Context-enriched interactome powered by proteomics helps the identification of novel regulators of macrophage activation

The role of pro-inflammatory macrophage activation in cardiovascular disease (CVD) is a complex one amenable to network approaches. While an indispensible tool for elucidating the molecular underpinnings of complex diseases including CVD, the interactome is limited in its utility as it is not specific to any cell type, experimental condition or disease state. We introduced context-specificity to the interactome by combining it with co-abundance networks derived from unbiased proteomics measurements from activated macrophage-like cells. Each macrophage phenotype contributed to certain regions of the interactome. Using a network proximity-based prioritization method on the combined network, we predicted potential regulators of macrophage activation. Prediction performance significantly increased with the addition of co-abundance edges, and the prioritized candidates captured inflammation, immunity and CVD signatures. Integrating the novel network topology with transcriptomics and proteomics revealed top candidate drivers of inflammation. In vitro loss-of-function experiments demonstrated the regulatory role of these proteins in pro-inflammatory signaling.

When human cells or tissues are injured, the body triggers a response known as inflammation to repair the damage and protect itself from further harm. However, if the same issue keeps recurring, the tissues become inflamed for longer periods of time, which may ultimately lead to health problems. This is what could be happening in cardiovascular diseases, where long-term inflammation could damage the heart and blood vessels.

Many different proteins interact with each other to control inflammation; gaining an insight into the nature of these interactions could help to pinpoint the role of each molecular actor. Researchers have used a combination of unbiased, large-scale experimental and computational approaches to develop the interactome, a map of the known interactions between all proteins in humans. However, interactions between proteins can change between cell types, or during disease. Here, Halu et al. aimed to refine the human interactome and identify new proteins involved in inflammation, especially in the context of cardiovascular disease.

Cells called macrophages produce signals that trigger inflammation whey they detect damage in other cells or tissues. The experiments used a technique called proteomics to measure the amounts of all the proteins in human macrophages. Combining these data with the human interactome made it possible to predict new links between proteins known to have a role in inflammation and other proteins in the interactome. Further analysis using other sets of data from macrophages helped identify two new candidate proteins – GBP1 and WARS – that may promote inflammation. Halu et al. then used a genetic approach to deactivate the genes and decrease the levels of these two proteins in macrophages, which caused the signals that encourage inflammation to drop.

These findings suggest that GBP1 and WARS regulate the activity of macrophages to promote inflammation. The two proteins could therefore be used as drug targets to treat cardiovascular diseases and other disorders linked to inflammation, but further studies will be needed to precisely dissect how GBP1 and WARS work in humans.

An easy and safe training method for trunk function improves mobility in total knee arthroplasty patients: A quasi-randomized controlled trial

Objective

Total knee arthroplasty (TKA) is aimed mainly at reducing pain and restoring mobility. However, mobility deficits can persist even longer than 1 year. The trunk function and movement velocity of any region have been recently recognized to be critical for determining mobility in older people. Therefore, the main goal of this quasi-randomized trial is to clarify the effectiveness of a novel training method, the seated side tapping (SST) training, for improving mobility by focusing on movement velocity of trunk function in the short term after TKA.

Methods

SST training consists of side trunk movements repeated as quickly as possible in a seated position. All participants after TKA were randomly assigned to the SST training group (n = 37) or control training group (n = 38). The participants in the SST group performed SST training plus the standard rehabilitation program 5 days per week for 3 weeks after TKA, while the control group performed only the standard rehabilitation programs. The primary outcome was the effect of SST training on mobility, indicated by gait speed and the timed up and go test (TUG) time. Measurements were performed before and 1, 2, and 3 weeks after surgery.

Results

At all-time points, the patients in the SST group showed significantly better mobility, despite that knee function, represented by muscle strength, range of motion, and degree of pain at the knee joint, was similar in both groups. The difference in gait speed between the groups was >0.1 m/s at all time points, which is clinically significant.

Conclusion

SST training significantly improved patients’ mobility within 3 weeks after TKA, despite that no additional benefit was observed in knee function. The findings in this study indicate that SST training may be considered as a part of the rehabilitation program after TKA, although further evaluation of its long-term effectiveness is needed.

Trial registration

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; UMIN000027909).

CPAP effects on atherosclerotic plaques in patients with sleep-disordered breathing and coronary artery disease: The ENTERPRISE trial

BACKGROUND

Sleep-disordered breathing (SDB) is a novel cardiovascular risk factor. To date, the effects of continuous positive airway pressure (CPAP) on coronary plaque atheroma in SDB patients with coronary artery disease (CAD) have remained unclear. The CPAP Effects on Atherosclerotic Plaques in Patients with Sleep-Disordered Breathing and Coronary Artery Disease (ENTERPRISE) trial was designed to evaluate the effects of CPAP treatment in addition to optimal medical treatment on coronary plaque regression in SDB patients.

METHODS

This study is planned as a prospective, randomized, open-label, single-center study. The presence of SDB is defined as a 3% oxygen desaturation index (ODI) of ≥15 events/h as measured by nocturnal pulse oximetry. A total of 100 eligible SDB patients undergoing intravascular ultrasound (IVUS)-guided percutaneous coronary intervention will be randomly assigned to either CPAP as add-on therapy or no CPAP for SDB (1:1 ratio for CPAP vs. no CPAP). The intervention will consist of 12 months of CPAP treatment. The primary endpoint will be percentage changes in plaque atheroma volume of the non-culprit lesion segment as measured by IVUS. A specialist sleep cardiology team will carefully monitor patients receiving CPAP treatment in order to quickly detect and resolve problems, and to motivate patients to continue treatment.

CONCLUSION

This study will provide novel information on the effects of SDB and its treatment with CPAP on coronary plaque stability with regard to secondary prevention of CAD.

Mean platelet volume and long-term cardiovascular outcomes in patients with stable coronary artery disease

BACKGROUND AND AIMS

Although an elevated mean platelet volume (MPV) has been associated with poor clinical outcomes after acute coronary syndrome (ACS), the association between MPV and long-term outcomes in patients with stable coronary artery disease (CAD) remains uncertain. We aimed to investigate the impact of pre-procedural MPV levels in patients following elective percutaneous coronary intervention (PCI).

METHODS

We studied 2872 stable CAD patients who underwent their first PCI and who had available data on pre-procedural MPV between 2002 and 2016. Patients were divided into quartiles based on their MPV. The incidences of major adverse cardiac events (MACE), including all-cause death and non-fatal myocardial infarction, were evaluated.

RESULTS

The median MPV was 10.4 fL (interquartile range: 9.8-11.0). During a median follow-up of 5.6 years, 498 (17.3%) MACE were identified, with a cumulative incidence significantly higher in the lowest MPV group than in other groups (p < 0.01). After adjustment for platelet count and the other cardiovascular risk factors, the lowest MPV group had a significantly higher risk of MACE compared with the highest MPV groups (hazard ratio: 1.43, 95% confidence interval 1.10-1.86, p = 0.009). Decreasing MPV as a continuous variable was associated with the incidence of MACE (hazard ratio: 1.16 per 1 fL decrease, 95% confidence interval 1.04-1.30, p = 0.007).

CONCLUSIONS

Contrary to previous studies on ACS patients, this study showed that a low MPV was associated with worse clinical outcomes among stable CAD patients.

High-Dose Versus Low-Dose Pitavastatin in Japanese Patients With Stable Coronary Artery Disease (REAL-CAD): A Randomized Superiority Trial

BACKGROUND

Current guidelines call for high-intensity statin therapy in patients with cardiovascular disease on the basis of several previous "more versus less statins" trials. However, no clear evidence for more versus less statins has been established in an Asian population.

METHODS

In this prospective, multicenter, randomized, open-label, blinded end point study, 13 054 Japanese patients with stable coronary artery disease who achieved low-density lipoprotein cholesterol (LDL-C) <120 mg/dL during a run-in period (pitavastatin 1 mg/d) were randomized in a 1-to-1 fashion to high-dose (pitavastatin 4 mg/d; n=6526) or low-dose (pitavastatin 1 mg/d; n=6528) statin therapy. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring emergency hospitalization. The secondary composite end point was a composite of the primary end point and clinically indicated coronary revascularization excluding target-lesion revascularization at sites of prior percutaneous coronary intervention.

RESULTS

The mean age of the study population was 68 years, and 83% were male. The mean LDL-C level before enrollment was 93 mg/dL with 91% of patients taking statins. The baseline LDL-C level after the run-in period on pitavastatin 1 mg/d was 87.7 and 88.1 mg/dL in the high-dose and low-dose groups, respectively. During the entire course of follow-up, LDL-C in the high-dose group was lower by 14.7 mg/dL than in the low-dose group (P<0.001). With a median follow-up of 3.9 years, high-dose as compared with low-dose pitavastatin significantly reduced the risk of the primary end point (266 patients [4.3%] and 334 patients [5.4%]; hazard ratio, 0.81; 95% confidence interval, 0.69-0.95; P=0.01) and the risk of the secondary composite end point (489 patients [7.9%] and 600 patients [9.7%]; hazard ratio, 0.83; 95% confidence interval, 0.73-0.93; P=0.002). High-dose pitavastatin also significantly reduced the risks of several other secondary end points such as all-cause death, myocardial infarction, and clinically indicated coronary revascularization. The results for the primary and the secondary composite end points were consistent across several prespecified subgroups, including the low (<95 mg/dL) baseline LDL-C subgroup. Serious adverse event rates were low in both groups.

CONCLUSIONS

High-dose (4 mg/d) compared with low-dose (1 mg/d) pitavastatin therapy significantly reduced cardiovascular events in Japanese patients with stable coronary artery disease.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01042730.

Prerequisites to Salvage Profound Biventricular Failure Patients with Ventricular Assist Devices

We conducted chronic experiments to determine how to treat profound biventricular failure systematically with ventricular assist devices (VADs) and to analyze the factors that affect prognoses for this condition. Anoxic arrest was induced in ten goats by aortic cross-clamping under normothermic conditions (38.5° C) for 30 (n= 3), 45 (n= 1), and 60 (n= 6) minutes. A left ventricular assist device (LVAD) was implanted in eight animals, and a biventricular assist device (BVAD) was used in two. Three goats — two of which had undergone anoxic arrest for 30 minutes and one for 60 minutes — whose right atrial pressure (RAP) was approximately 18 mm Hg during the acute stage, recovered in two to three weeks, and the pumps were successfully removed. Pathological findings in these animals showed scattered areas of surviving myocardium, with connective tissue replacing the degenerated myocardium. The remaining five LVAD goats required higher RAPs to maintain circulation and died from various causes. Maintaining circulation without volume loading, even in the presence of arrhythmias, was easier with the BVAD. One BVAD animal that underwent 45 minutes of anoxic arrest recovered from right ventricular failure, and the right pump was removed. The second goat (anoxic arrest, 60 min) on the BVAD failed to recover. Autopsy of the myocardium revealed a thin ventricular wall. Our studies show that the use of VADs allows time for a failing heart to recover, but the potential for healing is affected by the severity of myocardial damage prior to VAD application. We believe that although LVADs can maintain circulation with high RAPs, the use of BVADs might be more beneficial for maintaining systemic organ function in cases of persistent biventricular failure.

Rationale and Design of Randomized Evaluation of Aggressive or Moderate Lipid Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) Trial

Large-scale clinical trials in patients in Western countries with coronary artery disease (CAD) have found that aggressive lipid-lowering therapy using high-dose statins reduces cardiovascular (CV) events further than low-dose statins. However, such evidence has not yet been fully established in Asian populations, including in Japan. The Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study addresses whether intensification of statin therapy improves clinical outcomes in Japanese patients with CAD.REAL-CAD is a prospective, multicenter, randomized, open-label, blinded-endpoint, physician-initiated phase 4 trial in Japan. The study will recruit up to 12,600 patients with stable CAD. Patients are assigned to receive either pitavastatin 1 mg/day or pitavastatin 4 mg/day. LDL-C levels are expected to reach approximate mean values of 100 mg/dL in the low-dose pitavastatin group and 80 mg/dL in the high-dose group. The primary endpoint is the time to occurrence of a major CV event, including CV death, non-fatal myocardial infarction, non-fatal ischemic stroke, and unstable angina requiring emergency hospitalization during an average of 5 years. The large number of patients and the long follow-up period in the REAL-CAD study should ensure that there is adequate power to definitively determine if reducing LDL-C levels to approximately 80 mg/dL by high-dose statin can provide additional clinical benefit.After the study is completed, we will have categorical evidence on the optimal statin dose and target LDL-C level for secondary prevention in Japanese patients.

Chest X-Ray Revealed a Slowly Progressive Giant Right Coronary Artery Aneurysm in an Asymptomatic Patient

A giant right coronary artery aneurysm (60 × 70 mm in size) was incidentally found by chest X-ray as an abnormal right atrial enlargement, and it needed surgical resection. Although the majority of giant coronary artery aneurysms present with symptoms of coronary ischemia, this case presented without any specific symptom. This study indicates that when chest X-ray shows abnormal atrial enlargement, a differential diagnosis of giant coronary artery aneurysm may need to be considered.

Abstract P3-13-03: NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy

Background: Whether adjuvant chemotherapy is required for patients (pts) with intermediate-risk endocrine-responsive postmenopausal breast cancer (BC) remains unknown. Sufficient data have not been available about the long-term prognosis of patients with neoadjuvant endocrine therapy (ET). NEOS is a randomized phase III study that assessed the long-term prognosis of estrogen receptor positive (ER+) primary breast cancer (PBC) pts who received neoadjuvant ET with/without adjuvant chemotherapy.

Methods: Postmenopausal BC pts with ER +/HER2 negative, T1c-2, clinically node negative, under 76 years old were enrolled at primary registration. Pts were treated by leterozole (LET) in weeks 24-28 after primary enrollment. Pts experienced progression (PD) during neoadjuvant phase were excluded at randomization and received any systemic therapy driven by investigators before or after surgery. The long-term prognosis was followed in all registered pts including PD pts. Response to neoadjuvant ET was evaluated as complete response (CR), partial response (PR) or stable disease (SD) using calipers, ultrasound and MRI (or CT) at the baseline and end of treatment before surgery. Pts who met eligibility criteria were randomized 1:1 to LET for 4.5-5 years after chemotherapy or LET alone for 4.5-5 years without chemotherapy after surgery. Pts excluded at second registration were treated any systemic therapies driven by investigators. The primary endpoint was disease-free survival (DFS) and secondary endpoints included overall survival (OS), clinical response rate in neoadjuvant phase, pathological response, and breast-conserving surgery rate. The randomization code have been blinded to the investigators.

Results: Between May 2008 and June 2013, 904 patients were enrolled at primary registration from 100 institutions in Japan (median follow-up: 4.0 years) and 24 pts were withdrawn during neoadjuvant phase. The median age was 63 years, T1c:37%, T2:63%, and PgR+:78%. Clinical response rates (CR, PR, SD and PD) were2% (16pts), 48% (421pts), 45% (400pts) and 5% (43pts), respectively and, in each response category, 0% (0/16), 5.5% (23/421), 7.8% (31/400), and 20.9% (9/43) experienced DFS events. DFS in PD pts to neoadjuvant ET were statistically significantly worse than CR, PR, SD pts (p&lt;0.0001, hazard ratio 4.7 (95% CI:2.3-9.5). The prognosis after surgery in 669 randomized pts was good regardless with/without chemotherapy, forty four pts (6.6%) experienced DFS events after surgery. The predictive markers of PD for neoadjuvant ET were yet unclear among evaluated clinical factors.

Conclusion: This is the first report of DFS in the largest neoadjuvant ET trial (NEOS). The DFS of postmenopausal, ER+/HER2-, PBC pts excluding PD pts to neoadjuvant ET is highly good regardless with/without chemotherapy. Neoadjuvant ET with utilization of PD response as a prognostic marker can be considered as a standard treatment option for these patients. Clinical trial information: UMIN000001090.

Citation Format: Iwata H, Masuda N, Fujisawa T, Toyama T, Ohtani S, Yamamoto Y, Kashiwaba M, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Ohashi Y. NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-13-03.

Abstract P1-13-05: Timing of initiation of neratinib after completion of trastuzumab-based adjuvant therapy in early-stage HER2+ breast cancer: Exploratory analyses from the phase III ExteNET trial

Background: The international, randomized, placebo-controlled phase III ExteNET trial showed that 1 year of neratinib after trastuzumab-based adjuvant therapy significantly improved 2-year invasive disease-free survival (iDFS) in early-stage HER2+ breast cancer (HR 0.67; 95% CI 0.50–0.91; p=0.009) [Chan et al. Lancet Oncol 2016]. The significant iDFS benefit with neratinib was maintained after a median of 5 years' follow-up (HR 0.73; 95% CI 0.57-0.92; p=0.008) [Martin et al. ESMO 2017]. We present exploratory analyses from the ExteNET trial examining the effects of the interval between completion of trastuzumab and randomization to commence neratinib on iDFS.

Methods: Women with early-stage HER2+ breast cancer were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year after standard primary therapy and trastuzumab-based adjuvant therapy. Under the original study protocol, (neo)adjuvant trastuzumab was to be completed ≤24 months before randomization; this was revised to ≤12 months before randomization after the NCCTG-N9831/NSABP B-31 4-year analysis showed that the risk of relapse is greatest during the first 12 months after completing trastuzumab. Disease recurrences were collected prospectively during 1 and 2 years post-randomization, and from medical records during 3–5 years post-randomization. Patients randomized ≤12 months after completion of adjuvant trastuzumab were further separated to look at those who initiated neratinib ≤6 months of completing adjuvant trastuzumab. Primary endpoint: iDFS. HR (95% CI) estimated using Cox proportional-hazards models. Data cut-off: March 1, 2017. Clinicaltrials.gov: NCT00878709.

Results:The intention-to-treat population comprised 2840 patients (neratinib, n=1420; placebo, n=1420). Median time from last trastuzumab dose to randomization was 4.4 and 4.6 months in the neratinib and placebo groups, respectively. 81% of patients were randomized ≤12 months of completing trastuzumab. The effects of the interval between the last dose of trastuzumab and randomization/initiation of neratinib on iDFS after a median follow-up of 5.2 years are shown in the table.

  Estimated 5-year iDFS rate, % P-valueInterval from last dose of trastuzumab to randomizationnNeratinibPlaceboHR (95% CI)a(2-sided)≤6 months164190.085.40.62 (0.46–0.84)0.002≤12 monthsb229789.786.50.70 (0.54–0.90)0.006&gt;12 monthsb54392.392.61.00 (0.51–1.94)0.992a. Neratinib vs placebo; b. Protocol-defined subgroups

Conclusions: In ExteNET, patients who initiated neratinib within 12 months of completing trastuzumab-based adjuvant therapy appeared to derive greater benefit from treatment than those who started neratinib later. Further, exploratory analyses suggest that the magnitude of benefit with neratinib is greater if initiated sooner (i.e. within 6 months of completing trastuzumab). Given the benefits of neratinib overall in those initiating treatment ≤12 months from the end of adjuvant trastuzumab, extended adjuvant treatment with neratinib should be initiated early following completion of trastuzumab.

Citation Format: Ejlertsen B, Chan A, Gnant M, von Minckwitz G, Delaloge S, Buyse M, O'Shaughnessy J, Mansi J, Moy B, Iwata H, Wong A, Ye Y, Means-Powell J, Hui R, Ruiz-Borrego M, Ruiz Simon A, Shen Z-Z, Holmes FA, Lesniewski-Kmak K, Martin M. Timing of initiation of neratinib after completion of trastuzumab-based adjuvant therapy in early-stage HER2+ breast cancer: Exploratory analyses from the phase III ExteNET trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-05.

Abstract P2-01-09: Circulating tumor cells (CTCs) in the venous drainage of the breast in patients with primary breast cancer

Background:

CTCs are shed from tumors and circulate in the peripheral blood after passing through the drainage vein. Axillary lymph node dissection (ALND) provides access to the lateral thoracic vein which flows directly into the axillary vein. In this preliminary study, we evaluated the feasibility of detecting CTCs in the peripheral blood and in the lateral thoracic venous blood for breast cancer patients who underwent ALND.

Methods:

From June 2016 to March 2017, breast cancer patients who underwent ALND in our institute were eligible for this study. A peripheral blood sample,10ml, was drawn just before the surgery or one day before the surgery. A lateral thoracic venous blood sample was taken from the resected breast just after resection. A blood sample of 0.2ml or more was necessary for CTC isolation. The CTCs in the peripheral blood before surgery (periCTC) and in the blood from the lateral thoracic vein of the resected breast (ltvCTC) were quantitatively examined by using a size-selective CTC isolation platform.

Results:

A total of 21 patients with median age 51 years (37-75) were enrolled to the study. Of the 21 patients, 38% were premenopausal, 52% had neoadjuvant chemotherapy. Fifty-seven percent were ER and/or PgR positive, 24% were HER2 positive. Fifty-seven percent were stage II disease and 43% were stage III. In 3 patients, we couldn't obtain sufficient blood samples from the lateral thoracic vein. Of the remaining 18 patients, we were able to obtain the median 0.5ml (0.2-2.0) blood samples from the lateral thoracic vein. CTCs were detected in peripheral blood in 15 patients (71%) and median periCTC count was 1 CTC/10ml (0-39). In lateral thoracic venous blood, CTCs were detected in all patients who had sufficient blood samples and the median ltv CTC count was 35.5 CTC/ml (2.5-370). In 5 of 6 patients whom CTCs in peripheral blood samples were not detected, CTCs could be detected in the blood samples from lateral thoracic vein.

Conclusion:

CTCs can be detected in the peripheral blood and in the blood from lateral thoracic vein in patients with localized breast cancer, and can be detected at a higher rate and at a higher concentration in the blood from lateral thoracic vein than in peripheral blood.

Citation Format: Hattori M, Nakanishi H, Yoshimura A, Adachi Y, Iwase M, Gondo N, Kotani H, Sawaki M, Yatabe Y, Iwata H. Circulating tumor cells (CTCs) in the venous drainage of the breast in patients with primary breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-01-09.

Abstract P2-12-13: Withdrawn

This abstract was withdrawn by the authors.

Abstract P1-13-11: Neratinib in the extended adjuvant treatment of patients from Asia with early-stage HER2+ breast cancer after trastuzumab-based therapy: Exploratory analyses from the phase III ExteNET trial

Background: Current breast cancer knowledge is based largely on studies conducted in western populations. Their findings may not be generalizable to Asian women because of ethnic, genetic and lifestyle differences. Neratinib (N) is an irreversible tyrosine kinase inhibitor of HER1, 2 and 4. The international, randomized, placebo (P)-controlled phase III ExteNET trial showed that 1 year (yr) of N after trastuzumab (T)-based adjuvant therapy significantly improved 2-yr invasive disease-free survival (iDFS) in patients (pts) with early-stage HER2+ breast cancer (HR 0.67; 95% CI 0.50–0.91; p=0.009) [Chan et al. Lancet Oncol 2016]. The significant iDFS benefit with N was shown to be durable after 5 yrs' follow-up (HR 0.73; 95% CI 0.57-0.92; p=0.008) [Martin et al. ESMO 2017]. We report efficacy and safety findings from pts enrolled from Asian centers (China, Hong Kong, Japan, Korea, Malaysia, Singapore, and Taiwan) on the ExteNET trial to better characterize the effects of N in Asian women.

Methods: Pts with early-stage HER2+ breast cancer were randomly assigned to oral N 240 mg/day or P for 1 yr after standard primary therapy and T-based adjuvant therapy. Antidiarrheal prophylaxis was not required by protocol. Data concerning disease recurrences were collected prospectively during yr 1-2 post-randomization, and from medical records during yr 3–5 post-randomization. Primary endpoint: iDFS. HR (95% CI) estimated using Cox proportional-hazards models stratified by nodal status, hormone-receptor status and prior T regimen. Data cut-off: 2-yr analysis, July 2014; 5-yr analysis, March 2017. Clinicaltrials.gov:NCT00878709.

Results: Of 2840 randomized pts (N, n=1420; P, n=1420), 341 (12%) were enrolled from Asian centers (N, n=165; P, n=176). Baseline characteristics: median age 53 yr; hormone receptor-positive 48%. Median treatment duration was similar in both groups (N, 351 days; P, 352 days). iDFS events in Asian vs ITT populations are shown in the Table.

 Primary 2-yr analysisa5-yr analysis NPNPAsian population, n165176165176iDFS events, n10151222HR (95% CI)b0.71 (0.31-1.57)0.54 (0.26-1.08)P-value (2-sided)0.4040.085ITT population, n1420142014201420iDFS events, n67106116163HR (95% CI)b0.66 (0.49-0.90)0.73 (0.57-0.92)P-value (2-sided)0.0080.008a. Primary study endpoint; b. Neratinib vs placebo

The incidence of grade 3/4 diarrhea with N was slightly higher in Asian pts (46.1% vs ITT, 39.8%). All other grade 3/4 adverse events with N were rare among Asian pts (elevated ALT, mucosal inflammation, 2 pts each; other events, 1 pt each). Compliance with N in Asian pts was also improved (71% vs ITT, 61%).

Conclusions: In Asian pts enrolled into ExteNET, compliance with N was better and the magnitude of N effect was similar or greater that that observed in the ITT population. Although N-related grade 3/4 diarrhea was more common in Asian pts than in the ITT population, all other grade 3/4 events were rare. Despite small pt numbers, our analyses suggest that the findings from ExteNET are applicable to Asian pts, and support the conclusion that N reduces disease recurrences in Asian pts with early-stage HER2+ breast cancer after T-based adjuvant therapy.

Citation Format: Iwata H, Masuda N, Kim S-B, Inoue K, Rai Y, Fujita T, Shen Z-Z, Chiu JW, Ohtani S, Takahashi M, Yamamoto N, Miyaki T, Sun Q, Yen-Shen L, Xu B, Yap YS, Bustam AZ, Lee JR, Zhang B, Bryce R, Chan A. Neratinib in the extended adjuvant treatment of patients from Asia with early-stage HER2+ breast cancer after trastuzumab-based therapy: Exploratory analyses from the phase III ExteNET trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-11.

Abstract P1-13-03: Effects of neratinib after trastuzumab-based adjuvant therapy in hormone receptor-positive HER2+ early-stage breast cancer: Exploratory analyses from the phase III ExteNET trial

Background: The international, randomized, placebo-controlled phase III ExteNET trial showed that a 1-year course of neratinib after trastuzumab-based adjuvant therapy significantly improved 2-year invasive disease-free survival (iDFS) in patients with early-stage HER2+ breast cancer (BC) (hazard ratio 0.67; 95% CI 0.50–0.91; p=0.009) [Chan et al. Lancet Oncol 2016]. The significant iDFS benefit with neratinib was maintained after a median 5 years' follow-up (hazard ratio 0.73; 95% CI 0.57-0.92; p=0.008) [Martin et al. ESMO 2017]. At both time-points, marked benefit with neratinib was evident in patients with hormone receptor (HR)+ tumors, whereas in patients with HR– disease, initial improvements with neratinib diminished after completing treatment. We report exploratory analyses from the ExteNET trial done to better characterize the effects of neratinib in the HR+ subgroup.

Methods: Patients with early-stage HER2+ BC were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year after standard primary therapy and trastuzumab-based adjuvant therapy. Randomization was stratified by HR status (locally assessed), nodal status, and trastuzumab regimen. Adjuvant endocrine therapy was recommended for patients with HR+ disease. Data concerning disease recurrences were collected prospectively during year 1-2 post-randomization, and from medical records during year 3–5 post-randomization. Primary endpoint: iDFS. Secondary endpoints: DFS including ductal carcinoma in situ (DFS-DCIS); time to distant recurrence (TTDR); distant DFS (DDFS); cumulative incidence of central nervous system (CNS) recurrences; overall survival (OS). Hazard ratios (95% CI) were estimated using Cox proportional-hazards models. Data cut-off: March 2017. Clinicaltrials.gov: NCT00878709.

Results: 2840 patients were randomized (neratinib, n=1420; placebo, n=1420); 1631 (57%) patients had HR+ tumors (neratinib, n=816; placebo, n=815). 93% and 94% of HR+ patients in the neratinib and placebo groups, respectively, were receiving adjuvant endocrine therapy at baseline. Efficacy outcomes in the HR+ cohort after a median follow-up of 5.2 years are shown in the table. In subgroup analyses of the HR+ cohort, hazard ratios for iDFS were 0.49 in centrally confirmed HER2+ patients (n=951), and 0.58 in patients who had completed prior trastuzumab ≤12 months before randomization (n=1334). CNS recurrence and OS data are not yet mature.

 Updated 2-year analysis5-year analysis  Hazard ratiobP-value Hazard ratiobP-value Δ, %a(95% CI)(2 sided)Δ, %a(95% CI)(2 sided)iDFS4.10.49 (0.31–0.75)0.0014.40.60 (0.43–0.83)0.002DFS-DCIS4.80.45 (0.29–0.69)&lt;0.0015.10.57 (0.42–0.79)&lt;0.001DDFS3.10.52 (0.32–0.84)0.0084.00.60 (0.42–0.85)0.004TTDR2.90.52 (0.31–0.85)0.013.80.61 (0.42–0.86)0.006a. Difference in event rates between neratinib vs placebo; b. Neratinib vs placebo

Conclusions: Neratinib was associated with an absolute iDFS benefit of 4.4% in patients with HR+/HER2+ BC after 5 years' follow-up. HR/HER2 receptor cross-talk may underpin the notable effect of neratinib in patients with HR+ tumors when given in combination with endocrine therapy.

Citation Format: Chia SKL, Martin M, Iwata H, Moy B, Lalani AS, Holmes FA, Mansi J, von Minckwitz G, Buyse M, Delaloge S, Ejlertsen B, Yao B, Murias Rosales A, Hellerstedt B, Cold S, Inoue K, Shen Z-Z, Galeano T, Barrios CH, Chan A. Effects of neratinib after trastuzumab-based adjuvant therapy in hormone receptor-positive HER2+ early-stage breast cancer: Exploratory analyses from the phase III ExteNET trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-03.

Abstract P5-21-13: Olaparib monotherapy versus chemotherapy for patients with HER2-negative metastatic breast cancer and a germline BRCA mutation: Asian subgroup analysis from the phase III OlympiAD trial

Background

In the Phase III OlympiAD trial (NCT02000622, D0819C00003), olaparib (Lynparza™) showed a significant progression-free survival (PFS) improvement compared with chemotherapy treatment of physician's choice (TPC) in patients (pts) with metastatic breast cancer (mBC) and a germline BRCA mutation (gBRCAm) (Robson et al. NEJM 2017). Here, we present data from a subgroup analysis of Asian pts. It is not yet known whether Asian pts, in comparison with the global patient population, may experience instances of differential toxicity with olaparib therapy.

Methods

OlympiAD, an open-label, multicenter, Phase III trial, randomized (2:1) pts with HER2-negative mBC and a gBRCAm to olaparib tablets (300 mg twice daily) or single-agent TPC (21-day cycles of capecitabine, eribulin or vinorelbine). Pts must have received ≤2 lines of chemotherapy for mBC and prior anthracycline and taxane in the adjuvant, neo-adjuvant or metastatic setting. Primary endpoint was PFS by blinded independent central review (BICR). Region (Asia, Europe, North America, South America) was a pre-defined subgroup for PFS.

Results

The Asian subgroup analysis included pts randomized at centers in China, Japan, Korea and Taiwan. Of 87 Asian pts randomized (median age 46 years), 86 received study treatment (n=59, olaparib; n=27, TPC). In the olaparib group, 29/59 (49%) had estrogen receptor positive (ER+) and/or progesterone receptor positive (PR+) tumors, and 30/59 (51%) had triple negative breast cancer (TNBC). In the TPC group, 13/28 (46%) had ER+/PR+ tumors and 15/28 (54%) had TNBC. The primary endpoint, PFS by BICR, favored olaparib with a hazard ratio (HR) of 0.53 (95% confidence interval [CI] 0.29–0.97; median 5.7 vs 4.2 months; 77% maturity), and was supported by investigator-assessed PFS (HR 0.29, 95% CI 0.16–0.55). In the overall OlympiAD study population (N=302), the PFS by BICR favored olaparib with a HR of 0.58 (95% CI 0.43–0.80; P=0.0009). Within the Asian subgroup, objective response rate (ORR) (RECIST) was 64% for olaparib versus 38% for the TPC group. Time to second progression, PFS2, was longer for pts receiving olaparib versus TPC (HR 0.43, 95% CI 0.22–0.84; 57% maturity). Grade ≥3 adverse events (AEs) occurred in 46% and 59% of pts receiving olaparib and TPC, respectively. The most common grade ≥3 AE was anemia (olaparib, 20%; TPC, 15%). In both treatment groups, 7% of pts discontinued study treatment due to AEs (n=4, olaparib; n=2, TPC). The tolerability profile of olaparib between the subgroup of Asian pts and the overall OlympiAD population will be examined in our data presentation.

Conclusion

Olaparib demonstrated an efficacy benefit compared with TPC in pts with HER2-negative mBC and a gBRCAm in this subgroup analysis of Asian pts from the Phase III OlympiAD trial. Discontinuation rates due to toxicity were low, highlighting that olaparib was generally well-tolerated. The efficacy of olaparib within the subgroup of Asian pts was consistent with that shown for the full OlympiAD dataset; consistent hazard ratios were shown in favor of olaparib using the primary endpoint of PFS by BICR, and for the key secondary endpoints of PFS by investigator assessment, PFS2, and ORR.

Citation Format: Im S-A, Xu B, Li W, Robson M, Ouyang Q, Yeh D-C, Iwata H, Park Y-H, Sohn JH, Tseng L-M, Goessl C, Wu W, Runswick S, Masuda N. Olaparib monotherapy versus chemotherapy for patients with HER2-negative metastatic breast cancer and a germline BRCA mutation: Asian subgroup analysis from the phase III OlympiAD trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-13.

Abstract P3-11-06: A phase 1 study of KHK2375 (entinostat) as monotherapy and in combination with exemestane in Japanese patients with hormone receptor-positive, HER2-negative, advanced or recurrent breast cancer

Background: Patients (pts) with hormone receptor-positive (HR+) and non-life threatening advanced or metastatic breast cancer (BC) are usually treated with sequential endocrine therapies. Endocrine therapies are continued until tumor cells acquire resistance to them, following which pts are switched to cytotoxic chemotherapy. Entinostat (ENT) is an oral inhibitor of class I histone deacetylases (HDACs) and is expected to be used for endocrine therapy-resistant pts. The efficacy of ENT in combination with an aromatase inhibitor (AI) for HR+ BC was demonstrated in a previous randomized phase 2 study. Because of the lack of data on safety and pharmacokinetics (PK) in Japanese HR+ BC pts, we performed this dose escalation phase 1 study to investigate the safety of ENT monotherapy and combination therapy with exemestane (EXE) in postmenopausal women with advanced or recurrent HR+ BC. Secondary objectives were to assess PK and efficacy.

Methods: This study was based on a 3+3 dose escalation design. Postmenopausal women with advanced or recurrent HR+ HER2- BC previously treated with nonsteroidal AIs and with ECOG PS 0-1 were enrolled. The dose limiting toxicities (DLT) of ENT monotherapy (3 mg/qw, 5 mg/qw, or 10 mg/q2w) in Cohort 1-3 and those of ENT (5 mg/qw or 3 mg/qw) in combination with EXE 25 mg/qd in Cohort 4-5 were assessed for 7 and 28 days, respectively. Pts continued ENT (3 mg or 5 mg) in combination with EXE even after the DLT observation period until disease progression or discontinuation for other reasons. Adverse events (AEs) were graded per NCI-CTCAE version 4.03. Tumor response was evaluated by RECIST version 1.1 every 8 weeks. ENT concentration was measured intensively. Samples of peripheral blood mononuclear cells (PBMC) were collected to measure protein lysine hyperacetylation and for immune subset analysis. Optional tumor biopsies for biomarker assessment were collected before and during treatment.

Results: Twelve pts were enrolled and three each were assigned to Cohort 1-4 between Nov 2015 and Sept 2016. Neither DLT nor grade 3-5 AE occurred. As no DLT occurred in Cohort 4, Cohort 5 was omitted as originally planned. The drug-related AEs observed in ≥2 pts during the DLT observation period were grade 1-2 hypophosphatemia (1 pt each in Cohort 2, 3, and 4), grade 1 nausea (1 pt in Cohort 3 and 2 pts in Cohort 4), and grade 1-2 platelet count decreased (2 pts in Cohort 4). AUC0-168 increased in a dose proportional manner. As of May 2017, 4 pts continue to receive study treatment, including one treated for more than 18 months. Biomarker data including protein lysine hyperacetylation and immune subset in PBMC and results of paired biopsy samples will be reported.

Conclusions: This study showed the tolerability of the combination therapy of ENT 5 mg with EXE 25 mg in Japanese pts. There were no new safety concerns as compared to those reported previously. Following this result, a randomized phase 2 study for Japanese pts is planned.

Clinical trial information : NCT02623751.

Citation Format: Shimomura A, Masuda N, Tamura K, Yasojima H, Sawaki M, Nishimura Y, Saji S, Iwata H. A phase 1 study of KHK2375 (entinostat) as monotherapy and in combination with exemestane in Japanese patients with hormone receptor-positive, HER2-negative, advanced or recurrent breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-06.

Abstract PD5-03: TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients

Background: Neoadjuvant therapy for locally advanced breast cancer has the potential to improve surgical therapeutic outcomes without sacrificing the survival advantages of adjuvant therapy. However, determining whether ER+ patients (pts) will respond to neoadjuvant (NA) chemotherapy (CT) or hormone therapy (HT) can be difficult. Not all ER+ pts respond to NACT, while response to NAHT can vary across ER+ pts. Thus, the ability to select pts more likely to benefit from NAHT would represent progress in clinical management of breast cancer. NEOS is a randomized phase III study assessinglong-term prognosis of ER+ primary breast cancer with/without adjuvant CT following NAHT (UMIN 000001090, http://www.umin.ac.jp/). We used archived core biopsy tumor samples from the NEOS study to validate the RS result as a predictor of clinical response and its association with successful breast conserving surgery (BCS) in pts treated with 6 months of NAHT.

Methods: NEOS enrolled 904 postmenopausal pts with ER+, HER2-, clinically node negative (cN0) breast cancer to evaluate whether adjuvant CT was necessary for pts who responded to NAHT. In this current study, we enrolled pts with tumors ≥2cm from the NEOS study. Biopsy samples of 333 pts were assessed for the Oncotype DX assay. Response to NAHT was recorded as complete/partial response (CR/PR), or stable/progressive disease (SD/PD).

Primary endpoint of this study was to evaluate clinical response (CR/PR) to NA letrozole between pts with low (&lt;18) and high (≥31) RS result. Secondary endpoints include evaluating the relationships between clinical response and continuous RS results, and other covariates including age, tumor size, grade, Ki67 by IHC, ER and PR single gene scores, and ER and proliferation gene group scores by RT-PCR.

Results: The analysis included 294 pts with median age of 63 yrs, median tumor size of 25mm, and 66% were nuclear grade 1. 156 (53.0%), 83 (28.6%) and 54(18.4%) cases were low, intermediate, and high RS groups by Oncotype DX, respectively. Six (2%), 126 (42.8%), 149 (50.3%), 13 (4.4%) cases experienced CR, PR, SD, PD as clinical response, respectively, similar to that of all NEOS pts. Clinical response rate was 54%, 42% and 22% in low, intermediate, and high RS groups, respectively. The proportion of pts with clinical response was significantly higher in the low RS group vs the high RS group (p&lt;0.001). In univariate analyses, continuous RS was significantly associated with clinical response (p&lt;0.001), along with ER (p=.02), PR (p&lt;0.001), and ER gene group score (p&lt;0.001). Other covariates were not associated with clinical response.

Conclusion: The Oncotype DX RS test in core biopsy samples is validated as a predictive assay for clinical response of NAHT in postmenopausal, ER+/HER2-, cN0, primary early breast cancer pts. Further results on the association of RS results with BCS outcomes following NAHT will be presented. These results when combined with previously published data on RS in NACT studies help guide pts with ER+, HER2- breast cancer with NAHT vs NACT treatment options to maximize clinical response.

Citation Format: Yamamoto Y, Iwata H, Masuda N, Fujisawa T, Toyama T, Kashiwaba M, Ohtani S, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Sakamaki K, Chao C, McCullough D, Sugiyama N, Ohashi Y. TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD5-03.

Abstract PD3-12: PIK3CA alterations and benefit with neratinib after trastuzumab-based adjuvant therapy in early-stage HER2+ breast cancer: Correlative analyses of the phase III ExteNET trial

Background: Neratinib is a pan-HER tyrosine kinase inhibitor that blocks the PI3K/Akt and MAPK signaling pathways downstream from HER2. The international, randomized, placebo-controlled phase III ExteNET trial showed that a 1-year course of neratinib after trastuzumab-based adjuvant therapy significantly improved 2-year invasive disease-free survival (iDFS) in early-stage HER2+ breast cancer (HR 0.67; 95% CI 0.50–0.91; p=0.0091) [Chan et al. Lancet Oncol 2016]. Furthermore, the effects of neratinib on iDFS were shown to be durable at 5 years' follow-up (HR 0.73; 95% CI 0.57–0.92; p=0.008) [Martin et al. ESMO 2017]. PIK3CA alterations are common in HER2+ breast cancers, and in general are associated with a worse prognosis. We sought to assess the prognostic and predictive significance of PIK3CA alterations in an exploratory substudy of the ExteNET trial.

Methods: ExteNET is an international, multi-center, randomized, double-blind, placebo-controlled phase III trial (Clinicaltrials.gov: NCT00878709). Patients received oral neratinib 240 mg/day or placebo for 1 year. Of the intent-to-treat (ITT) population (n=2840), primary formalin-fixed paraffin-embedded (FFPE) tumor specimens were available from 991 patients for PIK3CA mutation testing by RT-PCR for two hot-spot mutations in exon 9 (E542K, E545K/D) and one hot-spot mutation in exon 20 (H1047R). 702 FFPE tumor slides underwent FISH analysis for PIK3CA amplification with a ratio of ≥2.2 considered as amplified. Primary endpoint: iDFS. iDFS events were tested by 2-sided log-rank tests, and HR (95% CI) were estimated using Cox proportional-hazards models. Data cut-off: March 2017.

Results: Baseline demographics and disease characteristics between treatment arms of the correlative cohort (n=1201) were balanced. Overall, 21.2% (n=210) of primary tumors harbored one of the specified PIK3CA mutations, and 8.7% (n=61) were PIK3CA FISH-amplified. Patients with PIK3CA-altered tumors (i.e. PIK3CA mutations or FISH-amplified) had fewer iDFS events with neratinib compared with placebo (HR 0.41; 95% CI 0.17-0.90, p=0.028). The interaction test was not significant (p=0.1842). Results of the various correlative analyses within treatment arms are shown in the table.

 NeratinibPlacebo   iDFS iDFS 2-sidedPopulationnevents, nnevents, nHR (95% CI)P valueaITT142011614201630.73 (0.57–0.92)b0.008bCorrelative cohort59345608700.67 (0.45–0.96)0.0317PIK3CA-mutation positive1047106170.43 (0.17–1.01)0.056PIK3CA-mutation negative38527396420.66 (0.40-1.06)0.089PIK3CA-amplified3312840.20 (0.01-1.33)0.106PIK3CA-non-amplified31629325360.85 (0.52-1.39)0.521PIK3CA-altered1308132200.41 (0.17-0.90)0.028a. Log-rank test; b. Stratified analysis

Conclusions: One year of neratinib treatment after trastuzumab-based adjuvant therapy significantly improves iDFS after 5 years in patients with early-stage HER2+ breast cancer. From this modest-sized exploratory cohort, it appears that PIK3CA may be a biomarker for differential sensitivity to neratinib after 1 year of trastuzumab in the adjuvant setting.These exploratory results should be validated in a larger subset.

Citation Format: Chia SKL, Martin M, Holmes FA, Ejlertsen B, Delaloge S, Moy B, Iwata H, von Minckwitz G, Mansi J, Barrios CH, Gnant M, Tomašević Z, Denduluri N, Šeparović R, Kim S-B, Hugger Jakobsen E, Harvey V, Robert N, Smith II J, Harker G, Lalani AS, Zhang B, Eli LD, Buyse M, Chan A. PIK3CA alterations and benefit with neratinib after trastuzumab-based adjuvant therapy in early-stage HER2+ breast cancer: Correlative analyses of the phase III ExteNET trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-12.

Abstract OT3-06-02: A phase Ib trial of xentuzumab and abemaciclib in patients with locally advanced or metastatic solid tumors, including hormone receptor-positive, HER2-negative breast cancer (plus endocrine therapy)

Background: Resistance to endocrine therapy remains an important clinical problem in hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer (BC), necessitating alternative treatment options. The insulin-like growth factor (IGF) axis and cyclin D-cyclin-dependent kinase (CDK) 4/6-retinoblastoma pathway have been implicated in the pathogenesis and resistance mechanisms of a variety of cancers, including BC. Binding of IGF-I and -II to the IGF receptor results in upregulation of cyclin D1, and subsequent progression through the cell cycle, thus providing rationale for the simultaneous inhibition of IGF-I and -II and CDK4/6. This Phase Ib trial assesses the maximum-tolerated dose (MTD)/recommended phase II dose (RP2D), safety and preliminary efficacy of the IGF-ligand-neutralizing antibody, xentuzumab, in combination with abemaciclib, a selective, small-molecule inhibitor of both CDK4 and 6, in patients (pts) with solid tumors. The trial includes four dose finding cohorts followed by two expansion cohorts. Only those cohorts that will include pts with postmenopausal HR+, HER2- BC will be presented here.

Trial design: In this phase Ib multicenter, non-randomized, open-label, dose escalation trial (BI 1280.18 [NCT03099174]), the key aims in the BC cohorts (Cohorts B–D, F) are to define the MTD or recommended phase 2 dose (RP2D), and to evaluate the preliminary efficacy, safety and tolerability of xentuzumab plus abemaciclib in combination with endocrine therapies. Eligible pts include adults ≥18 yrs (≥20 for Japan), with measurable or evaluable disease, adequate organ function, ECOG PS ≤1, and postmenopausal locally advanced or metastatic HR+, HER2- BC (Cohorts B–D, F). CDK4/6 inhibitor-naïve pts (Cohorts B–D) and pts who have received prior CDK4/6 inhibitors (palbociclib or ribociclib) plus aromatase inhibitors (Cohort F) are included. The MTD/RP2D of xentuzumab plus abemaciclib to be used in Cohorts B–D will be established in pts with solid tumors (Cohort A) who will receive xentuzumab (starting dose 1000mg weekly iv) plus abemaciclib (starting dose 150mg every 12 hours). CDK4/6 inhibitor-naïve pts with BC will receive xentuzumab plus abemaciclib at the RP2D determined in Cohort A in combination with letrozole (2.5mg/day; Cohort B), anastrozole (1mg/day; Cohort C), or fulvestrant (500mg/month; Cohort D). CDK4/6 inhibitor pre-treated pts with BC (Cohort F) will receive xentuzumab plus abemaciclib and fulvestrant at the RP2D determined in Cohort D. Primary endpoints in the BC cohorts are the MTD and/or RP2D of xentuzumab plus abemaciclib in combination with endocrine therapies, and the objective response (OR) in CDK4/6 inhibitor pre-treated pts with advanced BC (Cohort F); disease control (DC), duration of DC, time to OR, duration of OR, and progression-free survival (PFS) in Cohort F are secondary endpoints. Additionally, PK outcomes, safety and tolerability will be assessed in all cohorts. This study will be conducted in the US, Europe and Japan. Pt screening started in May 2017. Target enrolment is ˜88 pts, including ˜56 pts with advanced HR+, HER2- BC, of whom ˜20 had previously been treated with CDK 4/6 inhibitors.

Citation Format: Yee D, Sablin MP, Iwata H, Johnston EL, Bogenrieder T, Serra J, Hua H, Lo Russo P, Prat A. A phase Ib trial of xentuzumab and abemaciclib in patients with locally advanced or metastatic solid tumors, including hormone receptor-positive, HER2-negative breast cancer (plus endocrine therapy) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-06-02.

Efficacy and safety of trastuzumab, lapatinib, and paclitaxel neoadjuvant treatment with or without prolonged exposure to anti-HER2 therapy, and with or without hormone therapy for HER2-positive primary breast cancer: a randomised, five-arm, multicentre, open-label phase II trial

Background

Dual blockade of HER2 promises increased pathological complete response (pCR) rate compared with single blockade in the presence of chemotherapy for HER2-positive (+) primary breast cancer. Many questions remain regarding optimal duration of treatment and combination impact of endocrine therapy for luminal HER2 disease.

Methods

We designed a randomised phase II, five-arm study to evaluate the efficacy and safety of lapatinib and trastuzumab (6 weeks) followed by lapatinib and trastuzumab plus weekly paclitaxel (12 weeks) with/without prolongation of anti-HER2 therapy prior to chemotherapy (18 vs. 6 weeks), and with/without endocrine therapy in patients with HER2+ and/or oestrogen receptor (ER)+ disease. The primary endpoint was comprehensive pCR (CpCR) rate. Among the secondary endpoints, pCR (yT0-isyN0) rate, safety, and clinical response were evaluated.

Results

In total, 215 patients were enrolled; 212 were included in the full analysis set (median age 53.0 years; tumour size = T2, 65%; and tumour spread = N0, 55%). CpCR was achieved in 101 (47.9%) patients and was significantly higher in ER− patients than in ER+ patients (ER− 63.0%, ER+ 36.1%; P = 0.0034). pCR with pN0 was achieved in 42.2% of patients (ER− 57.6%, ER+ 30.3%). No significant difference was observed in pCR rate between prolonged exposure groups and standard groups. Better clinical response outcomes were obtained in the prolongation phase of the anti-HER2 therapy. No surplus was detected in pCR rate by adding endocrine treatment. No major safety concern was recognised by prolonging the anti-HER2 treatment or adding endocrine therapy.

Conclusions

This study confirmed the therapeutic impact of lapatinib, trastuzumab, and paclitaxel therapy for each ER− and ER+ subgroup of HER2+ patients. Development of further strategies and tools is required, particularly for luminal HER2 disease.

Electronic supplementary material

The online version of this article (10.1007/s12282-018-0839-7) contains supplementary material, which is available to authorized users.

Omega-6 Polyunsaturated Fatty Acid Levels and Delirium in Patients With Acute Cardiovascular Disease

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