On-treatment Research Articles

Adoptively Infused Memory-like Natural Killer Cells Impact Adaptive Immune Responses in Patients with Acute Myeloid Leukemia

Natural killer (NK) therapies have been challenging owing to antigen escape, restricted trafficking, and limited tumor infiltration, translating into modest clinical benefit. We have shown that memory-like (ML)-NK cells acquire an in vivo differentiated phenotype distinct from conventional NK cells and are well-tolerated without cytokine release syndrome, GVHD, or neurotoxicity. WU-NK-101 (W-NK) is an allogeneic cytokine-reprogrammed, expanded, cryopreserved ML-NK cell product derived from healthy human peripheral blood mononuclear cells, with scalable manufacturability, that is currently in clinical development in relapsed/refractory (R/R) AML (NCT# 05470140). We conducted a multi-modal analysis of the immune tumor microenvironment (TME) in 13 patients with R/R AML receiving ML-NK cells (NCT#01898793) with the aim to determine whether TME modifications induced by ML-NK cells correlate with clinical benefit. NK cells were purified from leukapheresate, and activated with IL-12, IL-15, and IL-18 for 12-16 hours. Patients were lymphodepleted with fludarabine and cyclophosphamide. NK cells were infused in escalating doses: 0.5 × 10 6/kg, 1.0 × 10 6/kg, and all NK cells from a single leukapheresis, capped at 10 × 10 6/kg. Response was defined as <5% BM blasts on d+28. BM trephines for immune gene expression profiling (nCounter IO360®) and spatial proteomics (GeoMx™ DSP; n=53 immuno-oncology [IO] targets; NanoString Technologies, Seattle) were collected at baseline (BL) and on treatment (OT). Immune infiltration, NK and T cell number from BM samples was quantified manually on immunofluorescent imaging. Oncomine™ TCR Pan-Clonality assay (Thermo Fisher) was used to profile TCRb and g repertoires by NGS. The Shannon index was used to describe TCR repertoire diversity, and clonal evenness was used as a measure of the similarity of clone sizes. BM infiltration with CD8 + effectors, enhanced glycolysis and cell cycling was higher in BM samples from responders (CR) to ML-NK cells. By contrast, OXPHOS RNA scores and gene signatures of immune senescence and terminal T-cell exhaustion were higher in non-responders (NR). We employed machine learning to construct an 8-gene predictor of response which encompassed T/NK markers, such as CD7, and IFN regulatory factors and TLRs. This score was significantly higher at baseline in CR and positively correlated with response duration. Principal component analysis (PCA) of spatially resolved IO proteins separated CR from NR, particularly in OT specimens, where T-cell markers CD3/CD8 and inhibitory receptors CTLA4/LAG3 were among the top contributing features. CD34, type I IFN signaling molecule STING1 and PARP1 were significantly higher at baseline compared with OT, with OT showing higher expression of cytotoxicity markers and inhibitory receptors (e.g., Tim-3 and CD276). This observation strongly suggests modulation of the immune TME after the infusion of ML-NK cells. Response to ML-NK cells was associated with coordinated up-regulation of T cell, NK cell and B cell protein markers. To further substantiate the co-localization of T cells and NK cells in the BM FFPE sections (Fig. A), and its correlation with clinical efficacy we annotated the 93 ROIs in our spatial proteomics dataset based on a median split of CD3 and CD56 protein barcodes. ROIs from CR were largely CD3 highCD56 high, both at BL and OT. Conversely, ROIs from BM sections of NR to ML-NK cells had a predominantly CD3 lowCD56 low phenotype. Quantitative analysis of T-cell infiltration post ML-MK dosing showed a significant association with response, 0.9 (PD) vs. 5.3 (CR)-fold-increase ( P=0.01). Interestingly, data demonstrate selected intra-BM clonal expansion as evidenced by decreased TCR diversity (mean ± SEM, 4.6±0.3 vs. 3.3±0.4, pre vs. post; P=0.013)and increased clonality (Fig. B). Thus, pre-existing T-cell responses appear to be co-opted in the AML TME of CR, suggesting the potential for durable effectiveness of ML-NK cells. Multi-modal analyses of WU-NK-101 highlight unique transcriptional and functional states, which could underpin in vivo potency and persistence. WU-NK-101 are currently being evaluated in a phase 1 study of R/R AML (#NCT05470140).

Englumafusp Alfa (CD19-4-1BBL) and Glofitamab Combination in Patients with Relapsed/Refractory Non-Hodgkin Lymphoma (R/R NHL): Biomarker Results from a Phase I Dose-Escalation Trial

Background: Englumafusp alfa is an antibody-like fusion protein that simultaneously targets CD19 on B cells and 4-1BB on T cells and other immune cells. In the presence of a T-cell receptor signal and strictly dependent on CD19 crosslinking, englumafusp alfa co-stimulates T cells via 4-1BB agonism that boosts T-cell effector functions and prevents T-cell anergy. An ongoing Phase I dose-escalation study (NCT04077723) is investigating the safety, efficacy, pharmacokinetics, and pharmacodynamics (PD) of intravenous administration of englumafusp alfa in combination with glofitamab in patients (pts) with R/R NHL. We recently presented preliminary clinical data demonstrating promising clinical activity and good tolerability in R/R NHL (Hutchings et al, ICML 2023). Here, we report preliminary peripheral blood (PB) and tissue biomarker analyses to demonstrate mechanisms of action (MoA), dose relationship, and baseline features associated with response. Methods: Exploratory biomarker analyses included data from 84 pts with indolent or aggressive NHL (aNHL) dosed with 0.36-75mg englumafusp alfa, starting on Cycle 2 Day 8 (C2D8) and followed by combination with the fixed target dose of glofitamab (30mg), once every 3 weeks, from C3D1 for up to 12 cycles. Immune profiling of PB by flow cytometry and plasma cytokines analysis by ELLA were performed. Circulating tumor DNA (ctDNA) dynamics were evaluated by the Avenio NHL CAPP-Seq assay (Stokowski et al, ASH 2022) at C3D1, C5D1, and the end of 12-cycle treatment (EoT) in patients with aNHL. Baseline tumor biopsies (n=65) were analyzed by immunohistochemistry/immunofluorescence assays. On-treatment (OT) PD changes during the first five cycles of treatment were evaluated and compared to historical glofitamab monotherapy PD data generated in a phase I/II study (NCT03075696). Results: Englumafusp alfa in combination with glofitamab induced PD changes in PB at all tested doses. Specifically, in a dose-dependent manner, englumafusp alfa in combination with glofitamab limited the PB expansion of fully differentiated PD1+ CD8+ effector memory T cells re-expressing CD45RA (Temra), previously shown to expand dose-dependently following glofitamab monotherapy (Broeske et al, Blood Advances 2022). Additionally, the combination also resulted in a significant PB expansion of the activated (HLA-DR+) and effector memory CD8+ T (T EM) cells, and the ratio of T EM to central memory and naïve CD8+ T cells compared to glofitamab monotherapy. Furthermore, we detected no significantly added cytokine release with the combination to that previously observed with glofitamab monotherapy, in line with the clinically observed safety profile. Preliminary analysis of ctDNA dynamics showed that at C3D1 33% (18/55), at C5D1 40% (15/38), and at EoT 53% (9/17) of the pts had no detectable ctDNA. Notably, 61% of pts with aNHL who achieved complete metabolic response (CMR) had no detectable ctDNA at any OT visit. Our preliminary analysis also indicated a significant (p=0.03) association between the observed OT expansion of CD8+ T EM cells and the extent of decrease in ctDNA levels (mean mutant molecules per milliliter) at EoT relative to baseline. Finally, we observed ~60% of pts with low tumor infiltrating CD8+ T cells (<500 cells/mm 2 CD8+) and a more aggressive disease (>5000 cells/mm 2 proliferative (Ki67+) tumor cells) at baseline, both poor outcome correlates of glofitamab monotherapy, achieved a CMR with higher doses of englumafusp alfa. Conclusions: In this study, we demonstrated the MoA of englumafusp alfa in R/R NHL and key PD effects in combination versus glofitamab monotherapy that will support optimal biological dose finding. Furthermore, the observed association between expansion of T EM cells in PB and changes in ctDNA dynamics at EoT, albeit preliminary, supports ctDNA as a marker for depth and durability of response. Overall, our PD and biomarker observations so far strengthen the rationale of combining glofitamab with englumafusp alfa to drive long-term responses in this heavily pre-treated NHL patient population. Acknowledgments: This study was sponsored by F. Hoffmann-La Roche Ltd. The authors would like to thank the patients who participated in this trial, their families, and their caregivers. Special thanks also to Daria Rukina, Iva Lelios, Philip Knuckles, Kat Reyskens, Grigori Singovski, and Joanne Hayward for their contributions to this work.

Putative Predictors of Response to WU-NK-101, an Allogeneic, Enhanced Memory (ML) Natural Killer (NK) Cell Therapy Product, for Relapsed/Refractory (R/R) Acute Myeloid Leukemia (AML)

Strategies to enhance NK-cell activity prior to adoptive transfer into patients with AML have yielded inconsistent clinical benefit. Immune cells in the AML tumor microenvironment (TME) are dysfunctional, in part due to enhanced interferon-γ signaling and acquisition of a senescent-like T/NK phenotype (Vadakekolathu, et al. Sci. Transl. Med. 2020). Cytokine-induced memory-like (CIML) NK cells are more potent for anti-tumor responses than conventional NK (cNK) cells, are well tolerated, and active in patients with R/R AML (NCT#01898793) with complete response (CR)/CR with partial/incomplete hematologic recovery rate of 47% and a median DOR of 9.4 months after a single infusion (Berrien-Elliott, et al. Cancer Discov. 2020). WU-NK-101 is a cell therapy derived from healthy donor NK cells, which are activated to induce a ML-NK cell program, expanded, and frozen to create an off-the-shelf cell therapy. This abstract 1) describes the approach for treatment of R/R AML with WU-NK-101, built upon prior clinical experience with CIML-NKs; 2) characterizes TME gene expression (GE) signatures associated with outcome after the infusion of CIML-NK in R/R AML and 3) functionally characterizes WU-NK-101. Bone marrow (BM) aspirates and trephine biopsies for immune GE profiling and spatially resolved proteomics (IO360® panel, n = 740 genes, and GeoMx® DSP; NanoString Technologies) were collected at baseline (BL) and on treatment (OT) from 15 patients receiving CIML-NK cells on study NCT #01898793. ssGSEA-based scores were computed using the IOBR package in R. Machine learning was used to select features that correlated with response. Cell phenotypes were evaluated by mass cytometry. NK cell function was assayed in either conventional (N-; 20% IMDM) or TME-aligned media. Multi-omics studies were performed by mass spectrometry. Cell trafficking to TME was measured in NSG mouse tumors by tracking fluorescent-labeled WU-NK-101. Correlative studies showed that BL GE signatures reflecting heightened neutrophil infiltration, chemokine receptor expression, and cancer antigen presentation predicted response to CIML-NKs (AUROC = 0.875, 0.875 and 0.850, respectively). We computed an 8-gene signature score (RPTOR, IRF9, TLR1, NLRP3, CD7, IL6R, FUT4, IL1RN) that was significantly higher at BL in responders and that correlated with response duration (Fig. 1A). Immune deconvolution of GE data with CIBERSORT highlighted critical differences in TME cellular composition at BL in responders to CIML-NKs, including a higher inferred abundance of macrophages, gamma/delta T cells and activated dendritic cells (Fig. 1B). In OT samples from responders, glycolytic GE programs as well as purine/pyrimidine and amino acid (AA) metabolism were upregulated compared with BL; no TME modulation was observed in non-responders (Fig. 1C). Analysis of WU-NK-101 cells revealed a unique phenotype compared with cNK cells, including higher expression of activating receptors, CD25, CD69, and GZMB, which positions WU-NK-101 for rapid activation and improved cytotoxicity. The latter hypothesis was confirmed by in vitro assays, with higher half maximal effective concentration (mEC50) for cNK vs WU-NK-101 (mEC50 = 5.2 vs 1.7; P = 0.032; Fig. 1D). The adverse impact of immunosuppressive TME-aligned media on cytotoxicity was evident on cNK but negligible to WU-NK-101 (mEC50 = 16.3 vs 2.0; P = 0.018; Fig. 1D). In N-media, WU-NK-101 used glucose as its main nutritional source; in hypoglycemic TME-aligned media, AA metabolic pathways were upregulated, indicating metabolic adaptability. This was supported by increased cell surface expression of AA transporters. WU-NK-101's homing to the BM averaged 16.5 ± 2.4%, which is 5.5-fold higher than previously reported for feeder-cell+IL-2-expanded NK cells (~3%; Sato et al. Clin. Cancer Res. 2020). In summary, an 8-gene TME signature showed excellent predictive ability for response to ML-NKs. In responders, ML-NK infusion was associated with TME modulation and with metabolic re-programming. Compared to cNK cells, WU-NK-101 had enhanced trafficking to the BM, anti-tumor activity, and a metabolic profile consistent with aerobic glycolysis, potentially contributing to mitigating TME adversity. Due to their resilience to an immunosuppressive TME, WU-NK-101 cells may represent an effective treatment modality for R/R AML; a phase 1 study of WU-NK-101 in R/R AML is in development (NCT #05470140). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Phase II study of durvalumab (anti-PD-L1) and trametinib (MEKi) in microsatellite stable (MSS) metastatic colorectal cancer (mCRC)

BackgroundMonotherapy with immune checkpoint blockade is ineffective for patients (pts) with microsatellite stable (MSS) metastatic colorectal cancer (mCRC). This study investigates whether the combination of trametinib (T) with durvalumab (D)...

Mechanisms of action and acquired resistance to atezolizumab plus nab-paclitaxel in metastatic triple-negative breast cancer (mTNBC).

1078 Background: In the IMpassion130 study (NCT02425891) first-line atezolizumab plus nab-paclitaxel (A+nP) provided clinical benefit compared with placebo plus nP (P+nP) in patients with mTNBC whose tumors were PD-L1+ (Schmid NEJM 2018). However, in many patients, disease that was initially controlled eventually progressed. The mechanism of action of A+nP and nP in the mTNBC tumor microenvironment (TME) and the biological changes associated with tumor progression with these therapies remain largely unknown. The goal of the current study was to evaluate biological changes in the TME induced by atezolizumab and nP early on treatment (OT) and at the time of progressive disease (PD) in IMpassion130. Methods: Paired tumor biopsies from IMpassion130 collected pre-treatment at baseline (BL), after 4 weeks OT, and at clinical PD were evaluated histologically for PD-L1 expression, CD8 content, stromal tumor infiltrating lymphocytes and immune phenotypes. RNA sequencing was also used to evaluate TNBC molecular subtypes and gene expression (hallmark gene sets, and immune cell and stromal gene signatures). Matched tumor pair samples from BL and PD were further analyzed by next-generation sequencing for genomic changes using the FoundationOne gene panel. Wilcoxon, Fisher, and McNemar’s tests were used for statistical analysis. Results: OT A+nP (n = 24 pairs), but not P+nP (n = 18 pairs) increased PD-L1 in both tumor-infiltrating immune cells and tumor cells, and increased frequency of immune-inflamed tumors. RNA-based signatures for A+nP showed an increase in lymphocytes (T-, B-, and NK cell), as well as IFN-α and IFN-γ responses, driven mainly by responders. While P+nP increased RNA-based stromal signatures (cancer-associated fibroblasts, pericytes, and angiogenesis) and epithelial mesenchymal transition, these changes were not observed with A+nP. OT A+nP and P+nP both reduced cell proliferation but only A+nP reduced metabolic pathways. At PD there was a significant reduction of RNA-based immune and stromal signatures in both A+nP (n = 59) and P+nP (n = 55) arms. Cell proliferation and DNA repair signatures were increased with A+nP but not P+nP. Evaluation of genomic changes suggested that both A+nP and P+nP increased tumor mutational burden (TMB), but only A+nP increased genomic scarring. At PD, the tumor immune phenotypes changed at PD with no directionality, while TNBC subtypes remained stable. Conclusions: A+nP boosted tumor immune inflammation and decreased tumor cell proliferation and metabolism in mTNBC patients, particularly in responders. Addition of atezolizumab prevented early stromal recruitment induced by nP. While decreased immune and stromal components and increased TMB were observed with both nP and A+nP, A+nP tumor escape was characterized by increased cell proliferation and DNA scarring. Clinical trial information: NCT02425891.

Real-life experience with bictegravir/emtricitabine/tenofovir alafenamide in a large reference clinical centre.

The use of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) is mainly based on robust, pivotal clinical trials. To provide data on clinical use of BIC/FTC/TAF in real life. This was an observational, retrospective and single-centre study. We included all adult, treatment-naive (TN) and treatment-experienced (TE) people living with HIV (PLWH) starting BIC/FTC/TAF from 8 June 2018. We evaluated effectiveness [on treatment (OT), modified intention-to-treat (mITT) and intention-to-treat (ITT)], tolerability and safety in those patients who reached 6 months of follow-up (M6). We included 1584 PLWH [213 TN (13%) and 1371 TE (87%)]. The median (IQR) follow-up was 16 (7-21) months, with 81% and 53% of PLWH reaching M6 and M12, respectively. By OT, mITT and ITT, HIV-RNA <50 copies/mL was 77%, 70% and 62% at M6 and 92%, 77% and 63% at M12 for TN PLWH and 94%, 89% and 83% at M6 and 93%, 85% and 78% at M12 for TE PLWH, respectively. In PLWH carrying an M184V/I substitution, OT RNA <50 copies/mL was 89.5% at M6. The median CD4 cell count increased from 329 to 511/μL in TN PLWH and from 630 to 683/μL in TE PLWH at M6. Of the total, 1148 (88%) PLWH continued on BIC/FTC/TAF at M6. The most frequent known reason for discontinuation was toxicity [42 (69%) cases]; only 7 cases were considered virological failures (0.6% of the total OT cohort at M6), with no emerging resistance substitutions. In real life, BIC/FTC/TAF showed high rates of virological suppression and also in PLWH carrying lamivudine/emtricitabine resistance substitutions. The tolerability and safety of BIC/FTC/TAF were good, with high persistence observed for patients on this regimen at M6.

Early Everolimus-Facilitated Reduced Tacrolimus in Liver Transplantation: Results From the Randomized HEPHAISTOS Trial.

Everolimus‐facilitated reduced‐exposure tacrolimus (EVR + rTAC) at 30 days after liver transplantation (LT) has shown advantages in renal preservation. This study evaluated the effects of early initiation of EVR + rTAC in de novo LT recipients (LTRs). In HEPHAISTOS (NCT01551212, EudraCT 2011‐003118‐17), a 12‐month, multicenter, controlled study, LTRs were randomly assigned at 7 to 21 days after LT to receive EVR + rTAC or standard‐exposure tacrolimus (sTAC) with steroids. The primary objective was to demonstrate superior renal function (assessed by estimated glomerular filtration rate [eGFR]) with EVR + rTAC versus sTAC at month 12 in the full analysis set (FAS). Other assessments at month 12 included the evaluation of renal function in compliance set and on‐treatment (OT) patients, efficacy (composite endpoint of graft loss, death, or treated biopsy‐proven acute rejection [tBPAR] and individual components) in FAS, and safety. In total, 333 patients (EVR + rTAC, 169; sTAC, 164) were included in the FAS. A high proportion of patients was nonadherent in maintaining tacrolimus trough levels (EVR + rTAC, 36.1%; sTAC, 34.7%). At month 12, the adjusted least square mean eGFR was numerically higher with EVR + rTAC versus sTAC (76.2 versus 72.1 mL/minute/1.73 m2, difference: 4.1 mL/minute/1.73 m2; P = 0.097). A significant difference of 8.3 mL/minute/1.73 m2 (P = 0.03) favoring EVR + rTAC was noted in the compliance set. Incidence of composite efficacy endpoint (7.7% versus 7.9%) and tBPAR (7.1% versus 5.5%) at month 12 as well as incidence of treatment‐emergent adverse events (AEs) and serious AEs were comparable between groups. A lower proportion of patients discontinued EVR + rTAC than sTAC treatment (27.2% versus 34.1%). Early use of everolimus in combination with rTAC showed comparable efficacy, safety, and well‐preserved renal function versus sTAC therapy at month 12. Of note, renal function was significantly enhanced in the compliance set.

277MO SAR439859, an oral selective estrogen receptor (ER) degrader (SERD), in ER+/ HER2- metastatic breast cancer (mBC): Biomarker analyses from a phase I/II study

SAR439859 has antitumor activity in patients (pts) with wild type (WT) and mutated ESR1 mBC. Here we describe tumor molecular features and evidence of on target activity in SAR439859-treated pts. Plasma circulating cell-free DNA (cfDNA) and paired biopsies were collected at baseline (BL), on treatment (OT) and end of treatment (EOT: cfDNA only) from heavily pretreated postmenopausal pts with ER+/HER2- mBC who received SAR439859 monotherapy (Part A: dose range 20–600 mg QD; Part B: 400 mg QD) in a phase I/II study (NCT03284957). In cfDNA at BL and EOT, mutation (mut) analysis was performed on a next generation sequencing panel of 77 genes. ESR1 muts in cfDNA at BL and OT were assessed by droplet digital polymerase chain reaction (ddPCR). In tumor tissue, ER and progesterone receptor (PgR), Ki67 and Bcl-2 expression over time were assessed by immunohistochemistry; changes in ER signaling pathway activation were assessed by gene set variation analysis (RNA sequencing). Response was assessed in pts who received SAR439859 ≥150 mg QD. At BL, in cfDNA from 63 pts, 95% had ≥1 mut, 52% had ≥1 ESR1 mut, 92% had ≥1 non-ESR1 mut and 49% had concurrent ESR1 and other muts. Most prevalent BL non-ESR1 muts were in PIK3CA (44% of pts), EGFR (33%), TP53 (30%) and MET (25%). ESR1 muts most commonly detected at BL and EOT were D538G, Y537S and Y537N. ESR1 muts tended to decrease OT; of 14 pts with ESR1 muts at BL, 2 had WT ESR1 OT. In 8 paired biopsies (7 were highly proliferative luminal B tumors), ER, PgR and Ki67 decreased (median relative change from BL: -58%, -88% and -33%), while Bcl-2 increased (24%). ER activation score decreased in 3/5 paired biopsies tested (median change from BL -0.38). SAR439859 showed clinical benefit (complete response + partial response [PR] + stable disease ≥24 weeks) in 40% (12/30) of WT ESR1 pts and 32% (9/28) of mutated ESR1 pts, per ddPCR. Of the 5 pts with PRs, 4 had WT ESR1 and 1 had 2 ESR1 muts, at BL. Common genomic alterations, including in ESR1 and PIK3CA, were detected in most mBC pts. SAR439859 showed clinical benefit irrespective of ESR1 mut status and resulted in ER degradation and pathway inhibition in heavily pretreated pts.

Rivaroxaban versus warfarin treatment among morbidly obese patients with venous thromboembolism: Comparative effectiveness, safety, and costs

IntroductionLimited data exist on direct-acting oral anticoagulants in morbidly obese patients with venous thromboembolism (VTE). We compared clinical and health/economic outcomes with rivaroxaban versus warfarin for VTE treatment in morbidly obese patients. Materials and methodsThis retrospective 1:1 propensity score matched cohort study analyzed data from 2 US claims databases. VTE patients initiating rivaroxaban or warfarin were identified who had diagnosis codes for morbid obesity (ICD-9:278.01,V85.4; ICD-10:E66.01,E66.2,Z68.4) 12 months pre- or 3 months post-initiation and followed ≥3 months. Intent-to-treat (ITT) and on-treatment (OT) analyses were conducted using conditional logistic regression and generalized linear models to compare recurrent VTE and major bleeding risks, healthcare resource utilization (HRU), and per patient per year (PPPY) costs. ResultsIn total, 2890 matched pairs of morbidly obese VTE patients initiating rivaroxaban or warfarin were identified. Risks of recurrent VTE (ITT: OR: 0.99; 95% CI: 0.85–1.14) and major bleeding (OT: OR: 0.75; 95% CI: 0.47–1.19) were similar for cohorts. Anti-Factor Xa laboratory measurement was performed on <1% of rivaroxaban cohort. Hospitalizations (OR: 0.86; 95% CI: 0.77–0.96) and outpatient visits (OR: 0.23; 95% CI: 0.10–0.56), were lower with rivaroxaban versus warfarin (ITT analysis). Average total medical costs PPPY were $2829 lower with rivaroxaban versus warfarin ($34,824 vs $37,653), mainly driven by hospitalization costs. Total healthcare costs (including pharmacy) were similar ($43,034 vs $44,565). ConclusionsMorbidly obese VTE patients receiving rivaroxaban had similar risks of recurrent VTE and major bleeding versus warfarin. Rivaroxaban treatment yielded significantly less HRU and total medical costs, with similar total healthcare costs between groups.

A viral genome wide association study and genotypic resistance testing in patients failing first line antiretroviral therapy in the first large countrywide Ethiopian HIV cohort

BackgroundAntiretroviral therapy (ART) was rolled-out in Ethiopia in 2005, but there are no reports on outcome of ART and human immunodeficiency virus drug resistance (HIVDR) at national level. We described acquired drug resistance mutations in pol gene and performed a viral genome wide association study in virologic treatment failure patients who started first line ART during 2009–2011 in the first large countrywide HIV cohort in Ethiopia.MethodsThe outcome of tenofovir (TDF)- and zidovudine (ZDV)-based ART was defined in 874 ART naïve patients using the on-treatment (OT) and intention-to-treat (ITT) analyses. Genotypic resistance testing was done in patients failing ART (> 1000 copies/ml) at month 6 and 12. Near full-length genome sequencing (NFLG) was used to assess amino acid changes in HIV-1 gag, pol, vif, vpr, tat, vpu, and nef genes between paired baseline and month 6 samples.ResultsHigh failure rates were found in ITT analysis at month 6 and 12 (23.3%; 33.9% respectively). Major nucleoside and non-nucleoside reverse transcriptase (NRTI/NNRTI) drug resistance mutations were detected in most failure patients at month 6 (36/47; 77%) and month 12 (20/30; 67%). A high rate of K65R was identified only in TDF treated patients (35.7%; 50.0%, respectively). No significant difference was found in failure rate or extent of HIVDR between TDF- and ZDV- treated patients. All target regions of interest for HIVDR were described by NFLG in 16 patients tested before initiation of ART and at month 6.ConclusionIn this first Ethiopian national cohort, a high degree of HIVDR was seen among ART failure patients, independent on whether TDF- or ZDV was given. However, the major reason to ART failure was lost-to-follow-up rather than virologic failure. Our NFLG assay covered all relevant target genes for antiretrovirals and is an attractive alternative for HIVDR surveillance.

Pretreatment drug resistance in a large countrywide Ethiopian HIV-1C cohort: a comparison of Sanger and high-throughput sequencing

Baseline plasma samples of 490 randomly selected antiretroviral therapy (ART) naïve patients from seven hospitals participating in the first nationwide Ethiopian HIV-1 cohort were analysed for surveillance drug resistance mutations (sDRM) by population based Sanger sequencing (PBSS). Also next generation sequencing (NGS) was used in a subset of 109 baseline samples of patients. Treatment outcome after 6– and 12–months was assessed by on-treatment (OT) and intention-to-treat (ITT) analyses. Transmitted drug resistance (TDR) was detected in 3.9% (18/461) of successfully sequenced samples by PBSS. However, NGS detected sDRM more often (24%; 26/109) than PBSS (6%; 7/109) (p = 0.0001) and major integrase strand transfer inhibitors (INSTI) DRMs were also found in minor viral variants from five patients. Patients with sDRM had more frequent treatment failure in both OT and ITT analyses. The high rate of TDR by NGS and the identification of preexisting INSTI DRMs in minor wild-type HIV-1 subtype C viral variants infected Ethiopian patients underscores the importance of TDR surveillance in low– and middle–income countries and shows added value of high-throughput NGS in such studies.

Darunavir/cobicistat showing similar effectiveness as darunavir/ritonavir monotherapy despite lower trough concentrations.

IntroductionWhen darunavir (DRV) 800 mg is boosted with 150 mg cobicistat (DRV cobi), DRV trough concentration (Ctrough) is about 30% lower as compared to 100 mg ritonavir (DRV rtv). DRV cobi shows similar virological efficacy as DRV rtv when combined with two nucleos(t)ide analogue reverse‐transcriptase inhibitors, but it is unknown whether a lower DRV Ctrough would undermine the effectiveness of DRV cobi when given as monotherapy (mtDRV cobi).MethodsProspective observational study on virologically suppressed HIV‐infected subjects who switched to mtDRV cobi. Virological failure was defined as two consecutive HIV‐RNA >200 copies/mL. Efficacy was evaluated by intention‐to‐treat (ITT) and on‐treatment (OT) analyses, and compared with data from a previous cohort of subjects on mtDRV rtv conducted at our centre. Plasma DRV Ctrough was measured using LC–MS/MS.ResultsA total of 234 subjects were enrolled. At week 96, the efficacy rates were 67.8% (CI 95, 61.8 to 73.7) by ITT and 86.9% (CI 95, 78.0 to 87.7) by OT analyses. The corresponding rates in our historical DRV rtv controls were 67.6% (CI 95, 60.0 to 75.2) and 83.6% (CI 95: 77.2 to 90.0). A total of 135 DRV determinations were performed in 83 subjects throughout the follow‐up period, with a median plasma DRV Ctrough of 1305 ng/mL (range, 150 to 5895) compared with 1710 ng/mL (range, 200 to 3838) in subjects on monotherapy with DRV rtv (p = 0.05).Conclusions DRV Ctrough was lower in HIV‐infected subjects receiving DRV cobi than with DRV rtv. However, this did not appear to influence the efficacy of DRV cobi, when administered as monotherapy.

Pharmacokinetics (PK) and pharmacodynamics (PD) of a novel carcinoembryonic antigen (CEA) T-cell bispecific antibody (CEA CD3 TCB) for the treatment of CEA-expressing solid tumors.

2549 Background: CEA CD3 TCB (RO6958688) targets CEA on tumor cells and is agonistic for CD3e on T cells. In mouse models, CEA CD3 TCB displays potent anti-tumor activity, leads to increased intra-tumoral T cell infiltration and activation and up-regulates the PD-1/PD-L1 pathway. Methods: Biodistribution was assessed in mice using SPECT/CT. Patient (pts) samples correspond to 2 dose-escalation studies in CEA+ solid tumors. Study 1 (S1): single agent weekly (qW) (0.052 to 600 mg, iv, n = 80), and Study 2 (S2): combination of RO6958688 qW (5 to 160 mg, iv) with 1200mg atezolizumab q3W (n = 38). Analytical methods: PK - population modeling approach; anti-drug antibodies (ADA) - ELISA; immunophenotyping in peripheral blood (PB) by flow cytometry (FCM), in pre- (BSL) and on-treatment (OT) biopsies by immunohistochemistry (IHC) and FCM; plasma cytokines - multiplex assays; PD-L1 - SP142 assay. Results: In mice, RO6958688 preferentially accumulated in CEA+ tumors. In pts with no ADAs tested thus far in both studies (S1 29; S2 21), RO6958688 showed near linear PK and exposure. In S1, OT biopsies demonstrated a statistically significant increase in density and activation profile of T cells (CD3: 2.6-fold, n = 21; CD3/CD8: 3.7 fold, n = 17; CD3/Ki67: 4-fold, n = 20; CD8/PD1: 1.7-fold, n = 15) without dose-dependence. In S2, preliminary data of T cell density (5-80mg) were similar to S1 (2-fold). In S1, a significant correlation was observed between treatment-induced tumor lesion reduction and increases of OT CD8/CD25 fluorescence intensity from BSL (p = 0.028). PD-L1 expression increased in OT biopsies in both studies. In S1, from week 4, a moderate expansion of activated CD8 T cells (HLA-DR/Ki67) but not of CD4, was detected in PB at doses &gt; 60mg ( &gt; 3.3 fold). Transient increases of several cytokines were seen in both studies with levels peaking within 24hrs. Conclusions: PK and PD results consistent with tumor inflammation and mechanism of action support that RO6958688 is the first tumor-targeted T cell bispecific to show intra-tumoral biological activity in pts with CEA+ solid tumors. Updated data will be presented. Clinical data are reported separately.

Abacavir/Lamivudine plus Rilpivirine Is an Effective and Safe Strategy for HIV-1 Suppressed Patients: 48 Week Results of the SIMRIKI Retrospective Study.

ObjectivesBased on data from clinical practice, we evaluated the effectiveness and safety of switching to abacavir/lamivudine plus rilpivirine (ABC/3TC+RPV) treatment in virologically suppressed HIV-1-infected patients.MethodsWe performed a multicenter, non-controlled, retrospective study of HIV-1-infected patients who switched treatment to ABC/3TC+RPV. Patients had an HIV-RNA <50 copies/mL for at least 24 weeks prior to changing treatments. The primary objective was HIV-1 RNA <50 copies/mL at week 48. Effectiveness was analyzed by intention-to-treat (ITT), missing = failure and on-treatment (OT) analyses. The secondary objectives analyzed were adverse effects changes in renal, hepatic or lipid profiles, changes in CD4+ cell count and treatment discontinuations.ResultsOf the 205 patients included, 75.6% were men and the median age was 49. At baseline, before switching to ABC/3TC+RPV, median time since HIV diagnosis was 13.1 years, median time with undetectable HIV-1 RNA was 6.2 years and median time of previous antiretroviral regimen was 3.1 years (48.3% patients were taking efavirenz and ABC/3TC was the most frequent backbone coformulation in 69.7% of patients). The main reasons for switching were drug toxicity/poor tolerability (60.5%) and simplification (20%). At week 48, the primary objective was achieved by 187 out of 205 (91.2%) patients by ITT analysis, and 187 out of 192 (97.4%) patients by OT analysis. The CD4+ lymphocyte count and CD4+ percentage increased significantly from baseline to week 48 by a median of 48 cells/μL (−50 to 189) and 1.2% (−1.3% to 4.1%), respectively, P<0.001. Thirty-eight adverse events (AE) were detected in 32 patients. Of these, 25 had no clear association with treatment. Three patients interrupted therapy due to AE. We observed a decrease in all lipid parameters, P<0.001, and a slight improvement in the glomerular filtration rate, P<0.01. Therapy was considered to have failed in 18 patients owing to virological failure (5 [2.4%]), toxicity/poor tolerability (4 [2%]), clinical decision (3 [1.5%]), loss to follow-up (3 [1.5%]), death (1 [0.5%]), and no clinical data (2 [1%]).ConclusionsThe results of this study confirms that ABC/3TC+RPV is an effective, safe, and cost-effective option for the treatment of patients with virologically stable HIV-1 infection.

Dolutegravir(DTG, S/GSK1349572) combined with other ARTs is superior to RAL- or EFV-based regimens for treatment of HIV-1 infection: a meta-analysis of randomized controlled trials.

BackgroundThe first-generation integrase inhibitors (INIs) raltegravir (RAL) and elvitegravir (EVG) have shown efficacy against HIV infection, but they have the limitations of once-more daily dosing and extensive cross-resistance. Dolutegravir (DTG, S/GSK1349572), a second-generation drug that overcomes such shortcomings, is under spotlight. The purpose of this study is to review the evidence for DTG use in clinical settings, including its efficacy and safety.MethodsPubMed, EMbase, Ovid, Web of Science, Science Direct, and related websites were screened from establishment until July 2013, and scientific meeting proceedings were manually searched. Two reviewers independently screened 118 citations repeatedly to identify randomized controlled trials comparing the efficacy and safety of DTG-based regimen with those of RAL- or elvitegravir-based regimens. Using the selected studies with comparable outcome measures and indications, we performed a meta-analysis based on modified intention-to-treat (mITT), on-treatment (OT), and as-treated (AT) virological outcome data. Independent data extraction and quality assessment were conducted.ResultsFour unique studies were included with the use of DTG in antiretroviral therapy-naive patients. In therapy-naive patients, DTG combined with abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) resulted in a significantly better virological outcome with a mITT relative risk (RR)of 1.07 (95 % confidence interval (95 % CI 1.03–1.12). Evidence further supported use of DTG had a better virological suppression in the 50 mg once daily group (mITT RR 1.07; 95 % CI 1.03–1.12) as well as in the sub-analysis in dolutegravir/efavirenz(DTG/EFV) and dolutegravir/raltegravir (DTG/RAL) groups (RR 1.09, 95 % CI 1.03–1.15; RR 1.06, 95 % CI 0.98–1.15, respectively). In the matter of safety of DTG-based regimen, the risk of any event was RR 0.98 (95 % CI 0.94–1.01), the risk of serious adverse events (AEs) was RR 0.84 (95 % CI 0.62–1.15), and the risk of drug-related serious AEs was RR 0.33 (95 % CI 0.13–0.79).ConclusionIn general, DTG 50 mg given once daily combined with an active background drug is a better choice in terms of both efficacy and safety.

Late‐breaking abstracts

Late‐breaking abstracts

Effectiveness and tolerability of abacavir-lamivudine-nevirapine (ABC/3TC/NVP) in a multicentre cohort of HIV-infected, ARV-naïve patients.

PurposeVery scarce information has been published to date with the combination of ABC/3TC/NVP but it is currently being used in clinical practice in Spain and Portugal. Our aim was to present the clinical experience with this regimen in a cohort of adult HIV-infected antiretroviral (ARV)-naïve patients.MethodsRetrospective, multicentre, cohort study. Consecutive adult HIV-infected ARV-naïve HLA-B*5701-negative patients, who started ABC/3TC/NVP between 2005-2013, with at least one follow-up visit, were included. Demographic, clinical and laboratory variables were assessed at baseline, month 1, and every three–four months thereafter. The primary end point was HIV-1 viral load (VL)<40 c/mL at 48 weeks. Data were analyzed by intent-to-treat (ITT) (switch=failure, and missing=failure) and on treatment (OT) analyses.Results78 patients were included. Median follow up was 26 (0.1-84) months. 86% were male, median age 41 (23-69) years, 9% had AIDS, 8% were HCV+, baseline CD4 was 275 (10-724) cells/µL and median VL 4.58 (3.02-6.92) log. After 48 weeks, VL was<40 c/mL in 89.8% (OT), 79.7% (M=F) and 65.4% (S=F) and at 96 weeks in 88.5%, 78.9% and 61.6%, respectively. CD4 increased +246 (p<0.001) and +292 (p<0.001) cells/uL after 48 and 96 weeks, respectively. One or more drugs of the regimen were discontinued in 33 (42.3%) patients. In 15 (19.2%) patients (13 NVP, 2 ABC/3TC) therapy was stopped due to toxicity after a median of one month (in only two cases after six months of follow up): 80% of them had rash/liver toxicity. Six (7.7%) patients discontinued ART due to virologic failure, five (6.4%) because of other reasons and seven (9%) were lost to follow-up. ALT but not AST significantly increased (+0.07 ukat/L at 96 weeks, p=0.033). A significant increase of 25%, 26% and 42% in total cholesterol, LDLc and HDLc, respectively, and a significant decrease in TC/HDL ratio (6%, p=0.008) was observed after 96 weeks.ConclusionsDespite a considerable proportion of patients had to stop therapy due to toxicity (most associated with NVP), those initially tolerating this regimen presented a high virologic and immunologic response after 96 weeks, as well as a favourable lipid profile. ABC/3TC/NVP may be a suitable alternative first regimen, mainly in countries with economic constraints.

Exercise capacity and N-terminal pro-brain natriuretic peptide levels with biventricular vs. right ventricular pacing for atrioventricular block: results from the PREVENT-HF German Substudy

Previous studies showed unfavourable effects of right ventricular (RV) pacing. Ventricular pacing (VP), however, is required in many patients with atrioventricular (AV) block. The PREVENT-HF study explored left ventricular (LV) remodelling during RV vs. biventricular (BIV) pacing in AV block without advanced heart failure. The pre-specified PREVENT-HF German Substudy examined exercise capacity and N-terminal pro-brain natriuretic peptide (NT-proBNP). Patients with expected VP ≥80% were randomized to RV or BIV pacing. Endpoints were peak oxygen uptake (pVO2), oxygen uptake at the anaerobic threshold (VO2AT), ventilatory efficiency (VE/VCO2), and logNT-proBNP. Considering crossover, intention to treat (ITT), and on-treatment (OT) analyses of covariance (ANCOVA) were performed. For exercise testing 44 (RV: 25, BIV: 19), and for NT-proBNP 53 patients (RV: 29, BIV: 24) were included. The ITT analysis revealed significant differences in pVO2 [ANCOVA effect 2.83 mL/kg/min, confidence interval (CI) 0.83-4.91, P = 0.007], VO2AT (ANCOVA effect 2.14 mL/min/k, CI 0.14-4.15, P = 0.03), and VE/VCO2 (ANCOVA effect -5.46, CI -10.79 to -0.13, P = 0.04) favouring BIV randomization. The significant advantage in pVO2 persisted in OT analysis, while VO2AT and VE/VCO2 showed trends favouring BIV pacing. LogNT-proBNP did not differ between groups. (ITT: ANCOVA effect 0.008, CI -0.40 to +0.41, P = 0.97; OT: ANCOVA effect -0.03, CI -0.44 to 0.30, P = 0.90). Our study suggests that BIV pacing produces better exercise capacity over 1 year compared with RV pacing in patients without advanced heart failure and AV block. In contrast, we observed no significant changes of NT-proBNP. Larger trials will allow appraising the clinical usefulness of BIV pacing in AV block. ClinicalTrials.gov Identifier: NCT00170326.

Sustained Virological Response on Second-Line Antiretroviral Therapy following Virological Failure in HIV-Infected Patients in Rural South Africa

ObjectiveThis study aims to describe the virological, immunological and clinical efficacy of protease inhibitor (PI)-based second-line antiretroviral therapy (ART) in rural South Africa.MethodsAn observational cohort study was performed on 210 patients (including 39 children) who initiated PI-based second-line therapy at least 12 months prior to data collection. Biannual clinical, immunological and virological monitoring was performed. Primary endpoints were adequate virological response (plasma HIV-1 RNA<400 copies/ml), full virological suppression (plasma HIV-1 RNA<50 copies/ml) and treatment failure (virological failure (plasma HIV-1 RNA>1000 after initial virological response) or on-going viremia (plasma HIV-1 RNA never<400 copies/ml for more than six months)). Data were analyzed by an on-treatment (OT) and intention-to-treat (ITT) approach. Analyses were primarily performed on the group of patients who switched following first-line virological failure.ResultsMedian duration of follow-up after switch to second-line treatment was 20 months [IQR 11–35]. 191 patients had switched to second-line ART due to first-line virological failure. 139/191 of them (72.8%, ITT) were in care and on treatment at the end of follow-up and 11/191 (5.8%, ITT) had died. After twelve months, an adequate virological response was seen in 92/128 patients (71.9%, OT), of which 78/128 (60.9%, OT) experienced full virological suppression. Virological response remained stable after 24 months. Virological efficacy was similar amongst adult and pediatric patients. As in first-line ART, we observed a lack of correlation between virological failure and WHO-defined immunological failure.ConclusionsGood virological outcomes following first-line failure can be achieved with PI-based, second-line antiretroviral therapy in both adult and pediatric patients in rural South Africa. Retention rates were high and virological outcomes were sustainable during the two-year follow-up period, although persisting low-level viremia occurred in a subset of patients. The observed viro-immunological dissociation emphasizes the need for virological monitoring.

Clinical Use of HIV Integrase Inhibitors: A Systematic Review and Meta-Analysis

BackgroundOptimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings.MethodsMEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted.Results48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59–0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11–0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89–2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir.ConclusionIn first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment.