Abstract P6-18-17: Ribociclib + letrozole in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC) with no prior endocrine therapy (ET) for ABC: CompLEEment-1 trial, preliminary results from Spanish population

Background: The phase III Monaleesa-2, Monaleesa-3 and Monaleesa-7 trials have shown significantly improved PFS for the combination ribociclib + ET vs ET + placebo in pre-, peri-, and postmenopausal women with HR+/HER2–, first and second line aBC. The Compleement-1 trial is a phase IIIb, single-arm, open-label, international study to assess the safety and efficacy of ribociclib + letrozole in men and women who have not received prior ET for HR+, HER2– ABC [J Clin Oncol 36, 2018 (suppl; abstr 1056)].

Methods: 526 patients with HR+, HER2– ABC, ≤1 line of prior CT, and no prior ET for aBC were enrolled in the Compleement-1trial in Spain from April 2017 to January 2018. Patients received ribociclib (600 mg/day, 3 weeks on/1 week off) + letrozole (2.5 mg/day); men and premenopausal women received concomitant goserelin (3.6 mg subcutaneous implant every 28 days). The primary objective was safety and tolerability. Here we report on a sub-analysis from the Spanish population of Compleement-1 trial including baseline characteristics and early safety results for the first patients enrolled who completed at least 56 days of follow-up or discontinued before the cut-off date (3rd Oct 2017).

Results: One hundred fifty four patients constituted the analytical cohort for this sub-analysis. Demographics and baseline characteristics: median age was 52 years (range 24-82); 1% of patients were male, 31.8% female pre-menopausal and 67.5% female post-menopausal; 44.2% vs 38.3% of patients had visceral disease vs bone only disease; 49.9% patients had ≥2 metastatic sites; and 34.4% of patients presented as de novo stage IV. The median exposure for study treatment was 1.8 months (range 0.8-1.8). The grade 3/4 events reported >1% included neutropenia (50%), increased GGT levels (3.2%), leukopenia (1.3%), and increased ALT (1.3%). QTcF prolongation >480ms based on ECG data was reported in 1.2% patients. Median dose intensity for ribociclib was 600mg/day (range 476.5-600); 11% of patients required one dose reduction (8.4% due to AEs), 59.7% had at least one dose interruption (57.1% due to AEs) and 9.7% were permanently discontinued (4.5% due to AEs).

Conclusions: Preliminary safety results from this Compleement-1 sub-analysis including Spanish population are consistent with previous data presented from Monaleesa-2, Monaleesa-3, Monaleesa-7 and Compleement-1. These data support the predictable and manageable safety profile of ribociclib in combination with letrozole. Clinical trial information: NCT02941926

Citation Format: Salvador J, Ciruelos EM, Prat A, Jiménez-Rodríguez B, de la Cruz L, Martínez N, Villanueva Vázquez R, de Toro R, Antón A, Moreno F, Alvarez I, Gavila J, Quiroga V, Vicente E, de la Haba J, González-Santiago S, Díaz N, Barnadas A, Cantos Sánchez de Ibargüen B, Delgado JI, Bellet M, Gimeno A, Sanz S, Martin M. Ribociclib + letrozole in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC) with no prior endocrine therapy (ET) for ABC: CompLEEment-1 trial, preliminary results from Spanish population [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 P6-18-17.

Abstract P6-16-01: Health-related quality of life in MONARCH 3: Abemaciclib plus an aromatase inhibitor as initial therapy in women with HR+, HER2- advanced breast cancer

Background: In the MONARCH 3 trial, abemaciclib plus an aromatase inhibitor (AI) significantly improved progression free survival and overall response rate with a generally tolerable safety profile compared to placebo plus AI. Here we report patient-reported outcomes (PRO) including health-related quality of life (Qol), functioning, and symptoms.

Methods: MONARCH 3 was a double-blind, randomized phase III study of abemaciclib or placebo plus an AI in 493 post-menopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer with no prior systemic therapy in the advanced setting. Two European Organization for Research and Treatment of Cancer (EORTC) questionnaires were included: Quality of Life Questionnaire (QLQ)-Core 30 (C30) and the EORTC QLQ-Breast 23 (BR23) that were assessed at baseline, every 2 cycles through cycle 19, then every 3 cycles until treatment discontinuation, and at short-term follow up. Higher scores on functional and health status/QoL outcomes indicate higher/better levels of functioning or health; conversely higher scores on symptom outcomes indicate higher/worse levels of symptom burden. Between-arm comparisons of change from baseline were conducted using mixed model methods. Statistical significance was set at 0.05 and clinical meaningfulness was set at ≥10 points on a 0-100 scale1.

Results: PRO completion rates were >91% through cycle 19; duration of treatment was longer for abemaciclib plus AI patients (median number of cycles 19 vs.15). Compared to the placebo arm, diarrhea PRO scores in the abemaciclib arm showed a clinically (18.68 points) and statistically significant (p<0.001) increase/worsening. By-cycle analysis showed group mean diarrhea scores returned to near-baseline levels post-therapy. Other symptom PROs showed statistically significant (<0.05) but not clinically meaningful differences; fatigue (4.96; p=0.004), systemic therapy side effects (4.48, p<0.001), appetite loss (4.03; p=0.034), and nausea/vomiting (2.77; p=0.013). These results were consistent with the investigator-reported treatment emergent adverse events (TEAEs). Several non-symptom results were also statistically significant but not clinically meaningful including global health/health status (-4.36; p=0.003), role function (-4.25; p=0.025), social function (-3.41, p=0.047), and body image (-5.11, p=0.009). No statistically significant between-treatment differences were observed for physical, emotional, and cognitive functioning or for symptoms of pain, dyspnea, insomnia, constipation, or financial difficulties.

Conclusions: The addition of abemaciclib to an AI resulted in clinically and statistically significant changes in diarrhea without clinically meaningful differences in other symptom scores. Increased GI-related symptoms were consistent with the manageable, reversible AE profile; the highest symptom burden was reported during early visits. No clinically meaningful differences in global health status or functional scores were observed.

ClinicalTrials.gov: NCT02246621

Reference:

1. Osoba D et al. J Clin Oncol 2002;20(14):3106-13.

Citation Format: Goetz MP, Johnston S, Martin M, Tokunaga E, Park IH, Huober J, Toi M, Price GL, Boye M, Li L, Forrester T, Gainford C, Gable J, Carter GC, Sood A, DiLeo A. Health-related quality of life in MONARCH 3: Abemaciclib plus an aromatase inhibitor as initial therapy in women with HR+, HER2- advanced breast cancer [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 P6-16-01.

Abstract PD1-11: nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer

Background

Abemaciclib is a selective CDK4 & 6 inhibitor approved on a continuous dosing schedule for HR+, HER2- advanced breast cancer (ABC) as monotherapy (MONARCH 1) and in combination with endocrine therapy (ET). A previous Phase 1b (NCT01394016) cohort of HR+ ABC patients (pts) demonstrated efficacy of abemaciclib monotherapy (150mg and 200mg Q12H starting dose); given the small sample size and nonrandomized design the impact of the starting dose was unclear. nextMONARCH 1 (NCT02747004) evaluated abemaciclib in 2 monotherapy arms, in a randomized setting. Abemaciclib has been associated with dose-dependent early onset diarrhea that is well managed with antidiarrheal therapy. nextMONARCH 1 also explored the 200mg Q12H abemaciclib dose in combination with prophylactic loperamide to reduce incidence/severity of diarrhea and dose adjustments. A third arm evaluated abemaciclib + tamoxifen as a strategy to overcome endocrine resistance.

Methods

nextMONARCH 1 is a multicenter, randomized, open-label, Phase 2 study of abemaciclib or abemaciclib + tamoxifen in women with HR+, HER2- ABC who have progressed on or after prior ET and previously received chemotherapy. Pts were stratified by presence of liver metastases and prior use of tamoxifen in the advanced setting. Randomization was 1:1:1 to abemaciclib 150mg Q12H + daily tamoxifen 20mg (Arm A) or abemaciclib 150mg Q12H (Arm B); or abemaciclib 200mg Q12H + prophylactic loperamide (Arm C). Key eligibilities were ≥2 chemotherapy regimens (1-2 administered in metastatic setting), measurable disease and no prior treatment with CDK4 & 6 inhibitors. Primary objective was progression free survival (PFS). Key secondary objectives included objective response rate (ORR), dclinical benefit rate (CBR), and safety. PFS analysis tested superiority of Arm A to C at ∼110 events across the 2 arms assuming a hazard ratio (HR) of 0.667 to achieve ∼80% power. Arm B would be considered non-inferior to Arm C if the observed PFS HR is <1.2.

Results

234 pts were randomized to Arms A (n=78), B (n=79) and C (n=77). 166 PFS events have been observed (A: 57; B: 54; C: 55). Median PFS was 9.1 months in Arm A, 6.5 in Arm B and 7.4 in Arm C (A vs C: HR=.815, 95% CI, .556-1.193, p=.293; B vs C: HR=1.045, 95% CI, .711-1.535 p=.811). Investigator-assessed ORR was 34.6%, 24.1% and 32.5% (confirmed ORR: 25.6%, 19.0%, 28.6%) and CBR was 61.5%, 49.4% and 51.9% in Arms A, B and C, respectively. Prophylactic loperamide reduced the incidence and severity of diarrhea (C: 62.3%, Gr 3: 7.8%) compared to MONARCH 1 (90.2%, Gr 3: 19.7%, Dickler et al. 2017) resulting in similar rates of diarrhea with 150mg abemaciclib without prophylaxis (A: 53.8%, Gr 3: 1.3%; B: 67.1%, Gr 3: 3.8%). The adverse event profile across arms was generally consistent with other breast studies of abemaciclib.

Conclusions

nextMONARCH 1 confirmed single-agent activity of abemaciclib in heavily pretreated pts with HR+, HER2- ABC. Efficacy of abemaciclib monotherapy at 150mg was similar to 200mg. Combining tamoxifen with abemaciclib did not demonstrate a statistically significant improvement in PFS compared to abemaciclib monotherapy. Addition of prophylactic loperamide to abemaciclib 200mg resulted in diarrhea similar to 150mg without prophylaxis.

Citation Format: Hamilton E, Cortes J, Dieras V, Ozyilkan O, Chen S-C, Petrakova K, Manikhas A, Jerusalem G, Hegg R, Lu Y, Bear MM, Johnston EL, Martin M. nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer [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 PD1-11.

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 P2-08-04: Prediction of distant recurrence by EndoPredict in patients with estrogen receptor-positive, HER2-negative breast cancer who received adjuvant endocrine therapy plus chemotherapy (ET+C) or endocrine therapy alone (ET)

Background: EndoPredict (EPclin) is a validated prognostic test combining expression of 12 cancer-related genes for breast cancer patients with estrogen receptor (ER) positive, HER2-negative disease who received 5 years of endocrine therapy (Buus et al., 2017; Dubsky et al. 2012) and for women who received chemotherapy (Martin et al., 2014). Here, we determine the EPclin and 10-year distant recurrence free interval (DRFI) rates for patients who received adjuvant endocrine therapy plus chemotherapy (ET+C) or endocrine therapy alone (ET) using data from five large clinical trials.

Methods: A total of 3746 women with ER-positive, HER2-negative disease were included in this analysis. 2630 patients received 5 years of ET alone (ABCSG-6/8, TransATAC) and 1116 patients received ET+C (GEICAM 2003-02/9906). EPclin incorporates tumor size and nodal status and accounts for different EPClin scores between ET+C and ET alone cohorts. The primary objective was to evaluate the 10-year DRFI rates as a continuous function of EPclin separately for patients in ET+C and ET. Secondary objectives included assessing the difference in the prognostic ability of EPclin between ET+C and ET overall (years 0-10) and for specific follow-up periods (years 0-5 and years 5-10). The primary endpoint was DRFI and the secondary endpoint was breast cancer free interval (BCFI). Cox proportional hazard models were used to estimate 10-year DRFI rates and to assess the prognostic information provided by EPclin.

Results: All of the women on ET alone and 49% of those on ET+C were postmenopausal. Women who received ET+C had more node positive disease, more poorly differentiated tumours, and higher EPclin scores than those who received ET alone. Women who received ET+C had significantly smaller increases in 10-year DRFI rates with increasing EPclin score than those receiving ET alone (Table). EPclin was highly prognostic for DRFI in all women who received ET alone (HR=2.79 (2.49-3.13), P<0.0001) as well as in those who received ET+C (HR=2.27 (1.99-2.59), P<0.0001), both in the overall cohort and in postmenopausal women only (ET+C: HR=2.64 (2.07-3.37), P<0.0001). We observed a significant interaction between EPclin and treatment for DRFI at 10 years (Pinteraction=0.022). EPclin was highly prognostic in ET alone and ET+C in years 0-5 and in particular in years 5-10. Similar results were observed when BCFI was the endpoint.

Conclusion: In our results from a non-randomized analysis, we observed significantly smaller increases in 10-year DRFI rates with increasing EPclin scores for women who received ET+C compared to those who received ET alone. Our indirect comparisons suggest that a high EPclin score can predict chemotherapy benefit in women with ER-positive, HER2-negative disease.

10-year DRFI risks (%) (95% CI) according to EPclin score for patients who received ET+C versus ET alone. ET+CETEPclin10-year DR risk (%)10-year DR risk (%)11.1% (0.5-1.7)1.0% (0.6-1.4)22.5% (1.5-3.5)2.8% (2.1-3.5)35.7% (4.1-7.2)7.6% (6.4-8.8)412.4% (10.1-14.6)19.8% (17.6-22.0)525.8% (22.0-29.5)46.1% (40.2-51.4)

Citation Format: Sestak I, Martin M, Dubsky P, Rojo F, Cuzick J, Filipits M, Ruiz A, Buus R, Hlauschek D, Rodriguez-Lescure A, Dowsett M, Gnant M. Prediction of distant recurrence by EndoPredict in patients with estrogen receptor-positive, HER2-negative breast cancer who received adjuvant endocrine therapy plus chemotherapy (ET+C) or endocrine therapy alone (ET) [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 P2-08-04.

Abstract PD3-11: HER2/ERBB2 status in “HER2 equivocal” breast cancers by FISH and ASCO-CAP guidelines: False-positives due to heterozygous deletions of alternative control loci

Background. The ASCO-CAP guidelines for HER2 testing by fluorescence in situ hybridization (FISH) have a category, referred to as “equivocal” (average HER2 copies per tumor cell >4-6 with HER2/CEP17 ratio <2·0), which is neither “HER2-positive” nor “HER2-negative”. Approximately 4% - 12% of invasive breast cancers are “HER2-equivocal” based on FISH. Cancers in this category may be resolved as “negative” or “positive” by FISH alternative control probes (2013/2014 guidelines) or HER2 immunohistochemistry (IHC) (2018 update). Our objectives were to evaluate the following hypotheses: 1.) Genetic loci used as alternative controls show heterozygous deletion in a substantial proportion of breast cancers; 2.) Use of these loci for assessment of HER2 by FISH leads to false-positives; 3.) HER2 FISH false-positive breast cancer patients have outcomes that do not differ from clinical outcomes for HER2-negative breast cancer patients; and 4.) HER2-equivocal breast cancers seldom show HER2 protein overexpression (IHC 3+).

Methods. We retrospectively assessed the use of chromosome 17 p-arm and q-arm alternative control genomic sites (TP53, D17S122, SMS, RARA, TOP2A), as recommended by the 2013/2014 ASCO-CAP guidelines, in patients whose data were available through the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC)(N=1980) or whose tissues were available from the BCIRG-005 clinical trial (N=3298). We used either FDA-approved HER2 IHC (HercepTest) or laboratory-developed HER2 (10H8) IHC assays to assess HER2 protein expression.

Results. Using METABRIC we found heterozygous deletions, particularly in specific p-arm sites, were common in both HER2-amplified and HER2-not-amplified breast cancers. Use of alternative control probes from these regions to assess HER2 by FISH in “HER2 equivocal” as well as HER2-not-amplified breast cancers resulted in high rates of false-positive ratios (HER2-to-alternative control ratio >2·0) due to heterozygous deletions of control p-arm genomic sites used as ratio denominators. Misclassifications of HER2 status was observed not only in breast cancers with ASCO-CAP “equivocal” status but also in breast cancers with an average of <4·0 HER2 copies per tumor cell. These deletions were also identified by FISH. IHC demonstrated <1% of FISH “HER2-equivocal” breast cancers in BCIRG-005 had IHC3+ immunostaining, consistent with HER2-not-amplified status. Clinical outcomes of “HER2-equivocal” breast cancer patients with HER2-to-alternative control ratio >2·0 did not differ significantly from clinical outcomes of those with HER2-to-alternative control ratio<2·0.

Conclusion. Using chromosome 17 p-arm alternative controls, as recommended by 2013/2014 ASCO-CAP guidelines, instead of CEP17 for resolution of “HER2 equivocal” cases, is problematic due to frequent heterozygous deletions of these loci in breast cancers. The indiscriminate use of alternative control probes to calculate a HER2 FISH ratio in “HER2-equivocal” breast cancers leads to false-positive interpretations of HER2 status resulting from unrecognized heterozygous deletions in one or more of these alternative control genomic sites and incorrect HER2 ratio determinations.

Citation Format: Press MF, Seoane JA, Curtis C, Quinaux E, Guzman R, Sauter G, Eiermann W, Mackey JR, Robert N, Pienkowski T, Crown J, Martin M, Valero V, Bee V, Ma Y, Villalobos I, Slamon DJ. HER2/ERBB2 status in “HER2 equivocal” breast cancers by FISH and ASCO-CAP guidelines: False-positives due to heterozygous deletions of alternative control loci [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 PD3-11.

Abstract P5-11-01: Phamacodynamic and circulating tumor DNA evaluation in a phase I study of GDC-0927, a selective estrogen receptor antagonist/ degrader (SERD)

Background: Modulation of estrogen activity and/or synthesis is the mainstay therapeutic strategy in the treatment of ER positive breast cancer. However, despite the effectiveness of available endocrine therapies, many patients ultimately relapse or develop resistance to these agents via estrogen-dependent and estrogen-independent mechanisms, including mutations in ESR1 affecting the ER ligand binding domain that drive ER-dependent transcription and proliferation in the absence of estrogen. Based on preclinical and clinical data, SERDs are expected be effective in patients harboring ESR1 mutations. Biomarker analysis was performed on plasma and tumor samples from the Phase I study of GDC-0927 in metastatic breast cancer (Dickler et al, SABCS 2017) with the goal of evaluating activity in both ESR1 mutant and wildtype tumors, and to assess ER pathway modulation.

Methods: Hotspot mutations in ESR1, PIK3CA, and AKT1 were analyzed in baseline, on-treatment and end of treatment plasma derived circulating tumor DNA (ctDNA) using the BEAMing assay in patients treated at multiple dose levels of GDC-0927. A subset of samples was analyzed with Foundation Medicine's next generation sequencing ctDNA assay (FACT), which covers genomic alterations in 62 commonly altered genes. Paired pre- and on-treatment biopsies were collected to assess ER pathway modulation. ER, PR, and Ki67 protein levels were analyzed by immunohistochemistry. Gene expression analysis was performed using Illumina's RNA Access library preparation kit followed by paired-end (2x50b, 50M reads) sequencing on the HiSeq.

Results: Baseline and on-treatment plasma samples were available for 40 patients. ESR1 and PIK3CA mutations were observed in 52% and 33% of patient baseline samples, respectively (BEAMing method). Mutant allele frequencies (MAF) generally declined in the first on-treatment samples collected for both ESR1 (16 out of 21 samples) and PIK3CA (7 out of 12 samples). The majority of the reductions were greater than 95% relative to baseline. Increases in ESR1 MAFs were observed in later time-points and were not associated with any particular ESR1 mutation. There were six instances for which an ESR1 mutation was detected in an on-treatment sample that was not detected in the baseline sample, three at L536P and one each at D538G, L536H, and S463P, and four out of six with MAFs close to the limit of detection. The FACT assay also detected alterations in CDH1, NF1, PTEN, and TP53 in baseline samples. The relationship between MAF changes and clinical benefit to GDC-0927 will be presented. A predefined, experimentally-derived set of ER target genes were evaluated in pre- and on-treatment tumor biopsy pairs from six patients. Four of the six patients showed evidence of suppression in ER pathway activity, one patient treated at the 1000 mg dose level and three at the 1400 mg dose. The degree of pathway suppression was associated with pre-treatment pathway levels and decreases of ER and Ki67 protein levels.

Conclusions: We report here evidence of consistent reduction of ESR1 and PIK3CA ctDNA in patients treated with GDC-0927. ER pathway suppression was observed at both the transcript and protein level confirming pharmacodynamic activity of the SERD.

Citation Format: Spoerke JM, Daemen A, Chang C-W, Giltnane J, Metcalfe C, Dickler MN, Bardia A, Perez Fidalgo JA, Mayer IA, Boni V, Winer EP, Hamilton EP, Bellet M, Urruticoechea A, Gonzalez Martin A, Cortes J, Martin M, Gates M, Cheeti S, Fredrickson J, Wang X, Friedman LS, Liu L, Li R, Chan IT, Mueller L, Milan S, Lauchle J, Humke EW, Lackner MR. Phamacodynamic and circulating tumor DNA evaluation in a phase I study of GDC-0927, a selective estrogen receptor antagonist/ degrader (SERD) [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 P5-11-01.

Abstract P5-07-03: Small molecule inhibition of smoothened in triple negative breast cancer-associated fibroblasts depletes cancer stem cells and sensitizes to cytotoxic chemotherapy in mice and humans

The cellular and molecular basis of stromal cell recruitment, activation and crosstalk in carcinomas is poorly understood, limiting the development of targeted anti-stromal therapies.

In mouse models of triple negative breast cancer (TNBC), we use single cell genomics to show that Hh ligand produced by neoplastic cells reprograms cancer-associated fibroblast (CAF) gene expression, driving tumor growth and metastasis. Hh-activated CAFs upregulated expression of FGF5 and deposition of fibrillar collagen, leading to FGFR and FAK activation in adjacent neoplastic cells and the acquisition of a stem-like, drug-resistant phenotype.

Treatment with smoothened inhibitors (SMOi) reversed these phenotypes. Stromal treatment of TNBC patient-derived xenograft (PDX) models with SMOi downregulated the expression of cancer stem cell markers and sensitized tumors to docetaxel, leading to markedly improved survival and reduced metastatic burden.

In the phase I clinical trial EDALINE, 3 patients with metastatic TNBC derived clinical benefit from combination therapy with the SMOi Sonedigib and docetaxel chemotherapy, with one patient experiencing a complete radiological response. Responders also exhibited high baseline FGFR activation and ECM deposition, suggesting a mechanism of action consistent with findings from the animal models.

These studies identify Hh signaling to CAFs as a novel mediator of cancer stem cell plasticity and drug resistance and an exciting new therapeutic target in TNBC.

Citation Format: Swarbrick A, Cazet A, Hui M, O'Toole S, Lim E, Martin M. Small molecule inhibition of smoothened in triple negative breast cancer-associated fibroblasts depletes cancer stem cells and sensitizes to cytotoxic chemotherapy in mice and humans [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 P5-07-03.

Abstract PD2-10: Treatment with abemaciclib modulates the immune response in gene expression analysis of the neoMONARCH neoadjuvant study of abemaciclib in postmenopausal women with HR+, HER2 negative breast cancer

Background: Abemaciclib is a selective inhibitor of CDK4 & 6 approved on a continuous dosing schedule for the treatment of HR+, HER2- metastatic breast cancer (MBC) patients (pts) in combination with endocrine therapy or as monotherapy. Recent studies have demonstrated the potential for CDK4 & 6 inhibitors, including abemaciclib, to promote anti-tumor immunity. Schaer et al., (Cell Reports 2018) showed that abemaciclib monotherapy results in upregulation of antigen presentation on tumor cells and increases T-cell activation. These activities synergized with anti-PD-L1 therapy to further enhance immune activation leading to complete tumor rejection in murine tumor models (Schaer et al., Cell Reports 2018). In this exploratory analysis, we evaluated the early and late immune-modulating effects of abemaciclib in the neoadjuvant study neoMONARCH (NCT02441946).

Methods: NeoMONARCH is a Phase II trial in women with stage I-IIIB HR+, HER2- BC evaluating neoadjuvant treatment with 2 weeks of abemaciclib, alone or in combination with anastrozole (abemaciclib+ANZ), or ANZ alone. All patients received 14 weeks of abemaciclib +ANZ after the first 2 weeks of treatment. Serial biopsies were collected at 3 time points: Baseline (BL) - prior to treatment, Early - after 2 weeks of therapy with abemaciclib, ANZ, or abemaciclib+ANZ, and Late – after 2 weeks of initial therapy followed by 14 weeks of abemaciclib+ANZ. RNA was extracted from formalin fixed paraffin embedded (FFPE) tumor biopsies at each time point and subjected to whole transcriptome RNA sequencing. The curated data were subjected to statistical analysis using ANOVA tests followed by pathway analysis using Ingenuity Pathway Analysis (IPA) and Gene Set Enrichment Analysis (GSEA).

Results: Consistent with the known activity of abemaciclib to inhibit the cell cycle, we observed at the early and late time points a significant treatment induced downregulation of genes related to mitotic spindle organization, replication stress response, G2M checkpoint, and E2F targets. Abemaciclib treatment for 2 weeks, alone or in combination with ANZ, followed by 14 weeks of combination therapy was associated with upregulation of gene expression signatures related to T-cell immune response and antigen presentation. Importantly, this phenomenon was notobserved with 2 weeks of ANZ treatment alone followed by 14 weeks of combination therapy.

Conclusion: These data lend support that continuous inhibition of CDK4 & 6 signaling by abemaciclib treatment leads to prolonged cell cycle arrest resulting in tumor cell apoptosis & senescence, which then leads to an enhanced immune activation.

Citation Format: Hurvitz S, Martin M, Press M, Wijayawardana S, Brahmachary M, Ebert PJ, Young S, Jansen V, Slamon D. Treatment with abemaciclib modulates the immune response in gene expression analysis of the neoMONARCH neoadjuvant study of abemaciclib in postmenopausal women with HR+, HER2 negative breast cancer [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 PD2-10.

Abstract PD1-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Cortes J, Martin M, Pernas S, Gomez Pardo P, Lopez-Tarruella S, Gil-Martin M, Manso L, Ciruelos E, Perez-Fidalgo JA, Hernando C, Ademuyiwa FO, Weilbaecher K, Mayer I, Pluard TJ, Martinez Garcia M, Vahdat L, Wach A, Barker D, Romagnoli B, Kaufman PA. Withdrawn [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 PD1-02.

Abstract P3-10-08: Markers of response to CDK4 & 6 inhibition from neoMONARCH: A phase II neoadjuvant study of abemaciclib in postmenopausal women with hormone receptor positive, HER2 negative breast cancer

Background: Combination treatments of endocrine therapy (ET) with CDK4 & 6 inhibitors have improved outcomes in patients with HR+ advanced breast cancer, both as initial therapy and after progression on ET. Abemaciclib is a selective inhibitor of CDK4 & 6 approved on a continuous dosing schedule for the treatment of HR+, HER2- MBC patients (pts), alone or in combination with ET. However, biomarkers that predict benefit from this class of agents remain elusive. We previously reported in the phase II neoadjuvant neoMONARCH study (NCT02441946), after 2 weeks of treatment, abemaciclib, alone or in combination with anastrozole (ANZ), led to a significantly higher rate of complete cell cycle arrest (CCCA, defined as Ki67 ≤2.7%) compared to ANZ alone in early stage HR+, HER2- breast cancer (Martin et al. SABCS 2017). As an exploratory aim of this trial, we evaluated the gene expression analyses in order to determine markers of sensitivity and resistance to therapy.

Methods: Serial biopsies were collected at 3 time points: Baseline (BL) - prior to treatment, Early – after 2 weeks of therapy with abemaciclib, ANZ, or abemaciclib+ANZ, and Late – after 2 weeks of initial therapy followed by 14 weeks of abemaciclib+ANZ. RNA was extracted from FFPE tumor biopsies at each timepoint and subjected to a Cell Cycle Associated Gene (CCAG) expression panel using the Modaplex® platform and whole transcriptome RNA sequencing. Ki67 was measured at each time point by immunohistochemistry (IHC). Tumors were categorized by the post-treatment Ki67 expression as either sensitive (Ki67 ≤2.7) or resistant (Ki67 ≥7.4), based upon the IMPACT and POETIC studies. Additionally, tumors intrinsically resistant/sensitive to therapy were also identified.

Results: ANZ-treated tumors that did not achieve CCCA at 2 weeks (N= 8) displayed higher expression of the cell cycle associated genes FOXM1, E2F1, TOPO2A, and RRM2. The addition of abemaciclib to ANZ decreased gene expression in a majority of the tumors (N=5, 62.5%). Tumors intrinsically resistant to treatment with abemaciclib+ANZ displayed persistently elevated levels of cell cycle associated genes compared to sensitive tumors. Finally, gene expression signature of Rb loss-of-function (Rbsig) and RB1 gene expression levels were associated with sensitivity to abemaciclib.

Conclusion: On-treatment Ki67 indicated treatment sensitivity and correlated with cell cycle associated gene expression in sensitive and resistant tumors. These exploratory analyses suggest that gene expression analyses may identify genomic markers for abemaciclib and ET treatment sensitivity and may help inform in which tumors to use abemaciclib.

Citation Format: Hurvitz S, Martin M, Wijayawardana S, Brahmachary M, Ebert PJ, Young S, Jansen V, Slamon D. Markers of response to CDK4 & 6 inhibition from neoMONARCH: A phase II neoadjuvant study of abemaciclib in postmenopausal women with hormone receptor positive, HER2 negative breast cancer [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 P3-10-08.

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.

Measurement of the Charm-Mixing Parameter y_{CP}

A measurement of the charm-mixing parameter y_{CP} using D^{0}→K^{+}K^{-}, D^{0}→π^{+}π^{-}, and D^{0}→K^{-}π^{+} decays is reported. The D^{0} mesons are required to originate from semimuonic decays of B^{-} and B[over ¯]^{0} mesons. These decays are partially reconstructed in a data set of proton-proton collisions at center-of-mass energies of 7 and 8 TeV collected with the LHCb experiment and corresponding to an integrated luminosity of 3  fb^{-1}. The y_{CP} parameter is measured to be (0.57±0.13(stat)±0.09(syst))%, in agreement with, and as precise as, the current world-average value.

Observation of Two Resonances in the Λ_{b}^{0}π^{±} Systems and Precise Measurement of Σ_{b}^{±} and Σ_{b}^{*±} Properties

The first observation of two structures consistent with resonances in the final states Λ_{b}^{0}π^{-} and Λ_{b}^{0}π^{+} is reported using samples of pp collision data collected by the LHCb experiment at sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. The ground states Σ_{b}^{±} and Σ_{b}^{*±} are also confirmed and their masses and widths are precisely measured.

Evidence for an η c ( 1 S ) π - resonance in B 0 → η c ( 1 S ) K + π - decays

A Dalitz plot analysis of B 0 → η c ( 1 S ) K + π - decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s = 7 , 8 and 13 Te V , corresponding to a total integrated luminosity of 4.7 fb - 1 . A satisfactory description of the data is obtained when including a contribution representing an exotic η c ( 1 S ) π - resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096 ± 20 - 22 + 18 Me V and 152 ± 58 - 35 + 60 Me V , respectively. The spin-parity assignments J P = 0 + and J P = 1 - are both consistent with the data. In addition, the first measurement of the B 0 → η c ( 1 S ) K + π - branching fraction is performed and gives B ( B 0 → η c ( 1 S ) K + π - ) = ( 5.73 ± 0.24 ± 0.13 ± 0.66 ) × 10 - 4 , where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions.

Search for lepton-flavour-violating decays of Higgs-like bosons

A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV / c 2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb - 1 . The tau leptons are reconstructed in both leptonic and hadronic decay channels. An upper limit on the production cross-section multiplied by the branching fraction at 95% confidence level is set and ranges from 22 pb for a boson mass of 45 GeV / c 2 to 4 pb for a mass of 195 GeV / c 2 .

Measurement of Antiproton Production in p-He Collisions at sqrt[s_{NN}]=110 GeV

The cross section for prompt antiproton production in collisions of protons with an energy of 6.5 TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of 0.5  nb^{-1}. The target is provided by injecting helium gas into the LHC beam line at the LHCb interaction point. The reported results, covering antiproton momenta between 12 and 110  GeV/c, represent the first direct determination of the antiproton production cross section in p-He collisions, and impact the interpretation of recent results on antiproton cosmic rays from space-borne experiments.

First Observation of the Doubly Charmed Baryon Decay Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+}

The doubly charmed baryon decay Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+} is observed for the first time, with a statistical significance of 5.9σ, confirming a recent observation of the baryon in the Λ_{c}^{+}K^{-}π^{+}π^{+} final state. The data sample used corresponds to an integrated luminosity of 1.7  fb^{-1}, collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Ξ_{cc}^{++} mass is measured to be 3620.6±1.5(stat)±0.4(syst)±0.3(Ξ_{c}^{+})  MeV/c^{2} and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be [B(Ξ_{cc}^{++}→Ξ_{c}^{+}π^{+})×B(Ξ_{c}^{+}→pK^{-}π^{+})]/[B(Ξ_{cc}^{++}→Λ_{c}^{+}K^{-}π^{+}π^{+})×B(Λ_{c}^{+}→pK^{-}π^{+})]=0.035±0.009(stat)±0.003(syst).

Creating a personalized evaluation framework for patient-reported outcomes: an illustration using the EQ-5D visual analogue scale

BACKGROUND

This paper outlines the creation of an intuitive, personalized evaluation framework for Patient-Reported Outcomes, using the EQ-5D visual analog scale (VAS) as an illustration.

METHODS

A draft framework asked patients to divide and label the EQ-5D-VAS into different levels or categories of health. Comprehension of the framework and patient-defined health level labels, and how they map onto the EQ-5D-VAS, were tested through in-person, semi-structured interviews with individuals self-reporting cardiovascular disease. Interviews were conducted in three waves, with the framework revised between waves.

RESULTS

Analyses included 14 participants. Eight participants (57.1%) felt that four levels of health were appropriate and there was general agreement on the labels; Poor, Fair, Good, and Excellent. There was substantial variability in where patients drew lines to indicate the level boundaries; Poor ranged between 0 and 50; Fair 10-75; Good 40-91; Excellent 60-100. In wave 3, all participants demonstrated appropriate comprehension of the framework.

CONCLUSIONS

The framework was well understood. The wide range of margins and the extent of overlap between the levels provide strong evidence for the relevance of the personalized evaluation framework approach, and specifically a personalized EQ-5D-VAS evaluation framework, to better understand and interpret each individual's response to the item.

Measurement of Angular and CP Asymmetries in D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays

The first measurements of the forward-backward asymmetry of the dimuon pair (A_{FB}), the triple-product asymmetry (A_{2ϕ}), and the charge-parity-conjugation asymmetry (A_{CP}), in D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. They are performed using data from proton-proton collisions collected with the LHCb experiment from 2011 to 2016, corresponding to a total integrated luminosity of 5  fb^{-1}. The asymmetries are measured to be A_{FB}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(3.3±3.7±0.6)%, A_{2ϕ}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(-0.6±3.7±0.6)%, A_{CP}(D^{0}→π^{+}π^{-}μ^{+}μ^{-})=(4.9±3.8±0.7)%, A_{FB}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(0±11±2)%, A_{2ϕ}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(9±11±1)%, A_{CP}(D^{0}→K^{+}K^{-}μ^{+}μ^{-})=(0±11±2)%, where the first uncertainty is statistical and the second systematic. The asymmetries are also measured as a function of the dimuon invariant mass. The results are consistent with the standard model predictions.

Measurement of the Ω_{c}^{0} Baryon Lifetime

We report a measurement of the lifetime of the Ω_{c}^{0} baryon using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0  fb^{-1} collected by the LHCb experiment. The sample consists of about 1000  Ω_{b}^{-}→Ω_{c}^{0}μ^{-}ν[over ¯]_{μ}X signal decays, where the Ω_{c}^{0} baryon is detected in the pK^{-}K^{-}π^{+} final state and X represents possible additional undetected particles in the decay. The Ω_{c}^{0} lifetime is measured to be τ_{Ω_{c}^{0}}=268±24±10±2  fs, where the uncertainties are statistical, systematic, and from the uncertainty in the D^{+} lifetime, respectively. This value is nearly four times larger than, and inconsistent with, the current world-average value.

Observation of a New Ξ_{b}^{-} Resonance

From samples of pp collision data collected by the LHCb experiment at sqrt[s]=7, 8 and 13 TeV, corresponding to integrated luminosities of 1.0, 2.0 and 1.5  fb^{-1}, respectively, a peak in both the Λ_{b}^{0}K^{-} and Ξ_{b}^{0}π^{-} invariant mass spectra is observed. In the quark model, radially and orbitally excited Ξ_{b}^{-} resonances with quark content bds are expected. Referring to this peak as Ξ_{b}(6227)^{-}, the mass and natural width are measured to be m_{Ξ_{b}(6227)^{-}}=6226.9±2.0±0.3±0.2  MeV/c^{2} and Γ_{Ξ_{b}(6227)^{-}}=18.1±5.4±1.8  MeV/c^{2}, where the first uncertainty is statistical, the second is systematic, and the third, on m_{Ξ_{b}(6227)^{-}}, is due to the knowledge of the Λ_{b}^{0} baryon mass. Relative production rates of the Ξ_{b}(6227)^{-}→Λ_{b}^{0}K^{-} and Ξ_{b}(6227)^{-}→Ξ_{b}^{0}π^{-} decays are also reported.

Measurement of the Lifetime of the Doubly Charmed Baryon Ξ_{cc}^{++}

The first measurement of the lifetime of the doubly charmed baryon Ξ_{cc}^{++} is presented, with the signal reconstructed in the final state Λ_{c}^{+}K^{-}π^{+}π^{+}. The data sample used corresponds to an integrated luminosity of 1.7  fb^{-1}, collected by the LHCb experiment in proton-proton collisions at a center-of-mass energy of 13 TeV. The Ξ_{cc}^{++} lifetime is measured to be 0.256_{-0.022}^{+0.024}(stat)±0.014(syst)  ps.

On the Reliability of Plasminogen Measurement Employing the Proactivator-Activator Converting Method

A simple plasminogen determination method is presented. It is based upon the conversion of plasminogen into activator by large and constant amounts of streptokinase. The activator contained in a standard coagulum consisting of bovine fibrin, streptokinase, and a 1:40 dilution of human plasma converts the plasminogen adsorbed on bovine fibrin into plasmin. Lysis of the test coagulum is hereby induced. The speed of such lysis is limited by the concentration of the activator incorporated in the test coagulum. The variable component of the activator being human plasminogen, the speed of lysis is directly dependent upon the concentration of human plasminogen in the standard coagulum. Using the thromboelastograph according to Hartert in recording the test clot lysis times, this method of plasminogen determination was shown to be a simple and quick procedure. The standard deviation ranged from ± 13.2 to 68 %, depending upon the plasminogen value to be measured (lower rates of error were attached to high, and higher rates of error to low, plasminogen concentrations). The biological variation of plasminogen values in a group of 26 men aged from 40 to 65 years was calculated to be ±21 %. Both plasminogen and plasmin, its activated form, were exchangeable in the test, i.e. plasminogen determinations performed by activator assay did not differentiate between plasminogen and plasmin. There was no influence by varying anti-SK titers in the plasma up to a circulating antibody content of 2 million. Furthermore, plasma antiplasmins did not affect the plasminogen measuring system. Plasminogen tested by activator assay displayed values closely related to those achieved by immunochemical methods. Plasminogen measurements were performed in patients undergoing streptokinase and urokinase infusion treatment. 5,000 u streptokinase per hour, as well as 270,000 CTA-u urokinase per hour, infused over a period of 2 days produced a fall in plasminogen down to 30-60% of normal. In contrast, 100,000 u streptokinase per hour lowered the plasminogen concentration down to values of below 1%. The foregoing data indicate that plasminogen measurement, according to the principles outlined here (activator assay), may be regarded as a valuable and rehable method for the routine control of streptokinase and urokinase therapy.

Intravasale Thrombusbildung durch elektrischen Strom und Thrombolyse

1. Elektronenmikroskopische Befunde an Venenendothelien der Maus nach Einwirken von elektrischem Strom, der über eine Anode zugeführt wurde, ergaben eine schwere Zellschädigung bis zu völliger Zerstörung des Endothels. Das Endothel der kleinen Arterien reagierte abweichend mit Bildung großer Vakuolen, die sich gegen das Gefäßlumen vorwölbten, es weitgehend verlegten und damit eine Thrombolyse erschwerten oder sogar unmöglich machten.

2. Die Reaktion auf derartige Venenendothelschädigungen bestand von der Blutseite her in einer Aggregation von mehr oder weniger stark degranulierten Thrombozyten. Aggregierte Plättchen im Bereich des Gefäßlumens ohne Kontakt mit Endothel wurden nur selten beobachtet. Kam es zu einer so starken Stromschädigung, daß eine völlige Vernichtung des Endothels mit freier Kommunikation zwischen Blut und subendothelialem Bindegewebe die Folge war, wurde regelmäßig Fibrin in großen Mengen im Bereich der Gefäßwand abgeschieden.

3. Da Thrombozytenaggregation und Fibrinbildung nicht allein von der Stromeinwirkung, sondern im wesentlichen vom Grad der Endothelschädigung abhingen, und da in zusätzlichen In-vitro-Versuchen keine Abhängigkeit der Vollbhitgerinnung von der Zufuhr elektrischen Stroms nachgewiesen werden konnte, wird die Hypothese einer primär durch elektrostatische Vorgänge eingeleiteten Thromboseentstehung verworfen.

4. 24 h und 3 Tage nach Auflösung strominduzierter Thromben durch Streptokinase konnte Endothel als organisierter Bestandteil der Gefäßwand nicht mehr nachgewiesen werden. Die Funktion der Endothelzellen wurde in diesem Stadium von einer ein- bis mehrschichtigen Lage mäßig degranulierter Thrombozyten eingenommen, die untereinander durch Ausbildung von »regiones densae« und gegenseitige Verzahnung dem Blutstrom ein festes Widerlager boten. Die Bedeutung dieser bisher wenig beachteten Thrombozytenfunktion im Rahmen experimenteller Eingriffe an Blutgefäßen wird diskutiert.

Studies on Activator Formation in Human Plasma with Streptokinase

A new method is presented for estimating the activator (plasminogen-streptokinase complex) concentration in native plasma of patients undergoing streptokinase infusion. The principle of the method is based on clot lysis time as recorded by the thromboelastograph. The test clot constituents were bovine fibrinogen, bovine plasminogen, EDTA, human plasma (with unknown activator concentrations), and thrombin. In order to obtain a standardization line, urokinase dissolved in NaCl solution was substituted for patients’ plasma. Thus, each lysis time could easily be converted into urokinase equivalent (CTA-u/ml). Streptokinase and plasminogen molecules in undiluted patients’ plasma were found to exist both in an activator-bound (equimolar plasminogen-streptokinase complex) and in a freely circulating form. This result is in agreement with earlier findings where the activator complex was demonstrated to be a widely dissociated complex in highly diluted plasma of patients, thus displaying an ample proportion of free streptokinase and plasminogen molecules. Streptokinase treatment using dosage schemes of 100,000 u SK/h, 150,000 u/h, and 200,000 u/h were monitored by quantitative activator, streptokinase, and plasminogen measurements. An average activator concentration of 50–100 CTA-u/ml and a SK-concentration of 7–16 u/ml were recorded during streptokinase infusion. Plasminogen values averaged 0.25%, independent of the amount of streptokinase infused. Each drop in streptokinase was accompanied by a drop in activator during the infusion, and each rise in streptokinase by a rise in activator. There was a strong correlation between streptokinase and activator concentrations in that, on the average, 1 u streptokinase equalled 8.4 CTA-u/ml activator (correlation coefficient r = 0.9). It is concluded that the activator concentration in the plasma of patients undergoing fibrinolytic treatment can easily be adjusted by regulating the hourly streptokinase influx.

Streptokinase Stability Pattern during Storage in Various Solvents and at Different Temperatures

The activity drop of 5 u streptokinase was measured in 1 ml each of various solutions (0.9% NaCl solution, 5% glucose solution, 5% levulose solution, 10% dextran solution, gelatin solution, 3% albumin solution, Michaelis buffer, glucose (5%)-heparin (750 u/ml) solution) at different incubation temperatures (–20° c, 4° c, 20 c, 37 C), and over different observation periods (15 min, 30 min, 45 min, 60 min, 6 h, 12 h, 24 h, and 48 h). Solution media tested for streptokinase-protecting quality were broken down into three groups.

Group I: Solvents displaying excellent stabilizing properties (gelatin and albumin solutions).

Group II: Solvents displaying medium stabilizing properties (dextran and levulose solutions).

Group III: Solvents displaying poor stabilizing properties (NaCl and glucose solutions, Michaelis buffer).

In testing streptokinase concentrations as used for therapeutic purposes (1500 u/ml, 50,000 u/ml), no decay was found to take place over observation periods of up to 48 h, and no influence by different solvents (Group I, II or III) was traceable. Heparin stored with streptokinase at room temperature over a period of 48 h did not alter the streptokinase stability.

Some mechanisms concerning the stability pattern of streptokinase are discussed. It appears that low streptokinase concentrations need negatively charged colloids to keep the protein structure intact. The streptokinase-protecting macro-molecules tested so far were albumin, gelatin, and streptokinase. Obviously, streptokinase by itself was able to preserve its own stability provided its concentration was of a certain order of magnitude (1500 u/ml, 50,000 u/ml).

Indirect Measurement of Streptokinase Concentration in the Plasma of Patients Undergoing Fibrinolytic Treatment

A new method of determining streptokinase concentrations on a quantitative basis in the plasma of patients undergoing streptokinase infusion is demonstrated. The principle of this method is based on the clot lysis time recorded by the thrombo-elastograph. The test clot constituents were bovine fibrin, bovine plasminogen, human euglobulin, EDTA, human plasma (with unknown streptokinase quantity) and thrombin. As plasminogen (euglobulin) and fibrinogen were present in the test coagulum in rather high concentrations (fixed excess) no interference with changing plasminogen and fibrinogen levels of the patient’s plasma was observed. Further, due to high EDTA concentrations, no interaction with platelet functions and coagulation factors took place. The standard error of measuring 5 u of streptokinase in one ml of human plasma was determined at s = ±0.47 u/ml.

Eleven patients undergoing fibrinolytic treatment with streptokinase were monitored by streptokinase determination in the plasma. In this group of patients, streptokinase concentration values varying between 15 and 0.5 units/ml plasma were measured. One striking feature was the continuous decrease in streptokinase concentration in the plasma, in spite of unchanged streptokinase infusion rates. This observation was consistent in regimens with both large (100,000 u/h) and small (30,000 u/h) streptokinase infusion rates. No explanation is available for this observation up to now. A rise in circulating anti-streptokinase contents was precluded. Possibly, an accelerated streptokinase metabolism rate in the course of long-term streptokinase administration may be involved.

Amplitude Analysis of the Decay B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} and First Observation of the CP Asymmetry in B[over ¯]^{0}→K^{*}(892)^{-}π^{+}

The time-integrated untagged Dalitz plot of the three-body hadronic charmless decay B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} is studied using a pp collision data sample recorded with the LHCb detector, corresponding to an integrated luminosity of 3.0  fb^{-1}. The decay amplitude is described with an isobar model. Relative contributions of the isobar amplitudes to the B[over ¯]^{0}→K_{S}^{0}π^{+}π^{-} decay branching fraction and CP asymmetries of the flavor-specific amplitudes are measured. The CP asymmetry between the conjugate B[over ¯]^{0}→K^{*}(892)^{-}π^{+} and B^{0}→K^{*}(892)^{+}π^{-} decay rates is determined to be -0.308±0.062.

Semiquantitative Plasminogenbestimmung mit Hilfe des Thrombelastographen

1. Es wird eine einfach durchzuführende Plasminogenbestimmung mit Hilfe des Thrombelastographen mitgeteilt. Das Prinzip benutzt die durch hohe Streptokinase-mengen induzierte Aktivatorfunktion des menschlichen Plasminogens. Dieser Aktivator wandelt in einem Standardgerinnsel aus Rinderfibrin und verdünntem Humanplasma das dort adsorbierte bovine Plasminogen in Plasmin um, so daß eine Lyse des Testgerinnsels zustande kommt. Limitierend für die Geschwindigkeit der Lyse ist dabei die Höhe des Aktivatorspiegels. Da ein Bestandteil des Aktivators Human-plasminogen ist, steht die Geschwindigkeit der Lyse in direkter Abhängigkeit zum Gehalt des im Rinderfibrin-Standardgerinnsel inkorporierten menschlichen Plasminogens. Mit Hilfe einer vorher konstruierten Eichkurve, in der Lysezeiten und verschiedene Humanplasma(Plasminogen)-konzentrationen gegeneinander aufgetragen sind, kann zu jeder sich ergebenden Lysezeit des Testgerinnsels der zugehörige Plasminogen-gehalt des beigefügten Humanplasmas in Prozent der Norm abgelesen werden.

2. Die Standardabweichung so erhaltener und im Thrombelastographen geschriebener Lysezeiten bewegt sich zwischen i 10% bei annähernd normalen und ±50% bei extrem niedrigen (um 0.01 %) Plasminogenspiegeln.

3. An Hand einer Serie von 10 Langzeitlysen mit Streptokinase konnte die beschriebene Bestimmungsmethode erprobt werden. Es handelte sich um eine 3 Tage dauernde kombinierte Infusionsbehandlung von Streptokinase und Heparin. Die Therapie wurde durch Gabe der titrierten Initialdosis gestartet und mit stündlicher Gabe von 100000 E Streptokinase fortgesetzt. Hierbei kam es durchschnittlich bereits 4 Std. nach Behandlungsbeginn zu einem Abfall des Plasminogens unter die 1%-Grenze. Von der 16. Behandlungsstunde an lagen die Werte zwischen 1 und 0.05% der Norm. 16 Std. nach Absetzen der Streptokinase hatte sich das Plasminogen weitgehend restituiert und zeigte Plasmaspiegel zwischen 30 und 100%.

4. Für schnell durchzuführende Routinekontrollen während einer Streptokinase-thérapie wurden zwei Modifikationen der hier erprobten Plasminogenbestimmung vorgeschlagen. Die erste Abwandlung beruht auf Glättung der leicht biphasisch geformten Eichkurve, die damit zu einer Eichgeraden wird und von nur zwei Eich werten charakterisiert ist. Eine zweite Modifikation, die weitere Vereinfachungen zur Folge hat, wurde durch die Beobachtung, daß alle untersuchten Eichgeraden konstante, mit nur geringer Abweichung behaftete Neigungswinkel im doppelt-logarithmischen System aufwiesen, möglich. Hierdurch enthält die mathematische Formel, welche die Eichgerade beschreibt, nur noch zwei Variable, nämlich die Lysezeit des Standardgerinnsels mit 100% Humanplasminogen und jene mit unbekanntem Plasminogen-spiegel. Damit kann der gesuchte Plasminogengehalt durch eine einfache Rechenoperation und ohne Konstruktion von Eichgeraden oder -kurven unmittelbar in einer einmalig aufgestellten Tabelle abgelesen werden.

Prevalence and impact of asthma among school-aged students in Lima, Peru

SETTING AND OBJECTIVE

The International Study of Asthma and Allergies in Childhood (ISAAC) reported asthma prevalence in Peru to be among the highest in the world. We assessed the prevalence and morbidity of self-reported asthma in an underserved, peri-urban area of Lima, Peru, with limited medical access.

DESIGN

The study was conducted in the outskirts of Lima from March to May 2011. Five hundred children aged 6-18 years were selected through cluster sampling. Parents completed a modified version of the ISAAC questionnaire. Children underwent spirometry testing. Those with a forced expiratory volume in one second (FEV1% predicted) 80% were tested for reversibility using salbutamol.

RESULTS

Of the 500 children selected, 71% participated. The prevalence of asthma was 16.7%. Asthma symptoms were associated with self-reported asthma (P < 0.001); 52.5% of children with asthma had ever used an inhaler (P < 0.001), and 27.1% had never been to the doctor for respiratory problems (P < 0.001).

CONCLUSION

We found a high prevalence of self-reported asthma and high morbidity related to asthma symptoms in the previous 12 months among the study cohort. Symptoms were poorly controlled due to limited availability of medication and access to medical services.

Studies of the resonance structure in D 0 → K ∓ π ± π ± π ∓ decays

Amplitude models are constructed to describe the resonance structure of D 0 → K - π + π + π - and D 0 → K + π - π - π + decays using pp collision data collected at centre-of-mass energies of 7 and 8 TeV with the LHCb experiment, corresponding to an integrated luminosity of 3.0  f b - 1 . The largest contributions to both decay amplitudes are found to come from axial resonances, with decay modes D 0 → a 1 ( 1260 ) + K - and D 0 → K 1 ( 1270 / 1400 ) + π - being prominent in D 0 → K - π + π + π - and D 0 → K + π - π - π + , respectively. Precise measurements of the lineshape parameters and couplings of the a 1 ( 1260 ) + , K 1 ( 1270 ) - and K ( 1460 ) - resonances are made, and a quasi model-independent study of the K ( 1460 ) - resonance is performed. The coherence factor of the decays is calculated from the amplitude models to be R K 3 π = 0.459 ± 0.010 ( stat ) ± 0.012 ( syst ) ± 0.020 ( model ) , which is consistent with direct measurements. These models will be useful in future measurements of the unitary-triangle angle γ and studies of charm mixing and C P violation.