Effects of neratinib on health-related quality of life in women with HER2-positive early-stage breast cancer: longitudinal analyses from the randomized phase III ExteNET trial

BACKGROUND

We report longitudinal health-related quality-of-life (HRQoL) data from the international, randomized, double-blind, placebo-controlled phase III ExteNET study, which demonstrated an invasive disease-free survival benefit of extended adjuvant therapy with neratinib over placebo in human epidermal growth factor receptor-2-positive early-stage breast cancer.

PATIENTS AND METHODS

Women (N  = 2840) with early-stage HER2-positive breast cancer who had completed trastuzumab-based adjuvant therapy were randomly assigned to neratinib 240  mg/day or placebo for 12  months. HRQoL was an exploratory end point. Patients completed the Functional Assessment of Cancer Therapy-Breast (FACT-B) and EuroQol 5-Dimensions (EQ-5D) questionnaires at baseline and months 1, 3, 6, 9, and 12. Changes from baseline were compared using analysis of covariance with no imputation for missing values. Sensitivity analyses used alternative methods. Changes in HRQoL scores were regarded as clinically meaningful if they exceeded previously reported important differences (IDs).

RESULTS

Of the 2840 patients (intention-to-treat population), 2407 patients were evaluable for FACT-B (neratinib, N  = 1171; placebo, N  = 1236) and 2427 patients for EQ-5D (neratinib, N  = 1186; placebo, N  = 1241). Questionnaire completion rates exceeded 85%. Neratinib was associated with a decrease in global HRQoL scores at month 1 compared with placebo (adjusted mean differences: FACT-B total, -2.9 points; EQ-5D index, -0.02), after which between-group differences diminished at later time-points. Except for the FACT-B physical well-being (PWB) subscale at month 1; all between-group differences were less than reported IDs. The FACT-B breast cancer-specific subscale showed small improvements with neratinib at months 3-9, but all were less than IDs. Sensitivity analyses exploring missing data did not change the results.

CONCLUSIONS

Extended adjuvant neratinib was associated with a transient, reversible decrease in HRQoL during the first month of treatment, possibly linked to treatment-related diarrhea. With the exception of the PWB subscale at month 1, all neratinib-related HRQoL changes did not reach clinically meaningful thresholds. ClinicalTrials.gov: NCT00878709.

Specific aspects of immunotherapy for multiple sclerosis in Switzerland: A structured commentary

More than a dozen substances are meanwhile available for the disease-modifying immunotherapy of multiple sclerosis (MS). However, for some substances, there is a clear difference between approval in Switzerland (Swissmedic) and neighboring countries (European Medicines Agency (EMA)). In addition, limitations imposed by the Swiss Federal Office of Public Health in the specialties list (SL) have significant effects on use in daily clinical practice. In the following, we present consensus recommendations, which were reviewed and agreed upon by the Scientific Advisory Board of the Swiss Multiple Sclerosis Society and the Swiss Neurological Society. We explicitly focus on practice-relevant differences in the approval of MS immunotherapies in Switzerland compared with the EMA area and discuss further limitations (SL) and their impact on the use in clinical practice. Immunotherapies with the same approval in Switzerland and the EMA area and symptomatic therapies are not discussed here.

The Long-Term Impact of Functional Disability on Hospitalization Spending in Singapore

Singapore is one of the fastest-aging populations due to increased life expectancy and lowered fertility. Lifestyle changes increase the burden of chronic diseases and disability. These have important implications for social protection systems. The goal of this paper is to model future functional disability and healthcare expenditures based on current trends. To project the health, disability and hospitalization spending of future elders, we adapted the Future Elderly Model (FEM) to Singapore. The FEM is a dynamic Markov microsimulation model developed in the US. Our main source of population data was the Singapore Chinese Health Study (SCHS) consisting of 63,000 respondents followed up over three waves from 1993 to 2010. The FEM model enables us to investigate the effects of disability compounded over the lifecycle and hospitalization spending, while adjusting for competing risk of multi-comorbidities. Results indicate that by 2050, 1 in 6 elders in Singapore will have at least one ADL disability and 1 in 3 elders will have at least one IADL disability, an increase from 1 in 12 elders and 1 in 5 elders respectively in 2014. The highest prevalence of functional disability will be in those aged 85 years and above. Lifetime hospitalization spending of elders aged 55 and above is US$24,400 (30.2%) higher among people with functional disability compared to those without disability. Policies that successfully tackle diabetes and promote healthy living may reduce or delay the onset of disability, leading to potential saving. In addition, further technological improvements may reduce the financial burden of disability.

Abstract P6-18-05: First-line ribociclib + endocrine therapy in hormone receptor-positive, HER2-negative advanced breast cancer: A pooled efficacy analysis

Background: In three separate Phase III randomized, placebo-controlled trials, ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) + various endocrine therapy (ET) partners prolonged progression-free survival (PFS) vs placebo (PBO) + ET in patients (pts) with hormone receptor-positive (HR+), HER2-negative (HER2–) advanced breast cancer (ABC). Here we further evaluate the efficacy of RIB-based regimens of interest (i.e. with a non-steroidal aromatase inhibitor [NSAI] or fulvestrant [FUL]) in pts who were ET-naïve in the ABC setting, using pooled data from three Phase III trials: MONALEESA (ML)-2 (NCT01958021; all pts), ML-3 (NCT02422615; no prior ET for ABC subgroup only), and ML-7 (NCT02278120; RIB + NSAI subgroup only).

Methods: Postmenopausal pts with no prior ET for ABC received RIB (600 mg/day; 3-weeks-on/1-week-off) or PBO + either letrozole (2.5 mg/day) in ML-2 or FUL (500 mg every 28 days, with an additional dose on Day 15 of Cycle 1) in ML-3. In ML-7, premenopausal pts with no prior ET and ≤1 line of chemotherapy for ABC received RIB or PBO + goserelin (3.6 mg every 28 days) + NSAI (anastrozole [1 mg/day]/letrozole [2.5 mg/day]). The primary endpoint of all three trials was locally assessed PFS. Secondary endpoints included overall response rate (ORR), clinical benefit rate (CBR), and duration of response (DoR; ML-3 and -7). DoR was an exploratory endpoint in ML-2.

Results: Data were pooled for 820 pts treated with RIB + ET (ML-2: n=334; ML-3: n=238; ML-7: n=248) and 710 pts treated with PBO + ET (ML-2: n=334; ML-3: n=129; ML-7: n=247). As of the data cutoffs (ML-2: January 2, 2017; ML-3: November 3, 2017; ML-7: August 20, 2017), in the RIB + ET vs PBO + ET arms, 385 (47%) vs 234 (33%) pts remained on-treatment; the most common reason for discontinuation was disease progression (n=292 [36%] vs n=391 [55%]). In this pooled analysis, median PFS was prolonged for RIB + ET vs PBO + ET, with a hazard ratio of 0.570 (95% confidence interval [CI] 0.491–0.662); median PFS was 25.3 months (95% CI 23.9–29.6) vs 15.6 months (95% CI 14.4–16.9), respectively. Consistent PFS benefit for RIB + ET vs PBO + ET was observed across pt subgroups, including ECOG performance status, age, race, or presence/absence of liver and/or lung metastases or bone-only disease. Among all pts in the pooled analysis, the ORR was 41% for RIB + ET vs 28% for PBO + ET and the CBR was 79% vs 70%, respectively. In pts with measurable disease at baseline (RIB + ET: n=639; PBO + ET: n=542), the ORR was 51% for RIB + ET vs 37% for PBO + ET and the CBR was 79% vs 68%, respectively. In the RIB + ET vs PBO + ET arms, the median DoR was 26.7 months vs 20.0 months. A decrease in best percentage change from baseline in the sum of longest diameters per RECIST was observed in 86% of pts receiving RIB + ET vs 73% of pts receiving PBO + ET.

Conclusions: RIB in combination with various ET partners demonstrates improved clinical outcomes vs PBO + ET across a broad population of pts with HR+, HER2– ABC. These data provide further support for the use of RIB-based combinations in pre- and postmenopausal pts with HR+, HER2– ABC who have received no prior ET for advanced disease.

Citation Format: Tripathy D, Hortobagyi G, Chan A, Im S-A, Chia S, Yardley D, Esteva FJ, Hurvitz S, Kong O, Bao W, Rodriguez Lorenc K, Diaz-Padilla I, Slamon DJ. First-line ribociclib + endocrine therapy in hormone receptor-positive, HER2-negative advanced breast cancer: A pooled efficacy analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-05.

Abstract P2-13-03: The impact of neratinib with or without anti-diarrheal prophylaxis on health-related quality of life in HER2+ early-stage breast cancer: Analyses from the ExteNET and CONTROL trials

Background: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor. ExteNET, a randomized placebo-controlled phase III study, showed that neratinib given for 12 months after trastuzumab-based adjuvant therapy significantly improved 2-year (HR 0.67; 95% CI 0.50–0.91; p=0.0091) and 5-year (HR 0.73; 95% CI 0.57-0.92; p=0.008) iDFS in pts with early-stage HER2+ breast cancer. Anti-diarrheal prophylaxis was not mandated by protocol; grade 3/4 diarrhea occurred in 40% of pts with a median cumulative duration of 5 days. The phase II CONTROL study was initiated to investigate the effectiveness of various prophylactic regimens in the prevention of neratinib-associated diarrhea. Loperamide (L) alone or in combination with add-on agents targeting underlying inflammation [i.e. budesonide (BUD)] or bile acid malabsorption [i.e. colestipol (COL)] were tested. We report longitudinal HRQoL findings from both ExteNET and CONTROL.

Methods: Pts with early-stage HER2+ breast cancer who had received trastuzumab-based adjuvant therapy were eligible for both studies. In ExteNET, pts received neratinib or placebo for 12 months. In CONTROL, pts received neratinib for 13 x 28-day cycles combined with L, L + BUD or L + COL for 1 or 2 cycles (see table for schedules). HRQoL was assessed using Functional Assessment of Cancer Therapy–Breast (FACT-B), v4.0, at baseline, months 1, 3, 6, 9, 12 (ExteNET) or baseline, cycles 2, 4, 7, 10, 13 (CONTROL). Changes in scores from baseline were considered to be clinically meaningful if greater than the lowest estimate for an 'important difference' (ID) reported in the literature. Evaluable pts were required to have HRQoL assessments at baseline and at least 1 post-baseline. ClinicalTrials.gov: NCT00878709 (ExteNET); NCT02400476 (CONTROL).

Results: HRQoL findings are summarized in the table. Hospitalization rates due to diarrhea: 1.5% (neratinib + L), 0% (other cohorts) in CONTROL; and 1.4% (neratinib), 0.1% (placebo) in ExteNET.

  Mean change from baselineStudyCohort/GroupM1M3M6M9M12 FACT-B TOTAL (ID range: 7–8 points)CONTROLN + La,b (N=40)–3.8–4.5–1.5–2.5–3.3 N + L + BUDa,b,c (N=62)–6.0–4.9–1.6–3.6–4.5 N + L + COLa,b,d (N=125)–3.8–2.0–4.0–4.6–3.6 N + L prn + COLa,d (N=85)–1.8–1.54.0e––ExteNETN + L prna (N=1124)–4.6–3.4–3.5–3.3–3.7 P (N=1188)–1.7–3.5–2.9–2.9–2.8 FACT-B PWB (ID range: 2–3 points)CONTROLN + La,b (N=40)–4.0–2.3–1.9–2.4–2.3 N + L + BUDa,b,c (N=62)–3.2–2.1–1.4–1.7–1.7 N + L + COLa,b,d (N=125)–2.8–2.0–2.4–2.5–2.4 N + L prn + COLa,d (N=85)–2.8–1.80.0e––ExteNETN + L prna (N=1124)–2.9–1.9–1.7–1.6–1.5 P (N=1188)–0.6–0.8–0.7–0.6–0.4C, cycle; L, loperamide; M, month; N, neratinib; prn, as needed; PWB, physical well-being. CONTROL cut-off: 1 May 2018. aN 240 mg qd for 13 x 28d cycles or 12 months; bL 4 mg, then 4 mg tid d1-14, then 4 mg bid d15-28 or d15-56, then prn; cBUD 9 mg qd d1-28; dCOL 2 g qd d1-28; en=1.

Conclusions: Adjuvant neratinib with or without anti-diarrheal prophylaxis was associated with small decreases in HRQoL. With the exception of the FACT-B PWB subscale, HRQoL changes did not reach clinically meaningful thresholds. Follow-up in CONTROL is ongoing.

Citation Format: Delaloge S, Hurvitz S, Chan N, Bose R, Jankowitz RC, Thirlwell M, Láng I, ten Tije A, Trudeau M, Osborne CR, Shen Z-Z, Lalla D, Xu F, Hunt D, Olek E, Tripathy D, Rugo HS, Chien J, Chan A, Barcenas CH. The impact of neratinib with or without anti-diarrheal prophylaxis on health-related quality of life in HER2+ early-stage breast cancer: Analyses from the ExteNET and CONTROL trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-13-03.

Abstract P6-18-15: Ribociclib + endocrine therapy in hormone receptor-positive, HER2-negative advanced breast cancer: A pooled safety analysis

Background: In Phase III trials, ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) + various endocrine therapy (ET) partners has demonstrated significantly prolonged progression-free survival vs placebo (PBO) + ET in patients (pts) with hormone receptor-positive (HR+), HER2-negative (HER2–) advanced breast cancer (ABC). Here we further evaluate the safety of RIB-based regimens of interest for the proposed indication (i.e. with a non-steroidal aromatase inhibitor [NSAI] or fulvestrant [FUL]) using pooled data from three Phase III trials (MONALEESA [ML]-2 [NCT01958021], -3 [NCT02422615], and -7 [NCT02278120]).

Methods: Postmenopausal pts with HR+, HER2– ABC received RIB (600 mg/day; 3-weeks-on/1-week-off) or PBO + letrozole (LET; 2.5 mg/day; ML-2 [no prior ET for ABC]) or FUL (500 mg, Days 1 and 15 of Cycle 1, then Day 1 of every cycle thereafter; ML-3; no or ≤1 prior line of ET for ABC]). Premenopausal pts (ML-7; no prior ET and ≤1 chemotherapy for ABC]) received RIB or PBO + anastrozole (1 mg/day)/LET (2.5 mg/day) + goserelin (3.6 mg every 28 days). Adverse events (AEs) were characterized per Common Terminology Criteria for Adverse Events v4.03; safety analyses included time to first event, duration of event, and rate of associated RIB/PBO discontinuations.

Results: Data for 1883 pts were pooled; 1065 pts received RIB + ET and 818 pts received PBO + ET (median exposure to study treatment: 17 and 13 months, respectively). Exposure-adjusted incidence rates for AEs of special interest were 561 and 131 per 100 pt-years in the RIB and PBO arms, respectively. The most common all-causality Grade 3/4 AEs (≥10% in any arm; RIB vs PBO) were neutropenia (59% vs 2%), leukopenia (18% vs 1%), and hypertension (13% vs 13%). A new Fridericia's corrected QT interval (QTcF) >480 ms occurred in (n/N) 52/1054 (5%) vs 11/814 (1%) pts in the RIB vs PBO arms; a new QTcF >500 ms occurred in 14/1054 (1%) vs 1/814 (<1%) pts. Median time to first event for Grade ≥2 neutropenia, elevated alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST), and QTc prolongation in the RIB arm was 2, 12, and 2 weeks, respectively; median duration of first Grade ≥2 event was 4, 4, and 2 weeks. In the RIB arm vs PBO arms, 7% vs 3% of pts discontinued study treatment due to AEs; common all-grade AEs leading to RIB/PBO discontinuation (≥2% in any arm) were elevated ALT (4% vs <1%) and elevated AST (2% vs 1%). Discontinuation due to QT prolongation occurred in 4 pts in the RIB arm and 2 in the PBO arm (both <1%). All-grade serious AEs occurred in 25% of pts in the RIB arm vs 15% of pts in the PBO arm.

Conclusions: RIB in combination with various ET partners continues to demonstrate a predictable and manageable tolerability profile across a broad population of pts with HR+, HER2– ABC.

Citation Format: Burris HA, Chan A, Im S-A, Chia S, Tripathy D, Esteva FJ, Campone M, Bardia A, Kong O, Bao W, Diaz-Padilla I, Rodriguez Lorenc K, Yardley DA. Ribociclib + endocrine therapy in hormone receptor-positive, HER2-negative advanced breast cancer: A pooled safety analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-15.

Abstract P3-11-08: Sperm associated antigen 5 (SPAG5) predicts pathological complete response (pCR) and distant relapse risk to HER2 targeting agents and anthracycline based chemotherapy in HER2 positive (HER2+) breast cancer (BC)

Background:

Previously we found that SPAG5 gene was amplified/gained in 20-35% of HER2+BC. Herein, we investigated the prognostic and predictive significance of SPAG5 (mRNA, protein) expression in 1726 HER+BC patients with median follow-up >5 years.

Methods:

Analysis of SPAG5 mRNA (cDNA array expression) and protein (immunohistochemistry) and their association with distant relapse risk (DRR) were determined in 446 and 642 cases of HER+2 early stage BC in which 36% and 40% of them had received adjuvant Herceptin (H) + Anthracycline based (AC) + Taxane (T); respectively. In 33% and 31% of SPAG5 mRNA cohort and 21% and 38% of SPAG5 protein cohort had received adjuvant (Adj) AC+T or chemotherapy (CT) naïve; respectively. The association between SPAG5 expression (mRNA, protein) and both pCR and DRR after receiving neoadjuvant chemotherapy (Neo-Adj-CT) were evaluated in 476 and 162 patients with HER2+ locally advanced BC; respectively. Neo-Adj AC+T+HER2 targeting (Herceptin, Herceptin+ Lapatinib or Lapatinib) and AC+/-T has been prescribed to 51% and 49% of mRNA cohort whereas the 45% and 55% of the protein expression cohort has received Neo-Adj AC+T+H and AC+/-T; respectively.

Findings:

In patients with SPAG5 mRNA overexpression (+;> median), those who had received AC+/-T Neo-Adj-CT alone achieved similar pCR to those who had received AC+T+HER2 targeting Neo-Adj (38% vs., 37%; OR (95% CI): 1.0 (0.6–1.6), p=0.923) in either ER- (46% vs., 52%; OR (95% CI): 1.3 (0.5–3.0), p=0.58) or ER+ subgroups (25% vs., 26%; OR (95% CI): 1.1 (0.4–3.4), p=0.88). Whereas in patients with low SPAG5 mRNA (-), those who had received AC+T+HER2 targeting Neo-Adj had achieved 2.5 fold increased in pCR compared to those who received AC+/-T alone (47% vs., 26%; OR (95% CI): 2.5 (1.4–4.4), p=0.001) in either ER- (60% vs., 31%; OR (95% CI): 3.4 (1.7–6.7), p<0.001) or ER+ subgroups (42% vs., 16%; OR (95% CI): 4.0 (1.2–12.9), p=0.018). Similarly in patients with SPAG5- protein expression; receiving AC+T+HER2 targeting Neo-Adj was associated with higher pCR compared to AC+/-T (21% vs., 4%; OR (95% CI): 6.6 (1.4–32.6), p=0.01). Whereas receiving AC+/-T was associated with similar pCR to AC+T+HER2 targeting Neo-Adj in patients with SPAG5+ protein (49% vs., 53%; OR (95% CI): 1.2 (0.5–3.2), p=0.702). Receiving AC+T+HER2 targeting Neo-Adj was associated with lower DRR compared to AC+/-T [HR (95% CI): 0.82 (0.08-0.97); p=0.045] in patients with SPAG5- protein expression but not in those with SPAG5+ protein [HR (95% CI): 1.08 (0.34-3.36); p=0.901]. Similarly, receiving Adj Herceptin+AC+T was associated with lower DRR compared to AC+/-T alone in those with SPAG5- (mRNA, protein) expression [HR (95% CI): 0.48 (0.25-0.93); p=0.029 and 0.82 (0.08-0.97); p=0.045; respectively] but not in those with high SPAG5+ (mRNA, protein) [HR (95% CI): 1.04 (0.48-2.26); p=0.924 and 1.00 (0.82-1.22); p=1.00; respectively.

Conclusion: SPAG5 expression could help in selecting patients who would benefit from both HER2-targeting agents and or AC-CT. Therefore patients with SPAG5- expression could avoid unnecessary AC-CT whereas those with SPAG5+ could receive a shorter Herceptin course.

Citation Format: Abdel-Fatah TM, Ball GR, Ellis IO, Chan A, Chan SY. Sperm associated antigen 5 (SPAG5) predicts pathological complete response (pCR) and distant relapse risk to HER2 targeting agents and anthracycline based chemotherapy in HER2 positive (HER2+) breast cancer (BC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-08.

Abstract PD3-12: Central nervous system as first site of relapse in patients with HER2 positive early breast cancer treated in the BCIRG-006 trial

Introduction: Central Nervous System (CNS) metastases as first site of relapse is seen in 2-3% of patients with HER2+ early breast cancer (EBC) during or after treatment with adjuvant trastuzumab. Data about long-term follow-up outcomes in this population is scarce. Methodology: BCIRG-006 was designed to assess the efficacy and safety of two trastuzumab-based regimens compared to a standard (non-trastuzumab) regimen in the adjuvant treatment of HER2+ EBC. 3,222 patients were randomized to standard AC-T or two trastuzumab-based regimens (AC-TH or TCH). Ten year follow-up outcomes were previously presented; we have used this data to assess the frequency and course of CNS relapses as first site of distant recurrence. DFS and OS in these patients were estimated and compared using the Kaplan-Meier method and Log-Rank test respectively. Univariate and multivariate analyses for DFS were conducted considering patient's age, nodal status, tumor size and estrogen receptor (ER) status in the primary tumor. Results: Of the 3,222 patients randomized, 575 (17.8%) experienced a distant relapse and in 17.5% of these (n=101) CNS was the first site of recurrence. With a median follow-up of 10.3 years, the frequency of CNS relapses did not differ when comparing the trastuzumab containing arms with the control arm (OR 0.86, 95% CI: 0.56-1.33; p= 0.519). No difference was observed either between AC-TH and TCH (OR 1.14, 95% CI: 0.67-1.94; p= 0.704). There were no differences in DFS (HR 1.21, 95% CI: 0.74-1.99; p= 0.621) nor in OS (HR 0.74, 95% CI: 0.43-1.27; p= 0.377) between AC-T, AC-TH and TCH arms. Positive axillary nodes (≥4 nodes) and ER negative status at baseline remained independent risk factors for CNS relapse after univariate and multivariate analysis (HR 0.60, 95% CI: 0.8-0.95; p= 0.007 for nodal status and HR 0.56, 95% CI: 0.37-0.85; p= 0.029 for ER status). Conclusion: Among the pivotal adjuvant trastuzumab trials, BCIRG-006 is the one with the longest median FUP in which data about CNS relapses has been presented. CNS relapse in patients in this trial was an infrequent event. Its frequency and outcomes were similar across the three treatment arms. Patients with ER negative and/or ≥ 4 positive nodes are at higher risk of CNS relapse irrespective of trastuzumab therapy and may be the patient population where research efforts should be focused.

BC outcomes in patients with CNS metastases per treatment arm in the BCIRG-006 trial AC-T N=1073 n(%)AC-TH N=1074 n(%)TCH N=1075 n(%)p valueFrequency of CNS relapse37 (3.44%)30 (2.79%)34 (3.16%)0.519 ^Median DFS (months; 95% CI)23.8 (13.3-30.4)19.9 (16.6-25.1)19.9 (15.0-27.2)0.621 ⫲Median OS (months; 95% CI)42.5 (28.3-62.7)53.2 (31.2-103.6)30.3 (23.4-39.0)0.377 ⫲

^ comparing control vs. trastuzumab-containing arm using Fisher's Exact test.

⫲ comparing control vs. trastuzumab-containing arms using Log Rank test.

Citation Format: Chan A, Spera G, Machado A, Fung H, Bee V, Fresco R, Slamon DJ. Central nervous system as first site of relapse in patients with HER2 positive early breast cancer treated in the BCIRG-006 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-12.

Abstract P2-13-01: Efficacy of neratinib in hormone receptor-positive patients who initiated treatment within 1 year of completing trastuzumab-based adjuvant therapy in HER2+ early-stage breast cancer: Subgroup analyses from the phase III ExteNET trial

Background: The international, randomized, placebo-controlled phase III ExteNET trial showed that 1 year (yr) of neratinib 240 mg/day after trastuzumab-based adjuvant therapy significantly improved invasive disease-free survival (iDFS) in 2840 patients with early-stage HER2+ breast cancer at 2 yr (hazard ratio 0.67; 95% CI 0.50–0.91; p=0.009) [Chan 2016] and 5 yr (hazard ratio 0.73; 95% CI 0.57-0.92; p=0.008) [Martin 2017]. A prespecified subgroup analysis by hormone receptor (HR) status suggested enhanced efficacy with neratinib in patients with HR+ (2-yr hazard ratio 0.51; 95% CI 0.33–0.77) vs. HR– tumors (2-yr hazard ratio 0.93; 95% CI 0.60–1.43). The efficacy of neratinib was also greater in patients who initiated treatment within 1 yr of prior trastuzumab compared with those who started neratinib later. The European Medicines Agency's Committee for Medicinal Products for Human Use recently recommended neratinib for use in patients with HR+ tumors who initiate treatment within 1 yr of completing trastuzumab-based adjuvant therapy. Subgroup analyses from ExteNET examining iDFS benefits in this patient population are presented here.

Methods: Patients with early-stage HER2+ breast cancer who completed trastuzumab-based (neo)adjuvant therapy were assigned to oral neratinib 240 mg/day or placebo for 1 yr. Randomization was stratified by HR status (determined locally before trial entry), nodal status, and trastuzumab regimen. Endocrine therapy was allowed in patients with HR+ disease. The primary endpoint, iDFS, was tested by 2-sided log-rank test and hazard ratios (95% CI) were estimated using Cox proportional hazards models. Kaplan-Meier methods were used to estimate iDFS rates. Secondary endpoints were DFS-DCIS, time to distant recurrence, distant DFS, and CNS recurrences. The primary analysis was conducted at 2 yr, and a sensitivity analysis conducted at 5 yr. Clinicaltrials.gov:NCT00878709.

Results: Of the 2840 patients (neratinib, n=1420; placebo, n=1420), 1631 (57%) had HR+ disease (neratinib, n=816; placebo, n=815). Most (93%) HR+ patients were receiving endocrine therapy at baseline. 1334 of 1631 (82%) patients with HR+ tumors were randomized to start neratinib within 1 yr of last trastuzumab dose (neratinib, n=670; placebo, n=664). iDFS benefits from neratinib in this population are shown in the table. Secondary endpoints were also improved with neratinib vs. placebo in this population. Safety data in this subset will be presented at the meeting.

Table. iDFS in patients with an interval between last trastuzumab dose and randomization of ≤1 yr

 HR+ population (N=1334)ITT population (N=2297)  Hazard ratiob  Hazard ratiob  Δ, %a(95% CI)P-valueΔ, %a(95% CI)P-value2-yr analysisc+4.50.490.002+2.90.630.006  (0.30–0.78)  (0.45–0.88) 5-yr analysisd+5.10.580.002+3.20.700.006  (0.41–0.82)  (0.54–0.90) aDifference in iDFS rates between neratinib vs. placebo; bNeratinib vs. placebo; cData cut-off: July 2014; dData cut-off: March 2017

Conclusions: Neratinib may have enhanced and sustained efficacy in patients with HR+ disease who initiate treatment within 1 yr of trastuzumab-based adjuvant therapy.

Citation Format: Gnant M, Martin M, Holmes F-A, Jackisch C, Chia SK, Iwata H, Moy B, Martinez N, Mansi J, Morales S, Ruiz-Borrego M, von Minckwitz G, Buyse M, Delaloge S, Bhandari M, Murias Rosales A, Galeano T, Fujita T, Luczak A, Barrios CH, Saura C, Rugo HS, Chien J, Johnston SR, Spencer M, Xu F, Barnett B, Chan A, Ejlertsen B. Efficacy of neratinib in hormone receptor-positive patients who initiated treatment within 1 year of completing trastuzumab-based adjuvant therapy in HER2+ early-stage breast cancer: Subgroup analyses from the phase III ExteNET trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-13-01.

Abstract P6-18-07: Ribociclib + endocrine therapy in patients with hormone receptor-positive, HER2-negative advanced breast cancer presenting with visceral metastases: Subgroup analysis of phase III MONALEESA trials

Background: Patients (pts) with advanced breast cancer (ABC) who present with visceral metastases (mets) have a poorer prognosis vs pts with non-visceral disease. In the Phase III MONALEESA (ML) trials, ribociclib (RIB) + endocrine therapy (ET) prolonged progression-free survival (PFS) vs placebo (PBO) + ET in hormone receptor-positive (HR+), HER2-negative (HER2–) ABC. Here we show data for pts with and without visceral mets from the ML-2, -3, and -7 trials.

Methods: Data were collated from 3 trials in HR+, HER2– ABC: in ML-2 (NCT01958021; data cutoff [DCO] Jan 2/4, 2017), postmenopausal pts (no prior ET for ABC) received RIB or PBO + letrozole; in ML-3 (NCT02422615; DCO Nov 3, 2017), postmenopausal pts (no prior ET for ABC subgroup only) received RIB or PBO + fulvestrant; in ML-7 (NCT02278120; DCO Aug 20, 2017), premenopausal pts (no prior ET and ≤1 chemotherapy for ABC) received RIB or PBO + goserelin + anastrozole/letrozole. Endpoints; primary: local PFS; secondary: overall response rate (ORR), clinical benefit rate (CBR), safety.

Results: Of all 820 pts treated with RIB + ET, 484 (59%) had visceral mets (ML-2 197/334; ML-3 137/238; ML-7 150/248); of all 710 pts treated with PBO + ET, 416 (59%) had visceral mets (ML-2 196/334; ML-3 77/129; ML-7 143/247). Median PFS was prolonged for RIB vs PBO in pts with and without visceral mets (Table). ORR and CBR were also higher for RIB vs PBO in pts with and without visceral mets. The most common (≥10% of pts in any arm) Grade [G] 3 and 4 adverse events (AEs) for each trial are shown in the table; no G4 AEs occurred in ≥10% of pts in ML-3.

 Visceral metsNo visceral metsML-2 Median PFS (RIB/PBO), months (95% CI)24.9 (22.2–30.9)/13.4 (12.7–16.5)25.3 (22.2–NR)/18.2 (15.0–24.6)Hazard ratio (95% CI)0.538 (0.408–0.709)0.634 (0.448–0.897) ORR (RIB/PBO),* %48/3735/17 CBR (RIB/PBO),† %79/7282/75 Most common (≥10% in any arm) G3 AEs (RIB/PBO), %Neutropenia56/147/1Leukopenia19/121/<1Hypertension11/1115/15 Most common (≥10% in any arm) G4 AEs (RIB/PBO), %Neutropenia10/09/0 ML-3 Median PFS (RIB/PBO), months (95% CI)NR (19.1–NR)/16.5 (9.0–NR)NR (NR–NR)/21.9 (14.8–NR)Hazard ratio (95% CI)0.610 (0.403–0.926)0.521 (0.295–0.921) ORR (RIB/PBO),* %46/2931/21 CBR (RIB/PBO),† %74/6075/81 Most common (≥10% in any arm) G3 AEs (RIB/PBO), %Neutropenia50/045/0Leukopenia12/010/0Increased ALT6/012/0 ML-7 Median PFS (RIB/PBO), months (95% CI)23.8 (14.8–NR)/10.4 (7.2–12.9)27.5 (NR–NR)/19.3 (16.5–NR)Hazard ratio (95% CI)0.507 (0.367–0.700)0.609 (0.377–0.984) ORR (RIB/PBO),* %45/3630/19 CBR (RIB/PBO),† %79/5783/81 Most common (≥10% in any arm) G3 AEs (RIB/PBO), %Neutropenia54/356/4Leukopenia14/116/1 Most common (≥10% in any arm) G4 AEs (RIB/PBO), %Neutropenia11/<19/0CI, confidence interval; NR, not reached. *ORR = complete response + partial response; †CBR = complete response + partial response + (stable disease + non-complete response/non-progressive disease ≥24 weeks).

Conclusions: Although the presence of visceral mets is associated with a poorer prognosis, RIB + ET is an effective and well-tolerated treatment option for pts with HR+, HER2– ABC irrespective of the presence of visceral mets.

Citation Format: Yardley DA, Chan A, Nusch A, Sonke GS, Yap Y-S, Bachelot T, Esteva FJ, Slamon DJ, Burris HA, Gaur A, Kong O, Diaz-Padilla I, Rodriguez Lorenc K, Wheatley-Price P. Ribociclib + endocrine therapy in patients with hormone receptor-positive, HER2-negative advanced breast cancer presenting with visceral metastases: Subgroup analysis of phase III MONALEESA trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-07.

Abstract P6-18-06: Ribociclib treatment benefit in patients with advanced breast cancer with ≥1 dose reduction: Data from the MONALEESA-2, -3, and -7 trials

Background: In the MONALEESA (ML) trials, addition of ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) to endocrine therapy (ET) prolonged progression-free survival (PFS) in patients (pts) with hormone receptor-positive (HR+), HER2-negative (HER2–) advanced breast cancer (ABC). RIB was generally well tolerated, with adverse events (AEs) managed effectively by dose modifications. Here we present efficacy data for RIB-based regimens of interest for the proposed indication (i.e. with a non-steroidal aromatase inhibitor [NSAI] or fulvestrant [FUL]) from ML-2, -3, and -7 in pts who received no prior ET for ABC and who had ≥1 RIB dose reduction, to explore the efficacy of RIB in pts who need to dose reduce.

Methods: Pts included in this analysis were: postmenopausal women with HR+, HER2– ABC and no prior ET for ABC who received RIB (600 mg; 3-weeks-on/1-week-off) with letrozole (2.5 mg/day; ML-2 [NCT01958021]), or FUL (500 mg per label; ML-3 [NCT02422615]); and premenopausal women with no prior ET and ≤1 line of chemotherapy for ABC who received RIB with an NSAI (anastrozole: 1 mg/day; letrozole: 2.5 mg/day; ML-7 [NCT02278120]) plus goserelin (3.6 mg every 28 days). Dose reductions for RIB (600 to 400 to 200 mg) were permitted. Primary endpoint was PFS. Secondary endpoints included overall response rate (ORR), clinical benefit rate (CBR), and safety.

Results: In ML-2, -3, and -7, ≥1 RIB dose reduction occurred (n/N) in 169/334 (51%), 92/238 (39%), and 91/246 (37%) pts assigned to RIB, respectively. AEs were the main reason for dose reduction, with all-grade neutropenia the most common AE leading to dose reduction (ML-2 69%, ML-3 80%, ML-7 82%). Median PFS (months) was prolonged with RIB vs placebo in pts without a RIB dose reduction (ML-2: 27.7 vs 16.0; ML-3: not reached [NR] vs 18.3; ML-7: 23.8 vs 13.8); median PFS in pts with ≥1 RIB dose reduction was: ML-2 25.3, ML-3 NR, and ML-7 27.5 months. In pts with measurable disease and without a RIB dose reduction, ORR was 46% (ML-2), 43% (ML-3), and 48% (ML-7); CBR was 70%, 68%, and 79%, respectively. In pts with measurable disease and ≥1 RIB dose reduction, ORR was 62% (ML-2), 57% (ML-3), and 55% (ML-7); CBR was 88%, 85%, and 88%, respectively. The most common Grade 3/4 AEs in the RIB vs placebo groups (≥5% of pts in either ML trial, irrespective of causality or dose reduction) were neutropenia (ML-2: 62% vs 1%; ML-3: 55% vs 0; ML-7: 65% vs 4%), leukopenia (ML-2: 21% vs 1%; ML-3: 12% vs 0; ML-7: 16% vs 1%), hypertension (ML-2: 13% vs 13%; ML-3: 5% vs 5%; ML-7: 2% vs 3%), increased alanine aminotransferase (ML-2: 10% vs 1%; ML-3: 10% vs 0; ML-7: 5% vs 1%), and increased aspartate aminotransferase (ML-2: 6% vs 1%; ML-3: 6% vs 0; ML-7: 4% vs 1%).

Conclusions: Results from the ML-2, -3, and -7 trials suggest that pts who start on 600 mg of RIB and require dose reduction for the management of their AEs, or for other reasons, continue to derive clinical benefit.

Citation Format: Beck JT, Neven P, Sohn J, Chan A, Sonke GS, Bachelot T, Campos-Gomez S, Martin M, Bardia A, Alam J, Miller M, Diaz-Padilla I, Kong O, Hart L. Ribociclib treatment benefit in patients with advanced breast cancer with ≥1 dose reduction: Data from the MONALEESA-2, -3, and -7 trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-06.