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Immunotherapy failures can result from the highly suppressive tumour microenvironment that characterizes aggressive forms of cancer such as recurrent glioblastoma (rGBM) 1,2 . Here we report the results of a first-in-human phase I trial in 41 patients with rGBM who were injected with CAN-3110-an oncolytic herpes virus (oHSV) 3 . In contrast to other clinical oHSVs, CAN-3110 retains the viral neurovirulence ICP34.5 gene transcribed by a nestin promoter; nestin is overexpressed in GBM and other invasive tumours, but not in the adult brain or healthy differentiated tissue 4 . These modifications confer CAN-3110 with preferential tumour replication. No dose-limiting toxicities were encountered. Positive HSV1 serology was significantly associated with both improved survival and clearance of CAN-3110 from injected tumours. Survival after treatment, particularly in individuals seropositive for HSV1, was significantly associated with (1) changes in tumour/PBMC T cell counts and clonal diversity, (2) peripheral expansion/contraction of specific T cell clonotypes; and (3) tumour transcriptomic signatures of immune activation. These results provide human validation that intralesional oHSV treatment enhances anticancer immune responses even in immunosuppressive tumour microenvironments, particularly in individuals with cognate serology to the injected virus. This provides a biological rationale for use of this oncolytic modality in cancers that are otherwise unresponsive to immunotherapy (ClinicalTrials.gov: NCT03152318 )., (© 2023. The Author(s).)

A phase I trial (NCT03447314; 204686) evaluated the safety and efficacy of GSK1795091, a Toll-like receptor 4 (TLR4) agonist, in combination with immunotherapy (GSK3174998 [anti-OX40 monoclonal antibody], GSK3359609 [anti-ICOS monoclonal antibody], or pembrolizumab) in patients with solid tumors. The primary endpoint was safety; other endpoints included efficacy, pharmacokinetics, and pharmacodynamics (PD). Manufacturing of GSK1795091 formulation was modified during the trial to streamline production and administration, resulting in reduced PD (cytokine) activity. Fifty-four patients received GSK1795091 with a combination partner; 32 received only the modified GSK1795091 formulation, 15 received only the original formulation, and seven switched mid-study from the original to the modified formulation. Despite the modified formulation demonstrating higher systemic GSK1795091 exposure compared with the original formulation, the transient, dose-dependent elevations in cytokine and chemokine concentrations were no longer observed (e.g., IP-10, IL10, IL1-RA). Most patients (51/54; 94%) experienced ≥1 treatment-emergent adverse event (TEAE) during the study. Safety profiles were similar between formulations, but a higher incidence of TEAEs associated with immune responses (chills, fatigue, pyrexia, nausea, and vomiting) were observed with the original formulation. No conclusions can be made regarding GSK1795091 anti-tumor activity due to the limited data collected. Manufacturing changes were hypothesized to have caused the change in biological activity in this study. Structural characterization revealed GSK1795091 aggregate size in the modified formulation to be twice that in the original formulation, suggesting a negative correlation between GSK1795091 aggregate size and PD activity. This may have important clinical implications for future development of structurally similar compounds., (© 2022 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Parvovirus B19 (PVB19) infection has been implicated in allograft failure or dysfunction in solid organ transplantation (SOT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the literature is limited., Case: Two pediatric patients were diagnosed with PVB19 infection around the time of allo-HSCT graft failure. Both cases were secondary graft failure and required second allo-HSCT., Conclusion: There are many risk factors and potential confounders in determining the exact etiology of graft failure after allo-HSCT. These two cases highlight the importance of including PVB19 in the diagnostic evaluation for graft failure. PVB19 infection may be an important risk factor for allo-HSCT graft failure., (© 2021 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

Background: This phase III OAK trial (NCT02008227) subgroup analysis (data cutoff, January 9, 2019) evaluated the predictive value of 2 PD-L1 IHC tests (VENTANA SP142 and Dako 22C3) for benefit from atezolizumab versus docetaxel by programmed death ligand 1 (PD-L1) status in patients with previously treated metastatic non-small cell lung cancer., Methods: PD-L1 expression was assessed prospectively with SP142 on tumor cells (TC) and tumor-infiltrating immune cells (IC) and retrospectively with 22C3 using a tumor proportion score (TPS) based on TC membrane staining. Efficacy was assessed in the 22C3 biomarker-evaluable population (22C3-BEP) (n = 577; 47.1% of SP142-intention-to-treat population) and non-22C3-BEP (n = 648) in PD-L1 subgroups (high, low, and negative) and according to selection by 1 or both assays., Results: In the 22C3-BEP, overall survival benefits with atezolizumab versus docetaxel were observed across PD-L1 subgroups; benefits were greatest in SP142-defined PD-L1-high (TC3 or IC3: hazard ratio [HR], 0.39 [95% confidence interval (CI), 0.25-0.63]) and 22C3-defined PD-L1-high (TPS ≥ 50%: HR, 0.56 [95% CI, 0.38-0.82]) and low (TPS, 1% to < 50%: HR, 0.55 [95% CI, 0.37-0.82]) groups. Progression-free survival improved with increasing PD-L1 expression for both assays. SP142 and 22C3 assays identified overlapping and unique patient populations in PD-L1-high, positive, and negative subgroups. Overall survival and progression-free survival benefits favored atezolizumab over docetaxel in double PD-L1-positive and negative groups; patients with both SP142- and 22C3-positive tumors derived the greatest benefit., Conclusions: Despite different scoring algorithms and differing sensitivity levels, the SP142 and 22C3 assays similarly predicted atezolizumab benefit at validated PD-L1 thresholds in patients with non-small cell lung cancer., Competing Interests: Disclosure Dr. Gadgeel reports personal fees from Genentech/Roche, AstraZeneca, Merck, Bristol Myers Squibb, Novartis, Daichii-Sanyko, Boehringer-Ingelheim, Xcovery, Jazz Pharmaceuticals, Pfizer, and Janssen, outside the submitted work. Dr. Hirsch reports scientific advisory board for Genentech/Roche, Merck, Bristol Myers Squibb, Novartis, AstraZeneca/Daiichi, Regeneron/Sanofi, and Amgen, outside the submitted work. Dr. Kerr reports personal fees from AbbVie, Amgen, AstraZeneca, Archer Diagnostics, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Debiopharm, Diaceutics, Eli Lilly, Merck Serono, Merck Sharp & Dohme, Novartis, Pfizer, Regeneron, Roche, and Roche Diagnostics/Ventana, outside the submitted work. Dr. Barlesi reports personal fees from AstraZeneca, Bayer, Bristol Myers Squibb, Boehringer Ingelheim, Eli Lilly Oncology, F. Hoffmann-La Roche Ltd, Novartis, Merck, MSD, Pierre Fabre, Pfizer, and Takeda, outside the submitted work. Dr. Park has nothing to disclose. Dr. Rittmeyer reports grants from AbbVie, AstraZeneca, BMS, Boehringer Ingelheim, Eli Lilly, MSD, Pfizer, Roche, and Novartis, outside the submitted work. Dr. Zou reports employment from Genentech, outside the submitted work. Dr. Bhatia reports employment from Genentech, outside the submitted work. Dr. Koeppen reports employment from Genentech, outside the submitted work. Dr. Paul reports employment from Genentech, outside the submitted work. David Shames reports employment from Genentech and stock ownership from Roche, outside the submitted work. Dr. Yi reports employment and spousal employment from Genentech and stock ownership from Roche, outside the submitted work. Dr. Matheny reports employment from Genentech, during the conduct of the study, and employment from Genentech, outside the submitted work. Dr. Ballinger reports employment from Genentech and stock ownership from Roche, outside the submitted work. Dr. McCleland reports employment from Genentech, outside the submitted work. Dr. Gandara reports personal fees and institutional grants from Genentech, outside the submitted work., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: GSK2849330, an anti-HER3 monoclonal antibody that blocks HER3/Neuregulin 1 (NRG1) signaling in cancer cells, is engineered for enhanced antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. This phase I, first-in-human, open-label study assessed the safety, pharmacokinetics (PK), pharmacodynamics, and preliminary activity of GSK2849330 in patients with HER3-expressing advanced solid tumors., Patients and Methods: Patients with various tumor types were prospectively selected for HER3 expression by immunohistochemistry; a subset was also screened for NRG1 mRNA expression. In the dose-escalation phase, patients received GSK2849330 1.4-30 mg/kg every 2 weeks, or 3 mg/kg or 30 mg/kg weekly, intravenously (IV). In the dose-expansion phase, patients received 30 mg/kg GSK2849330 IV weekly., Results: Twenty-nine patients with HER3-expressing cancers, of whom two expressed NRG1, received GSK2849330 (dose escalation: n = 18, dose expansion: n = 11). GSK2849330 was well tolerated. No dose-limiting toxicities were observed. The highest dose, of 30 mg/kg weekly, expected to provide full target engagement, was selected for dose expansion. Treatment-emergent adverse events (AEs) were mostly grade 1 or 2. The most common AEs were diarrhea (66%), fatigue (62%), and decreased appetite (31%). Dose-proportional plasma exposures were achieved, with evidence of HER3 inhibition in paired tissue biopsies. Of 29 patients, only 1 confirmed partial response, lasting 19 months, was noted in a patient with CD74-NRG1-rearranged non-small cell lung cancer (NSCLC)., Conclusion: GSK2849330 demonstrated a favorable safety profile, dose-proportional PK, and evidence of target engagement, but limited antitumor activity in HER3-expressing cancers. The exceptional response seen in a patient with CD74-NRG1-rearranged NSCLC suggests further exploration in NRG1-fusion-positive cancers., Implications for Practice: This first-in-human study confirms that GSK2849330 is well tolerated. Importantly, across a variety of HER3-expressing advanced tumors, prospective selection by HER3/NRG1 expression alone was insufficient to identify patients who could benefit from treatment with this antibody-dependent cell-mediated cytotoxicity- and complement-dependent cytotoxicity-enhanced anti-HER3 antibody. The only confirmed durable response achieved was in a patient with CD74-NRG1-rearranged lung cancer. This highlights the potential utility of screening for NRG1 fusions prospectively across tumor types to enrich potential responders to anti-HER3 agents in ongoing trials., (© 2021 GlaxoSmithKline. The Oncologist published by Wiley Periodicals LLC on behalf of AlphaMed Press.)

Introduction: The phase 2 POPLAR and phase 3 OAK studies of the anti-programmed death-ligand 1 (PD-L1) immunotherapy atezolizumab in patients with previously treated advanced NSCLC revealed significant improvements in survival versus docetaxel (p = 0.04 and 0.0003, respectively). Longer follow-up permits evaluation of continued benefit of atezolizumab. This study reports the final overall survival (OS) and safety findings from both trials., Methods: POPLAR randomized 287 patients (atezolizumab, 144; docetaxel, 143) and OAK randomized 1225 patients (atezolizumab, 613; docetaxel, 612). The patients received atezolizumab (1200 mg fixed dose) or docetaxel (75 mg/m 2 ) every 3 weeks. Efficacy and safety outcomes were evaluated., Results: A longer OS was observed in patients receiving atezolizumab versus docetaxel in POPLAR (median OS = 12.6 mo versus 9.7 mo; hazard ratio = 0.76, 95% confidence interval [CI]: 0.58-1.00) and OAK (median OS = 13.3 versus 9.8 mo; hazard ratio = 0.78, 95% CI: 0.68-0.89). The 4-year OS rates in POPLAR were 14.8% (8.7-20.8) and 8.1% (3.2-13.0) and those in OAK were 15.5% (12.4-18.7) and 8.7% (6.2-11.3) for atezolizumab and docetaxel, respectively. Atezolizumab had improved OS benefit compared with docetaxel across all PD-L1 expression and histology groups. Most 4-year survivors in the docetaxel arms received subsequent immunotherapy (POPLAR, 50%; OAK, 65%). Of the 4-year survivors, most had Eastern Cooperative Oncology Group performance status of 0 and nonsquamous histological classification and approximately half were responders (POPLAR: atezolizumab, seven of 15; docetaxel, three of four; OAK: atezolizumab, 24 of 43; docetaxel, 11 of 26). Treatment-related grade 3/4 adverse events occurred in 27% and 16% of atezolizumab 4-year survivors in POPLAR and OAK, respectively., Conclusions: Long-term follow-up suggests a consistent survival benefit with atezolizumab versus docetaxel in patients with previously treated NSCLC regardless of PD-L1 expression, histology, or subsequent immunotherapy. Atezolizumab had no new safety signals, and the safety profile was similar to that in previous studies., (Copyright © 2020 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

PET imaging with radiolabeled drugs provides information on tumor uptake and dose-dependent target interaction to support selection of an optimal dose for future efficacy testing. In this immuno-PET study of the anti-human epidermal growth factor receptor (HER3) mAb GSK2849330, we investigated the biodistribution and tumor uptake of 89 Zr-labeled GSK2849330 and evaluated target engagement as a function of antibody mass dose. Methods: 89 Zr-GSK2849330 distribution was monitored in 6 patients with HER3-positive tumors not amenable to standard treatment. Patients received 2 administrations of 89 Zr-GSK2849330. Imaging after tracer only was performed at baseline; dose-dependent inhibition of 89 Zr-GSK2849330 uptake in tumor tissues was evaluated 2 wk later using increasing doses of unlabeled GSK2849330 in combination with the tracer. Up to 3 PET scans (2 hours post infusion [p.i.] and days 2 and 5 p.i.) were performed after tracer administration. Biodistribution and tumor targeting were assessed visually and quantitatively using SUV. The 50% and 90% inhibitory mass doses (ID 50 and ID 90 ) of target-mediated antibody uptake were calculated using a Patlak transformation. Results: At baseline, imaging with tracer showed good tumor uptake in all evaluable patients. Predosing with unlabeled mAb reduced the tumor uptake rate in a dose-dependent manner. Saturation of 89 Zr-mAb uptake by tumors was seen at the highest dose (30 mg/kg). Despite the limited number of patients, an exploratory ID 50 of 2 mg/kg and ID 90 of 18 mg/kg have been determined. Conclusion: In this immuno-PET study, dose-dependent inhibition of tumor uptake of 89 Zr-GSK2849330 by unlabeled mAb confirmed target engagement of mAb to the HER3 receptor. This study further validates the use of immuno-PET to directly visualize tissue drug disposition in patients with a noninvasive approach and to measure target engagement at the site of action, offering the potential for dose selection., (© 2019 by the Society of Nuclear Medicine and Molecular Imaging.)

Introduction: Cancer immunotherapy may alter tumor biology such that treatment effects can extend beyond radiographic progression. In the randomized, phase III OAK study of atezolizumab (anti-programmed death-ligand 1) versus docetaxel in advanced NSCLC, overall survival (OS) benefit with atezolizumab was observed in the overall patient population, without improvement in objective response rate (ORR) or progression-free survival (PFS). We examine the benefit-risk of atezolizumab treatment beyond progression (TBP)., Methods: Eight hundred fifty patients included in the OAK primary efficacy analysis were evaluated. Atezolizumab was continued until loss of clinical benefit. Docetaxel was administered until Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) disease progression (PD)/unacceptable toxicity; no crossover to atezolizumab was allowed. ORR, PFS, post-PD OS, target lesion change, and safety were evaluated., Results: In atezolizumab-arm patients, ORR was 16% versus 14% and median PFS was 4.2 versus 2.8 months per immune-modified RECIST versus RECIST v1.1. The median post-PD OS was 12.7 months (95% confidence interval [CI]: 9.3-14.9) in 168 atezolizumab-arm patients continuing TBP, 8.8 months (95% CI: 6.0-12.1) in 94 patients switching to nonprotocol therapy, and 2.2 months (95% CI: 1.9-3.4) in 70 patients receiving no further therapy. Of the atezolizumab TBP patients, 7% achieved a post-progression response in target lesions and 49% had stable target lesions. Atezolizumab TBP was not associated with increased safety risks., Conclusions: Within the limitations of this retrospective analysis, the post-PD efficacy and safety data from OAK are consistent with a positive benefit-risk profile of atezolizumab TBP in patients performing well clinically at the time of PD., (Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Background: The randomized phase III OAK (a study of atezolizumab compared with docetaxel in participants with locally advanced or metastatic non-small-cell lung cancer [NSCLC] who have failed platinum-containing therapy) trial investigated the anti-programmed cell death ligand 1 (PD-L1) antibody atezolizumab for advanced or metastatic, previously treated, NSCLC. Atezolizumab significantly improved overall survival (OS) compared with docetaxel (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.62-0.87; P = .0003; median OS, 13.8 vs. 9.6 months, respectively). Patient-reported outcomes (PROs) were collected to evaluate disease-related symptoms and health-related quality of life (HRQoL) to support the finding of a survival benefit., Patients and Methods: The first 850 patients were randomized to receive atezolizumab (1200 mg every 3 weeks) or docetaxel (75 mg/m 2 every 3 weeks). PROs were collected on day 1 of cycle 1, day 1 of every subsequent cycle, and at the end-of-treatment visit for patients who completed ≥ 1 baseline and 1 postbaseline PRO assessment. The European Organisation for the Research and Treatment of Cancer QoL questionnaire and lung cancer module were used to assess PROs., Results: Atezolizumab delayed the time to deterioration (TTD) in physical function (HR, 0.75; 95% CI, 0.58-0.98) and role function (HR, 0.79; 95% CI, 0.62-1.00) and numerically improved patients' HRQoL from baseline compared with docetaxel. Atezolizumab also prolonged the TTD in chest pain (HR, 0.71; 95% CI, 0.49-1.05; P = .0823), although both arms showed an objective reduction relative to baseline. Overall, the patients had no clinically significant worsening in treatment-related symptoms, although the scores favored atezolizumab., Conclusion: These PRO data support the clinical benefit of atezolizumab in patients with previously treated advanced or metastatic NSCLC. Atezolizumab prolonged the TTD of patients' limitations in role and physical functions compared with docetaxel., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: The efficacy and safety of atezolizumab versus the efficacy and safety of docetaxel as second- or third-line treatment in patients with advanced NSCLC in the primary (n = 850) and secondary (n = 1225) efficacy populations of the randomized phase III OAK study (respectively referred to as the intention-to-treat [ITT] 850 [ITT850] and ITT1225) at an updated data cutoff were assessed., Methods: Patients received atezolizumab, 1200 mg, or docetaxel, 75 mg/m 2 , intravenously every 3 weeks until loss of clinical benefit or disease progression, respectively. The primary end point was overall survival (OS) in the ITT population and programmed death-ligand 1-expressing subgroup. A sensitivity analysis was conducted to evaluate the impact of subsequent immunotherapy use in the docetaxel arm on the observed survival benefit with atezolizumab., Results: Atezolizumab demonstrated an OS benefit versus docetaxel in the updated ITT850 (hazard ratio [HR] = 0.75, 95% confidence interval: 0.64-0.89, p = 0.0006) and the ITT1225 (HR = 0.80, 95% confidence interval: 0.70-0.92, p = 0.0012) after minimum follow-up times of 26 and 21 months, respectively. Improved survival with atezolizumab was observed across programmed death-ligand 1 and histological subgroups. In the immunotherapy sensitivity analysis, the relative OS benefit with atezolizumab was slightly greater in the ITT850 (HR = 0.69) and ITT1225 (HR = 0.74) than the conventional OS estimate. Fewer patients receiving atezolizumab experienced grade 3 or 4 treatment-related adverse events (14.9%) than did patients receiving docetaxel (42.4%); no grade 5 adverse events related to atezolizumab were observed., Conclusions: The results of the updated ITT850 and initial ITT1225 analyses were consistent with those of the primary efficacy analysis demonstrating survival benefit with atezolizumab versus with docetaxel. Atezolizumab continued to demonstrate a favorable safety profile after longer treatment exposure and follow-up., (Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

NRG1 rearrangements are oncogenic drivers that are enriched in invasive mucinous adenocarcinomas (IMA) of the lung. The oncoprotein binds ERBB3-ERBB2 heterodimers and activates downstream signaling, supporting a therapeutic paradigm of ERBB3/ERBB2 inhibition. As proof of concept, a durable response was achieved with anti-ERBB3 mAb therapy (GSK2849330) in an exceptional responder with an NRG1 -rearranged IMA on a phase I trial (NCT01966445). In contrast, response was not achieved with anti-ERBB2 therapy (afatinib) in four patients with NRG1 -rearranged IMA (including the index patient post-GSK2849330). Although in vitro data supported the use of either ERBB3 or ERBB2 inhibition, these clinical results were consistent with more profound antitumor activity and downstream signaling inhibition with anti-ERBB3 versus anti-ERBB2 therapy in an NRG1 -rearranged patient-derived xenograft model. Analysis of 8,984 and 17,485 tumors in The Cancer Genome Atlas and MSK-IMPACT datasets, respectively, identified NRG1 rearrangements with novel fusion partners in multiple histologies, including breast, head and neck, renal, lung, ovarian, pancreatic, prostate, and uterine cancers. Significance: This series highlights the utility of ERBB3 inhibition as a novel treatment paradigm for NRG1 -rearranged cancers. In addition, it provides preliminary evidence that ERBB3 inhibition may be more optimal than ERBB2 inhibition. The identification of NRG1 rearrangements across various solid tumors supports a basket trial approach to drug development. Cancer Discov; 8(6); 686-95. ©2018 AACR. See related commentary by Wilson and Politi, p. 676 This article is highlighted in the In This Issue feature, p. 663 ., (©2018 American Association for Cancer Research.)

The purpose of this work was to use various molecular imaging techniques to non-invasively assess GSK2849330 (anti HER3 ADCC and CDC enhanced 'AccretaMab' monoclonal antibody) pharmacokinetics and pharmacodynamics in human xenograft tumor-bearing mice. Immuno-PET biodistribution imaging of radiolabeled 89Zr-GSK2849330 was assessed in mice with HER3 negative (MIA-PaCa-2) and positive (CHL-1) human xenograft tumors. Dose dependency of GSK2849330 disposition was assessed using varying doses of unlabeled GSK2849330 co-injected with 89Zr-GSK2849330. In-vivo NIRF optical imaging and ex-vivo confocal microscopy were used to assess the biodistribution of GSK2849330 and the HER3 receptor occupancy in HER3 positive xenograft tumors (BxPC3, and CHL-1). Ferumoxytol (USPIO) contrast-enhanced MRI was used to investigate the effects of GSK2849330 on tumor macrophage content in CHL-1 xenograft bearing mice. Immuno-PET imaging was used to monitor the whole body drug biodistribution and CHL-1 xenograft tumor uptake up to 144 hours post injection of 89Zr-GSK2849330. Both hepatic and tumor uptake were dose dependent and saturable. The optical imaging data in the BxPC3 xenograft tumor confirmed the tumor dose response finding in the Immuno-PET study. Confocal microscopy showed a distinguished cytoplasmic punctate staining pattern within individual CHL-1 cells. GSK2849330 inhibited tumor growth and this was associated with a significant decrease in MRI signal to noise ratio after USPIO injection and with a significant increase in tumor macrophages as confirmed by a quantitative immunohistochemistry analysis. By providing both dose response and time course data from both 89Zr and fluorescently labeled GSK2849330, complementary imaging studies were used to characterize GSK2849330 biodistribution and tumor uptake in vivo. Ferumoxytol-enhanced MRI was used to monitor aspects of the immune system response to GSK2849330. Together these approaches potentially provide clinically translatable, non-invasive techniques to support dose optimization, and assess immune activation and anti-tumor responses.

Rosuvastatin is a widely prescribed antihyperlipidemic which undergoes limited metabolism, but is an in vitro substrate of multiple transporters [organic anion transporting polypeptide 1B1 (OATP1B1), OATP1B3, OATP1A2, OATP2B1, sodium-taurocholate cotransporting polypeptide, breast cancer resistance protein (BCRP), multidrug resistance protein 2 (MRP2), MRP4, organic anion transporter 3]. It is therefore frequently used as a probe substrate in clinical drug-drug interaction (DDI) studies to investigate transporter inhibition. Although each of these transporters is believed to play a role in rosuvastatin disposition, multiple pharmacogenetic studies confirm that OATP1B1 and BCRP play an important role in vivo. Ronacaleret, a drug-development candidate for treatment of osteoporosis (now terminated), was shown to inhibit OATP1B1 in vitro (IC 50 = 11 µM), whereas it did not inhibit BCRP. Since a DDI risk through inhibition of OATP1B1 could not be discharged, a clinical DDI study was performed with rosuvastatin before initiation of phase II trials. Unexpectedly, coadministration with ronacaleret decreased rosuvastatin exposure by approximately 50%, whereas time of maximal plasma concentration and terminal half-life remained unchanged, suggesting decreased absorption and/or enhanced first-pass elimination of rosuvastatin. Of the potential in vivo rosuvastatin transporter pathways, two might explain the observed results: intestinal OATP2B1 and hepatic MRP4. Further investigations revealed that ronacaleret inhibited OATP2B1 (in vitro IC 50 = 12 µM), indicating a DDI risk through inhibition of absorption. Ronacaleret did not inhibit MRP4, discharging the possibility of enhanced first-pass elimination of rosuvastatin (reduced basolateral secretion from hepatocytes into blood). Therefore, a likely mechanism of the observed DDI is inhibition of intestinal OATP2B1, demonstrating the in vivo importance of this transporter in rosuvastatin absorption in humans., (Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.)

Targeting soluble acid hydrolases to lysosomes requires the addition of mannose 6-phosphate residues on their N-glycans. This process is initiated by GlcNAc-1-phosphotransferase, a multi-subunit enzyme encoded by the GNPTAB and GNPTG genes. The GNPTAB gene products (the α and ß subunits) are responsible for recognition and catalysis of hydrolases whereas the GNPTG gene product (the γ subunit) enhances mannose phosphorylation of a subset of hydrolases. Here we identify and characterize a zebrafish gnptg insertional mutant and show that loss of the gamma subunit reduces mannose phosphorylation on a subset glycosidases but does not affect modification of several cathepsin proteases. We further show that glycosidases, but not cathepsins, are hypersecreted from gnptg(-/-) embryonic cells, as evidenced by reduced intracellular activity and increased circulating serum activity. The gnptg(-/-) embryos lack the gross morphological or craniofacial phenotypes shown in gnptab-deficient morphant embryos to result from altered cathepsin activity. Despite the lack of overt phenotypes, decreased fertilization and embryo survival were noted in mutants, suggesting that gnptg associated deposition of mannose 6-phosphate modified hydrolases into oocytes is important for early embryonic development. Collectively, these findings demonstrate that loss of the zebrafish GlcNAc-1-phosphotransferase γ subunit causes enzyme-specific effects on mannose phosphorylation. The finding that cathepsins are normally modified in gnptg(-/-) embryos is consistent with data from gnptab-deficient zebrafish suggesting these proteases are the key mediators of acute pathogenesis. This work also establishes a valuable new model that can be used to probe the functional relevance of GNPTG mutations in the context of a whole animal., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective/method: Aggrecanase activity, most notably ADAMTS-5, is implicated in pathogenic cartilage degradation. Selective monoclonal antibodies (mAbs) to both ADAMTS-5 and ADAMTS-4 were generated and in vitro, ex vivo and in vivo systems were utilized to assess target engagement, aggrecanase inhibition and modulation of disease-related endpoints with the intent of selecting a candidate for clinical development in osteoarthritis (OA)., Results: Structural mapping predicts the most potent mAbs employ a unique mode of inhibition by cross-linking the catalytic and disintegrin domains. In a surgical mouse model of OA, both ADAMTS-5 and ADAMTS-4-specific mAbs penetrate cartilage following systemic administration, demonstrating access to the anticipated site of action. Structural disease modification and associated alleviation of pain-related behavior were observed with ADAMTS-5 mAb treatment. Treatment of human OA cartilage demonstrated a preferential role for ADAMTS-5 inhibition over ADAMTS-4, as measured by ARGS neoepitope release in explant cultures. ADAMTS-5 mAb activity was most evident in a subset of patient-derived tissues and suppression of ARGS neoepitope release was sustained for weeks after a single treatment in human explants and in cynomolgus monkeys, consistent with high affinity target engagement and slow ADAMTS-5 turnover., Conclusion: This data supports a hypothesis set forth from knockout mouse studies that ADAMTS-5 is the major aggrecanase involved in cartilage degradation and provides a link between a biological pathway and pharmacology which translates to human tissues, non-human primate models and points to a target OA patient population. Therefore, a humanized ADAMTS-5-selective monoclonal antibody (GSK2394002) was progressed as a potential OA disease modifying therapeutic., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To characterise ARGS neoepitope concentrations in various matrices from patients with knee osteoarthritis (OA) and assess performance of an immunoassay to facilitate clinical development of therapeutics affecting the A disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) pathway., Design: Matched sera, urine, and synovial fluid (SF) (surgical subjects only) were collected from healthy subjects, subjects with knee OA (non-surgical OA), and OA subjects undergoing total knee replacement (OA-TKR; n = 20 per group). Diurnal and inter-day variation was evaluated in the non-surgical OA group over 3 separate visits. Serum and urine samples were collected on two visits for the OA-TKR group with SF taken only at the time of surgery. ARGS neoepitope was quantitated using an optimized immunoassay., Results: Serum ARGS neoepitope concentrations were elevated in OA-TKR subjects compared to non-surgical OA subjects (P = 0.005) and healthy subjects (P = 0.0002). Creatinine corrected urinary ARGS neoepitope concentrations were more variable, but were also elevated in the OA-TKR subjects compared to healthy subjects (P = 0.008). No significant diurnal effect or inter-day variance was observed in serum or urine. Serum ARGS neoepitope concentrations correlated with age (P = 0.0252) but not with total number of joints with OA involvement. SF ARGS neoepitope concentrations correlated with Western Ontario and MacMaster OA Index (WOMAC) stiffness score (P = 0.04) whereas a weaker, non-significant trend towards positive correlation with combined WOMAC score and the number of concurrent joints was observed., Conclusions: This study utilized a sensitive and robust assay to evaluate ARGS neoepitope concentrations in various matrices in OA patients and healthy volunteers. ARGS neoepitope appears promising as a prognostic/stratification marker to facilitate patient selection and as an early pharmacodynamic marker for OA therapeutic trials., (Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Introduction: Pharmacokinetic drug interactions resulting from the inhibition of drug elimination mechanisms are of concern in drug development due to the clinical risk associated with elevated drug concentrations. Advances in understanding the mechanistic basis of these drug interactions has resulted in the widespread application of mechanistic in vitro assays and the conduct of clinical drug interaction studies to predict and quantify the risks in drug development., Areas Covered: The authors investigate co-medication prescriptions in target patient populations and characterize the mechanistic basis and clinical impact of known co-medication drug interactions. This has enabled identification of critical mechanistic in vitro studies and provided options to manage co-medication use in clinical studies. Furthermore, they demonstrate, for the pharmaceutical scientist, how improved understanding of the drug interactions risks associated with key medications in a target therapeutic area, can help prioritize the conduct of in vitro data and optimize the timing of the clinical drug interaction studies required to characterize drug interaction risks., Expert Opinion: This approach provides a more targeted strategy to drug interaction data generation, as routine application of assays may provide limited impact on drug progression decisions. Assessing co-medications in the target patient population enables early discharge of the safety risks associated with drug interactions and reduced investment in drug interaction studies.

Acute leukemias induced by MLL chimeric oncoproteins are among the subset of cancers distinguished by a paradoxical dependence on GSK-3 kinase activity for sustained proliferation. We demonstrate here that GSK-3 maintains the MLL leukemia stem cell transcriptional program by promoting the conditional association of CREB and its coactivators TORC and CBP with homedomain protein MEIS1, a critical component of the MLL-subordinate program, which in turn facilitates HOX-mediated transcription and transformation. This mechanism also applies to hematopoietic cells transformed by other HOX genes, including CDX2, which is highly expressed in a majority of acute myeloid leukemias, thus providing a molecular approach based on GSK-3 inhibitory strategies to target HOX-associated transcription in a broad spectrum of leukemias., (Copyright 2010 Elsevier Inc. All rights reserved.)

Pharmaceutical compounding-the process by which a pharmacist combines ingredients into a customized medication for an individual patient-has ancient roots, with popularity that has waxed and waned throughout history. Elderly individuals and other long-term care patients may be among those who need customized medications, so pharmacists should be aware of the current scope and regulations for compounded medications.

P-glycoprotein (P-gp) is a cell membrane-associated protein that transports a variety of drug substrates. Although P-gp has been studied extensively as a mediator of multidrug resistance in cancer, only recently has the role of P-gp expressed in normal tissues as a determinant of drug pharmacokinetics and pharmacodynamics been examined. P-glycoprotein is present in organ systems that influence drug absorption (intestine), distribution to site of action (central nervous system and leukocytes), and elimination (liver and kidney), as well as several other tissues. Many marketed drugs inhibit P-gp function, and several compounds are under development as P-gp inhibitors. Similarly, numerous drugs can induce P-gp expression. While P-gp induction does not have a therapeutic role, P-gp inhibition is an attractive therapeutic approach to reverse multidrug resistance. Clinicians should recognize that P-gp induction or inhibition may have a substantial effect on the pharmacokinetics and pharmacodynamics of concomitantly administered drugs that are substrates for this transporter.