Thea Kalebic

Phase II Study of Neoadjuvant Imatinib in Glioblastoma: Evaluation of Clinical and Molecular Effects of the Treatment

Purpose: Phase I-II studies indicate that imatinib is active in glioblastoma multiforme. To better understand the molecular and clinical effects of imatinib in glioblastoma multiforme, we conducted a neoadjuvant study of imatinib with pretreatment and posttreatment biopsies. Experimental Design: Patients underwent a computerized tomography-guided biopsy of their brain tumors. If diagnosed with glioblastoma multiforme, they were immediately treated with 7 days of imatinib 400 mg orally twice daily followed by either definitive surgery or re-biopsy. Pretreatment and posttreatment tissue specimens were tested by immunohistochemistry for Ki67 and microvessel destiny, and posttreatment specimens were analyzed for the presence of intact imatinib in tissue. Furthermore, pretreatment and posttreatment pairs were analyzed by Western blotting for activation of platelet-derived growth factor receptor, epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase/AKT, and mitogen-activated protein kinase signaling pathways. Pharmacokinetic studies were also done. Results: Twenty patients were enrolled. Median survival was 6.2 months. Intact imatinib was detected in the posttreatment tissue specimens using mass spectrometry. There was no evidence of a drug effect on proliferation, as evidenced by a change in Ki67 expression. Biochemical evidence of response, as shown by decreased activation of AKT and mitogen-activated protein kinase or increased p27 level, was detected in 4 of 11 patients with evaluable, matched pre- and post-imatinib biopsies. Two patients showed high-level EGFR activation and homozygous EGFR mutations, whereas one patient had high-level platelet-derived growth factor receptor-B activation. Conclusions: Intact imatinib was detected in glioblastoma multiforme tissue. However, the histologic and immunoblotting evaluations suggest that glioblastoma multiforme proliferation and survival mechanisms are not substantially reduced by imatinib therapy in most patients. (Clin Cancer Res 2009;15(19):6258–66)

Phase I Study of the Investigational Anti-Guanylyl Cyclase Antibody-Drug Conjugate TAK-264 (MLN0264) in Adult Patients with Advanced Gastrointestinal Malignancies.

Purpose: To assess the safety, tolerability, and preliminary antitumor activity of the investigational anti–guanylyl cyclase C (GCC) antibody–drug conjugate TAK-264 (formerly MLN0264) in adult patients with advanced gastrointestinal malignancies. Experimental Design: Adult patients with GCC-expressing gastrointestinal malignancies (H-score ≥ 10) were eligible for inclusion. TAK-264 was administered as a 30-minute intravenous infusion once every 3 weeks for up to 17 cycles. Dose escalation proceeded using a Bayesian continual reassessment method. At the maximum tolerated dose (MTD), 25 patients with metastatic colorectal cancer were enrolled in a prespecified dose expansion cohort. Results: Forty-one patients were enrolled, including 35 (85%) with metastatic colorectal cancer. During dose escalation (0.3–2.4 mg/kg), four of 19 patients experienced dose-limiting toxicities of grade 4 neutropenia; the MTD was determined as 1.8 mg/kg. Patients received a median of two cycles of TAK-264 (range, 1–12); nine received ≥four cycles. Common drug-related adverse events (AEs) included nausea and decreased appetite (each 41%), fatigue (32%), diarrhea, anemia, alopecia, and neutropenia (each 27%); grade ≥3 AEs included neutropenia (22%), hypokalemia, and febrile neutropenia (each 7%). Peripheral neuropathy was reported in four (10%) patients. Pharmacokinetic data showed approximately dose proportional systemic exposure and a mean plasma half-life of around 4 days, supporting the dosing schedule. Overall, 39 patients were response-evaluable; three experienced durable stable disease; and one with gastric adenocarcinoma had a partial response. GCC expression did not appear to correlate with treatment duration. Conclusions: These findings suggest that TAK-264 has a manageable safety profile, with preliminary evidence of potential antitumor activity in specific gastrointestinal malignancies. Further investigation is underway. Clin Cancer Res; 22(20); 5049–57. ©2016 AACR.

Antibody-drug conjugate directed against the guanylyl cyclase antigen for the treatment of gastrointestinal malignancies.

ABSTRACT Antibody‐directed cancer chemotherapy in the form of antibody–drug conjugates (ADCs) may improve the therapeutic index with the potential to enhance efficacy and decrease systemic toxicity. ADCs consist of three key components including an antibody that specifically binds to the target, a toxic agent and a linker which releases the toxic agent inside tumor cells. A novel ADC, MLN0264 (TAK‐264) was recently investigated in patients with gastrointestinal (GI) malignancies. TAK‐264 is an anti‐ guanylyl cyclase C (GCC) antibody conjugated via a protease‐cleavable linker to the potent anti‐microtubule agent monomethyl auristatin E (MMAE) (linker and toxin licensed from Seattle Genetics). Following binding to GCC, the ADC is internalized and transported to lysosomes where MMAE is released to bind to tubulin, leading to cell cycle arrest and apoptosis. This GCC targeting ADC has been evaluated in clinical studies in patients with advanced gastrointestinal malignancies. The early findings from Phase 1 study have shown preliminary activity signals in gastric, gastroesophageal, and pancreatic cancer. Results from two phase II studies in pancreatic and gastoesophageal adenocarcinoma showed only limited activity. Antibody–drug‐conjugates offer a promising therapeutic modality aimed at providing target‐directed cancer chemotherapy. Herein we discuss the GCC target and gastrointestinal malignancies where GCC based targeted therapies could further evolve and offer a significant clinical benefit.

Consistent expression of guanylyl cyclase-C in primary and metastatic gastrointestinal cancers

Background The transmembrane receptor guanylate cyclase-C (GCC) has been found to be expressed in colorectal cancers. However, limited data are available on GCC protein expression in non-colorectal gastrointestinal tumors and few studies have reported whether GCC protein expression was consistently preserved in synchronous primary and metastatic cancer tissues. Methods GCC protein status was assessed by immunohistochemistry in tumor specimens from individuals (n = 627) with gastrointestinal tumors, including esophageal (n = 130), gastric (n = 276), pancreatic (n = 136), and colorectal (n = 85) primary and metastatic tumors. Tissue specimens consisted of tissue microarrays containing esophageal, gastric, pancreatic tumors, and whole-slide tissue sections from colorectal cancer patients with matching primary and metastatic tumors Result Among the evaluated esophageal, gastric, and pancreatic tumors, the frequency of GCC positivity at the protein level ranged from 59% to 68%. GCC was consistently expressed in primary and matched/synchronous metastatic lesions of colorectal cancer tissues derived from the same patients. Conclusion This observational study demonstrated the protein expression of GCC across various gastrointestinal malignancies. In all cancer histotypes, GCC protein localization was observed predominantly in the cytoplasm compared to the membrane region of tumor cells. Consistent immunohistochemistry detection of GCC protein expression in primary colorectal cancers and in their matched liver metastases suggests that the expression of GCC is maintained throughout the process of tumor progression and formation of metastatic disease.

TAK-264 (MLN0264) in Previously Treated Asian Patients with Advanced Gastrointestinal Carcinoma Expressing Guanylyl Cyclase C: Results from an Open-label, Non-randomized Phase 1 Study.

Purpose This phase 1 dose-escalation portion of the study evaluated the safety, pharmacokinetics (PK), and antitumor activity of TAK-264 in Asian patients with advanced gastrointestinal (GI) carcinoma or metastatic or recurrent gastric or gastroesophageal junction adenocarcinoma expressing guanylyl cyclase C (GCC). Materials and Methods Adult patients with advanced GI malignancies expressing GCC (H-score ≥ 10) received TAK-264 on day 1 of 3-week cycles as 30-minute intravenous infusions for up to 1 year or until disease progression or unacceptable toxicity. The primary objectives were to evaluate the safety profile including dose-limiting toxicities (DLTs) during cycle 1, determine the maximum tolerated dose (MTD), and characterize the PK profile of TAK-264. Results Twelve patients were enrolled and treated with 1.2 mg/kg (n=3), 1.5 mg/kg (n=3), or 1.8 mg/kg TAK-264 (n=6). Median number of treatment cycles received was two (range, 1 to 10). None of the patients experienced a DLT and the MTD was not determined. Ten patients (83%) experienced adverse events (AEs). The most common were neutropenia, anorexia, and nausea (each reported by four patients). Five patients (42%) experienced grade ≥ 3 AEs consisting of tumor hemorrhage and hypertension, ascites, adrenal insufficiency, neutropenia and asthenia. Serum exposure to TAK-264 increased proportionally with the dose and the median half-life was approximately 5.5-6.6 days. No patients experienced an objective response. Conclusion TAK-264 demonstrated a manageable safety profile with limited antitumor activity consistent with studies conducted in Western patients with advanced GI malignancies. TAK-264 exposure increased proportionally with the dose.

Abstract CT117: A phase II trial of TAK-264, a novel antibody-drug conjugate (ADC), in patients with pancreatic adenocarcinoma expressing guanylyl cyclase C (GCC)

TAK-264 (formerly MLN0264) is a novel ADC consisting of a human monoclonal antibody that specifically targets GCC, the potent microtubule disrupting agent monomethyl auristatin E (MMAE), and a linker. GCC is selectively expressed in the gastrointestinal (GI) tract, and its expression is maintained through the spectrum of adenoma and carcinoma in the colorectum as well as the pancreas. A Phase 1 clinical trial has demonstrated a manageable safety profile and clinical activity of TAK-264 in patients with pancreatic and gastric carcinomas (NCT01577758). The primary objective of this Phase 2, open-label, non-randomized, multicenter study was to evaluate the overall response rate (ORR; complete response + partial response [PR]), safety, and tolerability of TAK-264 in previously treated adult patients with advanced or metastatic pancreatic adenocarcinoma expressing GCC. Here we report the findings from the interim analysis (IA). Per protocol, the IA was required to show objective responses in at least 2/12 patients with a defined GCC level to continue the second part of this study. Patients aged ?18 years with advanced or metastatic pancreatic adenocarcinoma expressing GCC (confirmed histologically by immunohistochemistry with an H score of ?10) who had received ?1 prior treatment, were eligible for inclusion. TAK-264 1.8 mg/kg was administered as a single 30 minute intravenous infusion on day 1 of a 21-day cycle for up to 1 year or until disease progression or unacceptable toxicity. At data cut-off (October 5, 2015), 43 patients had been enrolled. The median age was 61 years (range, 44-81). Participating patients had metastatic disease and received a median of 3 prior therapies (range, 1-8), with a median time since initial diagnosis of 16.6 months (range, 6-51). Of the 38 patients in the response-evaluable population, the ORR was 3% (PR, n = 1) and 9 patients (24%) had stable disease. A total of 28 (74%) patients experienced progressive disease. All patients received at least 1 dose of TAK-264 and were included in the safety population. The most common adverse events (AE) reported in ?15% of patients were abdominal pain (47%), nausea (37%), fatigue (35%), constipation and decreased appetite (each 28%), vomiting and neutropenia (each 26%), asthenia (21%), and dehydration (16%). Grade ?3 neutropenia, including febrile neutropenia, was reported in 7 (16%) and 2 (5%) patients, respectively. Grade ?3 GI AE included abdominal pain (9%), dyspepsia and vomiting (each 5%), and diarrhea (2%). Overall, a limited number of patients with GCC-positive pancreatic adenocarcinoma showed a modest clinical benefit from treatment with an ADC exploiting MMAE. The correlation between GCC levels and clinical outcomes is being explored. Based on the IA, these data do not support continuation of this study. Citation Format: Khaldoun Almhanna, David Wright, Teresa Macarulla Mercade, Jean-Luc Van Laethem, Antonio Cubillo Gracian, Carmen Guillen-Ponce, Jason Faris, Carolina Muriel Lopez, Richard Hubner, Johanna Bendell, Alain Bols, Jaime Feliu Batlle, Naureen Starling, Peter Enzinger, Devalingham Mahalingham, Wells Messersmith, Huyuan Yang, Adedigbo Fasanmade, Hadi Danaee, Thea Kalebic. A phase II trial of TAK-264, a novel antibody-drug conjugate (ADC), in patients with pancreatic adenocarcinoma expressing guanylyl cyclase C (GCC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT117.

Abstract CT107: Phase II trial of TAK-264 in previously treated patients (pts) with metastatic or recurrent adenocarcinoma of the stomach or gastroesophageal junction expression guanylyl cyclase C (GCC)

Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA Gastric cancer is the third-leading cause of cancer-related deaths worldwide. Outcomes of current treatment regimens remain unsatisfactory, particularly in pts with advanced gastric cancer. TAK-264 is a novel drug conjugate consisting of a human monoclonal antibody that specifically targets GCC, which is expressed in approximately 70% of gastric cancers, linked to the potent microtubule disrupting agent monomethyl auristatin E. In the first-in-human Phase 1 study ([NCT01577758][1]) evaluating the safety of TAK-264, preliminary signals of clinical activity were reported in pts with gastric, gastroesophageal, and pancreatic carcinoma. The primary objective of this Phase 2 open-label, non-randomized, multicenter study ([NCT02202759][2]) was to evaluate the overall response rate (ORR; complete response + partial response) of adult pts with metastatic or recurrent adenocarcinoma of the stomach or gastroesophageal junction. Here we report the findings from the Interim Analysis (IA). Pts aged ?18 years with histologically-confirmed metastatic or advanced adenocarcinoma of the stomach or gastroesophageal junction, who were GCC-positive as demonstrated by immunohistochemistry with an H score ?10 and who had received ?1 prior therapy were eligible for inclusion. TAK-264 1.8 mg/kg was administered as a single 30-minute intravenous infusion on day 1 of a 21-day cycle until disease progression or unacceptable toxicity occurred. Pts were evaluated for a response every 2 cycles. At data cut-off (October 1, 2015), 37 pts had been enrolled (81% male), of which 36 (97%) pts were response-evaluable. The median age at baseline was 63 years (range, 31-81) and the median time from the initial diagnosis was 19.7 months (range, 5-76). Pts had received a median of 3 prior therapies (range, 1-7). Of the 36 pts in the response-evaluable population, the ORR was 6% (2 pts) and stable disease was observed in 15 (42%) pts. Progressive disease was experienced by 19 (53%) pts. All pts received at least one dose of TAK-264 and were included in the safety population. Common adverse events (AEs) observed in ?15% of pts included nausea (49%), fatigue (30%), decreased appetite and asthenia (each 27%), constipation and vomiting (each 22%), peripheral edema (19%), and diarrhea and anemia (each 16%). Diarrhea and neutropenia were the most prevalent Grade ?3 AEs, (each 5%). Other Grade ?3 gastrointestinal AEs included dysphagia, nausea and decreased appetite (each 1%). Results from the current IA suggest that few pts with GCC-positive metastatic or advanced adenocarcinoma of the stomach or gastroesophageal junction experienced limited clinical benefit with TAK-264 treatment. The correlation between GCC levels and clinical outcomes is being explored. Based on the IA, these data do not support continuation of the study. Citation Format: Khaldoun Almhanna, Maria Luisa Limon Miron, David Wright, Antonio Cubillo Gracian, Richard Hubner, Jean-Luc Van Laethem, Carolina Muriel Lopez, Maria Alsina, Federico Longo Munoz, Johanna Bendell, Wells Messersmith, Huyuan Yang, Adedigbo Fasanmade, Hadi Danaee, Thea Kalebic. Phase II trial of TAK-264 in previously treated patients (pts) with metastatic or recurrent adenocarcinoma of the stomach or gastroesophageal junction expression guanylyl cyclase C (GCC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT107. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01577758&atom=%2Fcanres%2F76%2F14_Supplement%2FCT107.atom [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT02202759&atom=%2Fcanres%2F76%2F14_Supplement%2FCT107.atom

Abstract 4948: PET/CT clinical protocol design for the novel, first in class 68Ga labeled guanylyl cyclase C targeted peptide MLN6907 ([68Ga]MLN6907)

Acquisition and interpretation guidelines for clinical PET/CT imaging in oncology have been designed for whole-body 18F-FDG imaging and may not be optimized for assessment of other PET imaging tracers. Here we describe a methodology of PET/CT study design for the novel first in class 68Ga-labeled Guanylyl cyclase C (GCC) targeted peptide, [68Ga]MLN6907, based on a combination of in vitro, ex vivo, and in vivo preclinical imaging studies and model-based estimation of tumor parameters from simulated clinical PET data. GCC, a protein expressed in GI malignancies, is being targeted by the antibody drug conjugate MLN0264. GCC is also expressed on the healthy apical surface of the intestinal epithelium, which should be inaccessible to intravascular treatment. [68Ga]MLN6907 binds GCC with high affinity and is being developed as an imaging biomarker in an effort to help identify patients likely to respond to GCC-targeted therapy. In a series of experiments, the peptide affinity, internalization rate, and clearance were determined in patient-derived CRC xenografts with varied tumor microenvironmental phenotype. In addition to supporting the clinical development of the imaging agent, this data was used in combination with simulated clinical list-mode PET data to evaluate tumor parameter estimability under several clinically viable acquisition and reconstruction conditions. Specifically, liver CRC metastases of varying tumor diameter, antigen density, and vascularity were simulated in combination with PET imaging acquisition duration and reconstruction with and without partial-volume correction. Tumor, liver, and background time-activity curves (TACs) were generated from the reconstructed data and analyzed using a distributed tumor model to estimate the known tumor antigen density and vascularity. Analysis of the simulation studies revealed: 1) Partial volume correction is required for accurate antigen density and vascularity estimation; 2) Parameter estimation was most accurate within a tumor size range of 1-5 cm; 3) Parameter estimation was robust for all tested TAC reconstruction durations (e.g., 2, 3, 5, and 10 min); 4) Parameter estimation was optimal for common clinical acquisition times of 30-90 minutes; 5) Antigen density estimation was less accurate in poorly vascularized tumors. For the translation of a novel clinical biomarker, well controlled preclinical studies are critical; and, in this case, the findings combined with the distributed tumor model simulations directly guided the clinical image protocol. This rational and data-driven approach has the ability to not only improve the estimation of tumor properties in human subjects but also to guide the design of first-in-human oncology clinical imaging protocols with novel biomarkers. Citation Format: Jacob Y. Hesterman, Kelly D. Orcutt, Ozlem Yardibi, Jerome T. Mettetal, Shu-Wen Teng, Donna Cvet, Jack Hoppin, Thea Kalebic, Daniel P. Bradley. PET/CT clinical protocol design for the novel, first in class 68Ga labeled guanylyl cyclase C targeted peptide MLN6907 ([68Ga]MLN6907). [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 4948. doi:10.1158/1538-7445.AM2014-4948