Example patient (patient 009) with widespread hepatic metastasis who demonstrated a treatment response following therapy. (A) Selected axial images from FMX-MRI acquired from the FSPGR Fat-Sat breath-hold images (TE = 13.2 milliseconds). The lesion outlined by the red box highlights one of the target lesions that underwent biopsy analysis and subsequent response assessment by RECIST v1.1. The values above each of the axial images are the estimated iron concentrations. (B) Axial contrast-enhanced CT images demonstrating tumor shrinkage (red boxes with reduction in lesion size by 67.3% at cycle 8).
Correlation between FMX 72-hour signals and binding constant. (A) Mechanistic PK model for tumor deposition of FMX driven by permeability and binding parameters; example for lesion fits for low permeability/low signal retention is shown. (B) Correlation for tissue binding parameter B to FMX signal measured at 72 hours. The normalized FMX ratio between tumor and plasma values is shown to account for plasma FMX PK variability.
Additional Prussian blue and CD68 staining in a tumor core biopsy after FMX dosing. (A, B) Serial tumor sections from formalin-fixed, paraffin-embedded biopsies of liver lesions were stained for (A) FMX (Prussian blue) and (B) macrophages (CD68). FMX deposition is detectable primarily in vascular-accessible macrophages in stromal areas surrounding tumor lesions.
Supplementary Fig. 5. Histone marks expression associated with resistance to sunitinib
Supplementary Figures 1-6 from Aflibercept Exerts Antivascular Effects and Enhances Levels of Anthracycline Chemotherapy In vivo in Human Acute Myeloid Leukemia Models
Correlation between the average irinotecan concentration of the biopsied lesion of that patient and the patient's time on treatment. Biopsy samples were obtained 72 hours after nal-IRI infusion. Time on treatment is measured from the date of first nal-IRI dose to the treatment termination date.
ROC analysis of FMX lesion response. Receiver operating characteristics for lesion classification according to best lesion size reduction, either as overall lesion shrinkage or partial response criteria, had an AUC {greater than or equal to}0.8 for early FMX measurements at 1 hour (A) or 24 hours (B).
OBJECTIVE To evaluate platinum content in biodegradable carboplatin-impregnated beads and retrospectively assess tolerability and outcome data for dogs treated by intralesional placement of such beads following surgical excision of subcutaneous sarcomas. DESIGN Evaluation study and retrospective case series. SAMPLE 9 carboplatin-impregnated beads and 29 client-owned dogs. PROCEDURES Platinum content in 9 carboplatin-impregnated beads from 3 lots was measured by spectrophotometry, and calculated carboplatin content was compared with the labeled content. Medical records were searched to identify dogs with subcutaneous sarcomas for which treatment included placement of carboplatin-impregnated beads between 2011 and 2014. Signalment, tumor characteristics, surgical and histologic data, adverse events, and local recurrences were recorded. Associations between variables of interest and adverse events or local disease-free interval were analyzed. RESULTS In vitro analysis identified a mean ± SD platinum content of 5.38 ± 0.97 mg/bead. Calculated carboplatin content (10.24 ± 1.84 mg/bead) was significantly greater than the labeled amount (4.6 mg/bead). Bead weight and total platinum content differed significantly among lots, but platinum content per bead weight did not. Mild-to-moderate local adverse events were reported for 11 of 29 tumors; all resolved without additional surgery. No dogs had signs of systemic toxicosis. Overall local disease-free rates 1, 2, and 3 years after surgery were 70%, 70%, and 58%, respectively, as determined by Kaplan-Meier analysis. CONCLUSIONS AND CLINICAL RELEVANCE Carboplatin-impregnated beads were well tolerated; however, results of in vitro tests indicated that caution is needed because of manufacturing inconsistencies.
AbstractPurpose: To determine whether deposition characteristics of ferumoxytol (FMX) iron nanoparticles in tumors, identified by quantitative MRI, may predict tumor lesion response to nanoliposomal irinotecan (nal-IRI).Experimental Design: Eligible patients with previously treated solid tumors had FMX-MRI scans before and following (1, 24, and 72 hours) FMX injection. After MRI acquisition, R2* signal was used to calculate FMX levels in plasma, reference tissue, and tumor lesions by comparison with a phantom-based standard curve. Patients then received nal-IRI (70 mg/m2 free base strength) biweekly until progression. Two percutaneous core biopsies were collected from selected tumor lesions 72 hours after FMX or nal-IRI.Results: Iron particle levels were quantified by FMX-MRI in plasma, reference tissues, and tumor lesions in 13 of 15 eligible patients. On the basis of a mechanistic pharmacokinetic model, tissue permeability to FMX correlated with early FMX-MRI signals at 1 and 24 hours, while FMX tissue binding contributed at 72 hours. Higher FMX levels (ranked relative to median value of multiple evaluable lesions from 9 patients) were significantly associated with reduction in lesion size by RECIST v1.1 at early time points (P < 0.001 at 1 hour and P < 0.003 at 24 hours FMX-MRI, one-way ANOVA). No association was observed with post-FMX levels at 72 hours. Irinotecan drug levels in lesions correlated with patient's time on treatment (Spearman ρ = 0.7824; P = 0.0016).Conclusions: Correlation between FMX levels in tumor lesions and nal-IRI activity suggests that lesion permeability to FMX and subsequent tumor uptake may be a useful noninvasive and predictive biomarker for nal-IRI response in patients with solid tumors. Clin Cancer Res; 23(14); 3638–48. ©2017 AACR.
Preclinical activity of irinotecan has been seen in glioma models, but only modest efficacy has been noted in clinical studies, perhaps related to drug distribution and/or pharmacokinetic limitations. In preclinical testing, irinotecan liposome injection (nal-IRI) results in prolongation of drug exposure and higher tissue levels of drug due to slower metabolism and the effect of enhanced permeability and retention. The objective of the current study was to assess the safety and pharmacokinetics (PK) of nal-IRI and to determine the maximum tolerated dose (MTD) in patients with recurrent high-grade glioma stratified based on UGT1A1 genotyping.
Interstitial fluid pressure (IFP) is elevated in tumors and high IFP, a negative cancer prognosticator, is known to limit the uptake and efficacy of anti-tumor therapeutics. Approaches that alter the tumor microenvironment and enhance uptake of therapeutics are collectively referred to as tumor "priming". Here we show that the cytotoxic biological therapy Apo2L/TRAIL can prime the tumor microenvironment and significantly lower IFP in three different human tumor xenograft models (Colo205, MiaPaca-2 and a patient gastrointestinal adenocarcinoma tumor xenograft). We found that a single dose of Apo2L/TRAIL resulted in a wave of apoptosis which reached a maximum at 8h post-treatment. Apoptotic debris subsequently disappeared concurrent with an increase in macrophage infiltration. By 24h post-treatment, treated tumors appeared less condensed with widening of the stromal areas which increased at 48 and 72h. Analysis of tumor vasculature demonstrated a significant increase in overall vessel size at 48 and 72h although the number of vessels did not change. Notably, IFP was significantly reduced in these tumors by 48h after Apo2L/TRAIL treatment. Administration of gemcitabine at this time resulted in increased tumor uptake of both gemcitabine and liposomal gemcitabine and significantly improved anti-tumor efficacy of liposomal gemcitabine. These results suggest that Apo2L/TRAIL has a potential as a tumor priming agent and provides a rationale for developing a sequencing schema for combination therapy such that an initial dose of Apo2L/TRAIL would precede administration of gemcitabine or other therapies.
Abstract Sunitinib is considered a first-line therapeutic option for patients with advanced clear cell renal cell carcinoma (ccRCC). Despite sunitinib's clinical efficacy, patients eventually develop drug resistance and disease progression. Herein, we tested the hypothesis whether initial sunitinib resistance may be transient and could be overcome by dose increase. In selected patients initially treated with 50 mg sunitinib and presenting with minimal toxicities, sunitinib dose was escalated to 62.5 mg and/or 75 mg at the time of tumor progression. Mice bearing two different patient-derived ccRCC xenografts (PDX) were treated 5 days per week with a dose-escalation schema (40–60–80 mg/kg sunitinib). Tumor tissues were collected before dose increments for immunohistochemistry analyses and drug levels. Selected intrapatient sunitinib dose escalation was safe and several patients had added progression-free survival. In parallel, our preclinical results showed that PDXs, although initially responsive to sunitinib at 40 mg/kg, eventually developed resistance. When the dose was incrementally increased, again we observed tumor response to sunitinib. A resistant phenotype was associated with transient increase of tumor vasculature despite intratumor sunitinib accumulation at higher dose. In addition, we observed associated changes in the expression of the methyltransferase EZH2 and histone marks at the time of resistance. Furthermore, specific EZH2 inhibition resulted in increased in vitro antitumor effect of sunitinib. Overall, our results suggest that initial sunitinib-induced resistance may be overcome, in part, by increasing the dose, and highlight the potential role of epigenetic changes associated with sunitinib resistance that can represent new targets for therapeutic intervention. Mol Cancer Ther; 14(2); 513–22. ©2014 AACR.
No evaluation of sex and race influences on mycophenolic acid (MPA) pharmacokinetics and adverse effects (AEs) during enteric-coated mycophenolate sodium (ECMPS) and tacrolimus immunosuppression are available. The primary objective of this study was to investigate the influence of sex and race on MPA and MPA glucuronide (MPAG) pharmacokinetics in stable renal transplant recipients receiving ECMPS and tacrolimus
Irinotecan and topotecan are the only camptothecin analogues approved by the FDA for cancer treatment. However, inherent and/or acquired irinotecan and topotecan resistance is a challenging issue in clinical practice. In this report, we showed that FL118, a novel camptothecin analogue, effectively obliterated human xenograft tumors that acquire irinotecan and topotecan resistance. Consistent with this finding, Pharmacokinetics studies indicated that FL118 rapidly clears from circulation, while effectively accumulating in tumors with a long elimination half-life. Consistent with our previous studies on irinotecan, FL118 exhibited ≥25 fold more effectiveness than topotecan at inhibiting cancer cell growth and colony formation; we further showed that although topotecan can inhibit the expression of survivin, Mcl-1, XIAP or cIAP2, its effectiveness is about 10-100 fold weaker than FL118. Lastly, in contrast to both SN-38 (active metabolite of irinotecan) and topotecan are substrates of the efflux pump proteins P-gp/MDR1 and ABCG2/BCRP, FL118 is not a substrate of P-gp and ABCG2. Consistently, sildenafil, a multiple efflux pump inhibitor, sensitized SN-38 much more than these of the ABCG2-selective inhibitor KO143 in growth inhibition of SW620 and HCT-8 cells. In contrast, both inhibitors showed no effect on FL118 efficacy. Given that both P-gp and ABCG2 express in SW620 and HCT-8 cells and FL118 is not a substrate for P-gp and ABCG2, this suggests that FL118 appears to bypass multiple efflux pump protein-induced resistance, which may contribute to FL118 overcoming irinotecan and topotecan resistance in vivo. These new findings provide renewed perspectives for further development of FL118 for clinical applications.
Abstract Introduction MM-398, a stable nanoliposomal irinotecan (nal-IRI), is designed to exploit leaky tumor vasculature for enhanced drug delivery to tumors. Tumor deposition of nal-IRI and subsequent irinotecan conversion by CES enzymes in both neoplastic cells and tumor associated macrophages (TAM) may positively correlate with activity. Predictive biomarkers to measure tumor deposition could identify patients likely to benefit from nal-IRI. FMX is a 30nm iron-oxide, superparamagnetic nanoparticle with MRI contrast properties. The particle size, its propensity for uptake by TAMs and similar distribution patterns to nal-IRI in preclinical models led to a clinical study evaluating the feasibility of correlating FMX-based MRI (Fe-MRI) acquisition with tissue drug metabolite levels and other biomarkers to estimate drug delivery to tumor. Patients and methods Eligible patients (n=12) with refractory solid tumors with at least two metastatic lesions >2cm accessible for a percutaneous biopsy were enrolled from one institution. Fe-MRI scans were performed on a 1.5T MRI using T2* iron sensitive sequences prior to and following FMX infusion (0.5h, 24h, 72h). MR images were used to direct biopsies at 72h to FMX high or low regions, permitting intra- and inter-patient comparisons of FMX and nal-IRI tumor levels. Patients continued on nal-IRI at 80mg/m2 q2w until progression. Tissue iron and TAM distribution were assessed by IHC, tissue-bound metabolite levels by mass-spectrometry. T2* signal was used to calculate FMX levels in total lesions along with FMX estimates on biopsy images derived from fused MRI-CT biopsy images. The first 9 patients (2M 7F; median age 57 years, range 28-71 years) are reported. Results There were no safety-related or other potential interactions with nal-IRI and FMX. Adverse events of nal-IRI were consistent with previous studies. FMX levels, quantified in 36 tumor lesions from the first 9 subjects, showed mean FMX accumulation of 37.9 mcg/mL [3.3-101.2 mcg/mL] and 13.2 mcg/mL [0.1-41.0 mcg/mL] at 24h and 72h, respectively. Lesions were localized mostly in liver (67%) and lymph nodes/peritoneal sites (25%). A mechanistic PK model indicated that tissue permeability to FMX contributed to Fe-MRI signals at 24h, while FMX binding contributed at 72h. Levels of irinotecan and SN-38 were 3.59mcg/g [2.29-4.89mcg/g] and 11.43ng/g [4.04-18.8ng/g], respectively, at 72h in biopsies from the first 6 patients. Conclusions This study is one of the first to measure active metabolite SN-38 levels in patient tumors. FMX can be used as a tumor contrast agent prior to nal-IRI treatment. T2* MRI sequences allowed for quantitation of FMX concentrations in tumor and reference tissue. A mechanistic model provided an estimation of FMX tumor tissue permeability and binding that may be useful as a predictive biomarker of nanotherapeutics such as nal-IRI. Citation Format: Ramesh K. Ramanathan, Ronald L. Korn, Jasgit C. Sachdev, Gerald J. Fetterly, Katie Marceau, Vickie Marsh, John M. Neil, Ronald G. Newbold, Natarajan Raghunand, Joshua Prey, Stephan G. Klinz, Eliel Bayever, Jonathan B. Fitzgerald. Pilot study in patients with advanced solid tumors to evaluate feasibility of ferumoxytol (FMX) as tumor imaging agent prior to MM-398, a nanoliposomal irinotecan (nal-IRI). [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 CT224. doi:10.1158/1538-7445.AM2014-CT224
2606 Background: Single nucleotide polymorphisms (SNPs) in carbonyl reductase 3 (CBR3V244M and CBR3C4Y), may impact the variable pharmacodynamics of anthracyclines. For example, homozygosis for the CBR3 V allele (G) is associated with an 8-fold increased risk for anthracycline-related heart failure. The aim was to develop a population pharmacokinetic model to characterize the metabolism of doxorubicin and explore the influence of CBR3V244M and CBR3C4Y genotype status on the formation of doxorubicinol, a major contributor to doxorubicin-induced cardiotoxocity.METHODSAdvanced breast cancer patients received 60mg/m2 of doxorubicin. Blood was collected over three time windows to capture the PK profile. Doxorubicin and doxorubicinol was measured by UPLC. S-ADAPT-TRAN (v1.56) was used to co-model parent and metabolite data. For simplicity, a single metabolic pathway for doxorubicin was considered. Covariates including age, weight, BSA, and influence of CBR3V244M and CBR3C4Y were explored.RESULTSA total of 34 female patients (79.4% White, 17.6% Black, and 2.9% Native American) were evaluated. Patient demographics including mean (sd) weight, BSA, and age were 81.9kg (20.8), 1.87m2 (0.25), and 51.8 yrs (10.4), respectively. A 4-compartment model best characterized the bi-exponential decay of doxorubicin and doxorubicinol compared to a 3-compartment model (p<0.0033). Model estimated PK parameters were similar to those reported in the literature. The mean (sd) half-life of doxorubicin was estimated as 25.0hr (0.06). CBR3V244M and CBR3C4Y genotype status were similar in Black and White patients (α<0.05). Thus, analysis was conducted without stratifying by geographical ancestry/ethnicity. Patients with homozygous CBR3V244M G genotype status showed greater exposure to doxorubicin (AUC0-inf ) with one (G/A) or two (G/G) copies of the variant allele (p=0.0003).CONCLUSIONSSuccessful model development characterized the pharmacokinetics of doxorubicin and may further elucidate the role of polymorphic CBRs during anthracycline metabolism. Further analyses are ongoing to investigate the influence of age, weight, BSA, CBR3V244M and CBR3C4Y on PK parameters.
AbstractWe examined whether potent vascular endothelial growth factor (VEGF) blockade mediated by aflibercept, a decoy VEGF receptor (VEGFR) 1/2 moiety with stronger affinity for VEGF than bevacizumab, resulted in antileukemia effects and enhanced the efficacy of systemic chemotherapy. The efficacy of aflibercept alone and in combination with doxorubicin was evaluated in human VEGF-expressing acute myeloid leukemia (AML) cell lines and primary cells xenotransplanted into immunodeficient mice. Aflibercept reduced primary VEGF/VEGFR-positive AML colony formation growth in vitro and inhibited AML xenograft growth up to 93% in association with antiangiogenic and antiproliferative effects, hypoxia, and VEGF sequestration in multiple models. High VEGF-A expression by AML cells promoted in vivo xenograft growth and aflibercept sensitivity. Aflibercept therapy slowed disease progression in two systemic human AML xenograft models and reduced peripheral leukemia disease in a primary relapsed AML model in NOD/SCID/IL2Rγnull mice. Combination aflibercept and doxorubicin enhanced antitumor effects in local xenograft models. Sequential aflibercept followed by doxorubicin resulted in progressive anthracycline accumulation in marrow and extramedullary AML sites and resulted in 2-fold higher drug levels 24 hours after administration. In contrast, tissues (tumor, plasma, marrow) treated with chemotherapy only showed progressive drug clearance over time. Combination aflibercept and doxorubicin also resulted in vascular narrowing, decreased vessel number, and perivascular apoptosis. These data suggest that inefficient drug delivery by leukemia-associated vasculature may mediate chemoresistance and support further clinical evaluation of combination aflibercept and anthracycline therapy in refractory/relapsed AML patients. Mol Cancer Ther; 9(10); 2737–51. ©2010 AACR.