AB0186 NO PREDICTIVE VALUE OF ADALIMUMAB SERUM LEVELS AND ANTI-ADALIMUMAB ANTIBODIES AT TIME OF ADALIMUMAB FAILURE FOR PREDICTION OF RESPONSE TO THE NEXT BDMARD

Background:

After adalimumab treatment failure, TNFi and non-TNFi bDMARDs are equally viable as subsequent treatment in RA. However, preliminary data suggest that anti-drug antibodies (ADA) and adalimumab serum levels (ADL) predict response to a subsequent TNFi [1].

Objectives:

To assess the association of presence of ADA and/or low ADL with response to a subsequent TNFi bDMARD or non-TNFi bDMARD.

Methods:

A retrospective cohort study to assess the predictive value of ADA and ADL for response to a subsequent TNFi or non-TNFi bDMARD in RA patients.

All RA patients who received adalimumab (standard dose, ≥ 3 months) and subsequently switched to another TNFi or a non-TNFi (rituximab, tocilizumab, abatacept) in the Sint Maartenskliniek or Radboud University Medical Centre between January 2012 and January 2018 were considered for inclusion in the current study. Further inclusion criteria were the availability of (random timed) serum samples between ≥8 weeks after start, and ≤2 weeks (for ADL) or ≤12 weeks (for ADA) after discontinuation of adalimumab, and clinical outcome measurements (DAS28-CRP/BSE) between 3-6 months after treatment switch. Serum samples were derived from a period of biobanking at every visit of RA patients and an observational cohort study including consecutive bDMARD starters.

The primary outcome of this study was the association between ADL or ADA and EULAR good response (DAS28-CRP/ESR based) to the subsequent bDMARD. When DAS28-based response was unreliable due to glucocorticoid use, or low baseline DAS28 (if switching due to adverse effects), judgement of the rheumatologist was used.

A drug-tolerant competitive enzyme-linked immunosorbent assay (Sanquin, the Netherlands) was used to quantify ADA, and thereafter, ADL was determined via an ELISA. Reference values were ≥5 µg/ml for ADL and <12 AU/ml for ADA [2,3]. Treatment was blinded for ADL and ADA levels.

Prediction of response were assessed using the area under the receiver-operator characteristic (AUROC) and sensitivity/specificity. Sub-analyses were performed for primary and secondary non-responders. Correlations between ADL and ADA presence and clinical variables were also cross-sectionally explored.

Results:

137 patients were included, 47 of whom switched to a second TNFi and 90 to a non-TNFi. Sensitivity and specificity of the proposed ADA and ADL reference values were low (table 1). The AUROC did not differ appreciably or significantly from 0.5. Results were similar for both primary and secondary non-responders to adalimumab.

Table 1.

predictive values of ADA and ADL for response to a subsequent bDMARD in TNFi and non-TNFi switchers.

sensitivity (%)specificity (%)AUCCITNFi switchersADA presence (>12AU/mL)18750.460.32-0.59low ADL (<5mg/L)32690.500.29-0.71non-TNFi switchersADA presence (>12AU/mL)33700.520.42-0.63low ADL (<5mg/L)50520.500.34-0.65

Higher ADL (Spearman’s ρ = -0.68, p = 0.00) but not ADA (ρ = 0.23, p = 0.28) presence was associated with a lower DAS28 at the time of switching to a subsequent bDMARD, but not with follow-up DAS28 after starting the subsequent bDMARD (ρ = -0.29, p = 0.17, and ρ = 0.10, p = 0.65, respectively). In addition, higher ADL were associated with lower baseline CRP (ρ = – 0.67, p = 0.00) and ESR (ρ = – 0.546, p = 0.006) and higher ADA correlated with higher baseline ESR (ρ = 0.49, p = 0.01).

Conclusion:

No predictive value for response to a second TNFi or non-TNFi was found for either ADA or random timed ADL. Limitations of this study are the retrospective design and random timed serum sampling. An ongoing randomized blinded test-treatment trial will provide more definitive answers [4].

References:

[1]Van Herwaarden et al.Expert Opin Drug Metab Toxicol.2017;13:843–57.

[2]Pouw et al.Ann Rheum Dis.2015 Mar;74(3):513-8.

[3]Bartelds et al.Ann Rheum Dis.2007 Jul;66(7):921-6.

[4]ADDORA-SWITCH study,www.trialregister.nl,no NL 8210

Disclosure of Interests:

Nathan den Broeder: None declared, Evy Ulijn: None declared, Maike Wientjes: None declared, Noortje van Herwaarden: None declared, Inger Meek: None declared, Lieke Tweehuysen: None declared, Aatke van der Maas: None declared, Bart van den Bemt Grant/research support from: UCB, Pfizer and Abbvie, Consultant of: Delivered consultancy work for UCB, Novartis and Pfizer, Speakers bureau: Pfizer, AbbVie, UCB, Biogen and Sandoz., Alfons den Broeder: None declared

Abstract 5422: Predictive models of diffusive nanoparticle transport in 3D tumor spheroids

Nanotechnology offers a means to deliver diagnostics and therapeutics, and has emerged as an important tool in cancer translational research. We previously described a computational model that uses nanoparticle (NP)-cell biointerface data to predict diffusive NP transport in 3D tumor spheroids; the model predictions agreed with the experimental results for near-neutral liposomes and negatively-charged polystyrene beads but not for cationic liposomes that contained fusogenic lipid DOPE and underwent significant size change in the presence of tumor cells (Gao et al., AAPS J 15:816, 2013). The present study evaluated if the inferior model performance on cationic liposomes was due to fusogenic lipid, positive surface charge, and/or time-dependent NP size change. We studied eight cationic liposomes containing different levels of cationic lipid DOTAP (10-30 mol%) and fusogenic lipid DOPE (1-20 mol%), with an average initial size of ∼135 nm and 2-fold range in surface charge (+24 to +43 mV). The time-dependent NP size change was monitored by measuring NP size distribution and by live cell confocal microscopy; the results indicate the most substantial change for liposomes containing &gt;10 mol% DOPE. The required NP-cell biointerface parameters (NP association and dissociation with/from cells, NP internalization, maximum NP binding sites) were measured in monolayer cultures. Comparison of model-predicted profiles with experimental results in 3D spheroids showed good agreement (&gt;88% and &gt;95% of predicted data were within 95% and 97.5% confidence intervals of experimental results, respectively; &lt;26% average deviations) for cationic liposomes containing 10-30 mol% DOTAP and low levels DOPE (≤10 mol%), indicating the diffusive transport of these cationic NP in 3D systems could be predicted using the biointerface data. In comparison, inferior predictions were obtained for cationic liposomes with higher DOPE content (up to 88% deviations, average of 41%).In view of the substantial depletion of extracellular concentration and the substantial size increase for selected NP over the 12 hr study (e.g., &gt;8% depletion for 30 mol% DOTAPand 3-times larger size for 20 mol% DOPE), we modified the model to account for these time-dependent changes. The modified model yielded better predictions for liposomes with &lt;10 mol% DOPE, but worse predictions for liposomes containing 20 mol% DOPE (86% average deviations).This finding rules out the time-dependent changes in NP size and concentration, and suggests other DOPE properties not captured by the biointerface parameters, as potential causes of the inferior model performance. In summary, the present study, together with our earlier study, indicates the diffusive transport of NP with different sizes (20-135 nm) and varying surface charges (-49to +43mV) in 3D spheroids, with the exception of liposomes comprising &gt;10 mol% of fusogenic lipid DOPE, can be predicted based on the NP-cell biointerface parameters. RO1EB015253, DHHS.

Citation Format: Mingguang Li, Michael Wientjes, Bertrand Yeung, M. Guillaume Wientjes, Jessie L.S. Au. Predictive models of diffusive nanoparticle transport in 3D tumor spheroids. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5422. doi:10.1158/1538-7445.AM2014-5422

Comparative inhibition of prostate cell invasion by conformationally flexible and constrained bis(2,6-dioxopiperazine)s

Inhibition of the migration of human prostate cancer PC-3 cells by a series of 18 conformationally flexible and constrained bis(2,6-dioxopiperazine)s including selected bis(morpholinomethyl) derivatives was investigated in vitro using the Matrigel invasion assay. The anti-invasion effects were compared to the cytotoxic effects of these experimental drugs. The parent conformationally mobile ICRF-159 (razoxane) and its dextrorotatory isomer ICRF-187 (dexrazoxane) inhibited invasion at concentrations that were at least 19-fold lower than their cytotoxic concentrations. This indicates that the anti-invasion effect was achieved independent of cytotoxicity. Seven conformationally constrained compounds were found to have no appreciable anti-invasive activity. Generally, the morpholinomethyl pro-drug derivatives of seven of the dioxopiperazines, exhibited either anti-invasive or cytotoxic activities that were reduced or unchanged relative to the parent molecules. In summary, certain bis(2,6-dioxopiperazine)s exhibit a promising and selective anti-invasion effect in human prostate cells. This activity seems to require a flexible linker allowing for multiple conformational possibilities of the dioxopiperazine rings.