicity within 2 years of doxorubicin initiation in breast cancer patients was elevated with old age, metastasis, and concomitant trastuzumab. Regular imaging monitoring at least up to 9 months after doxorubicin initiation in patients treated without concomitant trastuzumab, and 15 months in patients treated with concomitant trastuzumab, is needed for early detection of chemotherapy-induced cardiotoxicity.

Clinical implications of HER2 mRNA expression and intrinsic subtype in refractory HER2-positive metastatic breast cancer treated with pan-HER inhibitor, poziotinib.

INTRODUCTION: We explored clinical implication of intrinsic molecular subtype in human epidermal growth factor receptor 2 (HER2) + metastatic breast cancer (BC) with pan-HER inhibitor from a phase II clinical trial of poziotinib in refractory HER2+BC patients. METHODS: For this translational research correlated with phase II clinical trial, we performed an nCounter expression assay, using gene panel including 50 genes for PAM50 prediction and targeted deep sequencing. RESULTS: From 106 participants, we obtained 97 tumor tissues and analyzed gene expression in 91 of these samples. Of 91 HER2+BCs, 40 (44.0%) were HER2-enriched (E) intrinsic molecular subtype, 17 (18.7%) of Luminal A, 16 (17.6%) of Basal-like, 14 (15.4%) of Luminal B and 4 (4.4%) of Normal-like. HER2-E subtype was associated with hormone receptor negativity (odds ratio [OR] 2.93; p = 0.019), 3 + of HER2 immunohistochemistry(IHC) (OR 5.64; p = 0.001), high mRNA expression of HER2 (OR 14.43; p = 0.001) and copy number(CN) amplification of HER2 (OR 12.80; p = 0.005). In genetic alterations, alteration was more frequently observed in HER2-E subtype (OR 3.84; p = 0.022) but there was no association between PIK3CA alteration and HER2-E subtype (p = 0.655). In terms of drug efficacy, high mRNA expression of HER2 was the most powerful predictor of poziotinib response (median progression-free survival [PFS): 4.63 months [high] vs. 2.56 [low]; p < .001). In a combination prediction model, median PFS of intrinsic subtypes except Her2-E with high HER2 mRNA expression without PIK3CA genetic alteration was 6.83 months and that of the remaining group was 1.74 months (p < .001). CONCLUSION: HER2-E subtype was associated with hormone receptor status, HER2 IHC, CN and mRNA expression and TP53 mutation. In survival analysis, the information of level of HER2 mRNA expression, intrinsic molecular subtype and PI3K pathway alteration would be independent predictors to poziotinib treatment. ClinicalTrials.gov identifier: NCT02418689.

A pilot study on intermittent every other days of 5-dose Filgrastim compared with single Pegfilgrastim in breast Cancer patients receiving adjuvant Docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy.

Aim To compare the efficacy and safety of intermittent every other days 5-dose filgrastim with single pegfilgrastim in patients with breast cancer receiving adjuvant docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy. Methods In this pilot study, Korean patients who had undergone complete resection for breast cancer and scheduled for adjuvant TAC chemotherapy were enrolled. Patients were randomized to receive either intermittent 5 doses of filgrastim (5 mcg/kg/day) or once-a-cycle pegfilgrastim (6 mg) as primary prophylaxis during the first three cycles of the TAC chemotherapy. Absolute neutrophil count (ANC) was analyzed as well. Results A total of 22 patients were randomly and equally divided into filgrastim or pegfilgrastim arms. Febrile neutropenia (FN) occurred in 1 patient in the pegfilgrastim arm (1 of 33 cycles) and none in the filgrastim arm. G3 neutropenia occurred in 1 patient (1 of 33 cycles) in the filgrastim arm and 2 patients (4 of 33 cycles) in the pegfilgrastim arm (P = 0.476). G4 neutropenia occurred in 11 patients (28 of 33 cycles) in the filgrastim arm and 9 patients (18 of 33 cycles) in the pegfilgrastim arm (P = 0.476). Except for on day 9 in cycle 3, there was no significant difference between the two groups in terms of ANC. Conclusion We observed no significant differences between the two methods of prophylaxis in terms of FN and G3/4 neutropenia incidence in patients receiving adjuvant TAC chemotherapy. Intermittent every other days 5-dose filgrastim may be available alternative to pegfilgrastim.

Molecular alterations and poziotinib efficacy, a pan-HER inhibitor, in human epidermal growth factor receptor 2 (HER2)-positive breast cancers: Combined exploratory biomarker analysis from a phase II clinical trial of poziotinib for refractory HER2-positive breast cancer patients.

We aimed to investigate the impact of genetic alterations on the efficacy of poziotinib in a phase II clinical trial of patients with heavily treated HER2-positive metastatic breast cancer (BC). We performed targeted ultra-deep sequencing with a customized cancer gene panel and RNA expression assay using BC specimens. Of 106 patients, biomarker data were available for 85. Copy number (CN) amplifications of HER2 were observed in 72 patients (85%), and CN >8 in 50 (59%). Single nucleotide variants (SNVs) of HER2 were found in 16 patients (19%). Genetic alterations of PIK3CA pathway were found in 40 patients (47%). Median progression free survival (PFS) of the biomarker analysis group was 3.61 months. In terms of PFS, HER2 with CN >8 prolonged (hazard ratio (HR) 0.61, 95% CI: 0.38, 0.97, p = 0.037) and alteration of PIK3CA pathway shortened the duration of survival (HR 2.25, 95% CI: 1.39, 3.63, p = 0.001). SNVs of HER2 increased survival duration, but the effect was not significant (HR: 0.58, 95% CI: 0.31, 1.08, p = 0.085). In addition, SNVs in the ERBB3 cytoplasmic domain decreased poziotinib response (HR: 4.58, 95% CI: 2.02, 10.37, p < 0.001). In multigene analysis, BC with HER2 CN >8 and intact PIK3CA pathway had significantly longer PFS compared to others (HR: 0.37, 95% CI: 0.21, 0.66, p = 0.001), while SNVs in the ERBB3 cytoplasmic domain predicted poor prognosis (HR: 4.28, 95% CI: 1.71, 10.71, p < 0.001). In conclusion, HER2 CN amplification, PIK3CA pathway alteration, and ERBB3 cytoplasmic mutation showed predictive roles on clinical outcomes of HER2-positive MBC treated with poziotinib.

A multi-national, randomised, open-label, parallel, phase III non-inferiority study comparing NK105 and paclitaxel in metastatic or recurrent breast cancer patients.

BACKGROUND: NK105 is a novel nanoparticle drug delivery formulation that encapsulates paclitaxel (PTX) in polymeric micelles. We conducted an open-label phase III non-inferiority trial to compare the efficacy and safety of NK105 and PTX in metastatic or recurrent breast cancer. METHODS: Patients were randomly assigned in a 1:1 ratio to receive either NK105 (65 mg/m2) or PTX (80 mg/m2) on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was progression-free survival (PFS), with a non-inferiority margin of 1.215. RESULTS: A total of 436 patients were randomised and 211 patients in each group were included in the efficacy analysis. The median PFS was 8.4 and 8.5 months for NK105 and PTX, respectively (adjusted hazard ratio: 1.255; 95% confidence interval: 0.989-1.592). The median overall survival and overall response rates were 31.2 vs. 36.2 months and 31.6% vs. 39.0%, respectively. The two groups exhibited similar safety profiles. The incidence of peripheral sensory neuropathy (PSN) was 1.4% vs. 7.5% (≥Grade 3) for NK105 and PTX, respectively. The patient-reported outcomes of PSN were significantly favourable for NK105 (P < 0.0001). CONCLUSIONS: The primary endpoint was not met, but NK105 had a better PSN toxicity profile than PTX. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT01644890.

PF-05280014 (a trastuzumab biosimilar) plus paclitaxel compared with reference trastuzumab plus paclitaxel for HER2-positive metastatic breast cancer: a randomised, double-blind study.

BACKGROUND: This randomised, double-blind study compared PF-05280014 (a trastuzumab biosimilar) with reference trastuzumab (Herceptin®) sourced from the European Union (trastuzumab-EU), when each was given with paclitaxel as first-line treatment for HER2-positive metastatic breast cancer. METHODS: Between 4 April 2014 and 22 January 2016, 707 participants were randomised 1:1 to receive intravenous PF-05280014 plus paclitaxel (PF-05280014 group; n = 352) or trastuzumab-EU plus paclitaxel (trastuzumab-EU group; n = 355). PF-05280014 or trastuzumab-EU was administered weekly (first dose 4 mg/kg, subsequent doses 2 mg/kg), with the option to change to a 3-weekly regimen (6 mg/kg) from Week 33. Treatment with PF-05280014 or trastuzumab-EU could continue until disease progression. Paclitaxel (starting dose 80 mg/m2) was administered on Days 1, 8 and 15 of 28-day cycles for at least six cycles or until maximal benefit of response. The primary endpoint was objective response rate (ORR), evaluating responses achieved by Week 25 and confirmed by Week 33, based on blinded central radiology review. RESULTS: The risk ratio for ORR was 0.940 (95% CI: 0.842-1.049). The 95% CI fell within the pre-specified equivalence margin of 0.80-1.25. ORR was 62.5% (95% CI: 57.2-67.6%) in the PF-05280014 group and 66.5% (95% CI: 61.3-71.4%) in the trastuzumab-EU group. As of data cut-off on 11 January 2017 (using data up to 378 days post-randomisation), there were no notable differences between groups in progression-free survival (median: 12.16 months in the PF-05280014 group vs. 12.06 months in the trastuzumab-EU group; 1-year rate: 54% vs. 51%) or overall survival (median: not reached in either group; 1-year rate: 89.31% vs. 87.36%). Safety outcomes and immunogenicity were similar between the treatment groups. CONCLUSION: When given as first-line treatment for HER2-positive metastatic breast cancer, PF-05280014 plus paclitaxel demonstrated equivalence to trastuzumab-EU plus paclitaxel in terms of ORR. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT01989676.

Randomised Phase 2 study of lapatinib and vinorelbine vs vinorelbine in patients with HER2 + metastatic breast cancer after lapatinib and trastuzumab treatment (KCSG BR11-16).

BACKGROUND: The continuum of anti-HER2 agents is a standard treatment of HER2 + metastatic breast cancer (MBC). This study evaluated the efficacy of lapatinib plus vinorelbine in patients progressed on both trastuzumab and lapatinib treatments. METHODS: A total of 149 patients were randomly assigned to lapatinib with vinorelbine (LV) (n = 75; lapatinib, 1000 mg daily; vinorelbine 20 mg/m2 D1, D8 q3w) or vinorelbine (V) (n = 74; 30 mg/m2 D1, D8 q3w). The primary endpoint was progression-free survival (PFS) rate at 18 weeks. RESULTS: The median number of previous anti-HER2 therapies was 2 (range 2-5). There was no significant difference in PFS rate at 18 weeks between LV and V arms (45.9% vs 38.9%, p = 0.40). ORR was 19.7% in LV arm, and 16.9% in V arm (p = 0.88). PFS and OS did not differ between two arms (LV vs V; median PFS, 16 vs 12 weeks, HR = 0.86, 95% CI 0.61-1.22; median OS, 15.0 vs 18.9 months, HR = 1.07, 95% CI 0.72-1.58). Toxicity profiles were similar in both arms and all were manageable. CONCLUSIONS: Lapatinib plus vinorelbine treatment was tolerable; however, it failed to demonstrate the clinical benefits over vinorelbine alone in patients with HER2 + MBC after progression on both trastuzumab and lapatinib. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov number NCT01730677.

Exploratory biomarker analysis from a phase II clinical trial of eribulin plus gemcitabine versus paclitaxel plus gemcitabine for HER2-negative metastatic breast cancer patients (KCSG BR13-11).

PURPOSE: We conducted an exploratory biomarker study from a phase II clinical trial of eribulin plus gemcitabine (EG) versus paclitaxel plus gemcitabine (PG) in HER2-negative metastatic breast cancer (BC) patients. METHODS: We performed targeted deep sequencing with a customized cancer gene panel and RNA expression assay. Tumor mutation burden (TMB) and mutation signatures were determined based on genetic alteration in targeted regions. Gene set variation analysis was performed with PanCancer Immune Profiling and PanCancer Pathway Panels. Statistical analyses were conducted to identify the associations between genetic alterations and clinical outcomes. RESULTS: Of 119 patients, 40 had available biomarker data. Among the 40 patients, 4 supported their post-treatment tissues. In targeted deep sequencing, FAT3 (48%) was the most frequently mutated gene, followed by PKHD1, TP53, GATA3, PARP4, and PIK3CA. In terms of gene expression, low expression of epithelial-mesenchymal transition (EMT) pathway genes was associated with prolonged progression-free survival (PFS) in the EG group, while high expression of the EMT pathway was associated with good prognosis in the PG group. Median TMB was 6.5 (range 2.44-46.34) and there was no relationship between TMB and patient prognosis. Analysis of mutation signatures showed that signatures 3, 20, and 26 were frequently observed in our cohort. Further survival analysis according to mutation signature showed that mutation signature 3, as a homologous recombinant deficiency-related signature, was highly associated with disease progression (hazard ratio (log2 scale) 8.21, 95% confidence interval 2.93-13.48, p = 0.002). Kaplan-Meier plot also showed that BCs with signature 3 had short PFS compared to those without these signatures (median PFS (months) for signature 3 (low vs. high): 17.2 vs. 8.1, p = 0.0026). CONCLUSIONS: Mutation signature 3, found in about 30% of MBCs regardless of hormone receptor status, was associated with short PFS for patients with cytotoxic chemotherapy. TRIAL REGISTRY: ClinicalTrials.gov number: NCT02263495.