TSR-033, a Novel Therapeutic Antibody Targeting LAG-3, Enhances T-Cell Function and the Activity of PD-1 Blockade In Vitro and In Vivo

Progressive upregulation of checkpoints on tumor-infiltrating lymphocytes promotes an immunosuppressive tumor microenvironment, severely compromising tumor immunity. Lymphocyte activation gene-3 (LAG-3) is a coinhibitory receptor associated with impaired T-cell function and is frequently coexpressed with programmed cell death protein-1 (PD-1) in the context of human cancers. Targeting LAG-3 in conjunction with PD-1 thus represents a strategy to amplify and broaden the therapeutic impact of PD-1 blockade alone. We have generated a high affinity and selective humanized monoclonal IgG4 antibody, TSR-033, which binds human LAG-3 and serves as a functional antagonist, enhancing in vitro T-cell activation both in mixed lymphocyte reactions and staphylococcal enterotoxin B-driven stimulation assays. In a humanized mouse non-small cell lung carcinoma model, TSR-033 boosted the antitumor efficacy of PD-1 monotherapy, with a concomitant increase in immune activation. Analogous studies in a murine syngeneic tumor model using surrogate antibodies demonstrated significant synergy between LAG-3 and PD-1 blockade-combination treatment led to a marked improvement in therapeutic efficacy, increased T-cell proliferation, IFNγ production, and elicited durable immunologic memory upon tumor rechallenge. Taken together, the pharmacologic activity of TSR-033 demonstrates that it is a potent anti-LAG-3 therapeutic antibody and supports its clinical investigation in cancer patients.

Response-Derived Input Function Estimation for Dynamic Contrast-Enhanced MRI Demonstrated by Anti-DLL4 Treatment in a Murine U87 Xenograft Model

PURPOSE

Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) is an accepted method to evaluate tumor perfusion and permeability and anti-vascular cancer therapies. However, there is no consensus on the vascular input function estimation method, which is critical to kinetic modeling and K ^trans estimation. This work proposes a response-derived input function (RDIF) estimated from the response of the tumor, modeled as a linear, time-invariant (LTI) system.

PROCEDURES

In an LTI system, an unknown input can be estimated from the system response. If applied to DCE MRI, this method would eliminate need of distal image-derived inputs, model inputs, or reference regions. The RDIF method first determines each tumor pixel's best-fit input function, and then combines the individual fits into a single input function for the entire tumor. The method was tested with simulations and a xenograft study with anti-vascular drug treatment.

RESULTS

Simulations showed successful estimation of input function expected values and good performance in the presence of noise. In vivo, significant reductions in K ^trans and AUC occurred 2 days following anti-delta-like ligand 4 treatment. The in vivo study results yielded K ^trans consistent with published data in xenograft models.

CONCLUSION

The RDIF method for DCE analysis offers an alternative, easy-to-implement method for estimating the input function in tumors. The method assumes that during the DCE experiment, the changes observed by MRI result solely from vascular perfusion and permeability kinetics, and that information can be used to model the input function. Importantly, the method is demonstrated in a murine xenograft study to yield K ^trans results consistent with literature values and suitable for compound studies.

Abstract 3036: PEGylated hyaluronidase increases tumor uptake of 89Zr-DFO-HuMab-5B1 (MVT-2163) in a CA19-9 positive hyaluronan-accumulating pancreatic cancer model

Hyaluronan (HA) accumulates in the extracellular matrix of many solid tumors, and is associated with poor prognosis in pancreatic ductal adenocarcinoma. In non-clinical models, enzymatic degradation of HA with PEGylated recombinant human hyaluronidase PH20 (PEGPH20) has been shown to remodel the tumor stroma, reduce tumor interstitial fluid pressure, and expand tumor blood vessels, resulting in enhanced delivery of therapeutic and imaging agents, such as monoclonal antibodies. 89Zr-DFO-HuMab-5B1 (MVT-2163) is a targeted ImmuoPET imaging agent for CA19-9 positive malignancies currently in clinical evaluation. CA19-9 plays a role in tumor adhesion and metastasis, and is an independent prognostic indicator of cancer survival. CA19-9 is expressed in pancreatic and other cancers, including small cell lung and colon. In this study, we aimed to show the effects of PEGPH20 on the biodistribution of MVT-2163 in a CA19-9 positive HA-rich human pancreatic tumor xenograft model.

Nude mice were peritibially implanted on the right hind limb with 5x106 human pancreatic tumor cells engineered to overexpress hyaluronan synthase 3 (BxPC3/HAS3). Tumor volumes were measured by MR imaging, and mice were staged when average tumor size reached 320 mm3. The control group received intravenous (IV) vehicle, and the test group received PEGPH20 (IV, 1 mg/kg). Both control and test groups also received MVT-2163 (IV, 3 mg/kg) 24 hours later. PET images were captured from 2 to 120 hours post MVT-2163, and region of interest (ROI) of tumor and liver were analyzed (N=6/group). After the final PET image, tumors and livers were harvested for ex vivo gamma counting.

Ex vivo gamma counting demonstrated improved MVT-2163 accumulation in animals treated with PEGPH20, with a 50.9% increase in counts in the excised tumors. ROI analysis of the tumors showed increased tumor SUV of 8.0, 9.4, and 24.1% at 72, 96, and 120 hours post-injection, respectively, with PEGPH20 compared to vehicle. ROI analysis of liver regions showed an 11.4 to 26.4% reduction in SUV in the PEGPH20 group compared to control. Ex vivo counts of liver tissue confirmed the PET signal reduction with PEGPH20. Analysis of tumor-to-liver ratios showed average increases of 34.1, 35.7, and 58.5% at 72, 96, and 120 hours, respectively, post MVT-2163 injection in PEGPH20 treated mice.

In summary, as measured by SUV, PEGPH20 increased both the tumor uptake and the tumor-to-liver ratios of MVT-2163 in a CA19-9 positive xenograft mouse model of HA accumulating pancreatic cancer. Ex vivo analysis confirmed in vivo results. Taken together, the increased tumor uptake and the decreased liver uptake support further investigation into the potential clinical utility for the combination of PEGPH20 and MVT-2163.

Citation Format: Jonah Rainey, Paul Maffuid, Wolfgang W. Scholz, Jack Ostrowski, H Toni Jun, Paul Resnick, Xiaoming Li, Jesse D. Bahn, Susan Zimmerman, Kelly Chen, Barbara Blouw, Curtis B. Thompson, Daniel C. Maneval, David W. Kang. PEGylated hyaluronidase increases tumor uptake of 89Zr-DFO-HuMab-5B1 (MVT-2163) in a CA19-9 positive hyaluronan-accumulating pancreatic cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3036.

Abstract A062: Using CA19-9 as a translational biomarker for sLea targeted agents MVT-5873 and MVT-1075 in cancer

Background: Sialyl Lewis A (sLea) modification occurs on transmembrane and secreted proteins in pancreatic ductal adenocarcinoma (PDAC) and other GI cancers, leading to a high level of expression on cancer cells compared to normal tissue. sLea, also known as CA19-9, can be detected in patient serum using a CA19-9 diagnostic assay, which detects shed or secreted sLea modified proteins. MVT-5873, a fully human antibody that specifically targets the sLea antigen, is in a phase 1 clinical trial for the treatment of CA19-9 positive disease as a monotherapy (MVT-5873), as an imaging agent (MVT-2163), and as a radioimmunotherapy (MVT-1075). Methods: To understand the relevance of CA19-9 as a stratification marker, both annotated primary as well as patient-derived xenograft (PDX) tissue microarrays (TMAs) were stained with MVT-5873. To evaluate sLea as a response biomarker, serum samples from patients in the MVT-5873 phase 1 clinical trial were analyzed for CA19-9 levels using the diagnostic assay, and compared to their MVT-5873 PK profile. Available samples were also characterized by ELISA assay to determine the representation of sLea modification on MUC family proteins. Results: For the human CRC TMA, >75% of tumor cores displayed moderate to high levels of positive staining. In the PDX array, 21% of non-small cell lung cancer (NSCLC), 50% of small cell lung cancer (SCLC), and 69% of CRC cores stained positive. Overall, staining was observed with similar frequency regardless of mutational status of the tumor, suggesting that CA19-9 expression is independent of KRAS, BRAF, PIK3CA, or MMR pathway mutations. Staining was also relatively unchanged in lung PDX cancer tumor cores that were rendered chemoresistant compared to their chemosensitive precursor. The serum CA19-9 analysis of PDAC patients treated with MVT-5873 demonstrated that detectable CA19-9 is inversely proportional to MVT-5873 drug levels when CA19-9 levels are >100 U/ml. CA19-9 is not detected after MVT-5873 treatment when CA19-9 levels are <100 U/ml, suggesting that MVT-5873 can fully occupy all serum CA19-9 at those levels. Taken together, these data indicate that the CA19-9 diagnostic assay may be used as a measure for target engagement, and imaging data from the MVT-2163 phase 1 trial confirmed that the drug can efficiently accumulate at tumor sites in a time-dependent manner in patients. When pancreatic cancer patient serum was analyzed for protein scaffold composition, Muc1 and Muc16 were found to be present. Conclusions: These data support the use of sLea targeted therapeutics such as MVT-5873 and MVT-1075 in CRC and lung cancer, including for patients with KRAS or other genetic lesions. Additionally, for patients treated with MVT-5873, data suggest that the serum CA19-9 assay is a potential measure of target occupancy and is worthy of further investigation.

Citation Format: H. Toni Jun, Christian Lohrmann, Viola Allaj, Wolfgang Scholz, G. Jonah Rainey, Wolfgang A. Weber, Jason S. Lewis, John Poirier, Paul W. Maffuid. Using CA19-9 as a translational biomarker for sLea targeted agents MVT-5873 and MVT-1075 in cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A062.

Abstract LB-B25: Preliminary phase I data comparing HuMab-5B1 (MVT-5873), a monoclonal antibody targeting sLea, as a single agent and in combination with first line nab-paclitaxel and gemcitabine in patients with CA19-9 positive pancreatic cancer

IntroductionMVT-5873, a fully human IgG1 monoclonal antibody (mAb), targets sialyl Lewis A (sLea), an epitope on CA19-9. CA19-9 is expressed in pancreatic (PDAC) and other GI cancers, plays a role in tumor adhesion and metastasis, and is a marker of an aggressive tumor phenotype. MVT-5873 is active as a single agent and in combination with nab-paclitaxel (nab-P) and gemcitabine (gem) in murine xenografts. MethodsSingle agent: for each 28-day treatment cycle, MVT-5873 was given IV every second week (Group 1) or weekly (Group 2) at doses ranging from 1 to 3 mg/kg. Combination with nab-P and gem: for each 28-day treatment cycle MVT-5873 was administered IV weekly (1.0mg/kg or 0.125mg/kg) followed by IV infusion of 125 mg/m2 of nab-P and then 1000mg/m2 gem, on day 1, 8 and 15 (Group 3). Eligible patients had recurrent progressive (single agent) or newly diagnosed (combination), locally-advanced or metastatic PDAC or other CA19-9+ malignancy and ECOG PS ≤1. Dose escalation followed a standard 3+3 design with a 10 patient expansion at the maximally tolerated dose (MTD). Trial endpoints include safety, MTD, dose limiting toxicities (DLT), pharmacokinetics (PK) and efficacy. Exploratory endpoints include changes in serum CA19-9 levels.ResultsAs of 7-September-2017, data are available for single agent N=32 in Groups 1 (N=9) and 2 (N=23) at 1, 2, 2.5 and 3 mg/kg and combination Group 3 (N=6) at 1.0 and 0.125mg/kg. DLTs of transient grade 3 elevations in AST, ALT, and total bilirubin were encountered in the single agent groups at 2, 2.5 and 3mg/kg in both single agent groups and in the combination group at 1mg/kg. Single agent liver function laboratory abnormalities typically emerged and resolved within a week of dosing although they were more persistent in the combination treated patients. Other toxicities associated with all groups included low grade GI toxicity (abdominal pain/cramps/diarrhea/nausea) and infusion reactions. Infusion reactions were mitigated with pre-medications and an increase in the infusion time. Combination DLTs for MVT-5873 at 1mg/kg included AST, ALT, and bilirubin elevations as well as neutropenia and pneumonitis resulted in significant dose de-escalation. MVT-5873 dosed at 0.125 mg/kg in combination was generally well tolerated. Single agent activity included SD of >4 months in 5 of 32 of patients with an MTD established at 1 mg/kg. Combination activity at 0.125 mg/kg MVT-5873 with nab-P/gem included 2 PRs and 1 SD in 3 patients. Interestingly, sustained suppression below ULN of CA19-9 levels was observed in 3 of the 6 patients in the combination arm and >95% CA19-9 reduction at the 0.125mg/kg combination dose. Dose escalation in this arm is in progress, and updated safety, PK/PD, and efficacy data will be presented.ConclusionsSingle agent MVT-5873 appears safe and tolerable at biologically active doses. DLTs included reversible liver function abnormalities. Determination of the MTD in combination with first line nab-P/gem is underway and preliminary response data are encouraging. Overall, the safety profile, efficacy, and reductions in serum CA19-9 levels over time support further development of MVT-5873 in this indication both as a single agent and in combination.

Citation Format: Eileen Mary O'Reilly, Judy Sing-Zan Wang, Kenneth H. Yu, Maeve Aine Lowery, Anna M. Varghese, Johanna C. Bendell, Erkut Hasan Borazanci, Hayley Estrella, Kimberly Fowler, Mariella Hoskins, Stephanie Bussen, Teresa J. Melink, Christine M. Kearns, H Toni Jun, Paul W. Maffuid, John C. Gutheil, Todd Michael Bauer. Preliminary phase I data comparing HuMab-5B1 (MVT-5873), a monoclonal antibody targeting sLea, as a single agent and in combination with first line nab-paclitaxel and gemcitabine in patients with CA19-9 positive pancreatic cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-B25.

Single agent HuMab-5B1 (MVT-5873), a monoclonal antibody targeting sLea, in patients with pancreatic cancer and other CA19-9 positive malignancies

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Background: MVT-5873, a fully human IgG1 monoclonal antibody (mAb), targets sialyl Lewis A (sLea), an epitope on CA19-9. CA19-9 is expressed in pancreatic (PDAC) and other GI cancers, plays a role in tumor adhesion and metastasis, and is a marker of an aggressive tumor phenotype. MVT-5873 is active as a single agent and with chemotherapy in murine xenografts. Methods: MVT-5873 was given IV every other week (Group 1) or weekly (Group 2). Eligible patients had progressive, locally-advanced or metastatic PDAC or other CA19-9+ malignancy and ECOG PS ≤1. Dose escalation followed a 3+3 design with a 10 patient expansion at MTD. Endpoints include safety, MTD, pharmacokinetics (PK) and efficacy. Exploratory endpoints include changes in serum CA19-9 levels. Results: As of 2-Feb 2017, data are available from N = 25 in Groups 1 (N = 9) and 2 (N = 16) at doses ranging from 1 to 3 mg/kg. Dose limiting toxicities of transient grade 3 elevations in AST, ALT, and total bilirubin were encountered at 3 mg/kg in both groups. Liver function laboratory abnormalities typically emerged and resolved within a week of dosing without significant clinical sequelae. Of toxicities deemed possibly related, most were low grade and included GI toxicity (abdominal pain/cramps/diarrhea/nausea) and infusion reactions. Infusion reactions were mitigated by using pre-medications and decreasing the infusion rate. Initial PK data demonstrate initial (20 hours) and terminal (211 hours) half-lives, comparable to other mAbs. Stable disease of > 4 months was observed in 24% of patients. CA19-9 levels were measured pre- and post-dose with each treatment. Immediate reductions showed dose-dependent reductions of up to 97% from baseline at 3 mg/kg. Downward trends of CA19-9 with successive doses were seen, with 48% and 22% of patients exhibiting ≥50% and ≥90% reductions in CA19-9 levels, respectively. Conclusions: Single agent MVT-5873 appears safe and tolerable at biologically active doses. DLTs included reversible serologic liver toxicity. The safety profile, efficacy, and reductions in serum CA19-9 levels over time support further development of MVT-5873 in this indication both as a single agent and in combination. Clinical trial information: NCT02672917.

Abstract LB-266: Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations

Among the most promising approaches in the treatment of cancer is the activation of antitumor immunity by blockade of immune checkpoints. These inhibitory immune checkpoints are crucial for maintaining self-tolerance in the normal immune system but can be co-opted in cancer to allow tumor escape from immune surveillance. Therapeutic validation has been provided using antibodies that inhibit the CTLA-4 and PD-1 signaling pathways, which have shown significant clinical activity. Interestingly, blockade of other T-cell inhibitory signaling molecules TIM-3 and LAG-3 has also been shown to be effective in mouse models of cancer. Potential therapeutic molecules that inhibit the negative signaling of TIM-3 or LAG-3 were identified by screening the AnaptysBio Evolvable Library (ABEL) of fully human germline antibodies. The initial ABEL screens used the soluble extra cellular domains (ECD) of either TIM-3 or LAG-3, followed by screening on cell-surface expressed antigens. The resulting panels of human antibodies were matured to high affinity and potency using SHM-XEL™ which uses mammalian cell display of human IgG followed by in vitro somatic hypermutation (SHM). We have explored the activity of these antibodies both as single agents as well as simultaneous blockade of multiple pathways in in vitro cell-based assays. Inhibition of each pathway in isolation demonstrated immune stimulatory activity as evidenced by increased secretion of IL-2 in a mixed lymphocyte reaction or an activated T-cell assay. Combination of an anti LAG-3 or an anti TIM-3 antibody with an anti-PD-1 inhibitory antibody could increase IL-2 secretion over that seen with blockade of a single checkpoint alone. The magnitude of this effect was donor cell dependent. These data are suggestive that combination immunotherapy towards these targets is worthy of clinical evaluation and may lead to increased efficacy.

Citation Format: H. Toni Jun, Patricia A. McNeeley, Andrew Lassen, Brandon Hynes, Larry Altobell, Mark Chhoa, Jesus Olvera, Josh MacLaren, Minjee Do, Michael Brown, Jean da Silva Correia, David King. Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations. [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 LB-266. doi:10.1158/1538-7445.AM2014-LB-266

Abstract LB-154: Generation of antagonistic anti-DDR1 monoclonal antibodies as a potential novel cancer therapeutic

Discoidin domain receptor 1 (DDR1) is a nonintegrin tyrosine kinase receptor for collagen implicated in diverse cellular roles, including cell adhesion, proliferation, and extracellular matrix remodeling. Multiple tumor types have been shown to overexpress DDR1, including lung, esophageal, breast, ovarian, and pediatric brain cancers, suggesting a potential role for DDR1 in tumor progression. Inhibition of DDR1 signaling may therefore represent a novel therapeutic approach for treating these cancers. Potential therapeutic molecules that modulate human DDR1 activity were identified by screening the AnaptysBio Evolvable Library (ABEL) of fully human germline antibodies. The initial ABEL screen used the soluble DDR-1 extra cellular domain, followed by secondary screening on cell-surface DDR-1. The resulting panel of human antibodies was affinity matured using SHM-XELTM which uses mammalian cell display of human IgG followed by in vitro somatic hypermutation (SHM) as described for a number of other antibodies (Bowers et al., 2014, Methods 65, 44-56). The matured antibodies bound specifically to DDR1 with high affinity (KD<1nM as measured by Biacore), and were able to functionally inhibit collagen triggered DDR1 signaling in multiple cell-based assays. The antibody panel shows selectivity for DDR1 over closely related molecules such as DDR2 and has other properties suitable for preclinical development, including cross-reactivity with the cynomolgus monkey DDR-1 ortholog and good biophysical properties. These antibodies are being further explored for their therapeutic efficacy in tumor types where DDR1 signaling plays a role in disease progression.

Citation Format: H. Toni Jun, Brandon Hynes, John L. Macomber, Andrew Lassen, Larry Altobell, Josh MacLaren, David King, Robert A. Horlick. Generation of antagonistic anti-DDR1 monoclonal antibodies as a potential novel cancer therapeutic. [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 LB-154. doi:10.1158/1538-7445.AM2014-LB-154

Abstract 2991: Triple combination of bevacizumab, anti-DLL4 (delta like ligand 4) and trebananib gives enhanced therapeutic effects in three xenograft tumor models

Bevacizumab is a monoclonal antibody targeting VEGF that is clinically approved for the treatment of multiple indications in oncology, including colorectal, lung and renal cancer as well as glioblastoma. Clinical activity has also been demonstrated in breast and ovarian cancer as well, however, the time periods of benefit for all of these indications is in months (1-5). Multiple pathways are known to participate in the process of angiogenesis, and the limited effects of bevacizumab may represent the maximum activity of targeting just one of them. The purpose of the present study was to examine the effect of simultaneously targeting multiple angiogenic axes including angiopoietins 1 and 2, Dll4 and VEGF. Trebananib is a recombinant peptide-Fc fusion protein that selectively blocks the Tie2 interactions of both Ang1 and Ang2. Trebananib, as well as a recombinant antibody to Dll4 were produced at Amgen, Inc., Thousand Oaks, CA. Bevacizumab was purchased from a local pharmacy. These reagents were employed in the combination treatment of three different preclinical murine tumor models (U87, glioblastoma; MiaPaca and BxPC3, pancreatic carcinoma), one of which (BxPC3) was specifically selected for its relative resistance to VEGF/KDR inhibition. Harlan Athymic nu/nu female mice at 6-7 weeks of age were injected subcutaneously on the right flank with 5 x 106 tumor cells in the presence of Matrigel and treated when the tumors were approximately 300 mm3. The results, as supported by histomorphometric analysis (percent blood vessel area, viable tumor burden), demonstrate that under conditions of optimal biological dosing, the addition of trebananib to a two-way combination of bevacizumab and anti-Dll4 resulted in a statistically significant enhancement of therapeutic effect for the three-way combination, an observation made consistently over 3 different tumor models and 3 different dose levels of bevacizumab and anti-Dll4 (p = or < 0.0024; RMANOVA). Furthermore, the therapeutic effect in all three models approximated prolonged stasis, the ultimate theoretical goal of antiangiogenesis in the treatment of cancer.

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Citation Format: Bethany Mattson, Jodi Moriguchi, H. Toni Jun, Angela Coxon, Dave Cordover, Steve Kaufman, Jon Oliner, Charlie Starnes. Triple combination of bevacizumab, anti-DLL4 (delta like ligand 4) and trebananib gives enhanced therapeutic effects in three xenograft tumor models. [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 2991. doi:10.1158/1538-7445.AM2014-2991

AMG 102, a fully human anti-hepatocyte growth factor/scatter factor neutralizing antibody, enhances the efficacy of temozolomide or docetaxel in U-87 MG cells and xenografts

PURPOSE

Hepatocyte growth factor (HGF/SF) and its receptor c-Met have previously been shown to be up-regulated in multiple human cancers, including glioblastoma multiforme. To better understand if AMG 102, a fully human, anti-HGF/SF-neutralizing antibody, could be incorporated into current clinical practice, AMG 102 was tested preclinically in combination with temozolomide or docetaxel to determine if enhanced efficacy was observed compared with AMG 102 alone.

EXPERIMENTAL DESIGN

The effects of AMG 102 were tested for antiproliferative activity in combination with temozolomide or docetaxel on U-87 MG cells in vitro and for antitumor activity in a U-87 MG xenograft model in vivo. Apoptotic activity was also measured for AMG 102 and docetaxel combined in vitro.

RESULTS

Treatment with temozolomide combined with AMG 102 resulted in increased inhibition of cell growth in vitro compared with treatment with either single agent alone. In U-87 MG xenografts in vivo, AMG 102 combined with temozolomide or docetaxel significantly increased the inhibitory effect on tumor growth when compared with treatment with either agent alone (P < 0.0001 and P < 0.015, respectively). In vitro, docetaxel alone induced both caspase-3/7 activity as well as poly(ADP)ribose polymerase and caspase-7 cleavage in U-87 MG cells; these events were enhanced when used in combination with AMG 102. Importantly, there was no evidence of interference between AMG 102 and either temozolomide or docetaxel in vitro or in vivo.

CONCLUSION

These studies support testing of AMG 102 in combination with temozolomide or docetaxel. Such combinations may represent promising, novel clinical therapeutic strategies for cancers that are dependent on the HGF/SF/SF:c-Met pathway in the oncology setting.