Efficacy and pharmacodynamic effect of anti-CD73 and anti-PD-L1 monoclonal antibodies in combination with cytotoxic therapy: observations from mouse tumor models

CD73 is a cell surface 5'nucleotidase (NT5E) and key node in the catabolic process generating immunosuppressive adenosine in cancer. Using a murine monoclonal antibody surrogate of Oleclumab, we investigated the effect of CD73 inhibition in concert with cytotoxic therapies (chemotherapies as well as fractionated radiotherapy) and PD-L1 blockade. Our results highlight improved survival in syngeneic tumor models of colorectal cancer (CT26 and MC38) and sarcoma (MCA205). This therapeutic outcome was in part driven by cytotoxic CD8 T-cells, as evidenced by the detrimental effect of CD8 depleting antibody treatment of MCA205 tumor bearing mice treated with anti-CD73, anti-PD-L1 and 5-Fluorouracil+Oxaliplatin (5FU+OHP). We hypothesize that the improved responses are tumor microenvironment (TME)-driven, as suggested by the lack of anti-CD73 enhanced cytopathic effects mediated by 5FU+OHP on cell lines in vitro. Pharmacodynamic analysis, using imaging mass cytometry and RNA-sequencing, revealed noteworthy changes in specific cell populations like cytotoxic T cells, B cells and NK cells in the CT26 TME. Transcriptomic analysis highlighted treatment-related modulation of gene profiles associated with an immune response, NK and T-cell activation, T cell receptor signaling and interferon (types 1 & 2) pathways. Inclusion of comparator groups representing the various components of the combination allowed deconvolution of contribution of the individual therapeutic elements; highlighting specific effects mediated by the anti-CD73 antibody with respect to immune-cell representation, chemotaxis and myeloid biology. These pre-clinical data reflect complementarity of adenosine blockade with cytotoxic therapy, and T-cell checkpoint inhibition, and provides new mechanistic insights in support of combination therapy.

CD73 controls Myosin II-driven invasion, metastasis, and immunosuppression in amoeboid pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) has a very poor prognosis because of its high propensity to metastasize and its immunosuppressive microenvironment. Using a panel of pancreatic cancer cell lines, three-dimensional (3D) invasion systems, microarray gene signatures, microfluidic devices, mouse models, and intravital imaging, we demonstrate that ROCK-Myosin II activity in PDAC cells supports a transcriptional program conferring amoeboid invasive and immunosuppressive traits and in vivo metastatic abilities. Moreover, we find that immune checkpoint CD73 is highly expressed in amoeboid PDAC cells and drives their invasive, metastatic, and immunomodulatory traits. Mechanistically, CD73 activates RhoA-ROCK-Myosin II downstream of PI3K. Tissue microarrays of human PDAC biopsies combined with bioinformatic analysis reveal that rounded-amoeboid invasive cells with high CD73-ROCK-Myosin II activity and their immunosuppressive microenvironment confer poor prognosis to patients. We propose targeting amoeboid PDAC cells as a therapeutic strategy.

Defining the spatial distribution of extracellular adenosine revealed a myeloid-dependent immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

BACKGROUND

The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. It has been suggested that the adenosine pathway contributes to the ability of PDAC to evade the immune system and hence, its resistance to immuno-oncology therapies (IOT), by generating extracellular adenosine (eAdo).

METHODS

Using genetically engineered allograft models of PDAC in syngeneic mice with defined and different immune infiltration and response to IOT and autochthonous tumors in KPC mice we investigated the impact of the adenosine pathway on the PDAC tumor microenvironment (TME). Flow cytometry and imaging mass cytometry (IMC) were used to characterize the subpopulation frequency and spatial distribution of tumor-infiltrating immune cells. Mass spectrometry imaging (MSI) was used to visualize adenosine compartmentalization in the PDAC tumors. RNA sequencing was used to evaluate the influence of the adenosine pathway on the shaping of the immune milieu and correlate our findings to published data sets in human PDAC.

RESULTS

We demonstrated high expression of adenosine pathway components in tumor-infiltrating immune cells (particularly myeloid populations) in the murine models. MSI demonstrated that extracellular adenosine distribution is heterogeneous in tumors, with high concentrations in peri-necrotic, hypoxic regions, associated with rich myeloid infiltration, demonstrated using IMC. Protumorigenic M2 macrophages express high levels of the Adora2a receptor; particularly in the IOT resistant model. Blocking the in vivo formation and function of eAdo (Adoi), using a combination of anti-CD73 antibody and an Adora2a inhibitor slowed tumor growth and reduced metastatic burden. Additionally, blocking the adenosine pathway improved the efficacy of combinations of cytotoxic agents or immunotherapy. Adoi remodeled the TME, by reducing the infiltration of M2 macrophages and regulatory T cells. RNA sequencing analysis showed that genes related to immune modulation, hypoxia and tumor stroma were downregulated following Adoi and a specific adenosine signature derived from this is associated with a poorer prognosis in patients with PDAC.

CONCLUSIONS

The formation of eAdo promotes the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway may represent a strategy to modulate the PDAC immune milieu and improve therapy response in patients with PDAC.

Evaluating Osteoarthritis Management Programs: outcome domain recommendations from the OARSI Joint Effort Initiative

OBJECTIVE

To develop sets of core and optional recommended domains for describing and evaluating Osteoarthritis Management Programs (OAMPs), with a focus on hip and knee Osteoarthritis (OA).

DESIGN

We conducted a 3-round modified Delphi survey involving an international group of researchers, health professionals, health administrators and people with OA. In Round 1, participants ranked the importance of 75 outcome and descriptive domains in five categories: patient impacts, implementation outcomes, and characteristics of the OAMP and its participants and clinicians. Domains ranked as "important" or "essential" by ≥80% of participants were retained, and participants could suggest additional domains. In Round 2, participants rated their level of agreement that each domain was essential for evaluating OAMPs: 0 = strongly disagree to 10 = strongly agree. A domain was retained if ≥80% rated it ≥6. In Round 3, participants rated remaining domains using same scale as in Round 2; a domain was recommended as "core" if ≥80% of participants rated it ≥9 and as "optional" if ≥80% rated it ≥7.

RESULTS

A total of 178 individuals from 26 countries participated; 85 completed all survey rounds. Only one domain, "ability to participate in daily activities", met criteria for a core domain; 25 domains met criteria for an optional recommendation: 8 Patient Impacts, 5 Implementation Outcomes, 5 Participant Characteristics, 3 OAMP Characteristics and 4 Clinician Characteristics.

CONCLUSION

The ability of patients with OA to participate in daily activities should be evaluated in all OAMPs. Teams evaluating OAMPs should consider including domains from the optional recommended set, with representation from all five categories and based on stakeholder priorities in their local context.

CD73 and PD-L1 dual blockade amplifies antitumor efficacy of SBRT in murine PDAC models

BACKGROUND

Stereotactic body radiotherapy (SBRT) induces immunogenic cell death, leading to subsequent antitumor immune response that is in part counterbalanced by activation of immune evasive processes, for example, upregulation of programmed cell death-ligand 1 (PD-L1) and adenosine generating enzyme, CD73. CD73 is upregulated in pancreatic ductal adenocarcinoma (PDAC) compared with normal pancreatic tissue and high expression of CD73 in PDACs is associated with increased tumor size, advanced stage, lymph node involvement, metastasis, PD-L1 expression and poor prognosis. Therefore, we hypothesized that blockade of both CD73 and PD-L1 in combination with SBRT might improve antitumor efficacy in an orthotopic murine PDAC model.

METHODS

We assessed the combination of systemic blockade of CD73/PD-L1 and local SBRT on tumor growth in primary pancreatic tumors, and investigated systemic antitumor immunity using a metastatic murine model bearing both orthotopic primary pancreatic tumor and distal hepatic metastases. Immune response was quantified by flow cytometric and Luminex analyses.

RESULTS

We demonstrated that blockade of both CD73 and PD-L1 significantly amplified the antitumor effect of SBRT, leading to superior survival. The triple therapy (SBRT+anti-CD73+anti-PD-L1) modulated tumor-infiltrating immune cells with increases of interferon-γ+CD8+ T cells. Additionally, triple therapy reprogramed the profile of cytokines/chemokines in the tumor microenvironment toward a more immunostimulatory phenotype. The beneficial effects of triple therapy are completely abrogated by depletion of CD8+ T cells, and partially reversed by depletion of CD4+ T cells. Triple therapy promoted systemic antitumor responses illustrated by: (1) potent long-term antitumor memory and (2) enhanced both primary and liver metastases control along with prolonged survival.

Abstract CT126: A phase 2 trial of first-line AZD0171 + durvalumab and chemotherapy (CT) in patients with metastatic pancreatic ductal adenocarcinoma (PDAC) and CD8+ T cell infiltration

Background: Leukemia inhibitory factor (LIF) is an immunosuppressive cytokine linked to tumor growth and metastasis. LIF overexpression correlates with poor prognosis and chemoresistance in multiple tumor types including PDAC. Preclinical data show that LIF promotes an immunosuppressive tumor microenvironment, hindering cytotoxic CD8+ T cell recruitment; low T cell infiltration also correlates with mortality in patients with PDAC. Preclinical studies show LIF-blocking antibodies sensitize tumors to PD-1/PD-L1 inhibition, inhibit epithelial-mesenchymal transition, and prolong survival in combination with CT. In patients with PDAC, higher LIF levels correlate with more aggressive pathology, elevated CA19-9 (a PDAC biomarker), and lower response and survival rates. AZD0171 (formerly MSC-1), a first-in-class, humanized, IgG1 monoclonal antibody, binds specifically and potently to LIF, preventing downstream signaling. In a phase 1 dose escalation study (NCT03490669), AZD0171 monotherapy had manageable safety and led to stable disease (SD) in 34.2% of patients with advanced solid tumors across all dose levels. AZD0171 + CT may improve survival outcomes vs CT alone. Based on preclinical data, AZD0171 may function to stimulate antitumor immune response, and combination with the PD-L1 inhibitor durvalumab could prolong that response and overcome peripheral tolerance in patients with metastatic PDAC.

Methods: This is a phase 2, open-label, single-arm, multicenter study of AZD0171 + durvalumab and CT in treatment-naive patients with metastatic PDAC (NCT04999969). Eligible patients must have an ECOG performance status 0 or 1, a Gustave Roussy Immune Score 0 or 1, ≥1 measurable target lesion per RECIST v1.1, and confirmed presence of tumoral CD8+ T cells. Patients with central nervous system metastasis, history of leptomeningeal disease or cord compression, a thromboembolic event ≤3 months prior to study treatment, unresolved grade ≥2 toxicities from prior therapy, or a sensitizing mutation or tumor characteristic for which there is a preferred treatment, are excluded. As PDAC is poorly immune infiltrated, a novel clinical trial assay will be used to select for patients who have existing resident CD8+ T cells and may therefore be more likely to respond. About 115 patients will receive intravenous AZD0171, durvalumab and CT until disease progression or unacceptable toxicity. The primary endpoints are safety and overall survival (OS) rate at 12 months. Secondary endpoints include objective response rate, disease control rate (confirmed response or SD ≥16 weeks), duration of response, median progression-free survival (PFS), PFS rate at 4 months, median OS, pharmacokinetics, pharmacodynamics (changes in serum CA19-9 level and tumor CD8+ T cell infiltration) and immunogenicity. The trial is currently recruiting.

Citation Format: Grainne O'Kane, Teresa Macarulla, Fiyinfolu Balogun, Antoine Hollebecque, Matthew J. Reilley, Sreenivasa R. Chandana, Jim Eyles, Oluwaseun Ojo, Philip Overend, Douglas C. Palmer, Nadia Luheshi, Mayukh Das, Antoine Italiano, Joan Seoane. A phase 2 trial of first-line AZD0171 + durvalumab and chemotherapy (CT) in patients with metastatic pancreatic ductal adenocarcinoma (PDAC) and CD8+ T cell infiltration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT126.

Abstract 6103: Reshaping the myeloid-dependent pro-tumorigenic microenvironment in PDAC by targeting the extracellular adenosine pathway: A therapeutic opportunity

The prognosis for patients with pancreatic adenocarcinoma (PDAC) remains extremely poor. PDAC is resistant to both conventional therapies and emerging immunotherapies (IOT), apart from tumors with mismatch repair deficiency. This may be explained in part by its low tumor mutational burden (TMB) but also by its immunosuppressive tumor microenvironment (TME). It has been suggested that CD73, a member of the adenosine pathway, expressed on cancer cells contributes to immune escape and resistance to cytotoxic/radiotherapy treatment. The adenosine pathway converts the immune activator ATP, released by dying cells during cell turnover or after treatment, to extracellular Adenosine (eAdo), which is immunosuppressive.

Using syngeneic, in vivo models by s.c. implantation of KPC-derived cell lines (courtesy of Ben Stanger, UPenn) with differential immune infiltration and response to IOT [resistant (IOTResi) or responsive (IOTResp)], we showed by flow cytometry that the adenosine pathway is enriched in the tumor-infiltrating immune cells (in particular myeloid populations) which co-express CD39 and CD73, enabling the formation of eAdo. Mass Spec Imaging (MSI) revealed that adenosine distribution is heterogeneous in the tumors with high concentrations in the hypoxic margins that surround necrotic areas. Subpopulations of myeloid cells infiltrating the lesions are a target for eAdo, expressing high levels of adenosine receptor Adora2a. We discovered that pro-tumorigenic M2 macrophages have the highest expression of the receptor and significantly higher in the IOTResi model. Blocking the in vivo formation and function of eAdo in IOTResi tumors, using a combination of anti-CD73 antibody (2C5, murine IgG1-Fc) and an inhibitor of Adora2a (AZD4635) reduced the presence of eAdo, slowed tumor growth and reduced the lung metastatic burden. The combination remodeled the TME, reducing the infiltration by M2 macrophages, particularly those that are PD-L1 positive and diminished the frequency of infiltrating Tregs. Bulk RNAseq analysis demonstrated a profound dependency of the TME on the presence of eAdo. Genes related to cytokine/chemokine signaling, immunosuppression/inflammation, hypoxia, metastasis and collagen production are strongly downregulated following administration of anti-CD73Ab/Adora2ai. In addition, blocking the adenosine pathway improved the efficacy of combinations of cytotoxics (gemcitabine/ATR inhibitor) and immunotherapy (aCD40/anti-PDL1Ab).

The formation of eAdo appears to be a factor in the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway using a CD73Ab and an Adora2ai may represent a strategy to modulate the PDAC stroma and improve therapy response in patients with PDAC.

Citation Format: Vincenzo Graziano, Andreas Dannhorn, Kate Williamson, Heather Hulme, Hannah Buckley, Sheng Y. Lee, Sabita Islam, James E. Thaventhiran, Richard Goodwin, Rebecca Brais, Simon J. Dovedi, Alwin Schuller, Jim Eyles, Duncan I. Jodrell. Reshaping the myeloid-dependent pro-tumorigenic microenvironment in PDAC by targeting the extracellular adenosine pathway: A therapeutic opportunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6103.

Abstract CT183: First-in-human study of MEDI1191 (mRNA encoding IL-12) plus durvalumab in patients (pts) with advanced solid tumors

Background: IL-12 is a key mediator of antitumor immune response. In preclinical models, IT IL-12 mRNA led to IFNγ release and CD8+ T cell-dependent tumor regression and potentiated PD-L1 blockade. MEDI1191, a lipid nanoparticle-formulated mRNA encoding IL-12 delivered by IT injection, drives IL-12 production and enhances antitumor immune response with improved tolerability. We hypothesized that combining MEDI1191 with PD-L1 blockade would augment antitumor immunity in vivo. Here we report updated results from the dose-escalation phase of the first-in-human study of IT MEDI1191 and IV durvalumab (D; anti-PD-L1) for advanced/metastatic solid tumors (NCT03946800).

Methods: In this multicenter, open-label study, MEDI1191 was dosed sequentially (seq, Part 1A) or concurrently (conc, Part 1B) with D. In Part 1A, MEDI1191 was given IT on Days 1 and 22 followed by D 1500 mg on day 43 and then Q4W IV. In Part 1B, MEDI1191 was given IT on Days 1, 29, 57 and then Q8W, along with D on Day 1 and then Q4W. Treatment continued until progression or unacceptable toxicity for up to 2 years. Eligible adult pts had any solid tumor with cutaneous or subcutaneous lesions suitable for IT injection and progression on standard therapy for recurrent/metastatic disease. Primary objectives were safety and tolerability and determination of maximum tolerated dose (MTD); secondary objectives included preliminary antitumor activity by RECIST v1.1.

Results: Starting in May 2019, 31 pts received seq MEDI1191 with D (Part 1A cohorts 0.1-12 μg; n=20) or conc MEDI1191 with D (Part 1B cohorts 1.0-3.0 μg; n=11); 23 pts had received prior anti-PD-1/PD-L1 therapy. Most common tumor types were melanoma, n=8; head and neck cancer, n=4; and breast cancer, n=4. At the data cutoff of Dec 7, 2021, there were no dose-limiting toxicities and no MTD was identified. One pt (3.2%) had a Gr ≥3 MEDI1191-related AE (Gr 3 pyrexia, resolved within 24 hr) and 1 (3.2%) had a MEDI1191-related serious AE (SAE; Gr 2 confusion). Two pts had Gr 3 D-related AEs (6.5%, pyrexia also related to MEDI1191 and pruritus; each n=1); none had a D-related SAE. There were no Gr 4 related AEs. 3 pts had partial responses (PR): 1 with head and neck cancer (unconfirmed, off study) and 2 with anti-PD-1 resistant melanoma (1 confirmed, >12 months on treatment; 1 unconfirmed, off study); 10 pts had stable disease (including the 2 unconfirmed PRs). Among pts with available biomarker data (up to 3 μg in Part 1A and 1 μg in Part 1B), MEDI1191 increased serum IL-12 in 15/17 pts, increased CD8+ T cell tumor infiltration by >2-fold in 8/14 pts and increased tumor PD-L1 expression in 6/14 pts.

Conclusions: IT MEDI1191 plus systemic anti-PD-L1 was safe and feasible. Preliminary antitumor efficacy and pharmacodynamics, including tumor CD8+ T cell recruitment, were consistent with expected mechanism of action. Pts with injectable deep visceral and superficial lesions are being recruited.

Citation Format: Benedito A. Carneiro, Dmitriy Zamarin, Thomas Marron, Inderjit Mehmi, Sandip P. Patel, Vivek Subbiah, Anthony El-Khoueiry, David Grand, Kirema Garcia-Reyes, Sanjay Goel, Phillip Martin, Jixin Wang, Yuling Wu, Steven Eck, Benjamin Ridgway, Nairouz Elgeioushi, Jim Eyles, Nicholas Durham, Analia Azaro, Omid Hamid. First-in-human study of MEDI1191 (mRNA encoding IL-12) plus durvalumab in patients (pts) with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT183.

Abstract 1293: AZD0171 (anti-LIF) combines productively with chemotherapy and anti-PD-L1 in mouse models of cancer

Leukemic inhibitory factor (LIF) is an IL-6 family member involved in embryonic stem cell maintenance and protection from maternal immune-attack. Emerging evidence indicates that LIF biology is hijacked by some tumors to promote immunosuppressive tumor associated macrophages, cancer initiating cells and epithelial-mesenchymal transition (EMT). In patients treated with anti-PD-1/anti-PD-L1 antibodies (IO), baseline high LIF expression correlated with poor outcome (Loriot et al. 2021). In preclinical models, LIF blockade has separately been reported to sensitize tumors to IO and to chemotherapy (chemo), but the impact of LIF blockade on chemo/IO combination activity is unknown. We therefore evaluated the hypothesis that LIF blockade sensitizes tumors to chemo/IO combinations. AZD0171 is a monoclonal antibody that binds to LIF and prevents signaling through LIF receptor. A murine surrogate of AZD0171 (mAZD0171) was generated and tested in vivo using three syngeneic murine cancer models, and AZD0171 was tested in patient derived xenograft models. Monotherapy mAZD0171 induced tumor gene expression changes consistent with its proposed mechanism of action in the syngeneic CT26 colon tumor model; including elevated CD8 attracting chemokines (CXCL9/10), cDC1 transcription factor (Batf3) and reduced stem cell (CD44), EMT (CY61) and hypoxic/angiogenic signatures, including CXCL12. Flow cytometry analysis highlighted changes consistent with suppressive macrophage re-education (reduced CD206/elevated MHCII). mAZD0171 sensitized mouse tumors to both IO and chemo. mAZD0171 + anti-PD-L1 treatment reversed CD8 T cell exclusion in the D2A1-m2 model; a LIF expressing cancer associated fibroblast rich, anti-PD-L1 resistant mouse mammary tumor syngeneic model (Jungwirth et al. 2018). mAZD0171 + anti-PD-L1 treatment further inhibited D2A1-m2 growth versus (vs) anti-PD-L1 treatment alone. In a non-small cell lung carcinoma patient derived xenograft model, AZD0171 improved the tumor growth inhibitory effect of Carboplatin + Paclitaxel. The triplet combination of mAZD0171 plus chemo and IO had the most marked impact on both tumor microenvironment and tumor growth. mAZD0171 addition to oxaliplatin (OHP) or Docetaxel (DTX) chemotherapy plus anti-PD-L1 significantly elevated CD8 abundance and granzyme B expression in MC38 colon tumors. mAZD0171 + anti-PD-L1 + OHP or DTX improved inhibition of MC38 tumor growth (63% for OHP triplet vs 34% for anti-PD-L1 + OHP; 49% for DTX triplet vs 36% for anti-PD-L1 + DTX) and extended median survival times (P<0.05 vs anti-PD-L1+OHP/DTX). Together these data support the hypothesis that AZD0171 has the potential to sensitize solid tumors to chemotherapy/IO combinations. The safety and activity of AZD0171 is currently being assessed in a Ph2 clinical trial in combination with durvalumab (anti-PD-L1) and chemotherapy in metastatic pancreatic cancer (NCT04999969).

Citation Format: Juliana Candido, Gozde Kar, Bairu Zhang, Grace Opoku-Ansah, Amit Grover, Elizabeth A. Kuczynski, Tim Slidel, Doug Palmer, Robert W. Wilkinsom, Nadia Luheshi, Jim Eyles. AZD0171 (anti-LIF) combines productively with chemotherapy and anti-PD-L1 in mouse models of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1293.

Recombinant Newcastle Disease Virus Immunotherapy Drives Oncolytic Effects and Durable Systemic Antitumor Immunity

A recombinant Newcastle Disease Virus (NDV), encoding either a human (NDVhuGM-CSF, MEDI5395) or murine (NDVmuGM-CSF) GM-CSF transgene, combined broad oncolytic activity with the ability to significantly modulate genes related to immune functionality in human tumor cells. Replication in murine tumor lines was significantly diminished relative to human tumor cells. Nonetheless, intratumoral injection of NDVmuGM-CSF conferred antitumor effects in three syngeneic models in vivo; with efficacy further augmented by concomitant treatment with anti-PD-1/PD-L1 or T-cell agonists. Ex vivo immune profiling, including T-cell receptor sequencing, revealed profound immune-contexture changes consistent with priming and potentiation of adaptive immunity and tumor microenvironment (TME) reprogramming toward an immune-permissive state. CRISPR modifications rendered CT26 tumors significantly more permissive to NDV replication, and in this setting, NDVmuGM-CSF confers immune-mediated effects in the noninjected tumor in vivo Taken together, the data support the thesis that MEDI5395 primes and augments cell-mediated antitumor immunity and has significant utility as a combination partner with other immunomodulatory cancer treatments.

Abstract 1695: Activation of B cells by CD73 blocking antibodies

The catabolism of ATP into immunosuppressive adenosine contributes to the dysfunction of tumor infiltrating leukocytes (TIL). CD73 is an ectonucleotidase which catabolizes conversion of AMP to adenosine and is expressed on a range of immune cells including B cells. Oleclumab (MEDI9447) is a monoclonal antibody specific for human CD73 and is currently in clinical development for the treatment of cancer. B cells constitute a significant proportion of human TIL; however, their importance to Immuno-Oncology (IO) treatments remains unclear. Recent publications demonstrate that B cells sustain inflammation and predict response to immune checkpoint blockade in human melanoma, their presence within the tumor microenvironment is correlated with improved prognosis in several human tumor types, and CD73 expression has been shown to vary on different human B cell subtypes. Further investigations into the role of CD73 in control of human B cell function are therefore warranted. We show that blockade of CD73 by oleclumab and other monoclonal antibodies on peripheral blood B cells from healthy human donors upregulates expression of CD69, CD83 and CD86, and induces secretion of IL-6, MIP-1α and MIP-1β. Activation is mediated by antibodies that block and internalize CD73 and is reduced by pharmacological inhibition of BTK, thus highlighting involvement of the canonical B-cell receptor signaling pathway. Furthermore, our analyses highlight a differential effect of CD73 blockade on individual B-cell populations, with the most robust increases in activation marker expression being observed on naïve subsets that retain expression of IgD. Our research has identified that oleclumab activates human peripheral blood B cells. Given the renewed interest in B-cell biology in IO, this is an area we believe warrants further clinical investigation.

Citation Format: James Hair, Fabien Garcon, Michelle Hsueh, Laura Dallaway, Elena Bibikova, Maria Letizia Giardino Torchia, Gordon Moody, Alwin Schuller, Simon J. Dovedi, Zachary A. Cooper, Kris Sachsenmeier, Rakesh Kumar, Jim Eyles, Robert W. Wilkinson. Activation of B cells by CD73 blocking antibodies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1695.

Abstract 1584: Efficacy and pharmacodynamic effect of anti-CD73/PD-L1 monoclonal antibodies in combination with chemotherapy: Observations from mouse tumor models

Intratumoral adenosine is a key immunosuppressive factor linked to poor prognosis and reduced efficacy of T cell checkpoint inhibitors. CD73 is an ectoenzyme and key node in the catabolic pathway responsible for sequential hydrolysis of extracellular ATP to adenosine. ATP is released from necrotic and damaged tumor cells; a phenomenon enhanced as consequence of cytotoxic chemotherapy or radiotherapy. A CD73 inhibiting human monoclonal IgG1-TM antibody, Oleclumab, is currently in phase 2 clinical development for treatment of patients with various solid tumors. The combination of CD73 inhibition with chemotherapy and T cell checkpoint inhibition was tested using two murine cancer models, CT26 (colorectal) or MCA205 (fibrosarcoma) implanted subcutaneously in BALB/c mice or C57BL/6 mice, respectively. Tumor bearing mice were treated with combinations of oxaliplatin and 5-fluorouracil and murine surrogate monoclonal antibodies for Oleclumab and Durvalumab (anti-PD-L1). CT26 implanted mice were also treated with the murine surrogate antibodies in the presence and absence of Docetaxel. In an attempt to define contribution of components, comparator groups received monotherapies and other iterations of the combination. Treatment with anti-CD73 and anti-PD-L1 antibodies, concomitantly with chemotherapy, resulted in improved tumor growth inhibition, plus increased proportions of complete tumor regression (P<0.05). FACS analysis of CT26 tumors highlighted elevated frequencies of intratumoral IFN-gamma secreting T and NK cells in the chemotherapy plus double IO combination group (P<0.05). Consistent with this, selective depletion of CD8 T cells significantly diminished tumor control and long term survival (P<0.05). RNAseq and Mass spectrometry based imaging techniques were utilized as tools to explore biomarker changes and mechanism.

Citation Format: Jim Eyles, Amanda Watkins, Kristina Ilieva, Stef Mullins, Jude Anderton, Elena Galvani, Fabien Garcon, Kelli Ryan, Brajesh P. Kaistha, Andreas Dannhorn, Stephanie Ling, Tim Slidel, Gozde Kar, Alwin Schuller, Zachary A. Cooper, Kris Sachsenmeier, Nadia Luheshi, Rakesh Kumar, Robert W. Wilkinson. Efficacy and pharmacodynamic effect of anti-CD73/PD-L1 monoclonal antibodies in combination with chemotherapy: Observations from mouse tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1584.

Efficacy and safety of a supplement combination on hand pain among people with symptomatic hand osteoarthritis an internet-based, randomised clinical trial the RADIANT study

OBJECTIVE

The RADIANT study aimed to investigate the efficacy and safety of a complementary medicine supplement combination in people with hand osteoarthritis (HOA).

METHOD

This was an internet-based, double-blind, randomised, placebo-controlled trial. Participants aged over 40 years with symptomatic HOA with radiographic confirmation (Kellgren Lawrence grade ≥ 2) throughout Australia were recruited and randomly assigned (1:1) to receive either a supplement combination composed of Boswellia serrata extract 250 mg/day, pine bark extract 100 mg/day, methylsulfonylmethane 1,500 mg/day and curcumin 168 mg/day or placebo for 12 weeks. The primary outcome was change in hand pain assessed using a visual analogue scale (VAS 0-100) from baseline to week 12. A range of secondary outcomes and additional measures were recorded. Adverse events were monitored weekly.

RESULTS

One hundred and six participants were included with mean age 65.6 years and 81% were women. 45% of the participants were graded as KLG 4, 40% KLG three and 39 (37%) had erosive OA. There was no significant difference in pain VAS reduction between groups. The adjusted between group difference in means (95%CI) was 5.34 (-2.39 to 13.07). Five participants (10%) in the supplement combination group discontinued study treatment due to AE vs four participants (7%) in the placebo group.

CONCLUSION

There were no significant differences in symptomatic relief between the two groups over 12 weeks. These findings do not support the use of the supplement combination for treating hand pain in people with HOA.

REGISTRATION

Prospectively registered (Australian New Zealand Clinical Trials Registry ACTRN12619000835145, 31/05/2019).

Significance of informal (on-the-job) learning and leadership development in health systems: lessons from a district finance team in South Africa

Background

The district health system (DHS) has a critical role to play in the delivery of primary healthcare (PHC). Effective district management, particularly leadership is considered to be crucial element of the DHS. Internationally, the debate around developing leadership competencies such as motivation or empowerment of staff, managing relationships, being solution driven as well as fostering teamwork are argued to be possible through approaches such as formal and informal training. Despite growing multidisciplinary evidence in fields such as engineering, computer sciences and health sciences there remains little empirical evidence of these approaches, especially the informal approach. Findings are based on a broader doctoral thesis which explored district financial management; although the core focus of this paper draws attention to the significance of informal learning and its practical value in developing leadership competencies.

Methods

A qualitative case study was conducted in one district in the Gauteng province, South Africa. Purposive and snowballing techniques yielded a sample of 18 participants, primarily based at a district level. Primary data collected through in-depth interviews and observations (participant and non-participant) were analysed using thematic analysis.

Findings

Results indicate the sorts of complexities, particularly financial management challenges which staff face and draws attention to the use of two informal learning strategies—learning from others (how to communicate, delegate) and fostering team-based learning. Such strategies played a role in developing a cadre of leaders at a district level who displayed essential competencies such as motivating staff, and problem solving.

Conclusions

It is crucial for health systems, especially those in financially constrained settings to find cost-effective ways to develop leadership competencies such as being solution driven or motivating and empowering staff. This study illustrates that it is possible to develop such competencies through creating and nurturing a learning environment (on-the-job training) which could be incorporated into everyday practice.

Localization performance of unilateral cochlear implant users for speech, tones and noise

Bilateral cochlear implants aim to improve sound localization compared to monaural implants, among other potential benefits. Monaural cochlear implants should not support localization in the horizontal plane as there are no interaural level and time difference cues available, although some previous studies have suggested limited capability. As background to other studies of bilateral implantation, the localization abilities of 18 monaural cochlear implantees were investigated experimentally in an anechoic chamber, using various sound stimuli with different amounts of temporal information. The effects of head movement and reverberation were also investigated. Localization performance was found to be close to chance for all stimuli. It is confirmed that monaural cochlear implants are unable to support useful auditory sound localization, even when head movements are allowed.

Linking perceptions of neighbourhood to health in Hamilton, Canada

STUDY OBJECTIVE

To investigate the association between perceptions of neighbourhood physical and social characteristics and three health outcomes (self assessed health status, chronic conditions, and emotional distress).

DESIGN

Cross sectional survey data analysed in small neighbourhoods.

SETTING

Hamilton, Ontario, Canada, a medium sized industrial city, located at the western end of Lake Ontario (population at the time of the study about 380 000).

PARTICIPANTS

Random sample of 1504 adults aged 18 years and older residing in four contrasting neighbourhoods.

MAIN RESULTS

Significant differences across the four neighbourhoods are apparent in self assessed health status and emotional distress, but not in chronic conditions. Neighbourhoods with lower SES reported poorer health and more emotional distress. Perceptions of the physical environment dominated social concerns in all neighbourhoods. For all three health outcomes, individual risk factors followed expectations, with measures of poverty, age, and lifestyle all significantly associated with poor health outcomes. Physical environmental problems were positively and significantly associated with poor physical and emotional health. Specifically, people reporting they dislike aspects of their neighbourhood's physical environment are 1.5 times more likely to report chronic health conditions (OR 1.56, 95% CI 1.19 to 2.05), while those reporting physical likes with their neighbourhood are less likely to report fair/poor health (OR 0.50, 95% CI 0.28 to 0.90) or emotional distress (OR 0.45, 95% CI 0.26 to 0.80).

CONCLUSIONS

These results demonstrate the importance of neighbourhood perceptions as a determinant of health, as well as conventional factors such as low income, lifestyle, and age. The dominance of physical environmental concerns may have arisen from the industrial nature of Hamilton, but this result merits further investigation.

Environmental influences on healthcare expenditures: an exploratory analysis from Ontario, Canada

STUDY OBJECTIVE

This paper explores the relation between healthcare expenditures (HCEs) and environmental variables in Ontario, Canada.

DESIGN

The authors used a sequential two stage regression model to control for variables that may influence HCEs and for the possibility of endogenous relations. The analysis relies on cross sectional ecological data from the 49 counties of Ontario.

MAIN RESULTS

The results show that, after control for other variables that may influence health expenditures, both total toxic pollution output and per capita municipal environmental expenditures have significant associations with health expenditures. Counties with higher pollution output tend to have higher per capita HCEs, while those that spend more on defending environmental quality have lower expenditures on health care.

CONCLUSIONS

The implications of our findings are twofold. Firstly, sound investments in public health and environmental protection have external benefits in the form of reduced HCEs. Combined with the other benefits such as recreational values, investments in environmental protection probably yield net social benefits. Secondly, health policy that excludes consideration of environmental quality may eventually result in increased expenditures. These results suggest a need to broaden the cost containment debate to ensure environmental determinants of health receive attention as potential complements to conventional cost control policies.

From diversity comes understanding: health promotion capacity-building and dissemination research in Canada

Non-communicable diseases are the major cause of preventable death in industrialized countries and a growing concern elsewhere (Singapore Declaration, 1998). Modifiable risk factors for these diseases are prevalent [e.g., in Canada, 75% of adults have at least one modifiable risk factor for cardiovascular disease (CVD)] (Heart and Stroke Foundation of Canada, 1997).

Mapping health in the Great Lakes areas of concern: a user-friendly tool for policy and decision makers

The role of the physical environment as a determinant of health is a major concern reported by the general public as well as by many policymakers. However, it remains one of the health determinants for which few available measures or indicators are readily available. This lack of data is compounded by the fact that evidence for direct cause-and-effect relationships in the literature is often equivocal, leading to feelings of uncertainty among the lay public and often leading to indecision among policymakers. In this article we examine one aspect of the physical environment--water pollution in the Great Lakes Areas of Concern (AOCs)--and its potential impacts on a wide range of (plausible) human health outcomes. Essentially, the International Joint Commission, the international agency that oversees Great Lakes water quality and related issues, worked with Health Canada to produce a report for each of the 17 AOCs on the Canadian side of the Great Lakes, outlining a long list of health outcomes and the potential relationships these might have with environmental exposures known or suspected to exist in the Great Lakes basin. These reports are based solely on secondary health data and a thorough review of the environmental epidemiologic literature. The use of these reports by local health policymakers as well as by public health officials in the AOCs was limited, however, by the presentation of vast amounts of data in a series of tables with various outcome measures. The reports were therefore not used widely by the audience for whom they were intended. In this paper we report the results of an undertaking designed to reduce the data and present them in a more policy-friendly manner, using a geographic information system. We do not attempt to answer directly questions related to cause and effect vis-à-vis the relationships between environment and health in the Great Lakes; rather, this work is a hypothesis-generating exercise that will help sharpen the focus of research into this increasingly important area of public health concern.

What determines health? To where should we shift resources? Attitudes towards the determinants of health among multiple stakeholder groups in Prince Edward Island, Canada

The population health perspective has become significant in academic and policy discourse. The purpose of this paper is to assess its significance among health care practitioners and administrators as well as the general public. Respondents in Prince Edward Island, Canada were asked to rank the broad determinants of health and comment on to where resources should be shifted to improve the health of the population. Important variations are noted between the groups with family physicians and front-line staff being similar in perceptions to the general public on most determinants than other groups. The paper concludes with discussion on the relevance of the findings for population health research and health policy.

Job strain and self-reported health among working women and men: an analysis of the 1994/5 Canadian National Population Health Survey

This paper explores the associations, for working women and men, of high strain jobs with self-rated health in the 1994/95 Canadian National Population Health Survey (NPHS). NPHS data were obtained on men (n = 4230) and women (n = 4043), aged 18-64 who answered an abbreviated version oF the job content questionnaire (JCQ). Using the upper and lower tertiles of psychological demands and decision latitude as cut points we classified workers into high strain and other jobs. Self-rated health was the outcome. We used polytomous logistic regression analyses and controlled for potential personal and home confounders; two risk parameters were estimated: for the odds of reporting poor/fair and good health both vs. very good/excellent health. High strain work was reported by 11% of women and 9% of men. After adjusting for potential confounders, high job strain was consistently associated with worse self-rated health in both models for each gender.

Public health responses for skin cancer prevention: the policy framing of Sun Safety in Australia, Canada and England

This paper employs the policy analytic approaches of framing and narrative to examine national differences in public health policies using a case study of Sun Safety programs in Australia, Canada and England. The study shows how a single public health issue identified at the global scale (rising skin cancer rates) is framed differently based upon specific social, cultural and political situations. The result is a different story, or narrative, embedded in each national policy. This study provides an example of how health policy is defined, constrained and limited through the process of problem identification and policy resolution. The paper concludes that framing and narrative analysis are powerful tools for understanding the place-specific implementation of public health policies and initiatives.

Work correlates of back problems and activity restriction due to musculoskeletal disorders in the Canadian national population health survey (NPHS) 1994-5 data

OBJECTIVES

To describe the prevalence of musculoskeletal problems in the Canadian working population and to determine cross sectional associations between such problems and work factors, particularly job strain and physical demand variables.

METHODS

The Canadian 1994 national population health survey (NPHS) sampled 4230 working men and 4043 working women (ages 18-64) who answered an abbreviated version of the job content questionnaire. Workers were classified into four strain categories: high, passive, active, and low. Outcomes were restricted activity due to musculoskeletal disorders and the diagnosis of a back problem (both yes or no). Survey weights were incorporated to allow for different probabilities of selection. Logistic regression analyses were carried out separately for women and men, controlling for sociodemographic factors.

RESULTS

Prevalence of chronic back problems diagnosed by a health practitioner was 14.5% among men and 12.5% among women. Men had a 6.6% prevalence of restricted activity due to musculoskeletal disorders, whereas the corresponding figure for women was 5.3%. Women, but not men, in high strain jobs were more likely to report both back problems (odds ratio (OR) 1.60, 95% confidence interval (95% CI) 1.14 to 2.28) and restricted activity (OR 1.98, 95% CI 1.16 to 3.48) compared with those in low strain jobs. High physical exertion was an independent predictor of back problems in both sexes. For both men and women, low social support at work and high job insecurity were independent predictors of restricted activity due to musculoskeletal disorders. Conversely, chronic back problems contributed to explanation of high job strain among women (OR 1.76, 95% CI 1.30 to 2.39) and high physical exertion among men (OR 1.39, 95% CI 1.09 to 1.77), whereas restricted activity due to musculoskeletal disorders contributed to explanation of high job insecurity in both sexes.

CONCLUSIONS

Associations of interest between work stressors and musculoskeletal problems in this cross sectional study provide evidence for physical and psychosocial factors both affecting disability and being affected by disability in a working population.

Organochlorines and breast cancer: the uses of scientific evidence in claimsmaking

This paper explores the role and utilization of scientific evidence concerning one of the potential adverse health impacts (breast cancer) of the use of chlorine through examining the aims of an environmental group, Greenpeace, and its opponents. Specifically, the paper identifies the claims of Greenpeace and the scientific evidence used to justify those claims in its (Thornton, 1993) report Chlorine, Human Health and the Environment: The Breast Cancer Warning. A media analysis was conducted over a ten year period to assess what counter-claims were generated. The claimsmaking activities of breast cancer advocacy groups, scientists, pro-chlorine groups, and environmentalists were monitored. To counter the Greenpeace claims, pro-chlorine supporters argued for the responsible use of science, and redefined the chlorine issue as one of public health and economic security. The counter-claims between the supporters and the opponents of the chlorine issue stemmed from differences in their agendas, values, and solutions proffered in the environmental health policy domain.

Testing relationships among determinants of health, health policy, and self-assessed health status in Quebec

By removing financial barriers, the Canada Health Act (1984) equalized access to health care services in Canada. Yet class, educational, and geographical disparities in individual and population health status persist. Recent health reform policies in Quebec assert that health and well-being are a function of income, educational level, housing conditions, employment, and other socioeconomic factors. They suggest that health policy should encompass social policies that influence individual and community socioeconomic factors which in turn affect health. Against the backdrop of these reforms, this study tests the importance of socioeconomic factors as a determinant of health--while controlling for other known determinants through a logistic regression model--with data from the Santé Quebec health surveys 1987 and 1992-93. The results confirm the importance of economic security as a determinant of individual health. This effect appears to operate through an individual income variable and through the community-level variable of regional unemployment. The importance of the income effect declined between 1987 and 1992-93. This may indicate that an increased focus on the socioeconomic determinants of health has reduced inequalities in health. It may also mean that health inequalities appear inevitable until health care policy merges completely with broader health and social policies. But such integration may well conflict with economic (and political) imperatives of the post-Fordist capitalist system.

An empirical evaluation of an expanded Nursing Stress Scale

In the study of work-related stress among nurses, the Nursing Stress Scale (NSS) is the best known and most widely used scale. This article presents an overview of the NSS and its use, and describes the development of an expanded instrument (ENSS) to measure sources and frequency of stress perceived by nurses. Findings are based on a random sample of 2,280 nurses in Ontario working in a wide range of work settings. Pretests for the study indicated that an expanded version of the NSS was necessary in order to adequately measure sources of stress among nurses. The sources of stress comprised nine subscales--death and dying, conflict with physicians, inadequate preparation, problems with peers, problems with supervisors, workload, uncertainty concerning treatment, patients and their families, and discrimination. Confirmatory factor analyses, run on two randomly selected halves of the sample, came close to meeting standard criteria levels. The alpha coefficients of eight of the subscales were .70 or higher, and concurrent and construct validity assessments provided strong support for the expanded NSS.

Applying Aristotle's doctrine of causation to Aboriginal and biomedical understanding of diabetes

Aristotle's doctrine on causation identifies four distinct types of cause: formal, efficient, material, and final. Science is said to have differentiated itself from philosophy by concentrating solely on efficient causes. Nonetheless, when applied to narratives of causation, Aristotle's doctrine provides a useful heuristic to explore the issues such as Aboriginal and biomedical perceptions of causal factors for non-insulin dependent diabetes mellitus (NIDDM) on Manitoulin Island, Ontario. This paper also outlines two divergent causal stories for NIDDM and the associated moral positions regarding the 'righteous' pursuit of health. Biomedical narratives emphasize the role of lifestyle factors, particularly the impact of obesity, in causation. In the case of diabetes, the moral course of action is pursued through lifestyle choices. In contrast, Aboriginal narratives emphasize the role of genetics in causation. These narratives describe diabetes as collectively affecting Aboriginal people - thus identifying Aboriginal people as different. Aboriginal frameworks for health venture beyond the 'efficient' cause of biomedicine and thus the moral pursuit of health within this framework involves returning to an initial state of health and purity through traditional knowledge.

Managing and treating risk and uncertainty for health: a case study of diabetes among First Nation's people in Ontario, Canada

'Risk' has become a key concept for understanding health care policies that are focused on prevention. Intervention no longer depends on the presence of an illness but rather an individual's risk of developing an illness. Through 'risk factors' individuals are subject to medical examination and surveillance to determine the real presence of danger, based on this abstract notion of risk. This paper explores 'risk' and its consequences for medical intervention by focusing on biomedical practices surrounding diabetes care among First Nations on Manitoulin Island, Ontario. The first section explores the process of diagnosing diabetes. The second section outlines the treatment regimens resulting from membership in this category. The theme linking these two processes is that both diagnosis and management of diabetes depend on inclusion into categories of 'risk'. Practices surrounding diagnosis focus on a population described 'at risk' for diabetes. First Nation's people. Similarly, practices surrounding management of diabetes focus on a population 'at risk' for secondary complications, referring to individuals with diabetes. As the following discussion outlines, it is through the quantitative assessment of risk that scientific uncertainty is translated into definitive therapy and the need for constant surveillance.

Environmental Health Policy: Analytic "Framing" of the Great Lakes Picture

/ The International Joint Commission (IJC) has overseen the implementation of the Great Lakes Water Quality Agreement between Canada and the United States for 25 years. Part of its mandate has been to facilitate international cooperation among a diversity of stakeholders focusing on the "waters" and the "ecosystem." In the 1970s policy focused on phosphorus reduction and individual contaminants, with some efforts (after 1978) to take an ecosystem (ecological perspectives) approach. In the last 15 years human health effects from (real and perceived) environmental causes have received considerable recognition. By contrast, less concern has been expressed for what is traditionally considered "environment" issues (such as protecting fish species). This shift at the policy level is well illustrated in the manner in which human health is increasingly used as a way for mobilizing environmental agendas. This paper analyzes nine IJC biennial reports to track how the framing of Great Lakes issues has shifted from concern for its waters to concern for human neurobehavior and reproductive systems. Frame analysis is used to conceptualize the controversies that are expressed through the Great Lakes policy documents. The analysis of the reports also reveals a shift in operational frames, used by the IJC to mobilize decision-makers into action.

Heterogeneity in the determinants of health and illness: the example of socioeconomic status and smoking

Systematic variations in health and illness among social groups have persisted and, in some cases increased, in many countries in spite of improvements in the availability of, and access to, health care services. Health policy makers have responded by showing increasing interest in non-clinical determinants of health as a way of explaining the observed systematic variations in health and illness. Yet health care and non-health care "factors" are often seen as competing for society's scarce resources in the production of health. The purpose of this paper is to augment this traditional approach to understanding the determinants of health in populations by exploring heterogeneity in the smoking-health relationship between social groups. Logistic regression analyses were performed using data from the 1992-93 Santé Quebéc survey, a weighted random sample of the non-institutionalized population of the province of Québec, Canada (N = 23,564). The findings suggest that the likelihood of reporting health as poor or fair was greater for smokers than non-smokers. However, the difference between smokers and non-smokers was significantly greater among groups of the population with low incomes and without employment, but significantly less among sub-groups with lower levels of education. These findings suggest that the identification, evaluation and implementation of health care programmes need to pay greater attention to the interface between social, behavioural and clinical determinants of health.

Needs-based primary medical care capitation: development and evaluation of alternative approaches

OBJECTIVE

To develop and evaluate alternative methods of adjusting primary medical care capitation payments for variations in relative need for health care among enrolled practice populations.

METHODS

We developed alternative needs-based capitation formulae and applied them to a sample of capitation-funded primary care practices to assess each formula's performance against a reference standard of capitation payments based on age, sex and self-assessed health status of the enrolled populations. The alternative formulae were based on: (1) age and sex; (2) age, sex and individually-measured socioeconomic characteristics; (3) age, sex and socioeconomic characteristics imputed from census data for enrollees' neighbourhood of residence; (4) age, sex and standardized mortality ratio for enrollees' neighbourhood of residence.

RESULTS

Age/sex-adjusted capitation payments for the six practices studied ranged from 10% higher to 18% lower than the reference standard payments. Capitation formulae based on socioeconomic and mortality data did not perform consistently better than the current age/sex-based formula.

CONCLUSIONS

Primary medical care capitation payments adjusted only for age and sex do not reflect the relative health care needs of enrolled practice populations. Our alternative formulae based on socioeconomic and mortality data also failed to reflect relative needs. Methods that use other approaches to adjusting for differences in relative need among enrolled populations should be investigated.

Equity and health care: analysis of the relationship between need for care and the utilization of nursing services in Canada

This paper examined the relationships between need for care and the utilization of nursing services using data from the 1985 Canada Social Survey. The incidence of nursing utilization was estimated using probit regression, and the quantity of utilization, using a self-selectivity model. Further analyses involved exploring use-need relationships by partitioning the sample by need level and by examining interaction effects. It was found that a lower likelihood of using nursing services was associated with lower levels of need, males, married persons, and lower levels of education. Need was also significantly associated with the number of contacts with nurses. While income was not significant, the size of the use-need relationship was affected by socioeconomic and demographic variables, pointing up the necessity of disaggregated analyses.

Environmental health metanarratives: an analysis of policy making in Ontario, Canada

This paper provides a narrative analysis of a policy document, issued by the Ontario Premier's Council on Health, Well-Being and Social Justice, entitled "Our Environment, Our Health". It begins by outlining the background for the production of the document and establishing the nature of narrative analysis. The intention of this method is to reveal dominant and suppressed ideas through identifying narrative, non-stories and counter-stories. It then goes on to provide an analysis of the overall policy piece and its constituent parts, healthy ecosystems, healthy communities and healthy workplaces. The document's power is seen not only in its authorship but also in demonstrating the moral basis of individual responsibility to achieve collective targets and to undertake collection action.

Complaints against nurses: a reflection of 'the new managerialism' and consumerism in health care?

This paper discusses the effects of restructuring on nursing as a profession through an examination of the issue of complaints in Ontario. It argues that new managerialist techniques and associated changes in the nature of work are reducing the autonomy of nurses and making it difficult for them to meet the standards of their profession. Simultaneously, the Ontario government has increased the power of the public in the disciplinary process and the College of Nurses of Ontario is encouraging patients to register their complaints. The growth of consumerism in health care, coupled with the disciplinary process, individualizes complaints and deemphasizes their relationship to restructuring. Moreover, in response to the increasing number of complaints - complaints which more often come from the public - nursing organizations have encouraged the legalization of the disciplinary process, thus fostering the individualization of the issues.

Perceiving and representing both health and the environment: an exploratory investigation

This article describes an exploratory study that examined the perceptions of both health and environment among men and women in higher and lower status areas in Hamilton, Canada. Situated in the literatures on health perceptions and environmental concerns, it not only describes health and environment perceptions, but also explores their interconnections, arguing that concern for self is more salient than that for any other, including environment, and that this salience is predicated on notions of control and responsibility. The article concludes by speculating on reasons for these findings by suggesting an empirically derived cultural model for representation of health-environment relations and the bases of information processing in this arena.

Indicators of human health in ecosystems: what do we measure?

Increasingly, scientists are being called upon to assist in the development of indicators for monitoring ecosystem health. For human health indicators, they may draw on environmental exposure, human morbidity/mortality or well-being and sustainability approaches. To improve the rigour of indicators, we propose six scientific criteria for indicator selection: (1) data availability, suitability and representativeness (of populations), (2) indicator validity (face, construct, predictive and convergent) and reliability; (3) indicator responsiveness to change; (4) indicator desegregation capability (across personal and community characteristics); (5) indicator comparability (across populations and jurisdictions); and (6) indicator representativeness (across important dimensions of concern). We comment on our current capacity to adhere to such criteria with examples of measures of environmental exposure, human health and sustainability. We recognize the considerable work still required on documenting environment-human health relationships and on monitoring potential indicators in similar ways over time. Yet we argue that such work is essential in order for science to inform policy decisions which affect the health of ecosystems and human health.

Socioeconomic and environmental covariates of premature mortality in Ontario

This paper contributes to debates on the broad determinants of health and on the policy shift from curative to preventive and protective interventions. It addresses empirically the relative importance of influences on health with a multiple regression analysis of ecologic data from the 49 counties of Ontario. One model achieved high predictive power (that is, Adj R2 > 75%, p < 0.0001). Educational levels were a strong predictor of population health, showing a consistent inverse relationship with premature mortality ratios for both sexes and it was the strongest predictor for females. A low income variable supplied the strongest prediction for male mortality. This variable displayed a positive association with male mortality. Municipal expenditures on environmental protection exerted a negative effect on male mortality. These findings raise questions about the current directions of health policy in Ontario where the provincial government has reduced funding to social and environmental programs, while promising to maintain health care funding.

Allocating resources in health care: alternative approaches to measuring needs in resource allocation formula in Ontario

Maintaining or improving the welfare of the population is a complex issue involving individual and collective actions and institutions. Despite questions regarding the relevance of health care systems to these aims, they remain vital policy and treatment arenas with respect to curative and preventative regimes. As a component of social welfare, health care resources should be distributed equitably, according to need for health care. This paper evaluates alternative indicators of health status within Ontario against self-reported health as a means of allocating health care resources. Proxies of need for health care include standardized mortality ratios (based on the population aged 0-64) and a socioeconomic based indicator. Mortality indicators are found to be more closely correlated with self-reported health status than the socioeconomic indicator, suggesting that mortality is better able to reflect variations in health status and health care needs.

Gender differences in work and family life

Work. What comes to mind? Most of us think in terms of the work for which we are paid or the jobs that we would like to have. Seldom do we also think of the things we do at home, the care that we provide for our families. Yet, this unpaid work can influence our job, just as the demands of the workplace can affect our home life. Together, the expectations of both types of work can sometimes be over-whelming.

Meanings in policy: a textual analysis of Canada's "Achieving Health For All" document

This paper presents a textual analysis of a key Canadian health policy document--Achieving Health for All (AHFA). It begins by establishing the importance of policy language and an interpretive approach to reveal dominant meanings and assumptions. This approach points out the significance of language and its contexts (text and intertext) and of developing a formal analytic strategy, based on semiotics. The paper concludes with a detailed, illustrated analysis of AHFA, suggesting that the document's discourse, through appealing to all, with emphases on the nation, community and all Canadians, establishes a frame of individual responsibility and rights, health promotion and broad health determinants--a frame that resonates with the cost-constrained nature of health care delivery-as found in provincial reform documents in the 1980s and 1990s.