Abstract P6-18-19: Real-world survival of heavily pretreated patients with refractory HR+, HER2- metastatic breast cancer receiving single-agent chemotherapy - A comparison with MONARCH 1

Background

In MONARCH 1 (NCT02102490), abemaciclib demonstrated promising single-agent activity and tolerability in a population of heavily pretreated women with refractory HR+, HER2- metastatic breast cancer (MBC).1 Confirmed objective response rate (ORR) was 19.7% (95% CI: 13.3, 27.5) and at 18 months minimum follow-up median overall survival (OS) was 22.3 months. Due to the single-arm trial design of MONARCH 1, there is a need to view these results in clinical context relative to available treatment options. This study compared the OS results of abemaciclib in MONARCH 1 vs that in a real-world single-agent chemotherapy cohort with similar patient and disease characteristics.

Methods

MONARCH 1 study design and key eligibility criteria were previously described.1 The real-world cohort was based on Flatiron Health electronic health records-derived, nationally representative (USA-based) database comprising patient-level structured and unstructured data, curated via technology-enabled abstraction, for patients with MBC between January 1, 2011 through February 28, 2018. A real-world single-agent chemotherapy cohort was created based on the key eligibility criteria of MONARCH 1 and included patients diagnosed with HR+, HER2- MBC who received single-agent chemotherapy (eribulin, capecitabine, gemcitabine, or vinorelbine) following 1-2 prior chemotherapy regimens in the metastatic setting, had an ECOG PS of 0-1, and no prior CDK4 & 6 therapy. The index date was the start of the eligible single-agent chemotherapy, and patients were followed from the index date until date of death, loss to follow-up, or end of the database, whichever occurred earlier. OS results were adjusted using 2 methods (Mahalanobis distance matching and entropy balancing with bootstrapping) to account for baseline demographic and clinical differences between the real-world and trial cohorts.

Results

A real-world cohort (n=281) with eligibility criteria similar to the MONARCH 1 population (n=132) was identified. A subsequent matching based on Mahalanobis distance was performed to match MONARCH 1 population (n=108) with the real-world cohort (n=108). The matched cohorts demonstrated similar patient and disease characteristics. Median OS was 22.3 months in the abemaciclib arm vs 13.6 months in the matched cohort with an estimated hazard ratio (HR) of 0.54 (95% CI: 0.37, 0.77). Results of a sensitivity analysis performed using entropy balancing were consistent with an adjusted median OS of 12.7 months in the real-world cohort (n=281)with HR of 0.57 (95% CI from bootstrapping: 0.44, 0.78).

Conclusion

Methodological advances to adjust for potential biases, and improvements in data quality, have evolved enabling the ability to leverage a real-world cohort as an external comparator arm. This study demonstrates the ability to create a real-world chemotherapy cohort suitable to serve as a comparator for MONARCH 1. These exploratory results suggest a survival advantage and adequately place the clinical benefit of abemaciclib monotherapy in clinical context.

References

Dickler et al, CCR 2017

Citation Format: Rugo H, Dieras V, Cortes J, Patt D, Wildiers H, O'Shaughnessy J, Zamora E, Yardley DY, Carter GC, Sheffield KM, Li L, Andre VA, Derbyshire RE, Li XI, Frenzel M, Huang Y-J, Dickler MN, Tolaney SM. Real-world survival of heavily pretreated patients with refractory HR+, HER2- metastatic breast cancer receiving single-agent chemotherapy - A comparison with MONARCH 1 [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 P6-18-19.

Abstract OT3-05-05: MonarchE: A randomized, open-label, phase 3 study of abemaciclib combined with standard adjuvant endocrine therapy versus standard adjuvant endocrine therapy alone in patients with high risk, node positive, early stage, HR+, HER2- breast cancer

Background: Abemaciclib, an oral, selective inhibitor of cyclin-dependent kinases 4 and 6 dosed on a twice daily continuous schedule, has demonstrated clinical efficacy and tolerability in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer when administered as monotherapy (MONARCH 1) and in combination with endocrine therapy (ET) in MONARCH 2 and MONARCH 3. In neoMONARCH, abemaciclib plus anastrozole as neoadjuvant therapy reduced the breast tumor cell proliferation marker Ki67 to a greater extent than anastrozole alone after 2 weeks of treatment. Endocrine monotherapy is the current standard of care in the adjuvant setting. However, a proportion of pts relapse despite this therapy. A population with a higher risk of recurrence (15% at 5 years) may be identified based on the clinical and pathological characteristics of disease. Optimizing adjuvant therapy for these pts is an important need.

Trial Design: MonarchE (NCT03155997) is a multicenter, randomized, open-label Phase 3 trial that will evaluate the potential for abemaciclib to enhance adjuvant ET. Pts will be randomized 1:1 to abemaciclib 150 mg twice daily continuous schedule plus standard of care (SOC) adjuvant ET versus SOC adjuvant ET alone and stratified by prior chemotherapy (neoadjuvant, adjuvant, or none), menopausal status (pre- or post-), and region (N. America/Europe, Asia, or other). Pts may have started ET within 8 weeks prior to randomization. Pts will receive abemaciclib for up to 2 years in combination with ET per physician's choice (such as tamoxifen or an aromatase inhibitor, +/- ovarian suppression). ET alone will be continued as clinically indicated. All randomized pts will be followed for a total of 10 years.

Eligibility Criteria: Eligible pts (male or female) must have early stage resected HR+, HER2- invasive breast cancer with either ≥ 4 positive pathological axillary lymph nodes (pALNs), or 1 to 3 positive pALNs and at least one of the following high risk markers: primary tumor size ≥5 cm, histological grade 3 tumor, or centrally assessed Ki67 index of ≥20% (in a subset of pts). Pts must have completed definitive locoregional therapy (+/- (neo)adjuvant chemotherapy) and be randomized no more than 12 weeks after completion of last non-ET (surgery, chemotherapy, or radiotherapy). Pts must have tumor tissue available for biomarker analysis prior to randomization.

Specific Aims: The primary objective of monarchE is to evaluate invasive disease-free survival (IDFS) per the STEEP System.1 Secondary objectives include evaluation of IDFS in pts with Ki67 index of ≥20%, distant relapse-free survival, overall survival, safety, pharmacokinetics, and pt health outcomes.

Statistical Methods: Assuming an IDFS hazard ratio of .73, the study is powered to approximately 80% to test the superiority of abemaciclib plus standard ET at a 1-sided α=0.025 using a stratified log-rank test.

Target accrual: Approximately 3580 pts

Contact information: 1-877-285-4559

Reference:

1. Hudis et al. J Clin Oncol. 2007;25(15):2127-2132.

Citation Format: Rastogi P, Toi M, Harbeck N, Bourayou N, Frenzel M, Johnston S. MonarchE: A randomized, open-label, phase 3 study of abemaciclib combined with standard adjuvant endocrine therapy versus standard adjuvant endocrine therapy alone in patients with high risk, node positive, early stage, HR+, HER2- 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 OT3-05-05.

Impact of quercetin and fish oil encapsulation on bilayer membrane and oxidation stability of liposomes

Unsaturated soy phosphatidyl choline (PC) liposomes were systematically analyzed for chemical and physical stability and for influence on membrane fluidity, when quercetin and fish oil were encapsulated. The physical stability of liposomes was lowered with loading, which is mainly due to fish oil leakage. While fish oil did not induce oxidative acceleration, quercetin did not reduce lipid-derived radical formation but it did inhibit hexanal formation. It also showed no relevant effects on membrane fluidity, polarity or partitioning of the spin probe TEMPOL-benzoate (TB), as proved by EPR measurements and simulation. However, increasing concentration of fish oil in a membrane might increase the acyl chain dynamics and therefore apply a more attractive environment for TB. In contrast to the encapsulates increasing fluidity of saturated membranes by disturbing the lipid packing, membrane properties of unsaturated systems with a Tm below 0 °C were not influenced by encapsulation of quercetin or fish oil.

Telomere shortening: a new prognostic factor for cardiovascular disease post-radiation exposure

Telomere length has been proposed as a marker of mitotic cell age and as a general index of human organism aging. Telomere shortening in peripheral blood lymphocytes has been linked to cardiovascular-related morbidity and mortality. The authors investigated the potential correlation of conventional risk factors, radiation dose and telomere shortening with the development of coronary artery disease (CAD) following radiation therapy in a large cohort of Hodgkin lymphoma (HL) patients. Multivariate analysis demonstrated that hypertension and telomere length were the only independent risk factors. This is the first study in a large cohort of patients that demonstrates significant telomere shortening in patients treated by radiation therapy who developed cardiovascular disease. Telomere length appears to be an independent prognostic factor that could help determine patients at high risk of developing CAD after exposure in order to implement early detection and prevention.

From protons to OXPHOS supercomplexes and Alzheimer's disease: structure-dynamics-function relationships of energy-transducing membranes

By the elucidation of high-resolution structures the view of the bioenergetic processes has become more precise. But in the face of these fundamental advances, many problems are still unresolved. We have examined a variety of aspects of energy-transducing membranes from large protein complexes down to the level of protons and functional relevant picosecond protein dynamics. Based on the central role of the ATP synthase for supplying the biological fuel ATP, one main emphasis was put on this protein complex from both chloroplast and mitochondria. In particular the stoichiometry of protons required for the synthesis of one ATP molecule and the supramolecular organisation of ATP synthases were examined. Since formation of supercomplexes also concerns other complexes of the respiratory chain, our work was directed to unravel this kind of organisation, e.g. of the OXPHOS supercomplex I(1)III(2)IV(1), in terms of structure and function. Not only the large protein complexes or supercomplexes work as key players for biological energy conversion, but also small components as quinones which facilitate the transfer of electrons and protons. Therefore, their location in the membrane profile was determined by neutron diffraction. Physico-chemical features of the path of protons from the generators of the electrochemical gradient to the ATP synthase, as well as of their interaction with the membrane surface, could be elucidated by time-resolved absorption spectroscopy in combination with optical pH indicators. Diseases such as Alzheimer's dementia (AD) are triggered by perturbation of membranes and bioenergetics as demonstrated by our neutron scattering studies.

Vardenafil protects isolated rat hearts at reperfusion dependent on GC and PKG

BACKGROUND AND PURPOSE

The type-5 PDE inhibitor vardenafil reduces myocardial infarct size in situ, following ischemia/reperfusion, when applied at reperfusion in animal models. Little is known about the underlying protective signaling. Here, we test whether vardenafil is protective in rat isolated hearts and in a cell model of calcium stress.

EXPERIMENTAL APPROACH

Infarct size in rat isolated hearts was measured after a 30 min regional ischemia and 120 min reperfusion. Vardenafil (1 nM-1 microM) was infused during reperfusion. HL-1 cardiomyocytes were loaded with tetramethylrhodamine ethyl ester (TMRE), a fluorescent marker of mitochondrial membrane potential (psi m).

KEY RESULTS

Vardenafil at reperfusion reduced infarct size as percentage of the ischemic zone from 45.8+/-2.0% in control hearts to 26.2+/-2.7% (P<0.001) only at 10 nM, whereas higher or lower dosages failed to protect. This protective effect was blocked by co-administration of either the GC inhibitor, 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ), or the PKG inhibitor, KT-5823. HL-1 cardiomyocytes, loaded with TMRE, were treated for 80 min with the calcium ionophore, calcimycin, to induce calcium stress. This reduced the mean cell fluorescence to 63.3 +/- 3.8% of baseline values and vardenafil protected against this fall (78.6 +/- 3.6%, P<0.01). The vardenafil-induced protection of HL-1 cells was blocked by ODQ, KT-5823 or the PKG-inhibiting peptides DT-2 and DT-3, confirming a role for GC and PKG.

CONCLUSIONS AND IMPLICATIONS

These results further support the hypothesis that PDE-5 inhibitors are protective in ischemic hearts, in addition to their known clinical effects in the treatment of erectile dysfunction in men.

Prediction uncertainty of environmental change effects on temperate European biodiversity

Observed patterns of species richness at landscape scale (gamma diversity) cannot always be attributed to a specific set of explanatory variables, but rather different alternative explanatory statistical models of similar quality may exist. Therefore predictions of the effects of environmental change (such as in climate or land cover) on biodiversity may differ considerably, depending on the chosen set of explanatory variables. Here we use multimodel prediction to evaluate effects of climate, land-use intensity and landscape structure on species richness in each of seven groups of organisms (plants, birds, spiders, wild bees, ground beetles, true bugs and hoverflies) in temperate Europe. We contrast this approach with traditional best-model predictions, which we show, using cross-validation, to have inferior prediction accuracy. Multimodel inference changed the importance of some environmental variables in comparison with the best model, and accordingly gave deviating predictions for environmental change effects. Overall, prediction uncertainty for the multimodel approach was only slightly higher than that of the best model, and absolute changes in predicted species richness were also comparable. Richness predictions varied generally more for the impact of climate change than for land-use change at the coarse scale of our study. Overall, our study indicates that the uncertainty introduced to environmental change predictions through uncertainty in model selection both qualitatively and quantitatively affects species richness projections.

Spatial genetic structure in a metapopulation of the land snail Cepaea nemoralis (Gastropoda: Helicidae)

Habitat fragmentation is a major force affecting demography and genetic structure of wild populations, especially in agricultural landscapes. The land snail Cepaea nemoralis (L.) was selected to investigate the impact of habitat fragmentation on the spatial genetic structure of an organism with limited dispersal ability. Genetic and morphological patterns were investigated at a local scale of a 500 m transect and a mesoscale of 4 x 4 km in a fragmented agricultural landscape while accounting for variation in the landscape using least-cost models. Analysis of microsatellite loci using expected heterozygosity (HE), pairwise genetic distance (FST/1-FST) and spatial autocorrelograms (Moran's I) as well as shell characteristics revealed spatial structuring at both scales and provided evidence for a metapopulation structure. Genetic diversity was related to morphological diversity regardless of landscape properties. This pointed to bottlenecks caused by founder effects after (re)colonization. Our study suggests that metapopulation structure depended on both landscape features and the shape of the dispersal function. A range of genetic spatial autocorrelation up to 80 m at the local scale and up to 800 m at the mesoscale indicated leptokurtic dispersal patterns. The metapopulation dynamics of C. nemoralis resulted in a patchwork of interconnected, spatially structured subpopulations. They were shaped by gene flow which was affected by landscape features, the dispersal function and an increasing role of genetic drift with distance.

[Surveillance of exposure in industrial styrene load]

Determinations of the styrene metabolites are reported with the high-performance liquid chromatography. The methodical investigations were used on a group of workers of the polyester processing. The establishment of the cumulation of metabolites and the appearance of pathological values of liver enzymes refer to the overcharge of biological regulations.

[Effectivity of intermittent treatment in patients with sputum-positive silico-tuberculosis (author's transl)]

89 patients with sputum-positive silico-tuberculosis got a fully supervised administered antituberculous treatment with intermittent regimens during the years 1969-1974. 65 of the patients had a history of former antituberculous treatment. In only 5 patients the treatment was unsuccessful. Four of the relapses were observed between the 6th and 11th month of treatment. One patient had a relapse 56 months after the onset of chemotherapy. The results indicate that only the quality of the anti-TB treatment is of importance for the course of the tuberculous component in silico-tuberculosis. The results are comparable with those of uncomplicated TB of the lungs.