Homologous repair deficiency score for identifying breast cancers with defective DNA damage response

Breast cancer (BC) in patients with germline mutations of BRCA1/BRCA2 are associated with benefit from drugs targeting DNA damage response (DDR), but they account for only 5-7% of overall breast cancer. To define the characteristics of these tumors and also to identify tumors without BRCA mutation but with homologous recombination deficiency (HRD) is clinically relevant. To define characteristic features of HRD tumors and analyze the correlations between BRCA1/BRCA2 and BC subtypes, we analyzed 981 breast tumors from the TCGA database using the signature analyzer. The BRCA signature was strongly associated with the HRD score top 10% (score ≥ 57) population. This population showed a high level of mutations in DDR genes, including BRCA1/BRCA2. HRD tumors were associated with high expression levels of BARD1 and BRIP1. Besides, BRCA1/2 mutations were dominantly observed in basal and luminal subtypes, respectively. A comparison of HRD features in BC revealed that BRCA1 exerts a stronger influence inducing HRD features than BRCA2 does. It reveals genetic differences between BRCA1 and BRCA2 and provides a basis for the identification of HRD and other BRCA-associated tumors.

Survival benefit of adjuvant chemoradiotherapy for positive or close resection margin after curative resection of pancreatic adenocarcinoma

BACKGROUND

This study was conducted to identify patients who may benefit from adjuvant chemoradiotherapy (CRT) for positive or close resection margin (RM) after curative resection of pancreatic adenocarcinoma.

METHODS

From 2004 to 2015, total of 472 patients with pancreatic adenocarcinoma underwent curative resection. After excluding patients with RM > 2 mm or unknown, remaining 217 patients were retrospectively analyzed. Forty-six (21.2%) patients were treated with adjuvant chemotherapy alone (CTx; mainly gemcitabine-based), 142 (65.4%) with adjuvant CRT (mainly upfront), and 29 (13.4%) patients didn't receive any adjuvant therapy (noTx group).

RESULTS

Locoregional recurrence rate was significantly lower in the CRT group (43.7%) than in the CTx group (71.7%) or noTx group (65.5%) (p = 0.001). Significant survival benefits of CRT over CTx (HR 0.602, p = 0.020 for overall survival (OS); HR 0.599, p = 0.016 for time to any recurrence (TTR)) were demonstrated in multivariate analysis. CRT group had more 5-year survivors than other groups. In the subgroup analysis, such benefits of adjuvant CRT over CTx was observed only in patients with head tumor & vascular RM > 0.5 mm, but not in patients with body/tail tumor or vascular RM ≤ 0.5 mm. In the CRT group, radiation dose≥54 Gy was significantly associated with better TTR and OS.

CONCLUSIONS

Adjuvant CRT could improve TTR and OS compared to adjuvant CTx alone in patients with close RM under 2 mm. Radiation dose escalation may be beneficial when feasible. Modern CRT regimen-based randomized evidence is needed for these high-risk patients.

Effect of Timing of Gonadotropin-Releasing Hormone Agonist Administration for Ovarian Protection in Patients with Breast Cancer

Purpose

This study was performed to investigate the effect of the interval between the start of gonadotropin-releasing hormone agonist (GnRHa) and the start of chemotherapy on ovarian protection in patients with breast cancer.

Methods

This was a prospective observational cohort study that included 136 patients with breast cancer below 40 years who received GnRHa during chemotherapy for fertility preservation. Plasma anti-Müllerian hormone (AMH) levels were measured before chemotherapy (baseline) and after chemotherapy. Subjects were divided into 3 groups according to the interval between the start of GnRHa and the start of chemotherapy for analysis: 1–6 days, 7–13 days, and ≥ 14 days. The ratio of the post-chemotherapy AMH value to the baseline AMH (pcAMH) at each time point were compared among the 3 groups. Ranked analysis of covariance was used for statistical analysis, adjusted for age, body mass index (BMI), and the existence of polycystic ovaries (PCOs). In addition, recovery of ovarian function (AMH ≥ 1 ng/mL) at 12 months was evaluated.

Results

The median age of the patients was 32 years. There was no difference in the baseline AMH levels among the 3 groups (mean ± standard error: 5.0 ± 0.4 ng/mL [1–6 days], 5.3 ± 0.7 ng/mL [7–13 days], and 8.1 ± 1.3 ng/mL [≥ 14 days]; p = 0.250). The pcAMH at 3, 6, 12, 24, and 36 months were not significantly different among the 3 groups (p-values were 0.332, 0.732, 0.830, 0.148, and 0.393, respectively). In multivariate analysis, young age (p = 0.024), low BMI (p = 0.013), and the existence of PCO (p = 0.015) were predictors for AMH ≥ 1 ng/mL at 12 months.

Conclusion

There was no difference in the ovarian protective effect according to the difference in the timing of administration of GnRHa.

Contrasting Epidemiology and Clinicopathology of Female Breast Cancer in Asians vs the US Population

BACKGROUND

The incidence of breast cancer among younger East Asian women has been increasing rapidly over recent decades. This international collaborative study systemically compared the differences in age-specific incidences and pathological characteristics of breast cancer in East Asian women and women of predominantly European ancestry.

METHODS

We excerpted analytic data from six national cancer registries (979 675 cases) and eight hospitals (18 008 cases) in East Asian countries and/or regions and, for comparisons, from the US Surveillance, Epidemiology, and End Results program database. Linear regression analyses of age-specific incidences of female breast cancer and logistic regression analyses of age-specific pathological characteristics of breast cancer were performed. All statistical tests were two-sided.

RESULTS

Unlike female colorectal cancer, the age-specific incidences of breast cancer among East Asian women aged 59 years and younger increased disproportionally over recent decades relative to rates in US contemporaries. For years 2010-2014, the estimated age-specific probability of estrogen receptor positivity increased with age in American patients, whereas that of triple-negative breast cancer (TNBC) declined with age. No similar trends were evident in East Asian patients; their probability of estrogen receptor positivity at age 40-49 years was statistically significantly higher (odd ratio [OR] = 1.50, 95% confidence interval [CI] = 1.36 to 1.67, P < .001) and of TNBC was statistically significantly lower (OR = 0.79, 95% CI = 0.71 to 0.88, P < .001), whereas the probability of ER positivity at age 50-59 years was statistically significantly lower (OR = 0.88, 95% CI = 0.828 to 0.95, P < .001). Subgroup analyses of US Surveillance, Epidemiology, and End Results data showed similarly distinct patterns between East Asian American and white American patients.

CONCLUSIONS

Contrasting age-specific incidences and pathological characteristics of breast cancer between East Asian and American women, as well as between East Asian Americans and white Americans, suggests racial differences in the biology.

Effectiveness of nivolumab versus regorafenib in hepatocellular carcinoma patients who failed sorafenib treatment

Background/Aims

Several treatment options are currently available for patients with hepatocellular carcinoma (HCC) failing previous sorafenib treatment. We aimed to compare the effectiveness of regorafenib and nivolumab in these patients.

Methods

Consecutive HCC patients who received regorafenib or nivolumab after failure of sorafenib treatment were included. Primary endpoint was overall survival (OS) and secondary endpoints were time to progression, tumor response rate, and adverse events. Inverse probability of treatment weighting (IPTW) using the propensity score was conducted to reduce treatment selection bias.

Results

Among 150 study patients, 102 patients received regorafenib and 48 patients received nivolumab. Median OS was 6.9 (95% confidence interval [CI], 3.0–10.8) months for regorafenib and 5.9 (95% CI, 3.7–8.1) months for nivolumab (P=0.77 by log-rank test). In multivariable analysis, nivolumab was associated with prolonged OS (vs. regorafenib: adjusted hazard ratio [aHR], 0.54; 95% CI, 0.30–0.96; P=0.04). Time to progression was not significantly different between groups (nivolumab vs. regorafenib: aHR, 0.82; 95% CI, 0.51–1.30; P=0.48). HRs were maintained after IPTW. Objective response rates were 5.9% and 16.7% in patients treated with regorafenib and nivolumab, respectively (P=0.04).

Conclusions

After sorafenib failure, the use of nivolumab may be associated with improved OS and better objective response rate as compared to using regorafenib.

Longitudinal and personalized detection of circulating tumor DNA (ctDNA) for monitoring efficacy of atezolizumab plus bevacizumab in patients with unresectable hepatocellular carcinoma (HCC)

3531

Background: ctDNA has emerged as a promising biomarker for noninvasive monitoring of treatment response and disease progression in many tumor types. However, the clinical use of ctDNA in patients with HCC has not been established. Here, we evaluated longitudinal and personalized detection of ctDNA for monitoring the treatment response to atezolizumab (atezo) + bevacizumab (bev) in patients with unresectable HCC not previously treated with systemic therapy. Methods: A subset (n = 48) of 104 patients with HCC who enrolled in Arm A of GO30140 (NCT02715531; Phase 1b) and received atezo + bev treatment were included in this study. These patients had 10 CR, 11 PR, 12 SD and 15 PD per IRF-assessed RECIST 1.1. Serial plasma samples were collected at baseline (Cycle [C]1 Day [D]1), during treatment (C2D1, C4D1) and at disease progression. Somatic mutations in individual tumors were identified via whole exome sequencing of archival tumor tissues or fresh biopsies collected before treatment. Personalized ctDNA assays (Signatera 16-plex multiplex PCR next-generation sequencing assay) specific to each patient’s tumor mutational signatures were successfully designed for 47 of 48 patients. Results: At C1D1, a median of 25.7 ng of cell-free DNA was extracted from 2-mL plasma samples. ctDNA was detected in 45 of 47 patients (96%), with a median of 70.6 mean tumor molecules/mL of plasma (MTM/mL) and a median of 1.8% mean variant allele frequency (mean VAF) in plasma. Higher ctDNA levels detected at C1D1 appeared to be associated with increased tumor burden ( P < 0.03). Dynamic changes in ctDNA levels post-treatment were associated with response at C4D1. ctDNA status changed from positive at baseline to negative in 7 of 10 CR (70%), 3 of 11 PR (27%), 1 of 11 SD (9%) and 0 of 11 PD (0%) patients. Longer PFS was observed in patients whose ctDNA became undetectable post-treatment. The median PFS in patients with ctDNA present vs cleared at C4D1 was 6.5 months and not reached, respectively (HR, 12 [1.7-93], log-rank P < 0.00029). Conclusions: Our study showed that Signatera, a personalized and tumor-informed ctDNA assay, could be used as a sensitive method for detecting ctDNA in patients with unresectable HCC. More importantly, our results illustrate the promise of ctDNA as an emerging biomarker that may potentially help to monitor treatment responses and disease progression in patients with HCC.

Phase II study assessing tolerability, efficacy, and biomarkers for durvalumab (D) ± tremelimumab (T) and gemcitabine/cisplatin (GemCis) in chemo-naïve advanced biliary tract cancer (aBTC)

4520

Background: In aBTC, GemCis is the standard of care as 1st-line treatment. Immunotherapies have shown early promising efficacy in some BTC patients (pts). We assessed D (anti-PD-L1) ± T (anti-CTLA-4) and GemCis in 1L BTC pts, including an extensive biomarker analysis (NCT03046862). Methods: Pts were first enrolled in the biomarker cohort (BMC) to receive 1 cycle of Gem 1000 mg/m2 + Cis 25 mg/m2 on D1 & D8, followed by GemCis + D 1120 mg and T 75 mg, Q3W until disease progression (PD). Subsequent pts were allocated to GemCis + D (3 combo cohort [3C]) or GemCis + D+T (4 combo cohort [4C]) until PD. In all cohorts, tumor biopsies were obtained pre-treatment, after 1 cycle, and at PD. Blood samples for ctDNA were obtained every cycle. Results: 121 pts were enrolled. Median follow-up durations were 28.5 months (m; 95% CI, 26.5-30.5), 11.3 m (95% CI, 9.1-13.5), and 11.9m (95% CI, 8.4-15.4) in the BMC, 3C, and 4C arms, respectively. Efficacy data are shown (Table). The most common adverse events (AEs, any grade) were neutropenia (54.5%), nausea (59.5%), and pruritus (55.44%). The most common grade 3/4 AEs were neutropenia (50.4%), anemia (35.5%), and thrombocytopenia (16.5%). In the BMC cohort, frequent mutations were found in DNA damage repair, cell cycle regulation, and genome instability genes (eg, ATM, BRCA2, POLE, MSH2, CDKN2A). Distinct somatic variants were detected in responders vs non-responders. Baseline tissue TMB did not correlate with PFS or OS. Reductions in ctDNA variant allele frequency (VAF) were more prominent among responders during early D+T cycles. ctDNA VAF on C3, D1 was significantly correlated with ORR ( P< 0.015). Pretreatment PD-L1 expression was not associated with efficacy, but PD-L1 expression after 1st GemCis cycle trended with improved PFS. Conclusions: These are the first clinical data of D±T plus chemotherapy in chemo-naïve aBTC pts. The addition of immunotherapy to chemotherapy was tolerable and showed very promising efficacy. Biomarker analyses show early signs of markers associated with response. The combination of GemCis + D is being investigated in the Phase 3 TOPAZ-1 trial (NCT03875235). Clinical trial information: NCT03046862 . [Table: see text]

Prognostic Role of Androgen Receptor Expression in Surgically Resected Early Breast Cancer Patients

PURPOSE

Endocrine therapy is a standard treatment for hormone receptor-positive breast cancer, which accounts for 60%-75% of all breast cancer. Hormone receptor positivity is a prognostic and predictive biomarker in breast cancer. Approximately 50%-80% of breast cancer is also positive for androgen receptor (AR), but the prognostic and predictive value of AR expression in breast cancer is controversial. Here, we investigated AR expression and its prognostic value in patients with surgically resected breast cancer in Korea.

METHODS

We retrospectively reviewed the medical records of patients who had surgically resected breast cancer to collect AR expression data and other clinicopathological data. The optimal cut-off for AR positivity was determined using a receiver operating characteristic curve analysis.

RESULTS

We reviewed 957 patients with surgically resected breast cancer from June 2012 to April 2013. The median follow-up was 62 months, and relapse events occurred in 101 (10.6%) patients. Unlike the cut-off value of 1% or 10% in previous reports, 35% was determined to be best for predicting relapse-free survival (RFS) in this study. At the cut-off value of 35%, 654 (68.4%) patients were AR-positive. AR expression was more prevalent in luminal A (87.6%) and luminal B (73.1%) types than in human epidermal growth factor receptor 2-positive (56.2%) or triple-negative (20.6%) types. AR expression of ≥ 35% was significantly related to longer RFS in a multivariate analysis (hazard ratio, 0.430; 95% confidence interval, 0.260-0.709; p = 0.001).

CONCLUSION

We propose a cut-off value of 35% to best predict RFS in patients with surgically resected breast cancer. AR expression was positive in 68.4% of patients, and AR positivity was found to be an independent prognostic factor for longer RFS.

The effect of perceived social support on chemotherapy-related symptoms in patients with breast cancer: A prospective observational study

OBJECTIVE

Few studies have examined the effect of perceived social support (PSS) on chemotherapy-related symptoms (CRS). This study examined the effect of PSS on CRS in 184 patients with breast cancer.

METHODS

Participants were consecutively enrolled from a tertiary general hospital in Seoul, South Korea. CRS were assessed eight times, from before the first neoadjuvant chemotherapy to six months after the end of neoadjuvant chemotherapy, with the MD Anderson Symptom Inventory. PSS was evaluated once, before the first neoadjuvant chemotherapy session, using the Multidimensional Scale of Perceived Social Support (MSPSS). Two groups were formed based on MSPSS scores: the low PSS group (n = 62) and the moderate-to-high PSS group (n = 122). Linear mixed model analyses were used to compare the change in CRS severity between the two groups during chemotherapy.

RESULTS

Results indicated a significant group-by-time (low PSS or moderate-to-high PSS; 8 periods of chemotherapy) interaction for pain (p = .005), nausea (p = .033), insomnia (p < .001), distress (p = .003), dyspnea (p = .014), memory loss (p = .021), vomiting (p = .016), and numbness (p = .008) in which the moderate-to-high PSS group showed significantly lower levels of increase in those symptoms during chemotherapy. Moreover, the effect of PSS on CRS differed depending on the sources of PSS.

CONCLUSION

Patients with moderate-to-high PSS experience less severe CRS compared with patients with low PSS during chemotherapy. The current findings indicate the potential benefits of providing social support in the management of CRS.

Abstract P2-19-02: Circulating osteocalcin-positive cells as a novel diagnostic biomarker for bone metastasis in breast cancer patients

Purpose: Diagnosis of bone metastasis (BM) in breast cancer relies on structural changes of bone. We investigated whether circulating osteocalcin-positivecells (cOC) could detect the incipient and/or progressive BM earlier than image-based diagnostics.

Experimental design: Metastatic breast cancer patients with or without bone metastasis (designated BM+ or BM-) were enrolled and cOC were quantified at baseline by flow cytometry. The progression of BM was evaluated after 18 months. Murine BM models were established by intra-tibial or -cardiac injection of MDA-MB-231 or 4T1 breast cancer cells.

Results: In the baseline analysis, cOC was significantly higher in BM+ than BM- group. In the 18-month follow-up study of BM+ patients (n=63), baseline cOC was significantly associated with BM disease progression. Among BM- patients (n=33), three patients developed new bone metastasis within 18 months and were found to have had higher cOC at baseline. The patients with higher cOC showed shortened BM progression-free survival, compared with those with lower cOC (cutoff=0.045%; P&lt;.001; HR 4.79; 95% CI 2.17-10.56). In murine intra-tibial injection models, cOC significantly increased at an early time-point, even when micro-metastases were evident only by histologic examination but undetectable by bioluminescence imaging. Additionally, in an intra-cardiac injection model, the mice with higher cOC developed BM at an earlier time point, compared with the mice with lower cOC.

Conclusions: cOC is increased in the early phase of breast cancer BM and predict the disease progression. cOC can be a novel biomarker for early diagnosis and progression of BM.

Citation Format: Sun Wook W Cho, Kyung-Hun Lee, Tae-Yong Kim, Serk In Park, Seock-Ah Im. Circulating osteocalcin-positive cells as a novel diagnostic biomarker for bone metastasis in breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-19-02.

Phase III study of pembrolizumab (pembro) versus best supportive care (BSC) for second-line therapy in advanced hepatocellular carcinoma (aHCC): KEYNOTE-240 Asian subgroup

526

Background: Pembro received accelerated approval for second-line therapy in aHCC based on KEYNOTE-224 (phase 2). KEYNOTE-240 (NCT02702401) is a randomized, phase 3 study of pembro v BSC in previously treated aHCC. We report outcomes for the Asian subgroup. Methods: Pts with a radiographic/pathologic HCC diagnosis, radiographic progression with/intolerance to sorafenib, Child-Pugh A disease, and ECOG PS 0/1 were randomized 2:1 to pembro (200 mg) + BSC or PBO + BSC Q3W (≤35 cycles or until confirmed PD/unacceptable toxicity). Pts were stratified by geographic region (Asia without Japan; non-Asia with Japan), AFP, and macrovascular invasion. Response was assessed Q6W (RECIST v1.1, central review). Primary end points: OS, PFS; secondary end points: ORR, DOR, safety. Data cutoff: Jan 2, 2019. Results: 413 pts were randomized (overall cohort: n = 278 pembro, n = 135 PBO; Asian subgroup [Hong Kong, Japan, Philippines, S Korea, Taiwan, Thailand]: n = 107, n = 50). HBV+ status and BCLC stage C were higher in Asian subgroup (HBV+: 51% v 24.5% overall; stage C: 86.6% v 79.4%). Median follow-up: pembro (21.3 mo overall; 23.5 mo); PBO (21.5 mo overall; 23.0 mo). Pembro improved OS v PBO (median OS [95% CI]: 13.9 [11.6-16.0] v 10.6 [8.3-13.5] mo; HR: 0.781; 95% CI, 0.611-0.998; P = 0.0238) and PFS (HR: 0.718; 0.570-0.904; P = 0.0022) for overall cohort and Asian subgroup (median OS: 13.8 [10.1-16.9] v 8.3 [6.3-11.8] mo; HR: 0.548; 0.374-0.804; P = 0.0009; PFS: HR: 0.475; 0.324-0.696; P < 0.0001). Differences did not meet prespecified significance level for overall cohort. ORR in overall cohort was 18.3% (14.0-23.4) for pembro; 4.4% (1.6-9.4; P = 0.00007) for PBO; in Asian subgroup, 20.6% (13.4-29.5) and 2.0% (0.1-10.6; P = 0.00135). Safety was consistent with that previously reported in pembro studies. No HBV/HCV flares were identified. Conclusions: Pembro reduced risk for death by 22% in overall cohort and 45% in Asian subgroup and improved PFS v PBO. Safety was comparable to that of pembro monotherapy. Results are consistent with KEYNOTE-224 and magnitude of OS benefit was enhanced in Asian subgroup, supporting a favorable risk-benefit balance for second-line pembro in HCC. Clinical trial information: NCT02702401.

Liposomal Irinotecan + 5-FU/LV in Metastatic Pancreatic Cancer: Subgroup Analyses of Patient, Tumor, and Previous Treatment Characteristics in the Pivotal NAPOLI-1 Trial

OBJECTIVES

The NAnoliPOsomaL Irinotecan (NAPOLI-1) study (NCT01494506) was the largest global phase 3 study in a post-gemcitabine metastatic pancreatic adenocarcinoma (mPAC) population (N = 417). The subanalyses reported here investigated the prognostic effect of tumor characteristics and disease stage, prior treatment characteristics, baseline patient characteristics on survival outcomes in NAPOLI-1, and whether liposomal irinotecan (nal-IRI) + 5-fluorouracil/leucovorin (5-FU/LV) benefited patients with mPAC across subgroups.

METHODS

Post hoc analyses were performed in the NAPOLI-1 population (4 across tumor characteristics and disease stage, 6 across prior treatment characteristics, and 4 across patient baseline characteristics). Survival outcomes were estimated by Kaplan-Meier analysis and patient safety data were evaluated.

RESULTS

Mortality and morbidity risk was lower on nal-IRI+5-FU/LV treatment across subgroups. Exceptions were patients who had received prior nonliposomal irinotecan and those who had undergone prior Whipple procedure (overall survival hazard ratio = 1.25 and 1.23, respectively). Decreased appetite, liver metastases, and number of measurable metastatic lesions seemed to be prognostic of survival in this population. Subgroup safety data were generally comparable with those in the overall NAPOLI-1 safety population.

CONCLUSIONS

A diverse population of patients with mPAC that progressed on gemcitabine-based therapy benefited from nal-IRI+5-FU/LV versus 5-FU/LV, potentially helping guide treatment decisions for challenging cases.

P279 Standard dose of rivaroxaban in Asian patients with atrial fibrillation: 20ms vs.15mg? Off label dose reduction of rivaroxaban should be avoided

Background

Rivaroxaban emerged as potential alternatives to warfarin for the prevention of thromboembolisim in patients with atrial fibrillation (AF). Because of the concern for the risk of major bleeding with rivaroxaban in Asian patients, off label rivaroxaban dose reduction to15mg is common in Asian real-world practice. We aimed to set standard rivaroxaban dose in Asian patients with AF by comparison between on-label rivaroxaban 20mg and off-label reduced rivaroxaban dose 15mg.

Methods

A total of 2,208 consecutive non-valvular AF patients were enrolled between 2011 and 2017. After propensity score matching, both warfarin (n = 804) and rivaroxaban group (n = 804) had comparable baseline characteristics. Rivaroxaban group was further divided into on-label rivaroxaban 20mg group (n = 390) and off-label reduced rivaroxaban 15mg group (n = 333). Efficacy outcome was stroke/systemic embolism. Safety outcome was major bleeding. Primary net clinical benefit (NCB) was defined as the composite of stroke, systemic embolism, major bleeding and all-cause mortality. Secondary NCB was defined as the composite of stroke, systemic embolism and major bleeding. Patients were followed upto one-year or until the first occurrence of any study outcomes.

Results

Both Rivaroxaban groups had comparable efficacy compared to warfarin. However, both on-label rivaroxaban 20mg (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.18-0.90, p = 0.026) and off-label reduced rivaroxaban 15mg (HR 0.37, 95% CI 0.16-0.88, p = 0.025) significantly reduced major bleeding. There were no differences in efficacy and safety outcomes between on-label rivaroxaban 20mg and off-label reduced rivaroxaban 15mg group. On-label rivaroxaban 20mg significantly reduced primary (HR 0.44, 95% CI 0.25-0.79, p = 0.006) and secondary (HR 0.51, 95% CI 0.27-0.96, p = 0.038) NCBs compared to warfarin. However, off-label reduced rivaroxaban 15mg did not reduce both primary and secondary NCBs.

Conclusion

Off-label rivaroxaban dose reduction to 15mg had no benefit compared to on-label rivaroxaban 20mg. Compared to warfarin, on-label rivaroxaban 20mg significantly improved primary and secondary NCBs, whereas off-label reduced rivaroxaban 15mg did not. Therefore, rivaroxaban 20mg is favorable as standard dose in Asian patients.

P99 Rapid ventricular stimulation induces augmented conduction delay in Brugada syndrome patients

Background

The exact mechanism for Brugada Syndrome (BrS) is still not clear. There are two main physiologic hypotheses that have been suggested: the repolarization and the depolarization disorder models. Right ventricular (RV) activation delay was verified by echocardiography, conduction time in an explanted heart or in computer simulation. Verification of prolonged longitudinal activation time in human RV of only 5 patients of type-1 BrS and 5 controls was reported in 2008.

Methods

Bidirectional longitudinal activation times were assessed between RV outflow tract (RVot) and RV-apex (RVa) by stimulating and mapping RV endocardium in BrS patients. Conduction velocity was calculated considering ventricle size and distance between catheters.

Results

The studies were performed in controls (n = 18) and BrS patients (n = 6). There was no statistical difference in RP interval and QRS duration (PR 146 ± 21.7 vs 167 ± 45.2 ms, p = 0.325; QRS 102 ± 28.2 vs 122 ± 32.2 ms, p = 0.163). There was no difference of longitudinal activation time on stimulation at 500 ms (RVa to RVot: 63 ± 14.3 versus 80 ± 34.2 ms, p = 0.290; RVot to RVa: 50 ± 12.2 versus 76 ± 35.1 ms, p = 0.122). The BrS patients had longer longitudinal activation time on stimulation at 400 ms (RVa to RVot: 61 ± 15.2 versus 87 ± 28.7 ms, p = 0.009; RVot to RVa: 52 ± 11.1 versus 76 ± 35.3 ms, p = 0.029). The difference was not significant when isoproterenol was infused.

Conclusions

BrS patients display bidirectional longitudinal conduction delay when rapid stimulation. These findings support that BrS might be partly attributable to depolarization abnormality.

Liposomal irinotecan in metastatic pancreatic adenocarcinoma in Asian patients: Subgroup analysis of the NAPOLI-1 study

The global, randomized NAPOLI‐1 phase 3 trial reported a survival benefit with liposomal irinotecan (nal‐IRI) plus 5‐fluorouracil/leucovorin (nal‐IRI+5‐FU/LV) in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) after previous gemcitabine‐based therapy. Median overall survival (OS) with nal‐IRI+5‐FU/LV was 6.1 vs 4.2 months with 5‐FU/LV alone (unstratified hazard ratio [HR] = 0.67, P = .012). Herein, we report efficacy and safety results from a post‐hoc subgroup analysis of Asian patients treated at Asian centers. Primary study endpoint was OS; secondary endpoints included progression‐free survival (PFS), objective response rate (ORR), and safety. Patients receiving nal‐IRI+5‐FU/LV (n = 34) had significantly longer median OS versus 5‐FU/LV (n = 35) (8.9 vs 3.7 months; unstratified HR = 0.51, P = .025). Patients had significantly increased median PFS with nal‐IRI+5‐FU/LV versus 5‐FU/LV (4.0 vs 1.4; unstratified HR = 0.48, P = .011), and increased ORR (8.8% vs 0; P = .114). nal‐IRI monotherapy (n = 50) numerically improved efficacy endpoints versus 5‐FU/LV (n = 48): median OS was 5.8 versus 4.3 months (HR = 0.83, P = .423) and median PFS was 2.8 versus 1.4 months (HR = 0.69, P = .155). Grade ≥3 neutropenia was reported more frequently with nal‐IRI+5‐FU/LV versus 5‐FU/LV (54.5% vs 3.4%), and incidence of grade ≥3 diarrhea was comparable between the two arms (3.0% vs 6.9%). This subgroup analysis confirms nal‐IRI+5‐FU/LV as an efficacious treatment option that improves survival in Asian patients with mPDAC that progressed after gemcitabine‐based therapy, with a safety profile agreeing with previous findings. The nal‐IRI+5‐FU/LV regimen should represent a new standard of care for these patients in Asia. (Clinicaltrials.gov: NCT01494506)

Amenorrhea and Menopause in Patients with Breast Cancer after Chemotherapy

Purpose

The probability of ovarian failure after cytotoxic chemotherapy in patients with breast cancer has not been well established in Korea. This study aimed to assess the rate of ovarian failure in a large cohort of Korean premenopausal patients with breast cancer 12 months after chemotherapy.

Methods

This retrospective cohort study included premenopausal women (aged 20−44 years) with breast cancer who underwent chemotherapy after surgery. The rates of treatment-related amenorrhea (TRA) and chemotherapy-induced menopause (CIM) at 12 months after chemotherapy were analyzed.

Results

A total of 237 patients met the inclusion criteria. The rate of TRA was 61.6% and that of CIM was 13.1% at 12 months after chemotherapy. The rates of TRA and CIM were 28.0% and 4.0%, respectively, in women aged 25−34 years, and they gradually increased up to 75.9% (TRA) and 15.8% (CIM), respectively, in women aged 40−44 years. The frequency of CIM was significantly lower than that of TRA in both age groups. In multivariate analyses, only tamoxifen use was significantly associated with a decreased risk of CIM (p < 0.001). Age of 40 years or higher and the regimens of doxorubicin plus cyclophosphamide followed by docetaxel or paclitaxel were associated with increased risk of TRA (p = 0.001 and p = 0.002, respectively).

Conclusion

Marked discrepancy in the rates of CIM and TRA was observed in this study. Further, the age-specific frequency of CIM and TRA observed in this study is a reliable and practical estimate of the risks of CIM and TRA in the absence of gonadal protection.

Immunogenicity of Influenza Vaccination in Patients with Cancer Receiving Immune Checkpoint Inhibitors

Among prospectively enrolled adult patients with cancer receiving immune checkpoint inhibitors (ICIs; n = 46) or cytotoxic agents (n = 90), seroprotection and seroconversion rates after seasonal quadrivalent influenza vaccinations were higher with ICI than with cytotoxic chemotherapy. These results support annual influenza vaccinations for cancer patients receiving ICIs.

Clinical Trials Registration clinicaltrials.gov (NCT03590808).

A phase I/II study of poziotinib combined with paclitaxel and trastuzumab in patients with HER2-positive advanced gastric cancer

BACKGROUND

Poziotinib (HM781-36B) is an irreversible pan-HER tyrosine kinase inhibitor which targets EGFR, HER2, and HER4. This prospective, multicenter, open-label, phase I/II study determined the maximum tolerated dose (MTD) and evaluated the safety and efficacy of poziotinib combined with paclitaxel and trastuzumab in patients with HER2-positive advanced gastric cancer (GC).

METHODS

Patients with HER2-positive GC previously treated with one line of chemotherapy received oral poziotinib (8 mg or 12 mg) once daily for 14 days, followed by 7 days off. Paclitaxel (175 mg/m2 infusion) and trastuzumab (8 mg/kg loading dose, then 6 mg/kg infusion) were administered concomitantly with poziotinib on day 1 every 3 weeks.

RESULTS

In the phase I part, 12 patients were enrolled (7 at dose level 1, 5 at dose level 2). One patient receiving poziotinib 8 mg and 2 receiving poziotinib 12 mg had dose-limiting toxicities (DLTs); all DLTs were grade 4 neutropenia, one with fever. The most common poziotinib-related adverse events were diarrhea, rash, stomatitis, pruritus and loss of appetite. The MTD of poziotinib was determined to be 8 mg/day and this was used in the phase II part which enrolled 32 patients. Two patients (6.3%) had complete responses and 5 (15.6%) had partial responses (objective response rate 21.9%). Median progression-free survival and overall survival were 13.0 weeks (95% CI 9.8-21.9) and 29.5 weeks (95% CI 17.9-59.2), respectively.

CONCLUSIONS

The MTD of poziotinib combined with paclitaxel and trastuzumab was 8 mg/day. This combination yielded promising anti-tumor efficacy with manageable toxicity in previously treated patients with HER2-positive GC.

A One-Bag Rapid Desensitization Protocol for Paclitaxel Hypersensitivity: A Noninferior Alternative to a Multi-Bag Rapid Desensitization Protocol

BACKGROUND

Desensitization is used to safely continue treatment with a culprit drug in patients with drug hypersensitivity. Currently, a multi-bag protocol is widely used for rapid desensitization, but performing the desensitization procedure is labor intensive as pharmacists and nurses need to prepare and administer diluted solutions. However, it has not been investigated whether dilution is essential for successful desensitization.

OBJECTIVE

To investigate the efficacy and safety of a nondilution, 1-bag protocol in comparison with a conventional multi-bag protocol for desensitization of patients with paclitaxel hypersensitivity.

METHODS

Patients who underwent paclitaxel desensitization between 2011 and 2018 were analyzed in this retrospective cohort study. The completion rate, time to completion, and occurrence and severity of breakthrough reaction (BTR) between a 1-bag protocol and a multi-bag protocol were compared.

RESULTS

A total of 211 desensitization procedures were performed, of which 207 procedures (98.1%) were completed successfully. The administration time was significantly shorter in the 1-bag protocol group compared with the conventional multi-bag protocol group (266.0 ± 149.3 minutes vs 484.2 ± 178.6 minutes, P < .05) without differences in the completion rate (97.6% vs 98.9%, P = .645), the incidence of BTR (16.1% vs 27.6%, P = .778), and the proportion of severe BTR (2.6% vs 5.7%, P = .134).

CONCLUSIONS

A nondilution, 1-bag protocol is noninferior to a multi-bag rapid desensitization protocol and can be a safe and effective option for paclitaxel desensitization.

Palbociclib plus exemestane with gonadotropin-releasing hormone agonist versus capecitabine in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer (KCSG-BR15-10): a multicentre, open-label, randomised, phase 2 trial

BACKGROUND

Endocrine treatment is recommended by clinical guidelines as the preferred treatment option for premenopausal as well as postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. In real-world clinical practice, however, a substantial number of patients are treated with chemotherapy. We aimed to compare the clinical antitumour activity and safety of palbociclib plus endocrine therapy with that of capecitabine chemotherapy in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer.

METHODS

This multicentre, open-label, randomised, phase 2 study was done in 14 academic institutions in South Korea. Premenopausal women aged 19 years or older with hormone receptor-positive, HER2-negative breast cancer that had relapsed or progressed during previous tamoxifen therapy and with an Eastern Cooperative Oncology Group performance status of 0-2 were included. One line of previous chemotherapy for metastatic breast cancer was allowed. Patients were randomly assigned, using a random permuted block design (with a block size of two), to receive palbociclib plus combination endocrine therapy (oral exemestane 25 mg per day for 28 days and oral palbociclib 125 mg per day for 21 days every 4 weeks plus leuprolide 3·75 mg subcutaneously every 4 weeks) or chemotherapy (oral capecitabine 1250 mg/m² twice daily for 2 weeks every 3 weeks). Randomisation was stratified by previous chemotherapy for metastatic breast cancer and visceral metastasis. The primary endpoint was progression-free survival. All analyses were done in a modified intention-to-treat population that excluded patients who did not receive study medication. This study is registered with ClinicalTrials.gov, NCT02592746, and is ongoing for follow-up of overall survival.

FINDINGS

Between June 15, 2016, and Dec 10, 2018, 189 patients were enrolled, of whom 184 were randomly assigned to the palbociclib plus endocrine therapy group (n=92) or the capecitabine group (n=92). Six patients in the capecitabine group withdrew from the study before drug administration; therefore, 92 patients in the palbociclib plus endocrine therapy group and 86 patients in the capecitabine group were included in the modified intention-to-treat analyses. 46 (50%) of 92 patients in the palbociclib plus endocrine therapy group and 45 (51%) of 92 in the capecitabine group were treatment naive for metastatic breast cancer. During a median follow-up of 17 months (IQR 9-22), median progression-free survival was 20·1 months (95% CI 14·2-21·8) in the palbociclib plus endocrine therapy group versus 14·4 months (12·1-17·0) in the capecitabine group (hazard ratio 0·659 [95% CI 0·437-0·994], one-sided log-rank p=0·0235). Treatment-related grade 3 or worse neutropenia was more common in the palbociclib plus endocrine therapy group than in the capecitabine group (69 [75%] of 92 vs 14 [16%] of 86 patients). 2 (2%) patients in the palbociclib plus endocrine therapy group and 15 (17%) patients in the capecitabine group had treatment-related serious adverse events. No treatment-related deaths occurred.

INTERPRETATION

Exemestane plus palbociclib with ovarian function suppression showed clinical benefit compared with capecitabine in terms of improved progression-free survival in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer. Palbociclib plus exemestane with ovarian suppression is an active treatment option in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer who have been pretreated with tamoxifen.

FUNDING

Pfizer, Shinpoong, and Daewoong Korea and Takeda.

Outcomes in Clinically Relevant Patient Subgroups From the EMBRACA Study: Talazoparib vs Physician's Choice Standard-of-Care Chemotherapy

Background

Talazoparib is a poly(adenosine diphosphate-ribose) polymerase inhibitor that causes death in cells with breast cancer susceptibility gene 1 or 2 (BRCA1/2) mutations.

Methods

EMBRACA (NCT01945775) was a randomized phase III study comparing efficacy, safety, and patient-reported outcomes (PROs) of talazoparib (1 mg) with physician’s choice of chemotherapy (PCT: capecitabine, eribulin, gemcitabine, vinorelbine) in locally advanced or metastatic breast cancer with a germline BRCA1/2 (gBRCA1/2) mutation. Prespecified patient subgroups were analyzed for progression-free survival, objective response, clinical benefit, duration of response, and safety. PROs were evaluated in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) or triple-negative breast cancer (TNBC) subgroups.

Results

Of 431 patients, 287 were randomly assigned to talazoparib and 144 to PCT. Prespecified subgroup analyses showed prolonged progression-free survival with talazoparib (HR+/HER2−: hazard ratio = 0.47, 95% confidence interval = 0.32 to 0.71; TNBC: hazard ratio = 0.60, 95% confidence interval = 0.41 to 0.87) and greater objective response rate (odds ratio = 1.97 to 11.89), clinical benefit rate (odds ratio = 2.05 to 7.77), and duration of response with talazoparib in all subgroups. PROs in HR+/HER2− and TNBC subgroups showed consistent overall improvement and delay in time to definitive clinically meaningful deterioration with talazoparib vs PCT. Across subgroups, common adverse events included anemia, fatigue, and nausea with talazoparib and neutropenia, fatigue, and nausea with PCT. Seven patients (2.4%) receiving talazoparib had grade II alopecia and 22.7% had grade I alopecia.

Conclusions

Across all patient subgroups with gBRCA-mutated advanced breast cancer, talazoparib demonstrated clinically significant superiority in outcomes compared with PCT.

Targeted next-generation DNA sequencing identifies Notch signaling pathway mutation as a predictor of radiation response

Purpose: Identifying the association between somatic mutations and the radiation response of tumor is essential for understanding the mechanisms and practicing personalized radiotherapy. The present study aimed to discover specific genes or pathways that are associated with radiation response using targeted next-generation DNA sequencing.Material and methods: Fifty-five patients with various solid tumors whose specimen were sequenced using institutional panel which includes 148 cancer-related genes and received radiotherapy for a measurable tumor were analyzed. Patients with irradiated tumors in complete or partial remission for more than 6 months were defined as responders. Association between mutations including pathogenic single nucleotide variants and insertions/deletions in the 148 genes and 39 molecular pathways and radiation response was investigated.Results: Analyzing 17 responders and 38 non-responders, biologically effective dose (BED), but not concurrent chemotherapy, was associated with radiation response. No single gene correlated with radiation response. Mutations in Notch signaling pathway were associated with radiosensitivity after correction for multiple comparison (adjusted p = .094). When BED and Notch signaling pathway mutation were tested with logistic regression, both variables were associated with radiation response.Conclusions: Our results suggest that somatic mutations in Notch signaling pathway may be related to sensitivity to radiation, although these results should be validated in a larger and more homogeneous cohort.