Haluska, Paul

271 Background: MEDI-573 is a dual-targeting human antibody that neutralizes IGF-I/-II ligands and inhibits IGF-1R and insulin receptor-A (IR-A) signaling pathways, which play a role in breast and other epithelial cancers. By sparing IR-B and its hybrid receptors, MEDI-573 is expected to achieve antitumor activity without perturbing glucose homeostasis. Methods: In a 3 + 3 dose-escalation trial ( NCT00816361 ), patients with advanced solid tumors, KPS ≥ 60, received MEDI-573 as a weekly 1-hr IV infusion at 0.5, 1.5, 5, 10, or 15 mg/kg every 21 days. Objectives included determination of MTD, safety profile, pharmacokinetics (PK), pharmacodynamics, and tumor response. In a separate biomarker study, mRNA expression of IR-A and IR-B was compared in HR+/HER- breast cancers. Results: Patients included 13M/12F (17 evaluable for efficacy at data cutoff); median age 59 yrs (range 37-78). No DLTs, drug-related SAEs, or significant toxicity patterns were reported. Forty-five AEs were considered treatment-related (% of patients): decreased appetite (28%), fatigue (24%), nausea (20%), diarrhea (16%), and anemia (12%). Hyperglycemia occurred in 2 patients, 1 with evidence of prestudy insulin resistance. No other significant changes in plasma glucose levels occurred. MEDI-573 had dose-proportionality, with AUC of 415 ± 165, 597 ± 298, and 1940 ± 904 d*μg/mL at 5, 10, and 15 mg/kg, respectively. Suppression of free IGF-1 and -2 was fully achieved at doses ≥ 5 mg/kg. Stable disease spanning ≥ 12 wks (range 12-36+) was seen in 6/17 patients. No antidrug antibodies were reported. In a study to identify breast cancer subsets that are dependent on IGF signaling, the IR-A:IR-B ratio was significantly higher in HR+/HER2- breast cancer than matched adjacent normal tissues and in proliferative luminal B than in luminal A breast cancer. Conclusions: MEDI-573 showed acceptable safety and favorable PK profiles without significant changes in glucose levels. The IR-A:IR-B ratio supports a biomarker approach for MEDI-573 patient stratification. A biomarker-rich phase Ib/II study of MEDI-573 with an aromatase inhibitor in patients with advanced HR+/HER2- breast cancer opens in 2011.

Abstract Background: At the time of ovarian cancer platinum resistance, standard therapies have limited activity. New anti-cancer drug combinations may lead to improved clinical outcomes. Activity of topoisomerase I (Top I) inhibitors or poly(ADP-ribose) polymerase (PARP) inhibitors have been reported in ovarian cancer and have demonstrated potentiation in other models. Objective: To investigate the efficacy of the Top I inhibitor etirinotecan pegol (NKTR-102) and the PARP inhibitor rucaparib (CO-338) as single agents and in combination in patient-derived xenograft (PDX) models of ovarian cancer. Methods: Five ovarian cancer PDX models in SCID mice were treated for 28 days with NKTR-102 (10 mg/kg/q7d IV), rucaparib (150 mg/kg/qd PO), or combination NKTR-102 plus rucaparib at the same doses and schedules. Of the five PDX models, four were platinum resistant and one was a platinum-sensitive positive control. Each treatment arm had a total of 10 mice and animals were observed daily for body weight and general condition. Tumor size was assessed weekly by ultrasound. The primary endpoint was change in tumor cross-sectional area (cm2) from pretreatment baseline to final tumor burden. Western blot was performed to investigate potential biomarkers of response. Results: Compared to vehicle-treated controls, statistically significant improvement (p<0.05) was observed in 3 of 5 models in single agent rucaparib treated tumors and in 5 of 5 models in single agent NKTR-102 treated tumors. The combination of NKTR-102 plus rucaparib also demonstrated statistically significant improvement compared to vehicle-treated controls in 5 of 5 models. The combination of NKTR-102 plus rucaparib induced maximal tumor regression in 2 of 5 tumors with a trend towards smaller tumors compared to single agent treatment arms. This was not found to be statistically significant in the 28 day study period under which the experiment was performed. Exploratory analysis to assess candidate drug response determinants (e.g.Top I, PAPR I, and PARP polymer formation levels) was investigated. Conclusion: NKTR-102 and rucaparib are well tolerated in mice and demonstrate activity in platinum-resistant and platinum-sensitive ovarian cancer PDX models. Combination therapy demonstrated a trend towards decreased tumor size when compared to single agent activity during treatment. Current efforts are focused on extending the time on study for the PDX models evaluated to determine if statistical superiority of the NKTR-102/rucaparib combination can be established. Citation Format: Caroline C. Nitschmann, Rachel M. Hurley, Marc A. Becker, Xiaonan Hou, Ute Hoch, Thomas C. Harding, Deborah H. Charych, Scott H. Kaufmann, Paul Haluska, Saravut J. Weroha. Antineoplastic activity of Top I inhibitor etirinotecan pegol (NKTR-102) and PARP inhibitor rucaparib (CO-388) in platinum-resistant high-grade serous BRCA WT ovarian cancer PDX models. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B50.

Abstract Ovarian cancer (OCa) is fifth leading cause of death among women. Most of OCa patients diagnosed with high stage invasive disease. Although, majority experience remission after surgical debulking and adjuvant chemotherapy, about 80% of patients relapse and/or develop chemoresistant disease. More efficient diagnostics and therapies are needed to improve outcome in ovarian cancer. We used an integrated approach to characterize genomic rearrangements in serous OCa inordet to identify potentially targetable alterations and test treatments with corresponding drugs using matching mouse avatar models. Mate-pair next generation sequencing protocol and BIMA2 algorithm were used to identify chromosomal rearrangements, including gene fusions and copy number changes, in primary tumors. Further analysis was then performed to determine alterations that may also be therapeutically targeted. Total of 25 primary tumors were analyzed, out of which four were selected for genomically guided treatments in corresponding mouse avatars. The tumors propagated in the selected mouse lines were also sequenced and showed identical to original patient tumor landscape of rearrangements. In addition, the selected targetable alterations were validated in both patient and avatar tumor DNA. For several of the analyzed cases pre-surgical and postsurgical blood was available for detection of selected alterations in cell free circulating tumor DNA. The analysis revealed presence of selected rearrangements in pre-surgical blood of all tested cases and in a number of those that showed presence of the disease after surgery. In summary, we showed that the whole genome sequencing of DNA rearrangements in conjunction with analyses of therapeutic targets and treatment testing in mouse avatars, developed using primary tumors, is a promising approach to aid treatment decisions for individual ovarian cancer patients. Note: This abstract was not presented at the conference. Citation Format: Faye R. Harris, Geoffrey C. Halling, Marc A. Becker, Paul Haluska, Jr., George Vasmatzis, Irina V. Kovtun. Individualized approach for ovarian cancer: Identification of potential therapeutic targets based on genomic analyses, testing efficiency of treatments, and monitoring. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Integrating Clinical Genomics and Cancer Therapy; Jun 13-16, 2015; Salt Lake City, UT. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(1_Suppl):Abstract nr 13.

Abstract Purpose: p38 MAPK regulates the production of cytokines in the tumor microenvironment and enables cancer cells to survive despite oncogenic stress, radiotherapy, chemotherapy, and targeted therapies. Ralimetinib (LY2228820 dimesylate) is a selective small-molecule inhibitor of p38 MAPK. This phase I study aimed to evaluate the safety and tolerability of ralimetinib, as a single agent and in combination with tamoxifen, when administered orally to patients with advanced cancer. Experimental Design: The study design consisted of a dose-escalation phase performed in a 3+3 design (Part A; n = 54), two dose-confirmation phases [Part B at 420 mg (n = 18) and Part C at 300 mg (n = 8)], and a tumor-specific expansion phase in combination with tamoxifen for women with hormone receptor–positive metastatic breast cancer refractory to aromatase inhibitors (Part D; n = 9). Ralimetinib was administered orally every 12 hours on days 1 to 14 of a 28-day cycle. Results: Eighty-nine patients received ralimetinib at 11 dose levels (10, 20, 40, 65, 90, 120, 160, 200, 300, 420, and 560 mg). Plasma exposure of ralimetinib (Cmax and AUC) increased in a dose-dependent manner. After a single dose, ralimetinib inhibited p38 MAPK–induced phosphorylation of MAPKAP-K2 in peripheral blood mononuclear cells. The most common adverse events, possibly drug-related, included rash, fatigue, nausea, constipation, pruritus, and vomiting. The recommended phase II dose was 300 mg every 12 hours as monotherapy or in combination with tamoxifen. Although no patients achieved a complete response or partial response,19 patients (21.3%) achieved stable disease with a median duration of 3.7 months, with 9 of these patients on study for ≥6 cycles. Conclusions: Ralimetinib demonstrated acceptable safety, tolerability, and pharmacokinetics for patients with advanced cancer. Clin Cancer Res; 22(5); 1095–102. ©2015 AACR.

Abstract Purpose: This phase II trial evaluated the efficacy and safety of cixutumumab, a human anti–insulin-like growth factor receptor 1 (IGF-1R) monoclonal IgG1 antibody, and explored potential biomarkers in postmenopausal women with hormone receptor–positive breast cancer. Experimental Design: Patients with hormone receptor–positive breast cancer that progressed on antiestrogen therapy received (2:1 randomization) cixutumumab 10 mg/kg and the same antiestrogen (arm A) or cixutumumab alone (arm B) every 2 weeks (q2w). Primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS) and safety. Correlative analyses of IGF-1R, total insulin receptor (IR), and IR isoforms A (IR-A) and B (IR-B) expression in tumor tissue were explored. Results: Ninety-three patients were randomized (arm A, n = 62; arm B, n = 31). Median PFS was 2.0 and 3.1 months for arm A and arm B, respectively. Secondary efficacy measures were similar between the arms. Overall, cixutumumab was well tolerated. IGF-1R expression was not associated with clinical outcomes. Regardless of the treatment, lower IR-A, IR-B, and total IR mRNA expression in tumor tissue was significantly associated with longer PFS [IR-A: HR, 2.62 (P = 0.0062); IR-B: HR, 2.21 (P = 0.0202); and total IR: HR, 2.18 (P = 0.0230)] and OS [IR-A: HR, 2.94 (P = 0.0156); IR-B: HR, 2.69 (P = 0.0245); and total IR: HR, 2.72 (P = 0.0231)]. Conclusions: Cixutumumab (10 mg/kg) with or without antiestrogen q2w had an acceptable safety profile, but no significant clinical efficacy. Patients with low total IR, IR-A, and IR-B mRNA expression levels had significantly longer PFS and OS, independent of the treatment. The prognostic or predictive value of IR as a biomarker for IGF-1R–targeted therapies requires further validation. Clin Cancer Res; 22(2); 301–9. ©2015 AACR.

Abstract Purpose: Treatment of recurrent ovarian cancer is limited by low response rates to salvage chemotherapy. Novel small molecule inhibitors to Chk1 (checkpoint kinase 1) have been proposed to potentiate the cytotoxic effect of one such salvage treatment, gemcitabine, by interrupting the DNA damage repair pathway. Patient derived tumorgrafts were characterized by responsiveness to gemcitabine +/- MK8776 (Chk1 inhibitor). Response was correlated with markers of Chk1 activity. Methods: Patient-derived tumorgraft models were created from patients undergoing surgery for epithelial ovarian cancer. Gemcitabine response was characterized in five high-grade serous models (PH044, PH048, PH070, PH080, and PH110). Two models (PH048 and PH080) were treated with gemcitabine monotherapy (240 mg/kg qweek x 4 doses), MK8776 monotherapy (32 mg/kg qweek x 4 doses), and with combination therapy (Gemcitabine 190 mg/kg and MK8776 32 mg/kg qweek x 4 doses). Animals were monitored for cytotoxicity, and tumors were measured weekly with ultrasound. Response to gemcitabine and to combination therapy was correlated to immunohistochemistry of γH2AX and immunoblotting for p345-Chk1 and p296-Chk1. Results: Gemcitabine monotherapy did not affect tumor growth in two models (PH044 and PH048). Significant in vivo response to gemcitabine was seen in PH070 and PH080. Significant growth attenuation but not tumor regression was seen in PH110. MK8776 did not have any effect on tumor growth as monotherapy or in combination with gemcitabine in the gemcitabine resistant model, PH048. In contrast, in a gemcitabine sensitive model, PH080, MK8776 monotherapy significantly attenuated tumor growth, and there was a trend for MK8776 to potentiate the cytotoxic effects of gemcitabine in PH080 (p=0.16). Final tumor weights in the PH080 model after 4 doses of chemotherapy were 1.7 g (90%CI: 1.5-1.9g), 0.3g (90%CI: 0.18-0.35g), and 0.14g (90%CI: 0.08-.19g) in the control, gemcitabine alone, and gemcitabine with MK8776 groups respectively. Decrease in the tumor auto-phosphorylation of Chk1 at Serine-296 was observed in some, but not all models in response to MK8766 treatment. γH2AX increased in response to the addition of MK8776 to gemcitabine. Conclusions: Chk1 inhibition may enhance the activity of gemcitabine in some, but not all ovarian tumors. Further work is needed to find markers that will predict response to Chk1 inhibitors to help select patients for future clinical trials. While pChk1-S296 previously demonstrated potential utility as a biomarker of Chk1 inhibition, in vivo assessments of its differential expression may demonstrate the unreliability of this marker. This work supports the use of patient derived tumorgrafts in drug development for ovarian cancer. Citation Format: A Kumar, S Weroha, M Becker, X Hou, S Greiner, L Karnitz, P Haluska. Chk1 inhibitor (MK8776) enhances cytotoxicity of gemcitabine in select patient-derived ovarian tumorgraft models [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-THER-1419.

Abstract Ovarian cancer is the most lethal gynecologic malignancy and the fifth leading cause of cancer deaths among women. The current standard of care post surgical cytoreduction is combination platinum/taxane chemotherapy. The initial response varies widely; subsets of carcinomas demonstrate resistance or sensitivity from the onset. The underlying cause of this response heterogeneity remains incompletely understood. Patient-derived xenografts (PDX) serve as useful in vivo models to study molecular response markers and test the efficacy of targeted therapies. Our group has demonstrated a high engraftment rate (>70%) of ovarian cancer PDXs (Avatars) by injecting treatment naïve patient tumor directly into the peritoneal cavity of an in immunocompromised mouse host in an effort to better mimic the anatomic context by which ovarian cancer naturally develops. We now have 328 engrafted Avatar models representing the wide range of ovarian cancer subtypes, including serous (65%), mixed epithelial (10%), endometrioid (7%), clear cell (4%), mucinous (3%), carcinosarcoma (1%) and other (10%). Using these models, we are performing a massively parallel sequencing strategy referred to as BROCA-HR to detect all mutation classes (e.g. gene rearrangements, copy number variations, etc.) and gene aberrations within the Fanconi Anemia-BRCA homologous recombination (HR), non-homologous end joining (NHEJ), PTEN, and DNA Mismatch repair pathways. To date, 148 Avatar models have undergone BROCA sequencing. Observed deleterious mutations included 12 BRCA1 (8%), 6 BRCA2 (4%), and 4 PIK3CA (3%); additional loss of function mutations were also evident in the following genes: ATM, RAD51C, FANCM, FANCD2, FANCA, CHEK2, PALB2, MHS6, CDK12 and GEN1. These models are representative of mutations seen in the TCGA mutation set. Models harboring said mutations are currently being tested with platinum agents and/or PARP inhibitors. Taken together, the Avatars represent a high throughput model system for pre-clinical testing in vivo that effectively recapitulates ovarian cancer (e.g. mutations in BRCA1, BRCA2 and other DNA damage response proteins). We have been able to establish avatars at a high rate, including those with mutations in BRCA1, BRCA2 and other DNA damage response genes. These models will be a unique resource for future studies of biomarkers and novel therapeutic approaches. This work is funded by the Ovarian Cancer Research Fund (750563), Mayo Ovarian SPORE (CA136393), National Cancer Institute (RO1 CA184502). Note: This abstract was not presented at the meeting. Citation Format: Kunal A. Lodhia, Marc A. Becker, Xiaonan Hou, Kimberly R. Kalli, Maria I. Harrell, Elizabeth M. Swisher, John S. Weroha, Paul Haluska. Characterization of 148 ovarian cancer tumografts (Avatars) using BROCA-HR deep sequencing. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1474. doi:10.1158/1538-7445.AM2015-1474

Abstract Neoadjuvant endocrine therapy (ET) in patients (pts) with locally advanced estrogen receptor positive (ER+) breast cancer (BC) improves breast conservation rate, and importantly offers an opportunity for individualized assessment of tumor responsiveness to ET to guide subsequent treatment. Previous neoadjuvant ET trials demonstrated that pathologic tumor size (pT), axillary lymph node status (N), and tumor Ki67 value at surgery predicted risk of relapse. Preoperative endocrine prognostic index (PEPI) was therefore developed to assign risk scores based on these factors. Modified PEPI 0, defined by pT1-2 N0 Ki67< 2.7%, was associated with extremely low risk of recurrence without adjuvant chemotherapy. In addition, high Ki67 post 2-4 weeks (wks) of neoadjuvant ET identified resistant tumors with poor outcome. ALTERNATE trial is a three-arm phase III neoadjuvant/adjuvant ET trial designed to achieve two primary objectives. The first is to prospectively validate that modified PEPI 0 predicts > 95% relapse-free survival (RFS). The second is to determine whether fulvestrant (F), or fulvestrant (F) plus anastrozole (A), is superior to A in inducing a higher rate of modified PEPI 0. Secondary objectives include assessing RFS for pts with endocrine resistant tumor, defined by Ki67 > 10% at 4 or 12 wk, disease progression, or modified PEPI non-0, and pathologic responses of resistant tumors to neoadjuvant chemotherapy. Correlative studies include degrees of Ki67 suppression and ER level post treatment. In addition, ongoing research sequencing studies of DNA and RNA will be performed to contrast sensitive vs resistant tumors. During the first phase of the trial, 1200 pts are randomized 1:1:1 to the F, A or F/A. This provides an 82% chance, 1-sided alpha 0.025 chi-square test to detect at least 10% difference in modified PEPI 0 rate comparing F or F/A with A. While waiting for result of analysis, the A arm will continue for the 2nd phase enrollment. Only the F-containing arm(s) superior over A will be continued to the 2nd phase. During the 2nd phase, an additional 540 pts in each arm is estimated to obtain 317 pts with PEPI score 0. This will have a 90% chance, with a one-sided alpha=0.025 nonparametric Brookmeyer-Crowley type one sample survival test, rejecting that 5 year RFS rate is 95%. The maximum sample size is 2820 pts. Eligible pts include postmenopausal women with newly diagnosed clinical stage II or III ER+ (Allred score 6-8) HER2- BC. Tumor biopsy is required at baseline, 4 wk, and surgery for central Ki67 analysis. Treatment decision is individualized based on 4 wk Ki67 and modified PEPI score. Pts with Ki67 > 10% at 4 wk are switched to chemotherapy. Pts with a modified PEPI score of 0 are recommended not to receive chemotherapy, but continue the assigned ET for 1.5 years followed by 3 years of A. This trial is currently accruing pts through CTSU. This research is supported in part by NCI BIQSFP, and grants from Breast Cancer Research Foundation, Genentech, and the Investigator-Sponsored Study Program of AstraZeneca. The Clinical Trials.gov Identifier: NCT01953588. Citation Format: Cynthia X Ma, Vera Suman, A Marilyn Leitch, Souzan Sanati, Katherine DeSchryver, Gary W Unzeitig, Paul Haluska, Mark Watson, Olwen Hahn, Jo Anne Zujewski, Kelly Hunt, Eric P Winer, Cliff A Hudis, Matthew J Ellis. Alliance A011106: ALTernate approaches for clinical stage II or III Estrogen Receptor positive breast cancer NeoAdjuvant TrEatment (ALTERNATE) in postmenopausal women: A phase III study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT2-1-04.

Abstract Ovarian cancer is the most common and most lethal gynecologic malignancy. Despite clear histologic and molecular differences between disease subtypes, all patients receive cytotoxic chemotherapy and survival has not improved significantly for several decades. Identifying avenues for targeted therapy is critical to improving clinical outcomes. Given the vast heterogeneity of ovarian cancer, therapeutic strategies will vary based on subtype and specific biomarkers. Estrogen receptor-alpha (ER) is expressed in ∼70% of serous ovarian tumors and epidemiologic evidence indicates estrogen contributes to the disease etiology. Further, clinical data suggest that a subset of patients with serous carcinoma benefit from endocrine therapy. However, the full potential of endocrine therapy in ovarian cancer has been understudied. We hypothesize that a subset of serous ovarian tumors are dependent upon estrogen and that expression of ER target genes will identify patients who can be successfully treated with endocrine therapy. We characterized response to estradiol (E2) in four ER+ serous ovarian cancer cell lines, focusing on cell proliferation, survival, and gene expression. Proliferation was evaluated in 2-D and in a 3-D matrigel system. Survival was assayed in low-attachment conditions. We also evaluated response to anti-estrogens 4-hydroxytamoxifen (4OHT) and fulvestrant (ICI). Expression of canonical ER targets (e.g. GREB1, IGFBP3) was measured by qPCR. Gene expression microarrays after E2 treatment were used to identify genome-wide effects of ER. Studies of endocrine response in vivo are ongoing in patient-derived xenograft models. E2 promotes growth of PEO1 and PEO4 cells in 2-D and 3-D culture, with PEO4 cells exhibiting greater E2 dependence. Preliminary results indicate that E2 also promotes survival in low-attachment conditions. Growth and survival are both decreased by treatment with fulvestrant or 4-hydroxytamoxifen. Conversely, OVCA432 and OVSAHO cells do not respond to treatment with ER ligands. Microarrays identified E2-regulated genes in PEO1 and PEO4 cells that may be utilized as biomarkers of ER activity. Several of these ER targets are differentially expressed between E2-responsive and E2-independent cell lines including DEPTOR, GREB1, GFRA2, and EPHB3. We are currently overlapping our array results with publicly available datasets to develop a gene signature of E2 response, which we will use to profile ER signaling in clinical specimens and patient derived xenografts. Our results suggest that a subset of serous ovarian cancers are endocrine responsive. These studies will determine if expression of specific ER targets correlates with endocrine response and thus if they can be harnessed to predict clinical response to endocrine therapy. Citation Format: Courtney L. Andersen, Matthew J. Sikora, Soumya Luthra, Uma Chandran, Paul Haluska, Steffi Oesterreich. Utilizing ER target genes as biomarkers of endocrine response in serous ovarian carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2103. doi:10.1158/1538-7445.AM2014-2103