Pre-surgical trial of the AKT inhibitor MK-2206 in patients with operable invasive breast cancer: a New York Cancer Consortium trial

INTRODUCTION

The PI3K/AKT/mTOR pathway is an oncogenic driver in breast cancer (BC). In this multi-center, pre-surgical study, we evaluated the tissue effects of the AKT inhibitor MK-2206 in women with stage I-III BC.

MATERIALS AND METHODS

Two doses of weekly oral MK2206 were administered at days - 9 and - 2 before surgery. The primary endpoint was reduction of pAkt^Ser473 in breast tumor tissue from diagnostic biopsy to surgery. Secondary endpoints included changes in PI3K/AKT pathway tumor markers, tumor proliferation (ki-67), insulin growth factor pathway blood markers, pharmacokinetics (PK), genomics, and MK-2206 tolerability. Paired t tests were used to compare biomarker changes in pre- and post-MK-2206, and two-sample t tests to compare with prospectively accrued untreated controls.

RESULTS

Despite dose reductions, the trial was discontinued after 12 patients due to grade III rash, mucositis, and pruritus. While there was a trend to reduction in pAKT after MK-2206 (p = 0.06), there was no significant change compared to controls (n = 5, p = 0.65). After MK-2206, no significant changes in ki-67, pS6, PTEN, or stathmin were observed. There was no significant association between dose level and PK (p = 0.11). Compared to controls, MK-2206 significantly increased serum glucose (p = 0.02), insulin (p < 0.01), C-peptide (p < 0.01), and a trend in IGFBP-3 (p = 0.06).

CONCLUSION

While a trend to pAKT reduction after MK-2206 was observed, there was no significant change compared to controls. However, the accrued population was limited, due to toxicity being greater than expected. Pre-surgical trials can identify in vivo activity in the early drug development, but side effects must be considered in this healthy population.

Abstract P3-07-52: Identification of serum biomarkers associated with Akt inhibitor MK-2206-induced toxicity in a pre-surgical breast cancer (BC) trial

Background: The PI3K/Akt/mTOR pathway is an important oncogenic driver in BC. A major hurdle in clinical Akt inhibitor development has been dose-limiting toxicities, such as rash. To facilitate the risk assessment of Akt inhibitor associated toxicity, we hypothesize that circulating biomarkers can be identified in proteins secreted by the tumor or tumor microenvironment and systemic response after treatment. Exosomes are small membrane bound vesicles containing proteins, mRNA, miRNA, and lipids that are secreted from host cells and remain viable after long-term storage of blood. In this study, we focused on identifying biomarkers associated with drug rash from serum exosomes in BC patients treated with the Akt inhibitor MK-2206.

Methods: In an open-label pre-surgical trial, 2 doses of weekly MK2206 were administered to patients (pts) with stage I-III invasive BC: first at day -9 and second at day -2 from surgery. Sera were collected before and after MK2206. 200 μL of serum was used to isolate total exosomes by precipitation and centrifugation, followed by trypsin digestion and multiplexing labeling analysis. The Orbitrap mass spectrometer was used to acquire LC-MS/MS data. 1,053 unique proteins were identified from the uniProt database. Maximum false discovery rate level (FDR) for predictive biomarkers was controlled at 26% (q&lt;0.26). Analysis was conducted on pre-MK-2206 and post-MK-2206 treated sera from pts to develop a protein signature associated with rash and identify candidate biomarkers of MK-2206-associated rash.

Results: The study was discontinued after 12 pts were enrolled due to toxicity. Notably, an acneiform/maculopapular rash was observed in 5 pts. Unsupervised principal component analysis on the pre-MK-2206 specimens and the entire set of 1,053 proteins demonstrated that 4 of the 5 pts with rash formed a distinct cluster. 30 proteins were differentially expressed in pre-MK-2206 samples from pts who developed rash vs. no rash (q&lt;0.26), with ≥1.5 fold difference in expression level in those with rash after MK-2206. Ingenuity pathway analysis revealed statistically significant over-representation of pathways involved in lipid metabolism (including MALRD1, AWAT2), nucleic acid synthesis (PPAT, ADSLL1), and protein synthesis (PPIB). 45 proteins were significantly different in post-MK-2206 samples (q&lt;0.285). Lipid metabolism was the most significantly over-represented pathway in post-MK-2206 samples.

Conclusions: We demonstrated that mass spectrometry-based proteomic analysis of patient-derived serum exosomes is a promising approach to study drug-induced toxicity. We found significant changes of circulating proteins before and after MK-2206. Increased expression of different proteins involved in lipid metabolism appears to predict skin toxicity, commonly seen with PI3K/Akt pathway inhibitors. Since the PI3K/Akt signaling pathway plays a role in physiological regulation of lipid metabolism, lipid metabolic profiles of BC patients might be important for predicting the risk and controlling toxicity induced by Akt inhibitors. These toxicity-associated biomarkers should be validated and then assessed prospectively in clinical trials.

Citation Format: Mundi PS, Chen E, Sparano J, Andreopoulou E, Taback B, Wiechmann L, Feldman S, Ananthakrishnan P, Hibshoosh H, Connolly E, Crew K, Maurer M, Hershman DL, Kalinsky K. Identification of serum biomarkers associated with Akt inhibitor MK-2206-induced toxicity in a pre-surgical breast cancer (BC) trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-52.

P5-21-01: A Renewable Tissue Resource of Phenotypically Stable Human Breast Cancer Xenografts for Preclinical Studies

Introduction Translational breast cancer research is hampered severely by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that accurately reflect patient tumor biology. These limitations are due, in part, to the fact that traditional immunocompromised mouse models are not generally permissive for growth. We sought to circumvent some of these limitations by transplanting and growing human mammary tumors in the mammary fat pad of SCID/Beige immunocompromised mice in the absence of exogenous human fibroblasts.

Aims and Methods To establish a set of stable human breast cancer xenografts for preclinical studies. Human breast cancer biopsies were received, minced into small fragments and then transplanted directly into “cleared” fat pads of recipient SCID/Beige immunocompromised mice. Transplanted fat pads were checked weekly. After initial tumor was palpated and harvested, tumor fragments were transplanted into new SCID/Beige hosts for subsequent transplant generations. Serial immunohistochemical evaluations were performed to confirm human origin and biomarker status. Analytical flow cytometry for evaluating expression of proposed “cancer stem cell” markers, and gene and protein expression analysis were carried out on all stable lines.

Results and Conclusions Xenograft lines were established directly from breast cancer patient samples, without intervening culture in vitro, using the epithelium-free mammary fat pad as the transplantation site. Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet without exogenous human fibroblasts. Thirty six stably transplantable xenograft lines representing 27 patients were established, using pre-treatment, mid-treatment, and/or post-treatment samples. Most patients yielding xenografts were “triple-negative” (ER-PR-HER2−) (n=21), we were able to establish lines from three ER-PR-HER2+ patients, one ER+PR+HER2−, one ER+PR-HER2−and one “triple-positive” (ER+PR+HER2+) patients. Serially passaged xenografts show phenotypic consistency with the tumor of origin at the histopathology level, and remarkable stability across multiple transplant generations at both the genomic, transcriptomic, and proteomic levels. Of 27 lines evaluated fully, thirteen xenografts showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource, and should prove useful for preclinical evaluation of experimental therapeutics.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-21-01.

Impact of HER2 Status on Risk of Sentinel Node Metastasis: An Independently Validated Multivariable Model

Purpose The presence of axillary lymph node metastases is dictated by tumor biology and is a strong prognostic indicator in breast cancer. We have previously published a user-friendly nomogram that provides a risk estimate for sentinel lymph node (SLN) metastasis in women with breast cancer (Bevilacqua et al. 2007, J Clin Oncol 25: 3670). At that time, HER2 testing was not uniformly performed, but is now standard of care. The purpose of this study was to determine if the addition of HER2 status or grouping of patients by molecular subtype improves the prediction of SLN metastasis.Patients and Methods: The ability of clinical and pathologic features to predict the presence of SLN metastasis in patients presenting with clinically node negative invasive breast cancer, was assessed with multivariable logistic regression (MVA) for 4723 sequential SLN biopsy procedures with known ER, PR, and HER2 from 1996 to 2004. HER2 status was defined as positive if IHC=3+ and/or FISH≥2. The modeling (n=3297) and validation (n=1426) groups were identified by simple random sampling. Two models were created using the modeling population: one included ER, PR, and HER2 as separate variables and one combined these markers into 4 subtypes defined as: Luminal A-like=ER or PR +, HER2 −; Luminal B-like=ER or PR +, HER2 +; HER2-like=ER and PR −, HER2 +; Basal-like=ER and PR −, HER2 −. The validation group was used to assess the calibration (intercept, slope, Emax, Eavg) and discrimination (AUC, area under the receiver operating curve) of the models.Results: In addition to age, tumor size, tumor type, lymphovascular invasion, tumor location, and multifocality, subtype was found to be an independent predictor of SLN metastasis on MVA (p=0.003). The Basal-like subtype was associated with a significantly lower risk of SLN metastasis (compared with referent Luminal A-like subtype, OR=0.58). HER2 alone was not found to be an independent predictor of SLN metastasis (p=0.56), while ER and PR remained significant (p=.05, p=.02). Compared to our previous model without HER2, the AUC was slightly decreased by the addition of either HER2 or subtype into the model, but the calibration was slightly improved (Table 1). DiscriminationCalibrationModelAUCInterceptSlopeEmaxEavgPrevious Model0.735- 0.0440.8690.0390.020Mew model with HER20.733- 0.0030.8890.0270.019New model with subtype0.731- 0.0010.8870.0270.020Table 1: Discrimination and calibration measures comparing the new model (with HER2 alone or subtype) with the previously published model (without HER2 or subtype).Conclusion: The addition of subtype, defined by combining HER2 status with ER and PR, slightly increases the calibration of the new model but does not increase its discrimination compared to the previous model. Breast tumor subtype is a significant independent predictor of risk of SLN metastasis, with basal-like subtype having a lower risk of SLN metastasis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1004.

Treatment of early breast cancer

Surgical intervention for breast cancer has continually evolved. The current review reports on updates from the pivotal trials, examines areas of controversy, and explores possible future directions.

Impact of molecular subtype on presenting characteristics of T1a,b tumors

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Background: Gene expression profiling of breast cancers has identified molecular subtypes (Lum A and B, basal, HER2) which impact upon the risk of both local and distant recurrence. There is interest in the impact of molecular subtype on outcome in T1a,bN0M0 tumors, a group thought to have good prognosis and to be amenable to breast conservation. The purpose of this study was to determine if presenting features of T1a,b tumors differ among molecular subtypes. Methods: Subtypes were classified using IHC as Lum A (ER±PR pos, HER2 neg); Lum B: (ER±PR pos, HER2 pos); HER2: (ER+PR neg, HER2 pos); or Basal: ER, PR, and HER2 neg. Data was obtained from a registered database which included patients treated in our institution between 1/98 and 6/07. Of 7906 eligible patients, 6016 were classifiable into molecular subtypes and 1974 tumors (32.8%) measured 10 mm or less. The Chi square test and ANOVA were used for statistical analysis. Results: Data are shown in Table 1 . Patients overexpressing HER2 were significantly younger, had more nodal involvement, multicentric/multifocal (Multi) disease, extensive intraductal component (EIC), and lymphovascular invasion (LVI) (all p<0.0001). On multivariate analysis the HER2 subtype had an odds ratio of 2.5 for Multi versus Lum A/B, but HER 2 was not predictive of nodal status. Conclusions: Even in small breast cancers, presenting features vary with molecular subtype. Unlike Multi, the higher incidence of positive nodes in HER2 patients is explained by traditional prognostic features such as grade, age, and size rather than subtype, suggesting that evaluation of traditional prognostic factors remains valuable in the molecular era. [Table: see text]

No significant financial relationships to disclose.

[Computer-assisted occlusal finishing]

The finishing of a fixed appliance case is one of the greatest challenges in our specialty and is playing an ever-increasing role in treatment considerations as patients become more demanding. The quality of the finishing is, in fact, often seen as an indicator of the orthodontist's skills. The finishing of a lingual case is subject to exceptionally exacting requirements. This often leads not only to longer chair times towards the end of the treatment but to longer treatment times overall. The procedure described in this article permits high-quality finishing with no greater clinical resource input than with conventional labial appliances. Five essential factors are presented and discussed.

Brain hemodynamic changes in preterm infants after maintenance dose caffeine and aminophylline treatment

OBJECTIVE

To investigate the acute effects of low-dose caffeine and aminophylline on cerebral blood flow in preterm infants, using both near-infrared spectroscopy (NIRS) and cerebral Doppler ultrasonography.

METHODS

Preterm infants with a gestational age of <32 weeks and birth weight of <1,500 g were randomized to receive either caffeine or aminophylline treatment for apnea of prematurity. The study period went from 30 min before to 60 min after the administration of the maintenance dose of pure caffeine (2.5 mg/kg once a day) or aminophylline (1.25 mg/kg twice a day). NIRS was used to measure changes in oxygenated hemoglobin (O(2)Hb), deoxygenated hemoglobin (HHb), oxidized-reduced cytochrome aa3 (CtOx), and mean cerebral oxygen saturation (SmO(2) = O(2)Hb/total Hb). Changes in cerebral blood volume (DeltaCBV) after caffeine or aminophylline administration were calculated. Cerebral blood flow velocity (CBV) in the pericallosal artery was evaluated by cerebral Doppler ultrasounds.

RESULTS

Data collected by NIRS and cerebral Doppler ultrasounds did not show significant differences before and after caffeine treatment. We observed a significant increase in O(2)Hb and HHb concentration and in CBV at 30 min after the infusion of aminophylline, which tended to return to baseline at the end of the study period.

CONCLUSION

Caffeine does not significantly affect brain hemodynamics, while aminophylline induces a significant transient increase in O(2)Hb and HHb concentration and CBV.

Changes in mesenteric blood flow response to feeding: conventional versus fiber-optic phototherapy

OBJECTIVE

To evaluate whether fiberoptic phototherapy influences the postprandial increase in mesenteric blood flow velocity similarly to conventional phototherapy in preterm infants.

PATIENTS AND METHODS

With the use of Doppler color ultrasonography, blood flow velocity in the superior mesenteric artery was measured both preprandially and postprandially in 19 preterm infants during and after conventional phototherapy, and in 20 preterm infants during and after fiber-optic phototherapy. The mean arterial blood pressure/mean flow velocity ratio was calculated as an estimate of relative vascular resistance of the superior mesenteric artery.

RESULTS

The study shows that conventional phototherapy blunts the postprandial mesenteric blood flow response to feeding in preterm infants. Furthermore, it shows that the postprandial increase in intestinal blood flow is not attenuated when fiber-optic phototherapy is administered, and that such postprandial increase of blood flow is significantly greater than in infants receiving conventional phototherapy. During and after fiber-optic phototherapy, a significant reduction in postprandial relative vascular resistance was found; such reduction was significantly greater than during conventional phototherapy.

CONCLUSIONS

Fiber-optic phototherapy is preferable to conventional phototherapy for the treatment of hyperbilirubinemia in preterm infants because it does not affect the physiologic postprandial redistribution of blood flow from the periphery to the gastrointestinal system as does conventional phototherapy.

Risk factors for the development of respiratory distress syndrome and transient tachypnoea in newborn infants. Italian Group of Neonatal Pneumology

Respiratory distress syndrome (RDS) and transient tachypnoea (TT) are the most frequent acute respiratory diseases in the newborn. This study investigated the risk factors for RDS and TT in newborn infants. A population of 63,537 newborns was enrolled in a 12-month survey in Italy, 734 (1.15%) affected by RDS and 594 (0.93%) affected by TT. Multivariate regression analysis of maternal and perinatal data and the calculation of odds ratios (with 95% confidence intervals) were performed. It was demonstrated that gestational age, birthweight, maternal age, elective and emergency caesarean section (CS), and male sex were risk factors for RDS, while gestational age, maternal diseases, twinning, birthweight, operative vaginal delivery, elective and emergency CS, and male sex were risk factors for TT. The data confirm previous reports and demonstrate that advanced maternal age is a risk factor for RDS, while ruling out maternal diseases as independent risk factors for RDS.

Acute neonatal respiratory distress in Italy: a one-year prospective study. Italian Group of Neonatal Pneumology

A prospective multicentre 12-month survey of neonatal respiratory disorders in 63 537 Italian infants was performed to evaluate the incidence of acute neonatal respiratory disorders and of the main related complications. A total of 1427 developed respiratory disorders (2.2%), 208 of whom died (14.6%). The incidence of respiratory distress syndrome was 1.16%, with a case fatality rate (CFR) of 24%; that of transient tachypnoea was 0.93%, with a CFR of 1.3%. The rates of meconium aspiration syndrome, persistent pulmonary hypertension and pneumonia were 0.06%, 0.02% and 0.07%, with CFRs of 10.3%, 38.5% and 21.7%, respectively. The occurrences of the main complications in affected newborns were: bronchopulmonary dysplasia 5.6%, necrotizing enterocolitis 1.7%, patent ductus arteriosus 9.8%, 3 degrees and 4 degrees grade intraventricular haemorrhage 6.8% and air leak 4.9%. It was concluded that the incidence of acute neonatal respiratory disorders and the main related complications was lower than that reported two decades ago and that the CFR of acute neonatal respiratory disorders had increased. These results may be the consequences of (i) progress in the management of high-risk pregnancies, (ii) an increased number of viable infants with extremely low birth weight and (iii) diffusion of antenatal treatment with corticosteroids which, in this series, seemed to reduce the morbidity but not the mortality in the high-risk infants.