Glycemia and Gluconeogenesis With Metformin and Liraglutide: A Randomized Trial in Youth-onset Type 2 Diabetes

OBJECTIVE

Elevated rates of gluconeogenesis are an early pathogenic feature of youth-onset type 2 diabetes (Y-T2D), but targeted first-line therapies are suboptimal, especially in African American (AA) youth. We evaluated glucose-lowering mechanisms of metformin and liraglutide by measuring rates of gluconeogenesis and β-cell function after therapy in AA Y-T2D.

METHODS

In this parallel randomized clinical trial, 22 youth with Y-T2D-age 15.3 ± 2.1 years (mean ± SD), 68% female, body mass index (BMI) 40.1 ± 7.9 kg/m2, duration of diagnosis 1.8 ± 1.3 years-were randomized to metformin alone (Met) or metformin + liraglutide (Lira) (Met + Lira) and evaluated before and after 12 weeks. Stable isotope tracers were used to measure gluconeogenesis [2H2O] and glucose production [6,6-2H2]glucose after an overnight fast and during a continuous meal. β-cell function (sigma) and whole-body insulin sensitivity (mSI) were assessed during a frequently sampled 2-hour oral glucose tolerance test.

RESULTS

At baseline, gluconeogenesis, glucose production, and fasting and 2-hour glucose were comparable in both groups, though Met + Lira had higher hemoglobin A1C. Met + Lira had a greater decrease from baseline in fasting glucose (-2.0 ± 1.3 vs -0.6 ± 0.9 mmol/L, P = .008) and a greater increase in sigma (0.72 ± 0.68 vs -0.05 ± 0.71, P = .03). The change in fractional gluconeogenesis was similar between groups (Met + Lira: -0.36 ± 9.4 vs Met: 0.04 ± 12.3%, P = .9), and there were no changes in prandial gluconeogenesis or mSI. Increased glucose clearance in both groups was related to sigma (r = 0.63, P = .003) but not gluconeogenesis or mSI.

CONCLUSION

Among Y-T2D, metformin with or without liraglutide improved glycemia but did not suppress high rates of gluconeogenesis. Novel therapies that will enhance β-cell function and target the elevated rates of gluconeogenesis in Y-T2D are needed.

EXTH-100. EVALUATION OF PANOBINOSTAT PLASMA AND CEREBROSPINAL FLUID (CSF) PHARMACOKINETIC PROFILE FOLLOWING ADMINISTRATION OF THE CAPSULE FORMULATION FARYDAK® IN A NON-HUMAN (NHP) PRIMATE PRECLINICAL MODEL

Panobinostat is an HDAC inhibitor with dose-dependent pre-clinical activity against pediatric glioma. Reported pharmacokinetic (PK) profiles of panobinostat, including CSF penetration, have varied. We hypothesized that this variability resulted from the utilization of differing panobinostat formulations. For comparison to the USP grade powdered formulation PK profile formerly reported (Rodgers, et al., Cancer Chemother Pharmacol. 2020 Apr;85(4):827-830) a plasma and CSF PK study was conducted with panobinostat administered as the capsule formulation, Farydak®, utilizing the same non-human primate (NHP) model, study design, analytical methods, and analysis.

METHODS

Three NHP previously developed for serial CSF access via a lateral ventricular CSF reservoir (n=2), or lumbar CSF port (n=1) received panobinostat orally (1.6 mg/kg, Human Dose Equivalent: 32 mg/m2) followed by serial paired plasma and CSF sample collections from 0-72 hours. Samples were quantified by LC-MS/MS. PK parameters were determined via noncompartmental analysis.

RESULTS

Mean plasma and CSF PK parameters Tmax (h), Cmax (nM), and AUCinf (h*nM/mg) are reported and compared to the corresponding PK parameters from the USP grade powdered formulation study formerly reported. Capsule Formulation: Plasma - Tmax: 5.3 □ 1.2, Cmax: 20 □ 1.9, AUClast: 14.5 □ 11.1, AUCinf: 15.2 □ 11.4 CSF - Tmax: 5.0 □ 3.6, Cmax: 1.7 □ 0.3, AUClast: 0.54 □ 0.47, AUCinf: unable to calculate Powdered Formulation – Mean PK of all dose levels formerly reported: Plasma -Tmax: 1.06 □ 0.13, Cmax: 1.27 □ 0.6, AUCinf: 7.7 □ 2.7 CSF - Cmax and Tmax: Unable to determine. Single quantifiable sample across all studies. AUCinf: unable to calculate.

CONCLUSION

The plasma and CSF Tmax, Cmax, the plasma AUCinf, and the CSF AUClast for panobinostat were increased following oral administration of the capsule formulation of panobinostat, Farydak®, compared to USP grade powder formulation of the drug.

EXTH-102. PLASMA AND CEREBROSPINAL FLUID (CSF) PHARMACOKINETICS (PK) OF MIRDAMETINIB IN A NON-HUMAN PRIMATE (NHP) MODEL

Mirdametinib is a MEK inhibitor with reported CSF penetration in pre-clinical models. Murine studies reported ERK phosphorylation inhibition in brain tissue at 1.15 nM (0.73 ng/mL) and tumor cell lines at 0.33–0.59 nM (0.16-0.28 ng/mL). A phase II clinical trial evaluating mirdametinib for neurofibromatosis type 1-related plexiform neurofibromas reported a 42% partial response rate and a mean plasma exposure (AUC0-12h) of 443 h*ng/mL. This study determined the plasma and CSF pharmacokinetic (PK) profile of mirdametinib in a non-human primate (NHP) model where CSF penetration serves as a proxy for CNS penetration.

METHODS

Four NHP received mirdametinib PO q.d, 0.50 mg/kg, in serial studies as a single dose (Single-Dose), three doses (Multiple-Dose), or IV, 0.20 mg/kg, followed by paired plasma and CSF sample collections through 96 hours. Mirdametinib was quantified by LC-MS/MS. PK parameters were calculated via noncompartmental methods. Plasma protein binding was determined by rapid equilibrium dialysis.

RESULTS

Mean □ standard deviation values reported. Three subjects were evaluable for both plasma (total and unbound) and CSF drug concentrations. Plasma – AUClast: Single-Dose 500.3 □ 253.4 and IV 552.3 □ 43 h*ng/mL; AUCtau: Multiple-Dose 456.3 □ 120.6 h*ng/mL. CSF Cmax (ng/mL): Single-Dose 0.43 □ 0.18, IV 2.0 □ 1.8, Multiple-Dose 0.56 □ 0.18. CSF Penetration (%): Single-Dose 1.3 □ 0.45, IV-1.6 □ 0.95 (AUCcsf-last:AUCplasma-last); Multiple-Dose 1.3 □ 0.56 (AUCcsf-tau:AUCplasma-tau). CSF/unbound plasma ratios ranged from 2.5-3.0 Plasma free fraction (%): 0.52 □ 0.1.

CONCLUSION

Notable mirdametinib CSF penetration was demonstrated in this NHP model. A higher CSF to unbound plasma ratio suggests that the efflux of mirdametinib from the CSF was delayed. The NHP CSF Cmax approached the ERK phosphorylation inhibition concentrations previously reported. The ability of this NHP model to predict human PK parameters was demonstrated via the comparable NHP to patient plasma exposure reported in the Phase II clinical trial.

Enhanced toxicity to chemoradiation in a patient with Anti-Jo-1-antisynthetase syndrome

Appropriate counseling of patients with autoimmune connective tissue disorders (ACTDs) is often challenging for radiation oncologists, especially regarding anticipated side-effects of radiation treatment. These patients can have highly variable and unpredictable sequelae from radiation therapy, and the uncertainty builds when radiation is convoluted by the addition of concurrent chemotherapy. While many patients may experience a mild intensification of toxicity above what is expected, some patients experience much more severe toxicity. These patients become critical learning cases, enabling a better understanding of the delicate and complex ways in which radiation response is altered in the context of ACTDs while allowing other patients with similar ACTD profiles to benefit from past experience. Our report makes an important contribution to this space by describing a particularly severe case of toxicity that manifested in such a patient and the ensuing clinical decision-making. Comprehensive genotyping of classic pharmacokinetic and pharmacodynamic pathway genes (including mutations in DPD and CDA) did not reveal any signatures that might explain her enhanced toxicity and we demonstrate that severe toxicity can still manifest in the era of modern conformal radiation treatments for rectal cancer. We urge caution in the treatment of patients with rare ACTDs, but also emphasize that curative treatment should not be withheld in such patients. We conclude by advocating for the development and maintenance of a prospective multiinstitutional database of patients with ACTDs to help inform and improve future practice.

EXTH-25. THE CSF PENETRATION OF THE PROCASPASE-ACTIVATING COMPOUND (PAC-1) IN COMBINATION WITH TEMOZOLOMIDE (TMZ) IN A NONHUMAN PRIMATE CSF ACCESS MODEL

BACKGROUND

The synergistic activity of temozolomide (TMZ) administered in combination with procaspase-activating compound (PAC-1) has been reported in pre-clinical mouse models and canine patients, leading to clinical trials in adults with glioblastoma. To optimize pediatric clinical trial design, a translational pharmacokinetic CSF penetration study was conducted using a pre-clinical nonhuman primate non-tumor bearing CSF access model with TMZ and PAC-1 administered alone and in combination.

METHODS

Four male rhesus macaques with CSF lateral ventricular reservoirs received PAC-1, 15 mg/kg orally [Human Equivalent Dose (HED) 558 mg/m2/day] or TMZ, 1-hr IV infusion, 7.5 mg/kg (HED 150 mg/m2) as single and combination agent administration. Paired plasma and CSF samples were collected for 0–96 hours. PAC-1 and TMZ were quantified by LC-MS/MS. Pharmacokinetic parameters were calculated using noncompartmental methods. Statistics were determined via Mann-Whitney test.

RESULTS

(Mean ± Standard Deviation): For TMZ: Plasma AUC0-24 (hr*ng/ml) single agent (n=4): 28590 ± 4888 and in combination (n=4): 32736 ± 10147. CSF AUC0-24 (hr*ng/ml) single agent (n=4):14406 ± 1279 and in combination (n=4):15614 ± 1767. CSF penetration (% AUCCSF: AUCPLASMA) single agent: 50.9% ± 2.2 and in combination:49.6% ± 8.4. For PAC-1: Plasma PAC-1 AUC0-24 (hr*ng/ml) single agent (n=4): 2556 ± 2157 and in combination (n=4): 1947 ± 1311. CSF PAC-1 AUC0-24 (hr*ng/ml) single agent (n=2): 8.7 ± 1.1 and in combination (n=3):12.9 ± 10.2. CSF penetration single agent: 0.2% ± 0.03 and in combination: 0.4% ± 0.38. CSF PAC-1 tlag and Tmax pharmacokinetic parameters decreased with concurrent TMZ administration.

CONCLUSIONS

In this non-tumor bearing pre-clinical nonhuman primate model the CSF penetration of PAC-1 was low and not notably affected by the concurrent administration of TMZ. TMZ CSF penetration for single administration was within previously reported ranges and also appeared unaffected when administered in combination with PAC-1.

Structure-Activity Relationship and Crystallographic Studies on 4-Hydroxypyrimidine HIF Prolyl Hydroxylase Domain Inhibitors

The 2-oxoglutarate-dependent hypoxia inducible factor prolyl hydroxylases (PHDs) are targets for treatment of a variety of diseases including anaemia. One PHD inhibitor is approved for use for the treatment of renal anaemia and others are in late stage clinical trials. The number of reported templates for PHD inhibition is limited. We report structure-activity relationship and crystallographic studies on a promising class of 4-hydroxypyrimidine-containing PHD inhibitors.

EXTH-65. PLASMA AND CEREBROSPINAL FLUID PHARMACOKINETICS COMPARISON OF BRAF AND MEK INHIBITORS FOLLOWING SINGLE AND EXTENDED ADMINISTRATION IN A PRE-CLINICAL NON-HUMAN PRIMATE MODEL

BACKGROUND

Aberrations in the MAPK signaling pathway are present in adult and pediatric CNS tumors. The BRAF and MEK inhibitors Dabrafenib, Vemurafenib, Selumetinib and Trametinib, alone or in combination, have demonstrated clinical efficacy. However, minimal CSF penetration has been demonstrated in pre-clinical models with single dose administration. CSF penetration of these agents was compared following single and extended oral administration in a nonhuman CSF Lateral Reservoir model to determine if CSF penetration increases at steady state.

METHODS

Agents were administered orally, to each subject (n=9), in single or multiple doses, as serial single agent studies, with washout periods between studies. The following dosages (Human equivalent dose HED) were utilized in the studies: Single Dosage-Selumetinib 2.5 mg/kg (50.0 mg/m2), Dabrafenib 8.0 mg/kg (160 mg/m2), Vemurafenib 26 mg/kg (520 mg/m2), Trametinib 0.06 and 0.12 mg/kg (1.2 and 2.4 mg/m2). Extended dosages-Selumetinib 2.5 mg/kg BID x 3 days (50.0 mg/m2), Dabrafenib 4.0 mg/kg BID x 2 days (160 mg/m2/day), Vemurafenib 26 mg/kg BID x 3 days (520 mg/m2), Trametinib 0.05 mg/kg x 10 days BID (1.0mg/m2). Paired serial plasma and CSF samples were collected. Agents were quantified by uHPLC-MS/MS. Pharmacokinetic parameters were calculated via noncompartmental methods. Plasma exposure reported as Area Under the Curve (AUC) and CSF penetration as ratio of CSF:plasma AUC. Statistical significance determined by t-test.

RESULTS

Single administration AUCinf/D (hr*ng/ml/mg) vs. extended administration AUCtau/D (hr*ng/ml/mg) for each agent: Vemurafenib-Plasma 30.9–351.4 vs.29.2–379.7, CSF-non-quantifiable; Dabrafenib-Plasma 29.3–102.6 vs.3.4–58.2, CSF-0.12–0.54 vs 0.04–0.19, % CSF:Plasma-0.3–0.84 vs.0.32–1.3; Trametinib-Plasma AUC indeterminable, CSF-non-quantifiable; Selumetinib-Plasma 69.8–133.0 vs.26.5–81.2; CSF-AUC indeterminable vs. 0.37–0.86, % CSF:Plasma-Indeterminable vs. 0.78–1.4. T-test: A downward trend in Dabrafenib and Selumetinib plasma AUC and a marked upward trend in Selumetinib CSF AUC.

CONCLUSIONS

With the exception of Selumetinib, the CSF exposure of BRAF and MEK inhibitors studied did not markedly increase following extended dosing.

Studies on spiro[4.5]decanone prolyl hydroxylase domain inhibitors

The 2-oxoglutarate (2OG) dependent hypoxia inducible factor (HIF) prolyl hydroxylases (PHDs) are targets for treatment of anaemia and other ischaemia related diseases. PHD inhibitors are in clinical trials; however, the number of reported templates for PHD inhibition is limited. We report structure-activity relationship and crystallographic studies on spiro[4.5]decanone containing PHD inhibitors. Together with other studies, our results reveal spiro[4.5]decanones as useful templates for generation of potent and selective 2OG oxygenase inhibitors.

Pilot Study Comparing Systemic and Tissue Pharmacokinetics of Irinotecan and Metabolites after Hepatic Drug-Eluting Chemoembolization

Differences in drug metabolism associated with UGT1A1 polymorphism could result in individualized local response to hepatic chemoembolization with irinotecan-eluting beads (DEBIRI) or predictable toxicities. Five patients with inoperable hepatic metastases from colorectal or anal malignancies treated with DEBIRI were assessed for UGT1A1 mutations. No difference in area under the curve (AUC) for SN38 in normal liver and tumor tissue samples was noted with variant or wild-type UBT1A1 (P = .16 and P = .05, respectively). Plasma SN-38 AUC was significantly lower in wild-type compared to variant patients (P < .0001). UGT1A1 genotype may not be predictive of hematologic toxicity after DEBIRI.

Abstract 2048: Pharmacodynamic biomarker studies of TRC105 anti-endoglin (CD105) antibody revealed anti-angiogenic activity associated with CD105 depletion

Introduction: CD105 is involved in normal vascular development. It is over expressed on the surface of proliferating vascular endothelial cells and is implicated in tumor angiogenesis. In hypoxic conditions, CD105 is upregulated through induction of hypoxia-inducible factor 1-α. TRC105 is a chimeric IgG1 antibody specific for CD105 and the agent for this phase I trial.

Methods: 20 patients with metastatic prostate cancer were treated with TRC105 at six dose levels in a phase I trial. Blood samples were analyzed for CD105 antigen depletion, VEGF as a marker for systemic hypoxia, and PSA.

Results: Maximum tolerated dose of 20 mg/kg every two weeks was reached. Significant plasma CD105 reduction was observed at high dose levels. The reduction of CD105 was associated with induction of plasma VEGF. Ten patients had stable disease, and the reduction of CD105 is associated with PSA stabilization.

Conclusion: A significant induction of VEGF was associated with CD105 reduction at three high dose levels, suggesting the anti-angiogenic activity of TRC105. Exploratory analysis showed a tentative correlation between the reduced CD105 and a decreased PSA velocity, suggestive of potential antitumor activity of TRC105 in metastatic prostate cancer.

Citation Format: Liang Cao, Fatima Karzai, Andrea Apolo, Ravi Madan, Yunkai Yu, James Gulley, William Figg, William Dahut. Pharmacodynamic biomarker studies of TRC105 anti-endoglin (CD105) antibody revealed anti-angiogenic activity associated with CD105 depletion. [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 2048.

Treatment With Carfilzomib-Lenalidomide-Dexamethasone With Lenalidomide Extension in Patients With Smoldering or Newly Diagnosed Multiple Myeloma

IMPORTANCE

Carfilzomib-lenalidomide-dexamethasone therapy yields deep responses in patients with newly diagnosed multiple myeloma (NDMM). It is important to gain an understanding of this combination's tolerability and impact on minimal residual disease (MRD) negativity because this end point has been associated with improved survival.

OBJECTIVE

To assess the safety and efficacy of carfilzomib-lenalidomide-dexamethasone therapy in NDMM and high-risk smoldering multiple myeloma (SMM).

DESIGN, SETTING, AND PARTICIPANTS

Clinical and correlative pilot study at the National Institutes of Health Clinical Center. Patients with NDMM or high-risk SMM were enrolled between July 11, 2011, and October 9, 2013. Median follow-up was 17.3 (NDMM) and 15.9 months (SMM).

INTERVENTIONS

Eight 28-day cycles were composed of carfilzomib 20/36 mg/m2 on days 1, 2, 8, 9, 15, and 16; lenalidomide 25 mg on days 1 through 21; and dexamethasone 20/10 mg (cycles 1-4/5-8) on days 1, 2, 8, 9, 15, 16, 22, and 23. Patients who achieved at least stable disease subsequently received 24 cycles of lenalidomide extended dosing.

MAIN OUTCOMES AND MEASURES

Primary end points were neuropathy of grade 3 or greater (NDMM) and at least very good partial response rates (SMM). Minimal residual disease was also assessed.

RESULTS

Of 45 patients with NDMM, none had neuropathy of grade 3 or greater. Of 12 patients with high-risk SMM, the most common of any-grade adverse events were lymphopenia (12 [100%]) and gastrointestinal disorders (11 [92%]). All patients with SMM achieved at least a very good partial response during the study period. Among the 28 patients with NDMM and the 12 with SMM achieving at least a near-complete response, MRD negativity was found in 28 of 28 (100% [95% CI, 88%-100%]), 11 of 12 (92% [95% CI, 62%-100%]) (multiparametric flow cytometry), 14 of 21 (67% [95% CI, 43%-85%]), and 9 of 12 (75% [95% CI, 43%-94%]) (next-generation sequencing), respectively. In patients with NDMM, 12-month progression-free survival for MRD-negative vs MRD-positive status by flow cytometry and next-generation sequencing was 100% vs 79% (95% CI, 47%-94%; P < .001) and 100% vs 95% (95% CI, 75%-99%; P = .02), respectively.

CONCLUSIONS AND RELEVANCE

Carfilzomib-lenalidomide-dexamethasone therapy is tolerable and demonstrates high rates of MRD negativity in NDMM, translating into longer progression-free survival in patients achieving MRD negativity. Carfilzomib-lenalidomide-dexamethasone therapy also demonstrates efficacy in high-risk SMM.

Abstract 2575: Results from the first-in-human phase I trials of recombinant human Interleukin 15 (rhIL-15) administered as a daily 30 minute intravenous infusion (IVB) for 12 consecutive days or as continuous intravenous infusion (CIV) for 240 hours in patients with refractory metastatic cancers

Preclinical laboratory experiments with Interleukin 15 (IL-15) have demonstrated significant immunotherapeutic potential for recombinant human IL-15 (rhIL-15) in cancer patients. We have completed a first-in-human (FIH), phase I dose escalation trial of E. coli produced rhIL-15 administered as a 30 minute intravenous bolus (IVB) infusion given daily for 12 consecutive days to patients with metastatic melanoma (MM) or renal cell carcinoma (mRCC). rhIL-15 treatment produced up to an 8-fold expansion of circulating NK cells, approximately 2 fold expansion of CD8+ CD45RO+ memory T-cells and up to 50 fold increases in serum level for multiple cytokines. Characteristic toxicities associated with cytokine treatment such as fever, rigors or chills, capillary leak, myalgias and blood pressure changes occurred at frequency and severity proportional to the dose of rhIL-15. Laboratory results showed early course transient leukopenia, lymphopenia, modest neutropenia, occasional thrombocytopenia and significant elevations of alanine and asparagine transaminase (ALT, AST) in a number of patients. Antibodies to rhIL-15 antibodies were not detected in any patient. The maximum tolerated dose for this schedule was 0.3 μg/kg/day with dose-limiting toxicities (DLTs) of grade 3 hypotension, thrombocytopenia, grade 3 or 4 ALT and AST elevation. There were no documented objective responses by RECIST criteria, but decreases in the sum of diameters for the marker lesions between 10 and 30% and improvement or clearance of parenchymal lung metastases were observed in several patients suggesting some antitumor activity.

A phase I dose escalation trial evaluating a 10 day (240 hour) continuous intravenous infusion (CIV) of rhIL-15 which is expected to produce greater expansion of CD8 effector cells and immune activation has been initiated. Patients treated at the first two dose levels have demonstrated improved clinical tolerability, immune activation; fewer laboratory abnormalities and no DLTs. Patient accrual and dose escalation to the third dose level are ongoing.

Citation Format: Kevin C. Conlon, Enrico Lugli, Steven A. Rosenberg, John C. Morris, Thomas Fleisher, Hugh Welles, Sigrid Dubois, Liyanage Perera, Carolyn Goldman, Bonita Bryant, Jean Decker, Joanna Shih, Tat'Yana Worthy, William Figg, Cody Peer, Michael Sneller, H. Clifford Lane, Jason Yovandich, Stephen Creekmore, Mario Roederer, Thomas A. Waldmann. Results from the first-in-human phase I trials of recombinant human Interleukin 15 (rhIL-15) administered as a daily 30 minute intravenous infusion (IVB) for 12 consecutive days or as continuous intravenous infusion (CIV) for 240 hours in patients with refractory metastatic cancers. [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 2575. doi:10.1158/1538-7445.AM2014-2575

A phase I/II study of sepantronium bromide (YM155, survivin suppressor) with paclitaxel and carboplatin in patients with advanced non-small-cell lung cancer

BACKGROUND

This phase I/II study examined the safety and efficacy of Sepantronium Bromide (S), a small-molecule selective survivin suppressant, administered in combination with carboplatin (C) and paclitaxel (P).

PATIENTS AND METHODS

Forty-one patients were treated on study. Twenty-two patients received escalating doses of S (3.6-12 mg/m(2)) and 19 with untreated stage IV non-small-cell lung cancer (NSCLC) were treated with the maximum tolerated dose of 10 mg/m(2) in combination with standard doses of C (AUC6) and P (200 mg/m(2)) for six cycles. S was administered as a continuous intravenous infusion (CIVI) over 72 h in 21-day treatment cycles. Study end points included safety and toxic effect, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates.

RESULTS

Treatment with S was well tolerated, and toxic effects were mostly hematological in the phase II study. Two (11%) partial responses were observed with a median PFS of 5.7 months and median OS 16.1 months. Pharmacodynamic analysis did not demonstrate an association with response.

CONCLUSION

The combination of S (10 mg/m(2)/day 72-h CIVI) administered with C and P every 3 weeks exhibited a favorable safety profile but failed to demonstrate an improvement in response rate in advanced NSCLC.

CLINICAL TRIAL NUMBER

NCT01100931.

The in-vitro response of 4 antisteroid receptor agents on the hormone-responsive prostate-cancer cell-line lncap

Previous reports indicate that flutamide withdrawal is associated with PSA declines and tumor shrinkage in selected patients with 'hormone-refractory' prostate cancer. Though the mechanisms underlying this effect are not clear, investigators have hypothesized that these effects are mediated by mutant androgen receptors recognizing hydroxy-flutamide as an androgenic agonist. Such receptors have been well described in the human prostate cancer cell line LNCaP. Despite the finding that the androgen receptor of LNCaP aberrantly recognizes a variety of steroids, including estrogen and progesterone, as androgenic agonists, there are no studies which examine the effect of estrogen antagonists and progesterone antagonist on baseline and androgen-stimulated LNCaP growth. In this report, LNCaP cells were cultured in phenol red-free media using charcoal-stripped sera. As previously reported, flutamide enhanced LNCaP growth and bicalutamide inhibited androgen-stimulated LNCaP proliferation. Neither tamoxifen nor RU486 influenced LNCaP growth (either in the presence or absence of exogenous androgens). From these data we conclude that antagonists of estrogen and progesterone action have no anti-proliferative effect on LNCaP cells and that the mutant androgen receptor expressed in these cells is quite restrictive in the recognition of compounds with antagonistic activity. The clinical implications of these findings are discussed.

Abstract LB-350: Tissue and serum miRNA profiling for detection of bladder, breast and prostate cancer

Biomarkers that can differentiate between normal and tumor state, and can be measured in easily accessible body fluids such as blood and urine, can be very important for cancer diagnostics and disease monitoring. MicroRNAs (miRNAs), short non-coding regulatory RNA molecules, are attractive as biomarkers because they are stable in different conditions and are easy to measure with quantitative PCR (qPCR) methods. In this study we aimed to identify a universal panel of miRNAs for cancer screening that can be easily tested in the serum of healthy individuals and patients with different types of cancer. First, we measured expression of ∼800 miRNAs in 40 controls and 60 patients with bladder, breast or prostate cancer using the low density TaqMan expression arrays (Applied Biosystems) and starting from 250 ul of serum. Based on these results we selected a panel of 24 miRNAs that showed best discrimination between normal and cancer samples. These miRNAs were then re-tested as a custom-designed mini-panel in serum samples of 44 healthy controls and cancer patients (31 bladder, 25 breast and 28 prostate) and in relevant normal and tumor tissue samples (42 normal bladder and 43 bladder tumors, 44 normal breast and 42 breast tumors and in 50 normal prostate and 20 prostate tumors). Only miRNAs that expressed in the same direction in serum and tissue samples and showed significant association with cancer in both sample types were used for further analysis.

The current panel consists of 16 miRNAs – 14 targets, one positive control and one negative control. Using this panel on serum samples from 44 controls, 31 bladder cancer patients, 25 breast cancer patients and 28 prostate cancer patients we performed ROC analysis and achieved complete discrimination (AUC ∼1.0) between all types of cancers and controls and good discrimination between different types of cancers (minimal AUC 0.89 for breast and bladder samples). Our results prove that miRNA detection from serum might be a promising method of cancer detection. Currently, we are performing validation studies in independent sets of samples. A combination of information on genetic susceptibility factors identified by genome-wide association studies (GWAS), other cancer-specific factors such as PSA for prostate cancer and miRNA expression profiling, might provide additional tools for early disease diagnostics and help to guide treatment options.

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 LB-350. doi:10.1158/1538-7445.AM2011-LB-350

Phase I trial of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) administered twice weekly

3566

Background: 17-DMAG binds to heat-shock protein 90, leading to degradation of oncogene client proteins, inhibiting tumor growth. Preclinically, 17-DMAG has potent antitumor activity. Methods: 17-DMAG was given by 1–2 hour infusion twice weekly for 4 weeks/28-day cycle. Starting dose: 1mg/m2/dose. Eligibility: ECOG = 2, adequate organ function. Exclusions: prolonged QTc/uncontrolled illness. An accelerated titration escalation design was used; one patient (pt)/dose level was entered until a single pt experienced dose-limiting toxicity (DLT) or 2 pts have grade (gr) = 2 toxicity during the first cycle. Ending the accelerated phase, it converts to a standard 3–6 pt/cohort design. Objectives: To determine the toxicity profile, pharmacokinetics (PK), pharmacodynamics (PD) and MTD of twice weekly 17-DMAG. Plasma samples collected before and up to 48 hours after 17-DMAG infusion were analyzed by LC-MS. Results: 23 pts were accrued and treated; Diagnosis: renal cell-1, pancreatic-2, medullary thyroid-1, NSCLC-3, colorectal -5, peritoneal mesotelioma-1 adrenocortical carcinoma-1, pheochromocytoma-2, malignant thymoma-1, melanoma-2, sarcoma-1, hepatocarcinoma-1 and head & neck -1 and ovary-1. 2 DLTs (gr 3 peripheral neuropathy and renal failure) were observed at 27 mg/m2/dose. Toxicities at the MTD dose (21 mg/m2/dose) have been acceptable: Myalgias/arthralgias being the most common. Other gr 1–2 toxicities included: diarrhea, weight loss, fatigue, elevated transaminases, hair loss, electrolyte abnormalities (hyponatremia and hypo/hyper-magnesemia) and leukocytopenia. PK is linear, with AUC and Cmax increasing as dose was escalated. Drug clearance is independent of dose, but highly variable (10.75 ± 5.56 L/hr/m2). Half-life: 10.0 to 31.7 h, with a median of 17.2 h. At the MTD: Cmax was 523.6 ± 265.3 ng/mL; Very high interindividual variability (CV = 70.3%) and a mean AUCinf of 2467.5 ± 1733.8 hr*ng/mL. Disease stabilization was achieved in a pt with mesothelioma (19 mos +) and another with head and neck cancer (8 mos +). Conclusions: We recommend 21mg/m2/dose twice weekly as the Phase II dose. The study continues to accrue at the MTD to collect paired biopsies for proteomic evaluation on Hsp90 client proteins analysis.

No significant financial relationships to disclose.

Update of the NCI multiinstitutional phase II trial of romidepsin, FK228, for patients with cutaneous or peripheral T-cell lymphoma

8027

Background: The histone deacetylase inhibitors (HDIs) are a class of differentiating agents undergoing clinical testing. Like other HDIs, romidepsin (FK228) modulates expression of genes involved in cell cycle regulation and markers of differentiation in cancer cell lines, leading to induction of differentiation or apoptosis. Romidepsin has demonstrated clinical activity in patients with T-cell lymphoma. Methods: Patients with CTCL (42) or PTCL (36) were enrolled in the NCI multi-institutional trial and assigned to cohorts based on extent of prior therapy and pathology. Romidepsin is administered on days 1, 8, and 15 of a 28 d cycle with a starting dose of 14mg/m2. Responses for patients with PTCL are measured using Cheson criteria, and CTCL using RECIST criteria. Results: Cohort one, composed of 27 patients who had previously received no more than 2 prior cytotoxic regimens of chemotherapy, has completed enrollment. Responses observed include 3 patients with CR and 7 patients with partial responses, yielding an overall response rate of 37%. Of note, responses were observed independent of stage of disease. Among 18 patients with stage IV disease, 6 patients had a complete or partial response, including 3 patients with Sézary syndrome. When including patients with greater than 2 prior cytotoxic regimens, the overall response rate was 31%. A replicate arm has been opened with the goal of confirming the response rate observed in the first cohort. Response data have not been evaluated from this arm at this time. Responses observed in 36 patients with refractory or relapsed PTCL includes 3 patients with CR and 8 patients with partial responses, comprising an overall response rate of 30%. Responses were observed independent of prior therapy, with some patients having undergone prior stem-cell transplant. Molecular endpoint analysis was performed on peripheral mononuclear cells (PBMNCs) and tumor biopsies from treated patients evaluating histone acetylation and changes in gene expression. Conclusions: Romidepsin as a single agent appears to have significant single agent activity in patients with CTCL and PTCL. Combination therapy with romidepsin may increase efficacy and should be pursued. This protocol remains open to accrual.

No significant financial relationships to disclose.

A pharmacokinetic study of Genetaxyl (G) together with cyclosporin A (CsA) administered orally in cancer patients

12002

Background: Oral administration of paclitaxel given with CsA has shown promising activity in Phase II trials, but the apparent bioavailability is low and dose-dependent due to the presence of high concentrations of Cremophor EL (CrEL). We hypothesized that the use of a novel oral paclitaxel formulation containing only 20% CrEL (Genetaxyl [G]; Genovate Biotechnology Ltd., Taiwan), given with CsA is associated with an improved pharmacokinetic (PK) profile. Methods: Cohorts of 6 patients with cancer were treated with oral G at a dose of 60, 120, or 180 mg/m2 and 10 mg/kg of oral CsA in cycle 1. In cycle 2, patients received IV G (175 mg/m2, 3-h infusion). Three additional patients received generic IV paclitaxel (GIP). Serial blood samples were analyzed by LC/MS/MS and equilibrium dialysis, to determine total and unbound paclitaxel PK. Results: The mean (± SD) total paclitaxel AUCs were 1299±189, 1682±636, and 2204±1407 ng.h/mL at the 3 consecutive dose levels, suggesting nonlinear PK. However, based on unbound AUC, the oral bioavailability was dose-independent (P=.62), with a mean value of 37.2±18.6% (n=15). As expected, the total paclitaxel AUC following IV G (9024±4648 ng·h/mL) was lower than that for IV GIP (13,732±3983 ng·h/mL), as a result of increased clearance (39.6 vs 18.3 L/h) and a larger volume of distribution (768 vs 268 L). Interestingly, the unbound paclitaxel AUC was similar between the two IV formulations (P=.25), as the ratio of unbound/total paclitaxel for G was 2.5 times higher than that for GIP (12.5 vs 4.9%). Toxicity profiles were mild, with only 2 patients experiencing ≥ Gr 3 myelosuppression following oral G at 180 mg/m2. Conclusions: The mean bioavailability of paclitaxel following oral Genetaxyl with CsA was about 37%, which is higher than that observed previously with paclitaxel (range, 21–31%). Further clinical exploration of oral Genetaxyl in taxane-sensitive diseases is warranted.

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Phase I trial of the oral histone deacetylase inhibitor MS-275 administered with food

13036

Background: The histone deacetylase (HDAC) inhibitor MS-275, a synthetic benzamide derivative, has demonstrated antitumor activity in vitro & in vivo. After determining maximum tolerable dose (MTD = 2 mg/m2) & dose limiting toxicity (DLT) for MS-275 given to fasting patients (pts) weekly ×4 q6 weeks, we explored toxicity profile, MTD, & pharmacokinetics (PK) of MS-275 when given po on the same schedule with food. Methods: MS-275 at 2, 4, or 6 mg/m2 was administered to pts with advanced malignancy & PS ≤2, LFTs ≤2.5 × normal, adequate hematopoietic & renal function, & normal resting MUGA. PK samples were analyzed by LC-MS. Data for pts in the fed state were compared to data obtained in previous cohorts of pts treated in the fasting state. Protein acetylation assessed by a novel flow cytometric assay & HDAC enzymatic activity were measured in peripheral blood mononuclear cells (PBMC). Results: 16 pts received a median of 2 cycles (1–5) of MS-275 2–6 mg/m2 with food. No DLT occurred on 2 or 6 mg/m2 (n = 3 each), while 1 pt on 4 mg/m2 (n = 10) had a DLT: grade 3 hypophosphatemia. For 2–6 mg/m2 other grade 3 toxicities were neutropenia & lymphopenia. Grade 1–2 toxicities in >1 pt were leucopenia, anemia, thrombocytopenia, fatigue, nausea, vomiting, headache, hypoalbuminemia, hypophosphatemia, hyponatremia, & hypocalcemia. MTD has not been reached; current dose level is 8 mg/m2. Comparing PK for fasting & fed pts on 2–4 mg/m2, there was no difference in Tmax (0.5h); average Cmax & AUC were 35% & 25% lower, respectively, in fed pts; this difference is not statistically significant. Interindividual variability in exposure to MS-275 increased from 52% in fasting pts to 100% in fed pts. PBMC protein acetylation & HDAC inhibition were seen at all dose levels (2–6 mg/m2) in fed pts. Of 9 pts evaluable for response (2–4 mg/m2), 2 of 6 pts on 4 mg/m2 had stable disease. Conclusions: MTD has not yet been established for MS-275 given with food on this schedule but is ≥4 mg/m2 weekly x4 q6 weeks. Interindividual variability in exposure increases with food. Whether intestinal absorption is decreased when MS-275 is given with food requires further evaluation with additional patients. Drug-related protein hyperacetylation & HDAC inhibition were observed.

[Table: see text]

Routine interval computed tomography in detecting new soft tissue disease in patients with androgen-independent prostate cancer (AIPC) and only bone metastasis

4621

Background: Bone is the most common metastatic site in AIPC and the only site of metastasis for many patients. However, some pts with only bone metastasis will eventually develop soft tissue disease. Thus many clinical trials include CT monitoring to exclude new soft tissue disease as the only manifestation of disease progression. The true incidence of the asymptomatic development of soft tissue metastases without PSA or bone scan progression is unknown. Here we have identified pts with bone metastasis only at the time of protocol enrollment. We analyzed their disease progression pattern to determine the utility of routine interval CT scans. Methods: We reviewed 100 pts with metastatic AIPC from three phase II clinical trials (docetaxel/thalidomide, docetaxel/vaccine, and ketoconazole/alendronate) between 1995 and 2004. Pts were assessed every 4 weeks with PSA measurement. CT and bone scans were performed 2 months after start of the trial and then at least every 3 months. Median follow-up time was 8 months (1–44 months). The pts with bone metastasis only were examined for the occurrence of soft tissue diseases by subsequent CT scans in association with bone scan and PSA. Results: Of 100 pts with metastatic AIPC, 33% had soft tissue disease alone or soft tissue and bone disease. 67% had no soft tissue involvement identified by CT but had bone metastasis revealed by bone scan. Of the pts with only bone metastasis, 3% (2 pts) developed new soft tissue disease. One pt developed new right illiac fossa lymphadenopathy after 8 months, and another a peri-rectal mass after 12 months. The one with new lymphadenopathy also had multiple new bone lesions identified by bone scan and PSA progression. The one with a peri-rectal mass had PSA progression and a palpable abnormality. Conclusions: The incidence of asymptomatic new soft tissue disease as the only manifestation of disease progression appears to be quite low in pts with only bone metastasis. Scheduled interval examination with CT to exclude new soft tissue disease does not appear to be warranted. CT scans should probably only be done at the time of disease progression shown by bone scan/PSA or when there are clinical signs or symptoms of new soft tissue disease.

No significant financial relationships to disclose.

Phase I trial of the angiogenesis inhibitor TNP-470 for progressive androgen-independent prostate cancer

Clinical and laboratory observations support the view that angiogenesis is necessary for prostate cancer progression. The angiogenesis inhibitor TNP-470 has demonstrated in vivo antitumor activity in a series of clinical models. To evaluate a possible therapeutic clinical value, we conducted a Phase I dose escalation trial of alternate-day i.v. TNP-470 in 33 patients with metastatic and androgen-independent prostate cancer. The patients were evaluated during therapy for evidence of neurological toxic effects. An assay of endothelial and vascular proliferation "markers" and a sequential assay of serum prostate-specific antigen concentration were performed. The effects of TNP-470 could be evaluated in 32 of the 33 patients. The maximum tolerated dose was 70.88 mg/m(2) of body surface area. The dose-limiting toxic effect was a characteristic neuropsychiatric symptom complex (anesthesia, gait disturbance, and agitation) that resolved upon cessation of therapy. The times to clinical recovery of neurological side effects were 6, 8, and 14 weeks. No definite antitumor activity of TNP-470 was observed; however, transient stimulation of the serum prostate-specific antigen concentration occurred in some of the patients treated. Additional studies of TNP-470 should be conducted using an alternate-day i.v. injection of 47.25 mg/m(2) body surface area and should focus on understanding and overcoming the neurological toxic effects. In addition, valid intermediate end points that reflect the status of tumor-associated neovascularity are needed to facilitate effective development of treatment strategies.

8:45-9:00. Using PET 18F-FDG, 11CO, and 15O-water for Monitoring Prostate Cancer During a Phase II Anti-angiogenic Drug Trial with Thalidomide

Assessing prostate metastases is difficult with conventional radiographic modalities as few patients have soft tissue involvement and most have only bone lesions. Even with FDG PET, problems due to decreased avidity compared to other tumor types can occur. We assessed PET's ability to monitor changes in such tumors during an anti-angiogenic therapy. We measured changes in tumor blood flow (15O), blood volume (11CO), 18F-FDG uptake and "metabolic volume" before and during thalidomide treatment, to see if these changes correlated with changes in PSA values.Six patients with androgen-independent prostate cancer were imaged with 18F-FDG, 11CO, and 15O water before and during (mean interval 63 days, range 55-76 days) thalidomide therapy (200-1200mg/day). Lesions were visually identified on FDG images (9 bone, 5 soft tissue lesions). VOI's were generated by 3D region growing, with a 50% maximum pixel threshold. These VOI's were registered with, and applied to, the 11CO and water studies. Correlations with PSA values were done using the Spearman rank test.The change in maximum (r = 0.77, p = 0.06) and mean FDG value (r = 0.83, p = 0.03), functional FDG volume (r = 0.66, p = 0.14), and 11-CO blood volume (r = 0.77, p = 0.06) all correlated with the change in PSA. Changes in blood flow values were smaller than the variance of the method for repeated measures, likely due to low flow values in bone.Changes in blood volume measured by 11CO, and the mean and peak activity and functional volume measured by 18F-FDG, correlate with changes in PSA and may be useful in monitoring anti-angiogenic therapy in prostate cancer.