Neal Goodwin

ABT-414, an Antibody Drug Conjugate Targeting a Tumor-Selective EGFR Epitope

Targeting tumor-overexpressed EGFR with an antibody–drug conjugate (ADC) is an attractive therapeutic strategy; however, normal tissue expression represents a significant toxicity risk. The anti-EGFR antibody ABT-806 targets a unique tumor-specific epitope and exhibits minimal reactivity to EGFR in normal tissue, suggesting its suitability for the development of an ADC. We describe the binding properties and preclinical activity of ABT-414, an ABT-806 monomethyl auristatin F conjugate. In vitro, ABT-414 selectively kills tumor cells overexpressing wild-type or mutant forms of EGFR. ABT-414 inhibits the growth of xenograft tumors with high EGFR expression and causes complete regressions and cures in the most sensitive models. Tumor growth inhibition is also observed in tumor models with EGFR mutations, including activating mutations and those with the exon 2–7 deletion [EGFR variant III (EGFRvIII)], commonly found in glioblastoma multiforme. ABT-414 exhibits potent cytotoxicity against glioblastoma multiforme patient-derived xenograft models expressing either wild-type EGFR or EGFRvIII, with sustained regressions and cures observed at clinically relevant doses. ABT-414 also combines with standard-of-care treatment of radiation and temozolomide, providing significant therapeutic benefit in a glioblastoma multiforme xenograft model. On the basis of these results, ABT-414 has advanced to phase I/II clinical trials, and objective responses have been observed in patients with both amplified wild-type and EGFRvIII-expressing tumors. Mol Cancer Ther; 15(4); 661–9. ©2016 AACR.

Tumor-targeting multifunctional micelles for imaging and chemotherapy of advanced bladder cancer

AIM This work aimed to determine if the treatment outcomes of bladder cancer could be improved by targeting micelles that are decorated with bladder cancer-specific ligands on the surface and loaded with the chemotherapeutic drug paclitaxel. MATERIALS & METHODS Targeting efficacy and specificity was determined with cell lines. An in vivo targeting and anti-tumor efficacy study was conducted in mice carrying patient-derived xenografts. RESULTS & DISCUSSION Targeting micelles were more efficient than nontargeting micelles in delivering the drug load into bladder cancer cells both in vitro and in vivo (p < 0.05). The micelle formulation of paclitaxel was less toxic than free paclitaxel in Cremophor(®) (Sigma, MO, USA) and allowed administration of three-times the maximum tolerated dose without increasing the toxicity. Targeting micelles were more effective than the nontargeting micelles in controlling cancer growth (p = 0.0002) and prolonging overall survival (p = 0.002). CONCLUSION Targeting micelles loaded with paclitaxel offer strong potential for clinical applications in treating bladder cancer.

Algorithm for codevelopment of new drug-predictive biomarker combinations: accounting for inter- and intrapatient tumor heterogeneity.

Background Personalized cancer therapy, based on molecular profiling of each patient’scancer,isincreasinglyviewedaslikelytoincreasetheoverall effectiveness of cancer treatment and to do so in both a clinically meaningful and cost-effective manner by sparing patients who are unlikely to benefit from the costs and adverse effects of ineffective therapies. 1-3 Thus, in the emerging era of new anticancer agents directed against molecular targets present in only a small subset of patients within a general population, such as non‐small-cell lung cancer (NSCLC), it is increasingly important to consider simultaneous and early codevelopment of an associated predictive biomarker. Toemphasizethispoint,oneneedonlyrecallthepoortrackrecordof phase III randomized controlled clinical trials (RCT) of chemotherapy with or without a so-called targeted agent in advanced NSCLC (Table 1), only 2 trials met the criterion gold standard of success, improved survival, regardless of the drug class or molecular target. Importantly,noneofthesetrialsincorporatedprospectiveevaluation of a potential predictive biomarker for the new agent being studied, with the sole exception of basic epidermal growth factor receptor (EGFR) protein expression in FLEX. 4 In retrospect, it now seems

A patient-derived xenograft model of parameningeal embryonal rhabdomyosarcoma for preclinical studies

Embryonal rhabdomyosarcoma (eRMS) is one of the most common soft tissue sarcomas in children and adolescents. Parameningeal eRMS is a variant that is often more difficult to treat than eRMS occurring at other sites. A 14-year-old female with persistent headaches and rapid weight loss was diagnosed with parameningeal eRMS. She progressed and died despite chemotherapy with vincristine, actinomycin-D, and cyclophosphamide plus 50.4 Gy radiation therapy to the primary tumor site. Tumor specimens were acquired by rapid autopsy and tumor tissue was transplanted into immunodeficient mice to create a patient-derived xenograft (PDX) animal model. As autopsy specimens had an ALK R1181C mutation, PDX tumor bearing animals were treated with the pan-kinase inhibitor lestaurtinib but demonstrated no decrease in tumor growth, suggesting that single agent kinase inhibitor therapy may be insufficient in similar cases. This unique parameningeal eRMS PDX model is publicly available for preclinical study.

Abstract IA20: Linking tumor genomics to patient outcomes through a large-scale patient-derived xenograft (PDX) platform.

Background: Preclinical models have generally proven suboptimal for directing clinical application of new anti-cancer therapies. Here we detail an integrated research platform engaging core resources at JAX-WEST and the clinical research and genomics facilities at UCDCCC. Pilot studies using this platform are focusing on non-small cell lung cancer (NSCLC) due to molecular targets of interest, such as epidermal growth factor receptor (EGFR), heterogeneity in NSCLC tumor biology and the complexity of related cancer signaling pathways. Methods: Clinically and demographically annotated cancer patients (pt) seen at UCDCCC and collaborating facilities undergo tumor biopsy of various types which are implanted into JAX Nod Scid Gamma (NSG) mice to develop PDXs. Pt tumors and subsequent PDXs are assessed by histomorphology, clinically applicable molecular biomarkers, gene expression arrays and genome-wide technologies (NGS). NSCLC PDXs are grouped as panels (EGFR mutant (MT), KRAS MT ALK+). PDX panels of interest undergo multi-regimen drug testing for differential efficacy, together with pre- and post-therapy NGS and timed tumor pharmacodynamics (PD) assessment, to determine mechanisms of primary and acquired resistance in individual PDX models and how to overcome them. Results: As of November 2013 over 1,200 cancer pt tumors have been xenotransplanted into NSG mice (~175 from NSCLC), including successful PDX formation from small FNA and, cell pellets and transportability of specimens by overnight shipping for implantation. NSCLC PDXs show excellent histomorphologic, gene expression and mutational fidelity to host pt tumors, including mutation status for KRAS, EGFR and gene expression levels. Pilot studies in a panel of EGFR MT PDXs with TKI-acquired resistance demonstrate differential drug activity which mimics that of the host pt to the same therapy, and tumor PD at baseline and timed intervals post-therapy provide the basis for subgrouping resistance mechanisms Conclusion: This UCDCCC-JAX collaboration has established a large resource applicable to multi-drug testing and tumor PD in a wide range of clinically and genomically characterized tumors, including PDX panels for representative oncogene-driven NSCLCs. An EGFR-directed pilot project supports the feasibility of systematically integrating data derived from these models in order to optimize drug development and treatment strategies to address drug resistance mechanisms. This approach to PDX development and testing will be prospectively integrated into a developing multi-institution clinical trial of the Southwest Oncology Group (S1403), designed to advance understanding of differences in inter- and intra-patient tumor biology and hasten the transition to personalized cancer therapy. Citation Format: David R. Gandara, T. Li, P.N. Lara, K. Kelly, D.T. Cooke, R. Gandour-Edwards, K. Yoneda, N. Goodwin, S. Kuslak-Meyer, P. Mack. Linking tumor genomics to patient outcomes through a large-scale patient-derived xenograft (PDX) platform. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr IA20.

Abstract A80: Cancer-specific targeting nanomicelles for diagnosis and treatment of bladder cancer.

Background: We previously developed a bladder cancer-specific targeting ligand named PLZ4 (amino acid sequence: cQDGRMGFc) that can specifically bind to both human and dog bladder cancer cells in vitro and in vivo. We have also developed a nanoscale micellular drug delivery platform. To minimize premature drug release during circulation, disulfide crosslinks are introduced to the micelles, which are cleaved under the intracellular reducing environment, where the drugs are released. Here, we assess the antitumor activity and toxicity of the PLZ4-coated and paclitaxel (PTX)-loaded micelles, with or without disulfide crosslinks. Materials and Methods: Micelle-building monomers (ie, telodendrimers) are synthesized through conjugation of polyethylene glycol with cysteine (for disulfide crosslink) and a cholic acid cluster at one end and PLZ4 at the other. Such monomers self-assemble under aqueous condition to form micelles. Human bladder cancer cell line 5637 and patient-derived xenografts (PDX) are used for in vitro and in vivo drug delivery studies. Results: PLZ4-coated micelles are about 20 nm in diameter. The PTX loading capacity is approximately 5 mg/ml in 20 mg of telodendrimers. PLZ4 confers cancer-specific drug delivery both in vitro and in vivo. Formulation of PTX in micelles significantly decreases the toxicity and allows intravenous administration of three times the maximum tolerated dose without increasing the toxicity, and improves the overall survival of mice carrying patient-derived bladder cancer xenografts to 64 days (without PLZ4 on micelle surface) and 76 days (PLZ4 targeting micelles) when compared to free parental PTX at 27 days (p<0.0001). In contrast to free paclitaxel in Cremophor (Taxol®), the micelle formulation of PTX does not induce mast cell degranulation. To determine the minimal requirement of PLZ4 for targeted drug delivery, we compared and found that micelles with 2% and 50% of PLZ4 on surface exhibited similar antitumor activity in mice carrying patient-derived xenografts. Conclusion: Micellular formation of PTX coated with PLZ4 shows promising antitumor activity with decreased toxicity in the treatment of bladder cancer. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A80. Citation Format: Amy Wang Pan, Tzu-yin Lin, Hongyong Zhang, Neal Goodwin, Chong-xian Pan, Yuanpei Li, Kit Lam. Cancer-specific targeting nanomicelles for diagnosis and treatment of bladder cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A80.

Abstract 336: Genomic annotation of non-small cell lung cancer patient-derived xenograft models for personalized cancer therapy.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: Recent studies have characterized non-small cell lung cancer (NSCLC) as one of the most genomically deranged of all cancers, necessitating that both new drug development and patient therapy account for intra- and inter-patient tumor heterogeneity. Clinically annotated NSCLC patient-derived xenograft (PDX) models represent a novel approach to integrate this genomic complexity into a clinically relevant pre-clinical platform. We here describe molecular characterization to profile all currently “druggable” oncogenes for NSCLC in paired PDXs and original patient NSCLC tumor (PT). Method: Genomic DNA from archival formalin-fixed, paraffin-embedded (FFPE) PT and fresh first human-to-mouse (P0) NSCLC PDX tumors were isolated and subjected to oncogene mutational profiling using Sequenoms OncoCarta Panel v1. This panel detects 238 mutations in 19 genes commonly altered in cancer. RT-PCR-based molecular analyses of EGFR and KRAS mutations, EML4-ALK fusion transcripts, and RNA expression levels of ERCC1, RRM1 and TS genes were performed by Response Genetics, Inc. Genomic DNA from 3 serially passaged NSCLC PDX tumors (2 KRAS and 1 EGFR mutation models) up to 5 passages were also analyzed. Results: In the first 7 of 9 patient-PDX NSCLC models tested, oncogene mutational fidelity was preserved between PDX and PT with a good correlation of molecular biomarker expression (p<0.01). Two paired models had discrepancies in genotyping: from harboring 2 or 3 oncomutations at a frequency of 5-17% in PT to no mutation detected in P0 tumors), likely due to intra-patient tumor heterogeneity from clonal evolution. Of 3 models that have serial passaged tumors, the frequencies of oncomutation in each model were similar among the same passage (P0) or serial passage (P0 to P5) tumors. In several models tested for in vivo drug efficacy based on the molecular biomarker expression, results matched treatment outcome of the original patients., Conclusion: Our results validate the overall genomic fidelity of PDX tumors compared to original PT. Molecular characterization of individual tumor results in a clinically and genomically annotated PDX model with potential utility for selecting and validating clinically relevant drug target(s) for personalized cancer therapy. Acknowledgement: Supported by UC Davis Comprehensive Cancer Center Developmental Award (NIH/NCI P30CA093373), UL1 RR024146 from the National Center for Research Resources, the Jackson Laboratory, Response Genetics Inc., and the Addario Foundation. Citation Format: Sonal J. Desai, Neal Goodwin, Regina Gandour-Edwards, Royce F. Calhoun, David T. Cooke, Laurel A. Beckett, Martin K.H. Maus, Stephanie H. Astrow, Philip C. Mack, Ralph deVere White, David R. Gandara, Tianhong Li. Genomic annotation of non-small cell lung cancer patient-derived xenograft models for personalized cancer therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 336. doi:10.1158/1538-7445.AM2013-336

Integrated research platform (iGXT) for enhancing drug development and personalizing cancer therapy: Pilot study results.

3053 Background: New approaches to drug development in both the laboratory and clinic will be required to achieve the goal of personalized and molecular-based cancer therapy. Here we describe an integrated research platform (iGXT) engaging unique resources at The Jackson Laboratory (JAX-WEST), the NCI Center for Advanced Preclinical Research (CAPR) and the UC Davis Cancer Center. Non-small cell lung cancer (NSCLC) was selected for pilot studies employing this strategy due to molecular targets of interest, such as epidermal growth factor receptor (EGFR), heterogeneity in NSCLC tumor biology and the complexity of cancer signaling pathways. METHODS In pilot studies, EGFR-directed drugs of interest (example AKT inhibitor MK2206) are studied at NCI CAPR in genetically engineered mice (GEMs) bearing tumors with defined EGFR-related characteristics while NSCLC patients (pts) and JAX Nod Scid Gamma (NSG) mice with patient-derived xenografts (PDXs) from those pts are concurrently treated in a co-clinical trial paradigm, taking advantage of superior properties of the NSG mouse for propagating PDXs. Results in NSG models and pt trials are assessed by genome-wide technologies, integrated with data from CAPR, and extrapolated back to individual pts. RESULTS Tumor specimens from over 180 cancer pts have been xenotransplanted into NSG mice (~50 from NSCLC). Pilot studies at CAPR in GEMs with EGFR mutant (Tet-op-EGFR L858R +/- T790M) tumors demonstrate efficacy of MK2206 +/- erlotinib, and with the pan-EGFR inhibitor BIBW2992. Complementary in vitro studies at UCD confirm the ability of MK2206 to overcome c-MET-related resistance to erlotinib. An erlotinib-MK2206 clinical trial is ongoing. Demographics of host pts, histopatholgic features and molecular profiles will be presented. CONCLUSIONS This pilot project supports the feasibility of systematically integrating data derived from iGXT models in order to optimize drug development and treatment strategies. Findings from this platform are likely to advance understanding of differences in intra-patient tumor biology and hasten the transition to personalized cancer therapy.

Abstract 1585: Novel human renal medullary carcinoma mouse model to evaluate chemotherapy efficacy and tumor biology

Renal medullary carcinoma (RMC) is a rare disease with only ∼100 cases having been reported to date with the majority of these patients also having the sickle cell disease or trait. Multiple therapies, including chemotherapy, radiation, and resection, have been tried; however, this disease is almost uniformly fatal. We developed new mouse models of RMC that were created using patient derived tumor xenografts in the NOD SCID IL2 receptor γ chain null (NSG) mouse. RMC was diagnosed in a 9 year old male with sickle cell trait and multiple metastases in liver and lungs. The patient was treated by resection of the renal tumor, followed by chemotherapy, including bortezomib, paclitaxel/carboplatin/ bevacizumab, doxil/bevacizumab, and sunitinib. The patient showed partial or no response to each regimen and developed malignant pleural effusion and died 9 months p=0.0043 from diagnosis. NSG xenograft models were formed from both the patient primary renal tumor specimen and malignant pleural effusion. Comparative microarray gene expression data collection, genomic SNP data collection for copy number variance (CNV), and histology analyses were performed with the original patient renal tumor specimen and the two xenograft models for determining predictive chemotherapy responses for therapeutic efficacy. Additionally, the xenograft tumors were used for chemotherapy efficacy studies for using these models for future predictive efficacy studies. Both primary renal tumor and the metastatic pleural effusion developed large mouse xenograft tumors (P0) that were passaged into secondary mouse passages (P1). H & E histology showed that both the patient renal tumor and the renal tumor-derived xenograft tumors were moderately differentiated and morphologically similar. The malignant pleural effusion xenograft tumors were highly differentiated and not morphologically similar to the primary patient renal tumor or the renal tumor-derived xenograft. Sunitinib and temsirolimus were evaluated in comparison to vehicle control for tumor growth delay in P1 malignant pleural effusion xenografted mice and sunitinib efficacy was established vs. vehicle controls. Sunitinib demonstrated was highly efficacious compared to vehicle control with 110% tumor growth delay (p=0.0043) and temsirolimus tumor growth delay was not efficacious (p>0.05). Since RMC is a rare disease for which there is currently no effective therapy, these new mouse models will be a useful for developing new treatments for this lethal disease. Furthermore, with a series of samples (normal, sickle cell trait kidney, RMC at diagnosis, and tumor cells from pleural effusion), we expect to understand molecular mechanisms underlying the disease progression pathway (pathogenesis). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1585. doi:10.1158/1538-7445.AM2011-1585