First-in-human Phase I Trial of TPST-1120, an Inhibitor of PPARα, as Monotherapy or in Combination with Nivolumab, in Patients with Advanced Solid Tumors.

PURPOSE: TPST-1120 is a first-in-class oral inhibitor of peroxisome proliferator-activated receptor α (PPARα), a fatty acid ligand-activated transcription factor that regulates genes involved in fatty acid oxidation, angiogenesis, and inflammation, and is a novel target for cancer therapy. TPST-1120 displayed antitumor activity in xenograft models and synergistic tumor reduction in syngeneic tumor models when combined with anti-PD-1 agents. EXPERIMENTAL DESIGN: This phase I, open-label, dose-escalation study (NCT03829436) evaluated TPST-1120 as monotherapy in patients with advanced solid tumors and in combination with nivolumab in patients with renal cell carcinoma (RCC), cholangiocarcinoma (CCA), or hepatocellular carcinoma. Objectives included evaluation of safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity (RECIST v1.1). RESULTS: A total of 39 patients enrolled with 38 treated (20 monotherapy, 18 combination; median 3 prior lines of therapy). The most common treatment-related adverse events (TRAE) were grade 1-2 nausea, fatigue, and diarrhea. No grade 4-5 TRAEs or dose-limiting toxicities were reported. In the monotherapy group, 53% (10/19) of evaluable patients had a best objective response of stable disease. In the combination group, 3 patients had partial responses, for an objective response rate of 20% (3/15) across all doses and 30% (3/10) at TPST-1120 ≥400 mg twice daily. Responses occurred in 2 patients with RCC, both of whom had previously progressed on anti-PD-1 therapy, and 1 patient with late-line CCA. CONCLUSIONS: TPST-1120 was well tolerated as monotherapy and in combination with nivolumab and the combination showed preliminary evidence of clinical activity in PD-1 inhibitor refractory and immune compromised cancers. SIGNIFICANCE: TPST-1120 is a first-in-class oral inhibitor of PPARα, whose roles in metabolic and immune regulation are implicated in tumor proliferation/survival and inhibition of anticancer immunity. This first-in-human study of TPST-1120 alone and in combination with nivolumab supports proof-of-concept of PPARα inhibition as a target of therapeutic intervention in solid tumors.

Phase Ib Study of Navicixizumab Plus Paclitaxel in Patients With Platinum-Resistant Ovarian, Primary Peritoneal, or Fallopian Tube Cancer.

PURPOSE: This phase Ib study evaluated the safety and efficacy of paclitaxel plus navicixizumab, a bispecific antiangiogenic antibody to vascular endothelial growth factor and delta-like ligand 4, against platinum-resistant ovarian cancer. PATIENTS AND METHODS: This open-label, nonrandomized, dose-escalation and -expansion study included 44 patients with previously treated, recurrent, platinum-resistant grade 2/3 ovarian cancer. Treatment was intravenous navicixizumab (3 mg/kg or 4 mg/kg once every 2 weeks) plus paclitaxel (80 mg/m2 intravenously on days 0, 7, and 14 of 28-day cycles). The primary and secondary objectives were to evaluate the safety and efficacy of navicixizumab plus paclitaxel. An RNA-based diagnostic panel was retrospectively used to test the hypothesis that tumors with high angiogenesis or immune-suppressed tumor microenvironment (TME) subtypes (biomarker-positive) are more likely to respond to navicixizumab than those with immune-active/-desert TME subtypes (biomarker-negative). RNA expression was analyzed in available pretreatment tumor tissue to classify 33 patients' TME subtypes, and TME panel findings were correlated with tumor response. RESULTS: The dose-escalation cohorts enrolled patients at navicixizumab doses of 3 mg/kg once every 2 weeks (n = 3) and 4 mg/kg once every 2 weeks (n = 2); 3 mg/kg was selected for expansion (n = 39). No dose-limiting toxicities occurred. The most common grade 3/4 treatment-related adverse events were hypertension (40.9%), neutropenia (6.8%), and thrombocytopenia (4.5%). Pulmonary hypertension occurred in 18.2% (grade 1-2). The overall objective response rate was 43.2% (95% CI, 28.3 to 59.0): 33.3% (95% CI, 17.3 to 52.8) in patients previously treated with bevacizumab, 64.3% (95% CI, 35.1 to 87.2) in bevacizumab-naive patients, and 62% (95% CI, 31.6 to 86.1) in biomarker-positive patients. The median duration of response was 6 months (95% CI, 5.4 months to not estimable). CONCLUSION: Navicixizumab plus paclitaxel demonstrated promising clinical activity in bevacizumab-treated and -naive patients with platinum-resistant ovarian cancer, with manageable toxicity.

A Phase 1a/b Open-Label, Dose-Escalation Study of Etigilimab Alone or in Combination with Nivolumab in Patients with Locally Advanced or Metastatic Solid Tumors.

PURPOSE: TIGIT (T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain) is a co-inhibitory receptor of T-cell and natural killer cell activity. Targeting TIGIT with or without PD-1/PD-L1 checkpoint inhibition may enhance antitumor immunity. PATIENTS AND METHODS: This Phase 1a/b trial was a first-in-human, open-label, multicenter, dose-escalation and -expansion study in patients with locally advanced or metastatic solid tumors. Using 3 + 3 design, patients underwent 14-day treatment cycles with anti-TIGIT antibody etigilimab alone (Phase 1a; 0.3, 1.0, 3.0, 10.0, 20.0 mg/kg intravenously) or in combination with anti-PD-1 antibody nivolumab (Phase 1b; 3.0, 10.0, 20.0 mg/kg etigilimab and 240 mg nivolumab). Primary objective was safety and tolerability. RESULTS: Thirty-three patients were enrolled (Phase 1a, n = 23; Phase 1b, n = 10). There were no dose-limiting toxicities (DLT). MTD for single and combination therapy was not determined; maximum administered dose was 20 mg/kg. The most commonly reported adverse events (AE) were rash (43.5%), nausea (34.8%), and fatigue (30.4%) in Phase 1a and decreased appetite (50.0%), nausea (50.0%), and rash (40%) in Phase 1b. Six patients experienced Grade ≥3 treatment-related AEs. In Phase 1a, 7 patients (30.0%) had stable disease. In Phase 1b, 1 patient had a partial response; 1 patient had prolonged stable disease of nearly 8 months. Median progression-free survival was 56.0 days (Phase 1a) and 57.5 days (Phase 1b). Biomarker correlative analyses demonstrated evidence of clear dose-dependent target engagement by etigilimab. CONCLUSIONS: Etigilimab had an acceptable safety profile with preliminary evidence of clinical benefit alone and in combination with nivolumab and warrants further investigation in clinical trials.

Phase Ib Study of Wnt Inhibitor Ipafricept with Gemcitabine and nab-paclitaxel in Patients with Previously Untreated Stage IV Pancreatic Cancer.

PURPOSE: The recombinant fusion protein ipafricept blocks Wnt signaling, and in combination with gemcitabine and nab-paclitaxel caused tumor regression in xenografts. This phase Ib study evaluated the combination of ipafricept with nab-paclitaxel + gemcitabine in patients with untreated metastatic pancreatic adenocarcinoma (mPDAC). PATIENTS AND METHODS: Dose escalation started with standard dose nab-paclitaxel + gemcitabine and ipafricept (3.5 mg/kg days 1, 15). Because of fragility fractures seen with different anti-Wnt agents, following cohorts had ≥6 patients treated with ipafricept 3 to 5 mg/kg on day 1, and included bone marker monitoring and prophylactic bisphosphonates as indicated. On the basis of preclinical data, sequential dosing was evaluated in cohort 4 (ipafricept day 1 followed nab-paclitaxel + gemcitabine day 3). Objectives included safety, MTD, recommended phase II dose, pharmacokinetics, immunogenicity, pharmacodynamics, and efficacy. RESULTS: A total of 26 patients were enrolled, five in cohort 1 and seven each in cohorts 2-4. ipafricept-related adverse events (AEs) of any grade included fatigue, nausea, vomiting, anorexia, and pyrexia. ipafricept-related AEs grade ≥3 included two events of aspartate aminotransferase elevation, and one each of nausea, rash, vomiting, and leucopenia. No dose-limiting toxicities or fragility fractures were observed. Nine patients (34.6%) had partial response, 12 (46.2%) stable disease as best response, with clinical benefit rate of 81%. Median progression-free survival was 5.9 m [95% confidence interval (CI), 3.4-18.4], median overall survival was 9.7 m (95% CI, 7.0-14). The study was terminated by the sponsor due to bone-related toxicity within this therapeutic program and concerns for commercial viability. One patient remains on therapy under compassionate use. CONCLUSIONS: Ipafricept can be administered with nab-paclitaxel + gemcitabine with reasonable tolerance. Wnt pathway remains a therapeutic target of interest in mPDAC.

Demcizumab combined with paclitaxel for platinum-resistant ovarian, primary peritoneal, and fallopian tube cancer: The SIERRA open-label phase Ib trial.

OBJECTIVES: To evaluate the safety and preliminary efficacy of demcizumab (DLL4 targeted IgG2 humanized monoclonal antibody; potent inhibitor of the Notch pathway) in combination with weekly paclitaxel in platinum-resistant epithelial ovarian cancer (EOC); and to determine the maximum tolerated dose (MTD) or maximum administered dose (MAD). METHODS: We conducted a 3 + 3 dose-escalation trial in patients with recurrent, platinum-resistant EOC with RECIST v. 1.1 measurable disease and ≤4 prior chemotherapy regimens. Two dosing cohorts (2.5 mg/kg and 5 mg/kg) were targeted; however, an intermediate dose level (3.5 mg/kg) was to be evaluated if the 5 mg/kg dose was not tolerable. Demcizumab was administered on days 1 and 15 and paclitaxel, weekly on days 1, 8, and 15 for each of three 28-day cycles: the 3-cycle doublet could be repeated once if safe. Thereafter, paclitaxel was administered until unacceptable toxicity or disease progression. RESULTS: Nineteen patients were enrolled. No dose-limiting toxicities (DLT) were observed; however, the intermediate dose level (3.5 mg/kg) was enrolled and expanded based on emerging safety data from other trials in the demcizumab program. The MTD was not reached. The most common treatment emergent adverse events (TEAE) were diarrhea (68%), fatigue (58%), peripheral edema (53%), and nausea (53%). Pulmonary hypertension, grade 2 (n = 2) and grade 1 (n = 1), was observed. Overall response rate (ORR) was 21% (95% CI: 6-45%); clinical benefit rate (CBR) was 42% (95% CI: 20-66%). CONCLUSIONS: Demcizumab in combination with paclitaxel has a manageable toxicity profile and showed activity in patients with heavily pretreated platinum-resistant ovarian cancer.

A phase 1b dose escalation study of Wnt pathway inhibitor vantictumab in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic pancreatic cancer.

Vantictumab is a fully human monoclonal antibody that inhibits Wnt pathway signaling through binding FZD1, 2, 5, 7, and 8 receptors. This phase Ib study evaluated vantictumab in combination with nab-paclitaxel and gemcitabine in patients with untreated metastatic pancreatic adenocarcinoma. Patients received vantictumab at escalating doses in combination with standard dosing of nab-paclitaxel and gemcitabine according to a 3 + 3 design. A total of 31 patients were treated in 5 dosing cohorts. Fragility fractures attributed to vantictumab occurred in 2 patients in Cohort 2 (7 mg/kg every 2 weeks), and this maximum administered dose (MAD) on study was considered unsafe. The dosing schedule was revised to every 4 weeks for Cohorts 3 through 5, with additional bone safety parameters added. Sequential dosing of vantictumab followed by nab-paclitaxel and gemcitabine was also explored. No fragility fractures attributed to vantictumab occurred in these cohorts; pathologic fracture not attributed to vantictumab was documented in 2 patients. The study was ultimately terminated due to concerns around bone-related safety, and thus the maximum tolerated dose (MTD) of the combination was not determined. The MAD of vantictumab according to the revised dosing schedule was 5 mg/kg (n = 16).

A phase 1b dose escalation study of ipafricept (OMP54F28) in combination with paclitaxel and carboplatin in patients with recurrent platinum-sensitive ovarian cancer.

OBJECTIVES: The WNT pathway is an important oncologic driver of epithelial ovarian cancer (EOC). The first-in-class recombinant fusion protein ipafricept (IPA) blocks Wnt signaling through binding of Wnt ligands. This phase Ib trial was designed to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RPh2) for IPA in combination with taxane and platinum therapy (C/P). METHODS: Dose escalation started with a standard 3 + 3 design for IPA/C/P with q3w intravenous IPA on Day 1, in cycles 1 to 6 with C (AUC = 5 mg/ml·min) and P (175 mg/m2). For enhanced bone safety the trial was revised to 6-patient cohorts with a q3w regimen of IPA on Day 1 and C/P on Day 3 (IPA → C/P). RESULTS: 37 patients have been treated; 30 of whom were treated following protocol revision to q3w IPA(D1) → C/P(D3) (2 & 4 mg/kg). IPA-related TEAEs that occurred in ≥15% included: fatigue (40%); nausea (35%); diarrhea and decreased appetite (22%) each; dysgeusia (19%); and vomiting (16.2%). 22% reported ≥1 IPA related TEAE Grade ≥3 the most common of which was neutropenia at 16%. There were no DLTs; the MTD was not reached. The maximum administered dose based on bone safety was 6 mg/kg. The overall response rate (ORR) was 75.7%. Median PFS was 10.3 months (95% CI 8.5-14.2) and OS 33 months (95% CI 23.4-NR). CONCLUSIONS: IPA is well tolerated in combination with sequential C/P. ORR, PFS and OS are comparable to historical data but bone toxicity at efficacy doses of this particular Wnt inhibitor limit further development in EOC.

A first-in-human phase 1a study of the bispecific anti-DLL4/anti-VEGF antibody navicixizumab (OMP-305B83) in patients with previously treated solid tumors.

Purpose Navicixizumab (OMP-305B83) is a bispecific antibody that inhibits delta-like ligand 4 and vascular endothelial growth factor. This Phase 1a trial assessed escalating doses of navicixizumab in refractory solid tumors patients. Design A 3 + 3 dose escalation design was used followed by the treatment of additional patients in an expansion cohort. Study objectives were determination of the maximum tolerated dose, safety, pharmacokinetics, pharmacodynamics, immunogenicity and efficacy. Results Sixty-six patients were treated once every 3 weeks in 8 dose-escalation cohorts (0.5, 1, 2.5, 3.5, 5, 7.5, 10, and 12.5 mg/kg) and an expansion cohort (7.5 mg/kg). The median age was 60 years and 68% of the patients were female. The most commonly enrolled tumor types were ovarian (12), colorectal (11) and breast, pancreatic, uterine and endometrial (4 each) cancers. As only 1 dose limiting toxicity occurred, the maximum tolerated dose was not reached, but 7.5 mg/kg was chosen as the dose for the expansion cohort. The treatment related adverse events (≥15% of patients) were hypertension (57.6%), headache (28.8%), fatigue (25.8%), and pulmonary hypertension (18.2%). Pulmonary hypertension was mostly asymptomatic at doses ≤5 mg/kg (6 Gr1, 1 Gr2), but was more severe at higher doses (4 Gr2, 1 Gr3). Navicixizumab's half-life was 11.4 days and there was a moderate (29%) incidence of anti-drug antibody formation. Four patients (3 ovarian cancer, 1 uterine carcinosarcoma) had a partial response and 17 patients had stable disease. Nineteen patients had a reduction in the size of their target lesions including 7/11 patients with ovarian cancer. Four patients remained on study for >300 days and 2 of these patients were on study for >500 days. Conclusions Navicixizumab can be safely administered with manageable toxicities and these data showed preliminary signs of antitumor activity in multiple tumor types, but was most promising in ovarian cancer. As a result these data justify its continued development in combination Phase 1b clinical trials.

A phase 1 dose escalation and expansion study of Tarextumab (OMP-59R5) in patients with solid tumors.

Purpose This Phase I trial evaluated the maximum tolerated dose, safety, pharmacokinetics, pharmacodynamics and preliminary efficacy of tarextumab (OMP-5948), a novel cross-reactive antibody which binds and selectively inhibits signaling via both Notch2 and Notch3, in adult patients with advanced malignancies. Methods Standard 3 + 3 design with tarextumab 0.5, 1, 2.5, or 5 mg/kg weekly, or 5, 7.5, or 10 mg/kg every other week, or 7.5 mg every 3 weeks. Dose-limiting toxicities (DLT) were assessed during the first 28 days. Results Forty-two patients received tarextumab (21 weekly, 15 every other week, 6 every three weeks). 2/6 subjects at the 5 mg/kg weekly dose, 2/3 at 10 mg/kg every other week, and 0/6 at 7.5 mg/kg every three weeks had a DLT. The maximum tolerated dose (MTD) was 2.5 mg/kg weekly, and 7.5 mg/kg on the every other and every three week schedules. Gastrointestinal (GI) toxicity was the most common adverse event with diarrhea (81%), fatigue (48%), nausea (45%), anorexia (38%), and vomiting (38%) and abdominal pain and constipation (24% each). Biomarker analysis showed regulation of stem cell and Notch gene signaling. Conclusion Tarextumab was generally well-tolerated at doses <2.5 mg weekly and 7.5 mg/kg every other and every third week. Diarrhea was dose-limiting above these levels, but relatively easily managed at lower doses. Inhibition of Notch pathway signaling was demonstrated at these doses. ClinicalTrials.gov Identifier: NCT01277146.

Phase IB Trial of the Anti-Cancer Stem Cell DLL4-Binding Agent Demcizumab with Pemetrexed and Carboplatin as First-Line Treatment of Metastatic Non-Squamous NSCLC.

BACKGROUND: Delta-like ligand 4-Notch (DLL4-Notch) signaling contributes to the maintenance of chemotherapy-resistant cancer stem cells and tumor vasculature. OBJECTIVE: This phase IB trial of demcizumab, an IgG2 humanized monoclonal antibody directed against DLL4, was undertaken to determine its maximum tolerated dose, safety, immunogenicity, preliminary efficacy, pharmacokinetics, and pharmacodynamics, combined with standard chemotherapy. PATIENTS AND METHODS: Forty-six treatment-naive patients with metastatic non-squamous non-small cell lung cancer (NSCLC) were enrolled in this open-label, dose-escalation study using a standard 6 + 6 design. Demcizumab (2.5, 5.0, and 7.5 mg/kg) was given once every 3 weeks with standard doses of pemetrexed and carboplatin using a continuous (six cycles followed by demcizumab maintenance) or a truncated demcizumab regimen (four cycles followed by pemetrexed maintenance). RESULTS: Initially, continuous demcizumab was given until progression but two patients developed grade 3 pulmonary hypertension and congestive heart failure after eight or more infusions. Thereafter, 23 patients were treated with a truncated regimen of demcizumab, which was not associated with any grade 3 or greater cardiopulmonary toxicity. Common adverse events were hypertension, raised brain natriuretic peptide, and those expected from carboplatin and pemetrexed alone. Twenty of 40 evaluable patients (50%) had objective tumor responses. In peripheral blood, demcizumab treatment modulated the expression of genes regulating Notch signaling and angiogenesis, and achieved concentrations exceeding those saturating DLL4 binding. CONCLUSIONS: This study has identified a truncated dosing regimen and recommended phase II dose of demcizumab (5 mg/kg q3-weekly ×4) for subsequent clinical evaluation in combination with standard carboplatin and pemetrexed chemotherapy. NCT01189968.

Safety and efficiency of porous-tip contact-force catheter for drug-refractory symptomatic paroxysmal atrial fibrillation ablation: results from the SMART SF trial.

Aims: THERMOCOOL SMARTTOUCH® SF Catheter is a new contact-force (CF)-sensing catheter with 56-hole porous tip designed for improved cooling and reduced fluid delivery compared with a standard 6-hole open-irrigated catheter. The SMART SF study examined the periprocedural safety, acute effectiveness, and procedural efficiency of the catheter for drug-refractory symptomatic paroxysmal atrial fibrillation (PAF) ablation. Methods and results: The prospective, open-label, non-randomized SMART-SF was conducted at 17 US sites. Circumferential pulmonary vein (PV) isolation was performed with confirmation of entrance block in all PVs. Stable ablation sites were identified using CARTO VISITAG™ Module. Primary adverse events (AEs; ≤1 week of index procedure), periprocedural AEs within 30 days of ablation procedure, acute effectiveness (confirmation of entrance block for targeted PVs), CF, and procedural parameters were assessed. Overall, 165 patients were enrolled (mean age, 62.7 years; male, 57.9%; white, 97%; left ventricular ejection fraction, 60.1 ± 7%; left atrium diameter, 38.8 ± 6 mm); 159 underwent radiofrequency ablation and comprised the safety cohort. Primary safety performance criteria were met: primary AE rate was 2.5% (4/159; cardiac tamponade [n = 2], thrombo-embolism [n = 1], transient ischaemic attack [n = 1]). All primary AEs resolved/improved within the 1-month follow-up period. Acute procedural effectiveness was attained in 96.2% (95% confidence interval: 92.0-98.6%) of patients. Procedure time, fluoroscopy time, and fluid delivered were observed in comparison to predecessor catheters. Conclusion: In the SMART-SF trial, the predetermined safety performance goal was met, demonstrating the safety and acute effectiveness of the THERMOCOOL SMARTTOUCH® SF Catheter for PAF ablation.

A First-in-Human Phase I Study of the Anticancer Stem Cell Agent Ipafricept (OMP-54F28), a Decoy Receptor for Wnt Ligands, in Patients with Advanced Solid Tumors.

Purpose: Wnt signaling is implicated in tumor cell dedifferentiation and cancer stem cell function. Ipafricept (OMP-54F28) is a first-in-class recombinant fusion protein with the extracellular part of human frizzled 8 receptor fused to a human IgG1 Fc fragment that binds Wnt ligands. This trial evaluated ipafricept in patients with solid tumors.Experimental design: A 3+3 design was used; ipafricept was given intravenously every 3 weeks. The objectives were determination of dose-limiting toxicities (DLTs), recommended phase 2 dose (RP2D), safety, pharmacokinetics (PK), immunogenicity, pharmacodynamics (PD), and preliminary efficacy.Results: 26 patients were treated in seven dose-escalation cohorts (0.5, 1, 2.5, 5, 10, 15, and 20 mg/kg). No further dose escalation was pursued as PK modeling indicated that the target efficacious dose was reached at 10 mg/kg, and fragility fractures occurred at 20 mg/kg. Most common related grade 1 and 2 adverse events (AEs; ≥20% of patients) were dysgeusia, decreased appetite, fatigue, and muscle spasms. Ipafricept-related grade 3 TEAEs included hypophosphatemia and weight decrease (1 subject each, 3.8%). Ipafricept half-life was ∼4 days and had low incidence of antidrug antibody formation (7.69%) with no impact on drug exposure. Six patients had ß-C-terminal telopeptide (ß-CTX) doubling from baseline, which was reversible. PD modulation of Wnt pathway genes in hair follicles occurred ≥2.5 mg/kg. Two desmoid tumor and a germ cell cancer patient experienced stable disease for >6 months.Conclusions: Ipafricept was well tolerated, with RP2D of 15 mg/kg Q3W. Prolonged SD was noted in desmoid tumor and germ cell cancer patients. Clin Cancer Res; 23(24); 7490-7. ©2017 AACR.

A phase I dose escalation and expansion study of the anticancer stem cell agent demcizumab (anti-DLL4) in patients with previously treated solid tumors.

PURPOSE: This phase I trial evaluated the safety, pharmacokinetics, and pharmacodynamics of demcizumab (OMP-21M18), a humanized IgG2 mAb targeting the Notch ligand DLL4 in adult patients with advanced malignancies. EXPERIMENTAL DESIGN: Standard 3+3 design, with demcizumab 0.5, 1, 2.5, or 5 mg/kg weekly or 2.5, 5, or 10 mg/kg every other week, with an expansion cohort at 10 mg/kg every other week. Dose-limiting toxicities (DLT) were assessed during the first 28 days. RESULTS: Fifty-five patients received demcizumab (15 weekly, 18 every other week, 21 expansion cohort, 1 loading dose). No more than one DLT was seen at any dose level. The MTD was not reached for either schedule. Treatment-related adverse events occurring in >10% of patients were hypertension or blood pressure increased (47%), fatigue (31%), anemia (22%), headache (20%), nausea (13%), hypoalbuminemia (11%), dizziness (11%), and dyspnea (11%). One patient dosed at 2.5 mg/kg developed reversible right-sided heart failure after 63 days on treatment and 4 dosed at 10 mg/kg developed congestive heart failure after ≥98 days on treatment. Five patients were hospitalized with bleeding episodes (2 episodes of tumor-associated bleeding). Sixteen of 25 (64%) evaluable patients at 10 mg/kg had evidence of stabilization of disease or response. CONCLUSION: Demcizumab was generally well tolerated at doses ≤5 mg weekly with disease stabilization and decreases in tumor size demonstrating antitumor activity. Hypertension was the most common adverse event that was clearly related to treatment. Prolonged administration was associated with an increased risk of congestive heart failure.

Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial.

BACKGROUND: Catheter ablation is important for treatment of paroxysmal atrial fibrillation (PAF). Limited animal and human studies suggest a correlation between electrode-tissue contact and radiofrequency lesion generation. OBJECTIVES: The study sought to assess the safety and effectiveness of an irrigated, contact force (CF)-sensing catheter in the treatment of drug refractory symptomatic PAF. METHODS: A prospective, multicenter, nonrandomized study was conducted. Enrollment criteria included: ≥3 symptomatic episodes of PAF within 6 months of enrollment and failure of ≥1 antiarrhythmic drug (Class I to IV). Ablation included pulmonary vein isolation with confirmed entrance block as procedural endpoint. RESULTS: A total of 172 patients were enrolled at 21 sites, where 161 patients had a study catheter inserted and 160 patients underwent radiofrequency application. Procedural-related serious adverse events occurring within 7 days of the procedure included tamponade (n = 4), pericarditis (n = 3), heart block (n = 1, prior to radiofrequency application), and vascular access complications (n = 4). By Kaplan-Meier analyses, 12-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 72.5%. The average CF per procedure was 17.9 ± 9.4 g. When the CF employed was between investigator selected working ranges ≥80% of the time during therapy, outcomes were 4.25 times more likely to be successful (p = 0.0054; 95% confidence interval: 1.53 to 11.79). CONCLUSIONS: The SMART-AF trial demonstrated that this irrigated CF-sensing catheter is safe and effective for the treatment of drug refractory symptomatic PAF, with no unanticipated device-related adverse events. The increased percent of time within investigator-targeted CF ranges correlates with increased freedom from arrhythmia recurrence. Stable CF during radiofrequency application increases the likelihood of 12-month success. (THERMOCOOL® SMARTTOUCH® Catheter for Treatment of Symptomatic Paroxysmal Atrial Fibrillation; NCT01385202).

A novel glucosyltransferase involved in O-antigen modification of Shigella flexneri serotype 1c.

The O antigen of serotype 1c differs from the unmodified O antigen of serotype Y by the addition of a disaccharide (two glucosyl groups) to the tetrasaccharide repeating unit. It was shown here that addition of the first glucosyl group is mediated by the previously characterized gtrI cluster, which is found within a cryptic prophage at the proA locus in the bacterial chromosome. Transposon mutagenesis was performed to disrupt the gene responsible for addition of the second glucosyl group, causing reversion to serotype 1a. Colony immunoblotting was used to identify the desired revertants, and subsequent sequencing, cloning, and functional expression successfully identified the gene encoding serotype 1c-specific O-antigen modification. This gene (designated gtrIC) was present as part of a three-gene cluster, similar to other S. flexneri glucosyltransferase genes. Relative to the other S. flexneri gtr clusters, the gtrIC cluster is more distantly related and appears to have arrived in S. flexneri from outside the species. Analysis of surrounding sequence suggests that the gtrIC cluster arrived via a novel bacteriophage that was subsequently rendered nonfunctional by a series of insertion events.

Phase 2 study of T138067-sodium in patients with malignant glioma: Trial of the National Cancer Institute of Canada Clinical Trials Group.

We studied the activity of T138067-sodium in patients with malignant gliomas. T138067-sodium is a unique new chemotherapy agent that inhibits microtubule formation by binding irreversibly and specifically to beta(1), beta(2)and beta(4) isotypes of 3-tubulin, causing cell arrest at G(2)/M and inducing apoptosis. Patients with recurrent anaplastic astrocytoma or glioblastoma multiforme were treated intravenously with 330 mg/m(2) of T138067-sodium weekly. Treatment was continued until the patient experienced either unacceptable toxicity or progressive disease. Patients had to have histologically proven glioma, have bidimensionally measurable disease at least 1 cm x 1 cm, and have received no more than one prior adjuvant chemotherapy. No chemotherapy or radiotherapy for recurrent disease was permitted. Nineteen patients entered the trial. One patient was found to be ineligible. There were two patients with anaplastic astrocytoma and 16 with glioblastoma multiforme. Only two patients had received prior adjuvant chemotherapy. The first seven patients had full pharmacokinetic sampling. No dose-limiting toxicity was seen, and pharmacokinetic results were consistent with those from nonglioma patients. The most common drug-related effects were fatigue (33%), nausea (28%), neutropenia (28%), and anorexia (17%). No patients stopped the study because of toxicity. No responses were seen in the 15 eligible patients who completed at least one cycle. Three patients had stable disease with a median duration of 2.6 months. Our results suggest that given in this dose and schedule T138067-sodium does not have activity in this population of anaplastic astrocytoma and glioblastoma multiforme.