PIVOT-12: a phase III study of adjuvant bempegaldesleukin plus nivolumab in resected stage III/IV melanoma at high risk for recurrence.

Bempegaldesleukin (BEMPEG: NKTR-214) is an immunostimulatory IL-2 cytokine prodrug engineered to deliver a controlled, sustained and preferential IL-2 pathway signal. Nivolumab (NIVO), a PD-1 inhibitor, has been shown to prolong survival in patients with advanced melanoma and recurrence-free survival in the adjuvant setting. PIVOT-02 showed that BEMPEG plus NIVO was well-tolerated and demonstrated clinical activity as first-line therapy in metastatic melanoma. PIVOT-12 is a randomized, phase III, global, multicenter, open-label study comparing adjuvant therapy with BEMPEG plus NIVO versus NIVO alone in adult and adolescent patients with completely resected cutaneous stage III/IV melanoma at high risk of recurrence. The primary objective is to compare the efficacy, as measured by recurrence-free survival, of BEMPEG plus NIVO versus NIVO.

Following surgery, patients with advanced melanoma may require further treatment to reduce the likelihood of disease recurrence. Nivolumab (NIVO), a checkpoint inhibitor, reduces the risk of melanoma recurrence by enhancing the ability of the immune system to fight disease. Despite the availability of NIVO and other therapies, many patients with melanoma still experience disease recurrence after surgery. This article presents information on a clinical trial named PIVOT-12, which aims to assess the effectiveness of a new investigational drug called bempegaldesleukin that modifies the immune system and is given with NIVO to patients with stage III/IV melanoma following surgery. The main end point being measured is recurrence-free survival, which measures the time between a patient starting the study and the date of disease recurrence. Clinical Trial Registration: NCT04410445 (ClinicalTrials.gov).

PIVOT-10: Phase II study of bempegaldesleukin plus nivolumab in cisplatin-ineligible advanced urothelial cancer.

The choice of first-line therapy for patients with metastatic urothelial cancer (mUC) is based on cisplatin-eligibility and programmed death-ligand 1 (PD-L1) status. For patients with mUC who are ineligible for cisplatin and with low PD-L1 expression, chemotherapy-based regimens are the only approved first-line option. In a Phase I/II trial of the chemotherapy-free regimen, bempegaldesleukin (BEMPEG; NKTR-214) plus nivolumab, patients with locally advanced or mUC experienced tumor responses regardless of baseline PD-L1 expression (objective response rates: 50 and 45% in patients with PD-L1-positive and -negative tumors, respectively). The Phase II PIVOT-10 study (NCT03785925), evaluates efficacy and safety of first-line BEMPEG plus nivolumab in cisplatin-ineligible patients with locally advanced or mUC. Most patients will have low PD-L1 expression. Primary end point: objective response rates (including complete response).

A randomized, double-blind, single-dose, three-arm, parallel group study to determine pharmacokinetic similarity of ABP 959 and eculizumab (Soliris® ) in healthy male subjects.

OBJECTIVES: ABP 959 is a proposed biosimilar to eculizumab, a monoclonal antibody targeting the human C5 complement protein. The objective of this randomized, double-blind, three-arm, study was to demonstrate pharmacokinetic (PK) and pharmacodynamic (PD) similarity of ABP 959 relative to the eculizumab reference product (RP) in healthy adult male subjects. METHODS: Eligible subjects aged 18-45 years were randomized to receive a 300-mg IV infusion of ABP 959, or FDA-licensed eculizumab (eculizumab US), or EU-authorized eculizumab (eculizumab EU). Primary PK endpoint was area under the total serum concentration-time curve from 0 to infinity (AUC0-∞ ); primary PD endpoint was area between the effect curve (ABEC) of CH50-time data. RESULTS: The geometric mean of PK and PD parameters were similar between ABP 959 versus eculizumab US and eculizumab EU; PK and PD similarity was established based on 90% confidence intervals of the geometric mean ratio being within prespecified equivalence margin of 0.8 and 1.25. The incidence of treatment-emergent adverse events was similar across groups. The incidence of binding anti-drug antibodies was similar across treatments; no subjects developed neutralizing antibodies. CONCLUSIONS: This study demonstrated PK and PD similarity of ABP 959 to eculizumab RP; safety and immunogenicity profiles were also similar.

Effect of ketoconazole, a strong CYP3A inhibitor, on the pharmacokinetics of venetoclax, a BCL-2 inhibitor, in patients with non-Hodgkin lymphoma.

AIMS: To examine the effect of a strong cytochrome P450 (CYP) 3A inhibitor, ketoconazole, on the pharmacokinetics, safety and tolerability of venetoclax. METHODS: Twelve patients with non-Hodgkin lymphoma (NHL) were enrolled in this Phase 1, open-label, fixed-sequence study. Patients received a single 50 mg dose of venetoclax orally on Day 1 and Day 8, and a 400 mg once daily dose of ketoconazole on Days 5-11. Blood samples were collected predose and up to 96 h after each venetoclax dose on Day 1 and Day 8. RESULTS: Eleven patients had evaluable pharmacokinetic data and were therefore included in the statistical analyses. Compared to administration of a single 50 mg dose of venetoclax alone, ketoconazole increased the venetoclax mean maximum observed plasma concentration (Cmax ) and area under the plasma concentration-time curve from time 0 to infinity (AUC∞ ) by 2.3-fold (90% confidence interval [CI]: 2.0-2.7) and 6.4-fold (90% CI: 4.5-9.2; range: 2- to 12-fold), respectively. CONCLUSIONS: Coadministration of venetoclax with multiple doses of ketoconazole resulted in a significant increase of venetoclax exposures, strongly suggesting that CYP3A plays a major role in elimination of venetoclax in patients. These results suggest the need to avoid concomitant use with strong and moderate inhibitors or inducers of CYP3A during the venetoclax ramp-up phase in chronic lymphocytic leukaemia (CLL) patients. For patients who have completed the ramp-up phase, a modification in venetoclax dose for use with strong and moderate inhibitors or inducers of CYP3A is recommended.

Repeatability of hypoxia PET imaging using [¹8F]HX4 in lung and head and neck cancer patients: a prospective multicenter trial.

PURPOSE: Hypoxia is an important factor influencing tumor progression and treatment efficacy. The aim of this study was to investigate the repeatability of hypoxia PET imaging with [(18)F]HX4 in patients with head and neck and lung cancer. METHODS: Nine patients with lung cancer and ten with head and neck cancer were included in the analysis (NCT01075399). Two sequential pretreatment [(18)F]HX4 PET/CT scans were acquired within 1 week. The maximal and mean standardized uptake values (SUVmax and SUVmean) were defined and the tumor-to-background ratios (TBR) were calculated. In addition, hypoxic volumes were determined as the volume of the tumor with a TBR >1.2 (HV1.2). Bland Altman analysis of the uptake parameters was performed and coefficients of repeatability were calculated. To evaluate the spatial repeatability of the uptake, the PET/CT images were registered and a voxel-wise comparison of the uptake was performed, providing a correlation coefficient. RESULTS: All parameters of [(18)F]HX4 uptake were significantly correlated between scans: SUVmax (r = 0.958, p < 0.001), SUVmean (r = 0.946, p < 0.001), TBRmax (r = 0.962, p < 0.001) and HV1.2 (r = 0.995, p < 0.001). The relative coefficients of repeatability were 15 % (SUVmean), 17 % (SUVmax) and 17 % (TBRmax). Voxel-wise analysis of the spatial uptake pattern within the tumors provided an average correlation of 0.65 ± 0.14. CONCLUSION: Repeated hypoxia PET scans with [(18)F]HX4 provide reproducible and spatially stable results in patients with head and neck cancer and patients with lung cancer. [(18)F]HX4 PET imaging can be used to assess the hypoxic status of tumors and has the potential to aid hypoxia-targeted treatments.

Bempegaldesleukin plus Nivolumab in First-line Metastatic Urothelial Carcinoma: Results from PIVOT-02.

BACKGROUND: Despite recent changes in the treatment landscape, there remains an unmet need for effective, tolerable, chemotherapy-free treatments for patients with advanced/metastatic urothelial carcinoma (mUC), especially cisplatin-ineligible patients. OBJECTIVE: To evaluate the immunostimulatory interleukin-2 cytokine prodrug bempegaldesleukin (BEMPEG) plus nivolumab in patients with advanced/mUC from the phase 2 multicenter PIVOT-02 study. DESIGN, SETTING, AND PARTICIPANTS: This open-label, multicohort phase 1/2 study enrolled patients with previously untreated locally advanced/surgically unresectable or mUC (N = 41). INTERVENTION: Patients received BEMPEG 0.006 mg/kg plus nivolumab 360 mg intravenously every 3 wk. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary objectives were safety and the objective response rate (ORR) in patients with measurable disease at baseline and at least one postbaseline tumor response assessment (response-evaluable). Secondary objectives were overall survival (OS) and progression-free survival (PFS). Exploratory biomarker analyses via univariate logistic regression were performed to test the association between potential biomarkers (CD8+ tumor-infiltrating lymphocytes, tumor mutational burden, and IFN-γ gene expression profile) and response. RESULTS AND LIMITATIONS: The ORR was 35% (13/37 evaluable patients) and the complete response rate was 19% (7/37 patients); the median duration of response was not reached. Median PFS was 4.1 mo (95% confidence interval [CI] 2.1-8.7) and median OS was 23.7 mo (95% CI 15.8-not reached). Overall, 40/41 patients (98%) experienced at least one treatment-related adverse event (TRAE); grade 3/4 TRAEs occurred in 11 patients (27%), most commonly pyrexia (4.9%; 2 patients). Exploratory biomarker analyses showed no association between biomarkers and response. Limitations include the small sample size and single-arm design. CONCLUSIONS: BEMPEG plus nivolumab was well tolerated and showed antitumor activity as first-line treatment in patients with locally advanced/mUC. PATIENT SUMMARY: We investigated an immune-stimulating prodrug called bempegaldesleukin plus the antibody nivolumab as the first therapy for patients with advanced or metastatic cancer of the urinary tract. This combination had manageable treatment-related side effects and was effective in a subset of patients. This trial is registered at ClinicalTrials.gov as NCT02983045.

Bempegaldesleukin plus nivolumab in first-line renal cell carcinoma: results from the PIVOT-02 study.

BACKGROUND: Immune checkpoint inhibitor-based combinations have expanded the treatment options for patients with renal cell carcinoma (RCC); however, tolerability remains challenging. The aim of this study was to evaluate the safety and efficacy of the immunostimulatory interleukin-2 cytokine prodrug bempegaldesleukin (BEMPEG) plus nivolumab (NIVO) as first-line therapy in patients with advanced clear-cell RCC. METHODS: This was an open-label multicohort, multicenter, single-arm phase 1/2 study; here, we report results from the phase 1/2 first-line RCC cohort (N=49). Patients received BEMPEG 0.006 mg/kg plus NIVO 360 mg intravenously every 3 weeks. The primary objectives were safety and objective response rate (ORR; patients with measurable disease at baseline and at least one postbaseline tumor response assessment). Secondary objectives included overall survival (OS) and progression-free survival (PFS). Exploratory biomarker analyses: association between baseline biomarkers and ORR. RESULTS: At a median follow-up of 32.7 months, the ORR was 34.7% (17/49 patients); 3/49 patients (6.1%) had a complete response. Of the 17 patients with response, 14 remained in response for >6 months, and 6 remained in response for >24 months. Median PFS was 7.7 months (95% CI 3.8 to 13.9), and median OS was not reached (95% CI 37.3 to not reached). Ninety-eight per cent (48/49) of patients experienced ≥1 treatment-related adverse event (TRAE) and 38.8% (19/49) had grade 3/4 TRAEs, most commonly syncope (8.2%; 4/49) and increased lipase (6.1%; 3/49). No association between exploratory biomarkers and ORR was observed. Limitations include the small sample size and single-arm design. CONCLUSIONS: BEMPEG plus NIVO showed preliminary antitumor activity as first-line therapy in patients with advanced clear-cell RCC and was well tolerated. These findings warrant further investigation.

Washout of 8²Rb as a marker of impaired tissue integrity, obtained by list-mode cardiac PET/CT: relationship with perfusion/metabolism patterns of myocardial viability.

PURPOSE: Myocardial washout of the potassium analogue (82)Rb may indicate tissue impairment. Few studies have evaluated its usefulness for viability assessment, and controversial results were reported. We revisited this topic using list-mode positron emission tomography (PET)/CT. METHODS: A total of 22 patients with chronic ischemic cardiomyopathy (ICM) and 11 control subjects with normal CT coronary angiogram were studied. Rest (82)Rb PET/CT studies were acquired in list mode and resampled to static, gated, and dynamic images. Using a 17-segment model, (82)Rb washout was determined by monoexponential fitting of myocardial time-activity curves. In ICM patients, (18)F-fluorodeoxyglucose (FDG) studies were obtained in the same session and segments were classified as normally perfused, mismatch, or matched defect. RESULTS: (82)Rb washout was minimal and homogeneous in control subjects. Normally perfused segments of ICM did not differ (p = 0.33). ICM patients had a left ventricular ejection fraction (LVEF) of 25 ± 12%, 25/353 mismatched, and 46/353 matched defect segments. (82)Rb washout was higher in hypoperfused vs normal segments (p < 0.05), but not different between mismatch and matched defect (p = 0.18). Intraindividual analysis in nine patients showing both FDG mismatch and matched defect confirmed absence of differences. Overall, segmental (82)Rb washout correlated inversely with (82)Rb uptake (r = -0.70; p < 0.05) and less well with FDG uptake (r = -0.31; p < 0.05). CONCLUSION: Using state-of-the-art PET/CT technology for myocardial viability assessment, (82)Rb washout does not distinguish between perfusion/metabolism patterns of hibernating myocardium and scar. Tissue integrity may be at least partially impaired in hibernation.

Longevity of Polymer-Infiltrated Ceramic Network and Zirconia-Reinforced Lithium Silicate Restorations: A Systematic Review and Meta-Analysis.

The purpose of this study was to systematically review the existing literature to assess the clinical survival and success of PICN and ZLS indirect restorations as the clinical evidence for them remains lacking. PubMed, SCOPUS, Embase, Cochrane Library, Web of Science, LILACs, and SciElo databases were searched from 1 January 2000 to 1 February 2021. Clinical trials and cohort studies published in English were included while case studies, case series, and in vitro studies were excluded. Results were analyzed qualitatively and a meta-analysis using a random effects model was performed. A strength of recommendation taxonomy (SORT) analysis was conducted and risk of bias (RoB) was assessed using the Newcastle-Ottawa scale and Cochrane RoB tools. An electronic search through the databases yielded 2454 articles, of which 825 remained after duplicate removal. Five studies investigating PICN and four investigating ZLS indirect restorations remained after assessing for eligibility. The overall survival rate of PICN over 1 year was 99.6% and 99.2% over 2 years. The overall survival rate of ZLS over 1 year was 99%. The main mode of failure for both materials was catastrophic fracture. One study had a high RoB, four had a moderate RoB, and four had a low RoB. Both materials demonstrated moderate strength of recommendation at a level 2 evidence for all studies based on SORT analysis. PICN and ZLS show promising short-term clinical performance as full and partial coverage indirect restorations, but longer follow-up studies are required to confirm their long-term performance.

Memory CD8+ T cells are required for protection from persistent hepatitis C virus infection.

Few hepatitis C virus (HCV) infections resolve spontaneously but those that do appear to afford protective immunity. Second infections are usually shorter in duration and are less likely to persist but mechanisms of virus control in immune individuals have not been identified. In this study we investigated whether memory helper and/or cytotoxic T lymphocytes provide protection in chimpanzees serially reinfected with the virus. Clearance of the first infection took 3-4 mo and coincided with the delayed onset of CD4+ and CD8+ T cell responses. High frequencies of memory T cells targeting multiple HCV proteins were stable over 7 yr of follow-up. Animals were infected for a second time to assess the protective role of memory T cells. In contrast to the prolonged course of the first infection, viremia was terminated within 14 d. Control of this second infection was kinetically linked to rapid acquisition of virus-specific cytolytic activity by liver resident CD8+ T cells and expansion of memory CD4+ and CD8+ T cells in blood. The importance of memory CD8+ T cells in control of HCV infection was confirmed by antibody-mediated depletion of this lymphocyte subset before a third infection. Virus replication was prolonged despite the presence of memory CD4+ T helper cells primed by the two prior infections and was not terminated until HCV-specific CD8+ T cells recovered in the liver. These experiments demonstrate an essential role for memory CD8+ T cells in long-term protection from chronic hepatitis C.

Ubiquitin-independent degradation of hepatitis C virus F protein.

Hepatitis C virus (HCV) F protein is encoded by the +1 reading frame of the viral genome. It overlaps with the core protein coding sequence, and multiple mechanisms for its expression have been proposed. The full-length F protein that is synthesized by translational ribosomal frameshift at codons 9 to 11 of the core protein sequence is a labile protein. By using a combination of genetic, biochemical, and cell biological approaches, we demonstrate that this HCV F protein can bind to the proteasome subunit protein alpha3, which reduces the F-protein level in cells in a dose-dependent manner. Deletion-mapping analysis identified amino acids 40 to 60 of the F protein as the alpha3-binding domain. This alpha3-binding domain of the F protein together with its upstream sequence could significantly destabilize the green fluorescent protein, an otherwise stable protein. Further analyses using an F-protein mutant lacking lysine and a cell line that contained a temperature-sensitive E1 ubiquitin-activating enzyme indicated that the degradation of the F protein was ubiquitin independent. Based on these observations as well as the observation that the F protein could be degraded directly by the 20S proteasome in vitro, we propose that the full-length HCV F protein as well as the F protein initiating from codon 26 is degraded by an ubiquitin-independent pathway that is mediated by the proteasome subunit alpha3. The ability of the F protein to bind to alpha3 raises the possibility that the HCV F protein may regulate protein degradation in cells.

Correction to: Efficacy and safety results from a randomized double-blind study comparing proposed biosimilar ABP 798 with rituximab reference product in subjects with moderate-to-severe rheumatoid arthritis.

This article originally published with the family name and given names of all authors transposed.

Efficacy and safety results from a randomized double-blind study comparing proposed biosimilar ABP 798 with rituximab reference product in subjects with moderate-to-severe rheumatoid arthritis.

BACKGROUND/OBJECTIVES: ABP 798 is a proposed biosimilar to the originator biologic rituximab, an anti-CD20 monoclonal antibody. This comparative clinical study evaluated the pharmacokinetics (PK), safety, and efficacy of ABP 798 versus rituximab reference product (RP) in patients with moderate-to-severe rheumatoid arthritis (RA). METHODS: Adults with moderate-to-severe RA with an inadequate response or intolerance to other disease-modifying anti-rheumatic drugs including 1 or more tumor necrosis factor inhibitor therapies (n = 311) received ABP 798, US-sourced rituximab RP (rituximab US), or EU-sourced rituximab RP (rituximab EU) (1000 mg, 2 weeks apart). At week 24, ABP 798- or rituximab EU-treated subjects received a second dose of the same treatment, while rituximab US-treated subjects transitioned to receive ABP 798. The key efficacy endpoint was DAS28-CRP change from baseline at week 24. Other efficacy endpoints included DAS28-CRP at other time points; ACR20, ACR50, and ACR70 criteria; and hybrid ACR. The rituximab RP groups were pooled for all efficacy endpoints since PK equivalence had been established between rituximab US and rituximab EU. RESULTS: Clinical equivalence between ABP 798 and rituximab RP was established as the 90% confidence interval for DAS28-CRP change from baseline at week 24 fell within the prespecified equivalence margin (- 0.6, 0.6). Safety and immunogenicity profiles of ABP 798 were comparable across treatment groups and not affected by single transition from RP to ABP 798. CONCLUSIONS: Clinical equivalence in terms of efficacy, safety, and immunogenicity was established between ABP 798 and rituximab RP in this comparative clinical trial in patients with moderate-to-severe RA. Key Points • ABP 798 provided similar efficacy as rituximab reference product (RP) in patients with moderate-severe rheumatoid arthritis. • The safety and immunogenicity profiles for ABP 798 were similar to those for the rituximab RP. • The single transition from rituximab RP to ABP 798 did not show differences in efficacy, safety, or immunogenicity.

A Randomized, Double-Blind Study Comparing Pharmacokinetics and Pharmacodynamics of Proposed Biosimilar ABP 798 With Rituximab Reference Product in Subjects With Moderate to Severe Rheumatoid Arthritis.

ABP 798 is a proposed biosimilar to rituximab reference product (RP), an anti-CD20 monoclonal antibody. Pharmacokinetics (PK), pharmacodynamics (PD), and safety results from the comparative clinical study that evaluated the PK, PD, safety, efficacy, and immunogenicity of ABP 798 versus rituximab RP are presented here. Subjects with moderate to severe rheumatoid arthritis (RA) received 2 doses of ABP 798, United States-sourced RP (rituximab US) or European Union-sourced RP (rituximab EU), each consisting of two 1000-mg infusions 2 weeks apart. For the second dose (week 24), ABP 798- and rituximab EU-treated subjects received the same treatment; rituximab US-treated subjects transitioned to ABP 798. End points included area under the serum concentration-time curve from time 0 extrapolated to infinity and maximum observed serum concentration following the second infusion of the first dose (PK) and percentage of subjects with complete CD19+ cell depletion days 1-33 (PD). Primary analysis established PK similarity between ABP 798 and rituximab RP based on 90% confidence intervals of the adjusted geometric mean ratios being within a prespecified equivalence margin of 0.8 and 1.25. Complete CD19+ B-cell depletion on day 3 among groups confirmed PD similarity. These findings demonstrated PK/PD similarity between ABP 798 and rituximab RP in subjects with moderate to severe RA.

Correction to: Efficacy and Safety of ABP 798: Results from the JASMINE Trial in Patients with Follicular Lymphoma in Comparison with Rituximab Reference Product.

Page 608, 4 Discussion, right column, second paragraph.

Efficacy and Safety of ABP 798: Results from the JASMINE Trial in Patients with Follicular Lymphoma in Comparison with Rituximab Reference Product.

INTRODUCTION: ABP 798 is being developed as a biosimilar to rituximab reference product (RP), a CD20-directed cytolytic antibody that is approved in the US and EU for the treatment of non-Hodgkin lymphoma (NHL). METHODS: This randomized, double-blind, comparative clinical study (JASMINE) evaluated the efficacy and safety of ABP 798 compared with rituximab RP. Adult, anti-CD20 treatment naïve patients diagnosed with grade 1, 2, or 3a follicular B-cell NHL expressing CD20 were randomized 1:1 to receive a 375 mg/m2 infusion of either ABP 798 or rituximab RP once weekly for 4 weeks and at weeks 12 and 20. Tumor assessments were performed at baseline and weeks 12 and 28. Primary endpoint was the risk difference (RD) of overall response rate (ORR) of complete response, unconfirmed complete response, or partial response by week 28 based on data from central, independent, and blinded assessments of disease. RESULTS: Of the 256 randomized patients, 254 were treated with ABP 798 (n = 128; 100%) or rituximab RP (n = 126; 98.4%); 96 (78.0%) patients in the ABP 798 group and 87 (70.2%) in the rituximab RP group had a best ORR by week 28. The point estimate of RD in ORR between ABP 798 and rituximab RP from the adjusted generalized linear model for stratification factors was 7.7%. Clinical equivalence was based on sequential testing of the one-sided 95% lower confidence limits and one-sided 95% upper confidence limits of RD in ORR (- 1.4% and 16.8%, respectively) which was within the prespecified non-inferiority margin (- 15%) and non-superiority margin (35.5%), respectively. Results of sensitivity analyses were consistent with the primary efficacy analysis. ABP 798 was also comparable to rituximab RP across additional secondary endpoints, further supporting the conclusion of similarity, and including: RD of ORR at week 12; trough serum concentrations; percent of patients with complete depletion of CD19+ cell count at day 8; safety; and immunogenicity. CONCLUSIONS: These results support a conclusion of similar clinical efficacy between ABP 798 and rituximab RP in patients with follicular lymphoma. NCT NUMBER: NCT02747043; first posted April 21, 2016. EUDRACT NUMBER: 2013-005,542-11; submitted 14 October, 2014.

Induction of broad CD4+ and CD8+ T-cell responses and cross-neutralizing antibodies against hepatitis C virus by vaccination with Th1-adjuvanted polypeptides followed by defective alphaviral particles expressing envelope glycoproteins gpE1 and gpE2 and nonstructural proteins 3, 4, and 5.

Broad, multispecific CD4(+) and CD8(+) T-cell responses to the hepatitis C virus (HCV), as well as virus-cross-neutralizing antibodies, are associated with recovery from acute infection and may also be associated in chronic HCV patients with a favorable response to antiviral treatment. In order to recapitulate all of these responses in an ideal vaccine regimen, we have explored the use of recombinant HCV polypeptides combined with various Th1-type adjuvants and replication-defective alphaviral particles encoding HCV proteins in various prime/boost modalities in BALB/c mice. Defective chimeric alphaviral particles derived from the Sindbis and Venezuelan equine encephalitis viruses encoding either the HCV envelope glycoprotein gpE1/gpE2 heterodimer (E1E2) or nonstructural proteins 3, 4, and 5 (NS345) elicited strong CD8(+) T-cell responses but low CD4(+) T helper responses to these HCV gene products. In contrast, recombinant E1E2 glycoproteins adjuvanted with MF59 containing a CpG oligonucleotide elicited strong CD4(+) T helper responses but no CD8(+) T-cell responses. A recombinant NS345 polyprotein also stimulated strong CD4(+) T helper responses but no CD8(+) T-cell responses when adjuvanted with Iscomatrix containing CpG. Optimal elicitation of broad CD4(+) and CD8(+) T-cell responses to E1E2 and NS345 was obtained by first priming with Th1-adjuvanted proteins and then boosting with chimeric, defective alphaviruses expressing these HCV genes. In addition, this prime/boost regimen resulted in the induction of anti-E1E2 antibodies capable of cross-neutralizing heterologous HCV isolates in vitro. This vaccine formulation and regimen may therefore be optimal in humans for protection against this highly heterogeneous global pathogen.

Awareness, Knowledge, and Perceptions of Biosimilars Among Specialty Physicians.

INTRODUCTION: The Biosimilars Forum conducted a survey through an independent organization from November 20, 2015 to January 4, 2016 in order to assess current levels of awareness, knowledge, and perceptions of biosimilars among US specialty physicians who already prescribe biologics. The survey was intended to provide a baseline level of knowledge about biosimilars and will be repeated in 2-3 years in order to monitor trends over time. METHODS: A 19-question survey was created by the Biosimilars Forum and was administered by an independent third party. RESULTS: Responses were obtained from 1201 US physicians across specialties that are high prescribers of biologics, including dermatologists, gastroenterologists, hematologist-oncologists, medical oncologists, nephrologists, and rheumatologists. CONCLUSIONS: The results of this survey highlight a significant need for evidence-based education about biosimilars for physicians across specialties. Five major knowledge gaps were identified: defining biologics, biosimilars, and biosimilarity; understanding the approval process and the use of "totality of evidence" to evaluate biosimilars; understanding that the safety and immunogenicity of a biosimilar are comparable to the originator biologic; understanding the rationale for extrapolation of indications; and defining interchangeability and the related rules regarding pharmacy-level substitution. FUNDING: Biosimilars Forum.

Evaluation of Rifampin's Transporter Inhibitory and CYP3A Inductive Effects on the Pharmacokinetics of Venetoclax, a BCL-2 Inhibitor: Results of a Single- and Multiple-Dose Study.

Venetoclax is a selective, potent, first-in-class B-cell lymphoma-2 inhibitor that has demonstrated clinical efficacy in a variety of hematological malignancies. A single-dose and multiple-dose rifampin study was conducted to evaluate the effect of CYP3A induction and transporter inhibition on the pharmacokinetics of venetoclax. Subjects received a single dose of venetoclax 200 mg on day 1 of period 1 and days 1 and 14 of period 2, a single dose of rifampin 600 mg on day 1 of period 2, and rifampin 600 mg once daily on days 5 through 17 of period 2. Blood samples were collected up to 96 hours after each venetoclax dose on day 1 of period 1 and days 1 and 14 of period 2. Compared with venetoclax alone, coadministration with a single dose of rifampin increased venetoclax Cmax and AUC∞ by 106% (90%CI, 73%-145%) and 78% (90%CI, 50%-111%), respectively, whereas coadministration with multiple doses of rifampin decreased venetoclax Cmax and AUC∞ by 42% (90%CI, 31%-52%) and 71% (90%CI, 66%-76%), respectively. It was possible to isolate the net effect of chronic CYP3A induction from acute P-glycoprotein (P-gp) inhibition by comparing venetoclax exposures following coadministration with multiple doses of rifampin versus a single dose of rifampin, which showed that CYP3A induction decreased venetoclax Cmax and AUC by 72% and 84%, respectively. These results are consistent with venetoclax being a P-gp substrate and indicate that CYP3A plays a major role in venetoclax metabolism. Prescribers should consider agents with little or no CYP3A induction during treatment with venetoclax.

Effect of Low- and High-Fat Meals on the Pharmacokinetics of Venetoclax, a Selective First-in-Class BCL-2 Inhibitor.

Venetoclax is a selective, first-in-class, B-cell lymphoma-2 inhibitor that has demonstrated clinical efficacy in several hematological malignancies. Two studies evaluated the relative bioavailability of venetoclax in healthy subjects: (1) a bioequivalence study to compare the bioavailability of the film-coated tablet with that of an earlier uncoated tablet and (2) a food effect study to evaluate the effect of food on venetoclax pharmacokinetics. Both studies were open-label, single-dose, crossover studies. In the bioequivalence study, 15 subjects received a single dose of venetoclax 50 mg under nonfasting conditions, in each of 2 periods; one period used the uncoated tablet, and the other used the film-coated tablet. In the food effect study, 24 subjects received a single dose of venetoclax film-coated 100-mg tablet under fasting conditions, after a low-fat breakfast or after a high-fat breakfast in different periods. The venetoclax film-coated tablet was bioequivalent to the uncoated tablet, which indicates that the film coating does not affect bioavailability. The median Tmax of venetoclax was delayed by about 2 hours when administered with food. Compared with fasting conditions, Cmax and AUC increased by approximately 3.4-fold following a low-fat breakfast. High-fat meals increased Cmax and AUC by approximately 50% relative to low-fat meals. The mean terminal half-life was comparable between the high-fat meal and fasting conditions (19.1 versus 16.1 hours). Based on these results and the venetoclax exposure-response profile, venetoclax should be administered with food and without specific recommendations for fat content to ensure adequate and consistent bioavailability.