Randomized, double-blind, placebo-controlled phase II study of istiratumab (MM-141) plus nab-paclitaxel and gemcitabine versus nab-paclitaxel and gemcitabine in front-line metastatic pancreatic cancer (CARRIE)

BACKGROUND

Preclinical data suggest that dual blockade of the insulin-like growth factor-1 receptor (IGF-1R) and HER3 pathways has superior activity to IGF-1R blockade alone in pancreatic ductal adenocarcinoma (PDAC). We tested whether istiratumab, an IGF-1R- and ErbB3-bispecific antibody, can enhance the efficacy of standard of care (SOC) chemotherapy in patients with metastatic PDAC selected for high IGF-1 serum levels.

PATIENTS AND METHODS

CARRIE was an international, randomized, double-blind, placebo-controlled phase II study for patients with previously untreated metastatic PDAC. In part 1, 10 patients were evaluated for pharmacokinetics and safety. In part 2, patients with high free serum IGF-1 levels were randomized 1 : 1 to receive either istiratumab [2.8 g intravenously (i.v.) every 2 weeks] or placebo combined with gemcitabine/nab-paclitaxel at approved dose schedule. The co-primary endpoints were progression-free survival (PFS) in patients with high IGF-1 levels and PFS in patients with both high serum IGF-1 levels and heregulin (HRG)+ tumors. Key secondary endpoints were overall survival (OS), objective response rate (ORR) by RECIST v.1.1, and adverse events (AEs) rate.

RESULTS

A total of 317 patients were screened, with 88 patients randomized in part 2 (experimental arm n = 43; control n = 45). In the high IGF-1 cohort, median PFS was 3.6 and 7.3 months in the experimental versus control arms, respectively [hazard ratio (HR) = 1.88, P = 0.027]. In the high IGF-1/HRG+ subgroup (n = 44), median PFS was 4.1 and 7.3 months, respectively (HR = 1.39, P = 0.42). Median OS and ORR for the overall population were similar between two arms. No significant difference in serious or grade ≥3 AEs was observed, although low-grade AEs leading to early discontinuation were higher in the experimental (39.5%) versus control arm (24.4%).

CONCLUSIONS

Istiratumab failed to improve the efficacy of SOC chemotherapy in this patient setting. High serum IGF-1 levels did not appear to be an adverse prognostic factor when compared with non-biomarker-selected historic controls.

CLINICAL TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov: NCT02399137; EUDRA CT: 2014-004572-34.

Abstract P4-01-05: Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 equivocal breast cancer

Background:

Determination of ERBB2 (HER2) expression or amplification informs eligibility of HER2-targeted therapies. ASCO and NCCN guidelines recommend evaluation of HER2 status on primary invasive breast cancers and on a metastatic site if stage IV, where possible, as treatment is based on the status of the metastasis. Reassessment of HER2 status should also be considered in patients with disease recurrence as initially HER2-negative tumors may acquire HER2 amplification at progression. HER2 status can be complicated by equivocal results from in situ hybridization (ISH) and/or immunohistochemistry (IHC). Clarification requires reflex testing on the same tissue specimen or repeat testing on a new specimen, however some patients' tissue status remains equivocal. Furthermore, metastases to bone, lung, or brain may be difficult to re-biopsy or of low DNA quality. Rapid and non-invasive blood-based cell-free DNA (cfDNA) NGS may facilitate identification of HER2 targetable disease in advanced breast cancer.

Methods:

We assessed the frequency of ERBB2 amplification detectable by a blood-based cell-free DNA (cfDNA) assay among patients with metastatic breast cancer with equivocal HER2 results in tissue. cfDNA samples were ordered as part of routine clinical care using an assay validated for the detection of copy number amplification in ERBB2 (tests run between 03/2014-04/2017 by Guardant Health, Redwood City, CA). Submitted pathology reports were reviewed for HER2 status which was categorized as positive, negative, or equivocal based on the interpretation issued by the reading pathologist at the time the test was ordered. Patients were included if they had an equivocal result on IHC and/or ISH unless both assays were performed on the same specimen and one provided a definitive negative or positive HER2 result. Additionally, 4 patients with equivocal IHC or ISH results were excluded as biopsy of another tumor site revealed a positive HER2 result around the same time as the equivocal test. For the 349 patients with multiple cfDNA samples, the earliest pathology report was referenced.

Results:

Tissue HER2 status was available for 1,853 unique patients (98.8% female, median age at testing was 58y, range 26-91y). 141 patients (7.6%) had equivocal HER2 results in tissue; 99 by IHC alone, 14 by ISH alone, and 28 were equivocal by both assays. Among these, 126 patients (89.4%) had at least one sample with ctDNA detected. 12/126 (9.5%) had amplification of ERBB2 detected in at least one cfDNA sample. Samples were drawn a median of 267 days after tissue collection (range 4 days – 11.5 years). Frequency of ERBB2 amplification was similar regardless of time between tissue and blood collection but was higher among patients with ISH results alone (4/14, 36.4%) compared to those with IHC alone (6/89, 6.7%) or both assays (6/26, 7.6%; p=0.006).

Conclusion:

cfDNA testing identifies a significant number of patients with HER2-targetable advanced breast cancer whose tissue was HER2 equivocal. cfDNA testing may supplement tissue-based methods to help clarify HER2 status in metastatic disease as well as identify patients who may acquire HER2 amplification subsequent to their initial biopsy.

Citation Format: Rich TA, Raymond VM, Ahn ER, Banks KC, Brufsky A, Lee C, Lippman M, Pluard TJ, Schwab RB, Lanman RB. Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 equivocal 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 P4-01-05.

Abstract OT1-03-04: A phase II study of neoadjuvant aromatase inhibitor with pertuzumab and trastuzumab for patients with ER+HER2+ stage I-II breast cancer (NEOADAPT)

Background. Recent clinical trial results indicate that it is more appropriate than ever to conduct de-escalation clinical trials looking at less chemotherapy for patients with relatively early stage HER2+ breast cancer, particularly those with so called triple positive breast cancer (ER+PR+HER2+, or TPBC). TBCRC 006 showed that if hormone therapy is added to dual-HER2 blockade (lapatinib and trastuzumab) pathological complete response rate (pCR) can increase to 21% with another 22% having low residual disease (<1cm) with only 12 weeks of neoadjuvant therapy. After CLEOPATRA showed unprecedented improvement in OS comparing docetaxel trastuzumab and pertuzumab versus docetaxel and trastuzumab (15.7 mo median OS difference), we designed NEOADAPT to test the hypothesis that a flexible duration of neoadjuvant treatment based on clinical and radiographic response with an aromatase inhibitor coupled with pertuzumab and trastuzumab would have a >40% pCR rate. The potential impact of this trial is to provide more treatment options for women with early stage TPBC in a current environment when more than 40% of such patients are currently getting chemotherapy.

Trial Design. This single arm prospective cohort study is IRB approved and currently enrolling (NCT02689921). Intervention will be neoadjuvant aromatase inhibitor +/- LHRH agonist or oophorectomy if premenopausal with trastuzumab and pertuzumab in standard q 3-week dosing schedules. Duration of treatment will be determined by clinical exam, q 3mo dynamic breast MRI but no longer than 1 year maximum before surgery. Study ends upon definitive surgery. Duration of treatment will be 3 months after last radiographic CR seen on MRI barring progression or patient/physician choice.

Eligibility Criteria. Patients with stage I-II biopsy confirmed invasive breast cancer that is ER/PR+ and HER2+ by latest ASCO guidelines. Multifocal breast cancer is allowed on the provision that all lesions are biopsied and confirmed to also be TPBC and felt by the pathologist to be the same tumor. Age >18 yrs, ECOG PS 0-2, LVEF >50% at baseline. Rest of inclusion and exclusion criteria are typical for most studies in this setting.

Specific Aims. The primary endpoint is to document pCR rate. Secondary endpoints are to conduct an exploratory analysis of whether Mammaprint can identify patients who are more likely to obtain pCR or not and to describe sensitivity and specificity of breast MRI in predicting pCR.

Statistical Design. To identify a hypothesized pCR rate of >40% with 80% power, 32 patients will be enrolled. The Fleming two stage design will be implemented with stopping rules with the first stage of interim analysis done when the first 15 evaluable patients have surgical results. Further details will be provided in poster.

Present accrual and target accrual. At time of abstract submission 5 of 32 patients have been enrolled and the study is currently available at 2 Cancer Treatment Centers of America sites, Midwestern and Southeastern Regional Medical Center. Plan is to open the study at all 5 CTCA sites before end of 2017.

Contact information for those specifically interested in this trial. Principal investigator Eugene Ahn MD eugene.ahn@ctca-hope.com.

Citation Format: Ahn ER, Alvarez R, Maurie M. A phase II study of neoadjuvant aromatase inhibitor with pertuzumab and trastuzumab for patients with ER+HER2+ stage I-II breast cancer (NEOADAPT) [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 OT1-03-04.

Abstract P6-09-02: Improved clinical outcomes associated with vitamin D supplementation during adjuvant chemotherapy in patients with HER2+ non-metastatic breast cancer

Background

Vitamin D (VitD) supplementation decreases the risk of osteoporotic fractures in the elderly; however, its extraskeletal benefits, especially in the prevention and treatment of breast cancer, are less well-established. Many studies have shown an association of low VitD levels with higher cancer incidence, including breast cancer and poorer outcomes, but whether this association merely reflects a selection bias to healthier lifestyles, remains an area of controversy. We hypothesized that women with more aggressive HER2+ breast cancer would have improved clinical outcomes while on VitD supplements.

Methods

We performed a retrospective review of all patients (n = 300) given trastuzumab chemotherapy between 2006 and 2012 at UM/SCCC. We identified two groups of patients for comparison - those who received VitD supplementation (VD) during adjuvant chemotherapy (n = 130) or none (NVD) during adjuvant chemotherapy (n = 123). Patients who lacked sufficient records to clarify VitD supplement use, men, patients with de-novo-metastatic breast cancer, bilateral breast cancers, and patients without follow-up were excluded. Five-year disease-free survival (DFS) and overall survival (OS) were calculated. Univariate and multivariate analyses were performed using a Cox proportional hazards (CPH) model to evaluate the relationship between VD supplementation and death.

Results

The median age at diagnosis was 54 and 50 in the VD and NVD groups. In the VD group, the average VitD dose was 10,890 IU/wk, and the baseline and post-25-H VitD serum level was 35 and 41ng/ml, respectively. Descriptive analysis of the VD and NVD groups were as follows: postmenopausal (55.4%, 43.9%), tumor <2cm (42.3%, 36.6%), no lymph node involvement (42.3%, 36.6%), LVI (46.4%, 33.3%), high nuclear grade (60%, 61.5%), HR+ (66.2%, 54.5%), African American race (4.6%, 9.8%), and BMI>30 at end of chemotherapy (26.2%, 31.7%). At a median follow-up of 31 and 23 months, the estimated five-year DFS (69.4% vs. 44.7%, p = 0.009) and OS (97.5% vs. 85.6%, p = <0.0001) were significantly superior in the VD group versus the NVD group. These differences remained significant after adjustment for age, ethnicity, menopausal state, tumor size, node positivity, LVI, high-grade tumor, HR+, and BMI>30. Analysis showed an interaction between OS and ethnicity (African American = 0.008) and node positivity (p = 0.02) and near-significance for LVI (p = 0.07). Despite those confounding variables, VitD use remained significantly associated with improved OS (p = 0.003) and had a HR or 0.10 with a 95% CI of 0.02-0.45.

Conclusion

Our study suggests that Vitamin D supplementation in non-metastatic HER2 breast cancer patients is associated with improved DFS and OS, and the relationship remains significant after adjusting for potential confounding factors. It is unclear whether vitamin D supplementation might have pre-selected for HER2+ breast cancers with more favorable prognosis or synergized with anti-HER2 therapy. To our knowledge, this is the first study reporting improved outcomes associated with relatively high dose Vitamin D supplementation in the HER2+ breast cancer population. Further research is warranted to define the role of Vitamin D in breast cancer treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-09-02.

Increased procoagulant cell-derived microparticles (C-MP) in splenectomized patients with ITP

BACKGROUND

Splenectomy is frequently employed for therapeutic and diagnostic purposes in various clinical disorders. However its long-term safety is not well elucidated. Although risk of infection by encapsulated organisms is widely recognized, less well-known are risks of thrombosis and cardiovascular disease.

METHODS

We investigated levels of cell-derived microparticles (C-MP) in 23 splenectomized ITP (ITP-S) and 53 unsplenectomized ITP patients (ITP-nS). Assay of C-MP derived from platelets (PMP), leukocytes (LMP), red cells (RMP) and endothelial cells (EMP) were performed by flow cytometry. Coagulation parameters included PT, aPTT and activities of FVIII, IX and XI. Results of all measures were compared between the two groups, ITP-S vs ITP-nS.

RESULTS

Levels of all C-MP were higher in ITP-S than ITP-nS but only RMP and LMP reached statistical significance (p = 0.0035 and p < 0.0001, respectively). The aPTT was significantly shorter in ITP-S (p = 0.029). Interestingly, correlation analysis revealed that RMP, but not other C-MP, were associated with shortening of aPTT (p = 0.024) as well as with increased activities of factors VIII (p = 0.023), IX (p = 0.021) and XI (p = 0.0089).

CONCLUSIONS

RMP and LMP were significantly elevated in splenectomized compared to non-splenectomized ITP patients. This suggests that the spleen functions to clear procoagulant C-MP, and that elevation of C-MP might contribute to increased risk of thrombosis, progression of atherosclerosis and cardiovascular disease following splenectomy.

Endothelial microparticles induce formation of platelet aggregates via a von Willebrand factor/ristocetin dependent pathway, rendering them resistant to dissociation

Endothelial microparticles (EMP) released from activated or apoptotic endothelial cells (EC) are emerging as useful markers for detection of EC dysfunction. Our recent observation that EMP carry von Willebrand factor (vWf) led us to investigate their interaction with platelets. EMP were incubated with normal washed platelets in the presence or absence of ristocetin, then platelet aggregates were measured by flow cytometry. In the absence of ristocetin, negligible EMP conjugated with platelets (< 5%) but in the presence of ristocetin (1 mg mL(-1)), EMP induced up to 95% of platelets to aggregate. EMP-platelet interaction was 80% blocked by anti-CD42b, or by 0.1 microm filtration to remove EMP. Platelet aggregates induced by normal plasma or high molecular weight vWf (Humate-P) dissociated 50% within 15-25 min following 1:20 dilution. In contrast, aggregates formed with EMP persisted two- to threefold longer with the same treatment, indicating greater stability. A similar degree of prolongation of dissociation was observed using plasma from thrombotic thrombocytopenic purpura (TTP) patients compared with normal plasma. Addition of EMP to plasma from severe von Willebrand disease restored his ristocetin-induced platelet aggregation. Multimer analysis of vWf on EMP showed unusually large vWf (ULvWf). In summary, EMP carries ULvWf multimers, promote platelet aggregates, and increase the stability of the aggregates thus formed.