Abstract 6677: Preliminary immune correlatives from BCA101 trial show favorable modulation of tumor immune microenvironment

Background: BCA101 is a bispecific antibody targeting EGFR and TGF-β. TGF-β pathway activation is a hallmark of human immune-excluded tumors, and TGF-β expression is associated with resistance to anti-PD-1 blockade. Neutralization of TGF-β removes an immunosuppressive signal that drives accumulation and polarization of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in solid tumors, while EGFR inhibition targets tumor cell-intrinsic oncogenic signaling. Co-targeting of EGFR and TGF-β directly impacts tumor progression while enhancing the immunogenicity of tumors.

Methods: Patients with multiple solid tumor types (CRC, pancreatic, HNSCC, SqNSCLC, and others) were treated with escalating doses of either single agent BCA101 or in combination with anti-PD-1 (pembrolizumab) enrolled on NCT04429542 trial. We performed a variety of immune correlatives on pre- and on-treatment tumor biopsies, including Nanostring-based transcriptomic profiling and IHC for immunophenotypic markers, as well as multiparametric flow cytometric profiling of circulating PBMCs.

Results: Our preliminary evidence suggests that neutralization of TGF-β positively alters the systemic immune state (PBMCs) and tumor immune phenotype (mRNA, IHC). Circulating HLA-DR+ monocytes were significantly increased in on-treatment PBMC samples relative to screening. Pathway analysis of on-treatment tumor biopsies revealed enhanced costimulatory signaling, cytokine and chemokine signaling, immune infiltration, and interferon signaling. Top differentially regulated genes in on-treatment biopsies included CCL21, CXCL9, CXCL11, and CXCL13, which recruit T and NK cells. HDAC11, which negative regulates type-I interferon signaling, was significantly reduced in on-treatment biopsies. Notably, two patients with EGFR-amplified squamous non-small cell lung cancer, who both progressed on first-line immunotherapy treatment, were treated with BCA101 at 1250 mg and 1500 mg qw and achieved a partial response (ongoing for 10 months at the time of the data cutoff) and a prolonged stable disease for 11 months, respectively. They exhibited increased CD8+ T cell infiltration and a reduction in TAMs following treatment.

Conclusions: Increased abundance of circulating HLA-DR+ monocytes following treatment indicated polarization towards a more positive, Th1-like systemic immune state. We observed enhanced immunogenicity of tumors as assessed by a targeted IO transcriptomic analysis. The results of the pathway analysis were supported by IHC on post-treatment biopsies from a subsequent cohort showing enhanced CD8+ T cell infiltration and stable, or reduced expression of TAM marker CD163. These results indicate that neutralization of TGF-β induces a more permissive tumor immune microenvironment.

Citation Format: Patrick H. Lizotte, Paul Paik, Liviu Niculescu, Seng-Lai H. Tan, David Bohr, Elham Gharakhani, Ralf Reiners, Rachel Salazar, Avanish Varshney, Shiv Ram Krishn, Pradip Nair, Cloud Paweletz. Preliminary immune correlatives from BCA101 trial show favorable modulation of tumor immune microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6677.

POS0260 LONG-TERM HUMORAL RESPONSE TO SARS-CoV-2 VACCINATION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASE

Background

The first vaccine against SARS-CoV-2 was approved in December 2020. Immunogenicity of SARS-CoV2 vaccines in patients with immune-mediated inflammatory disease (IMID) have so far been evaluated in the 2-6 weeks following complete vaccination and risk groups for poor early vaccine response have been identified leading to specific vaccination recommendations. However, data on the long-term course and persistence of vaccine response in IMID patients, as well as the outcomes of the specific recommendations are lacking.

Objectives

To evaluate the long-term course of humoral response to SARS-CoV-2 vaccination in a large prospective cohort of IMID patients and non-IMID controls with a follow-up duration of up-to to 10 months after the first vaccine dose.

Methods

We have initiated a prospective dynamic cohort of IMID patients and healthy controls in February 2020 to monitor immune response to SARS-CoV-2 and respiratory infections including COVID-19 (1). Participants who contributed data starting from the 4 weeks before their first vaccination onwards were included in this analysis. Antibodies against SARS-CoV-2 spike protein were quantified with an ELISA from Euroimmun (Lübeck, Germany) with an optical density cutoff of 0.8. We fitted linear mixed-effect models for log-transformed antibody levels using time splines with adjustment for age and sex. Marginal mean antibody levels with 95% confidence intervals (CI) were estimated at selected time points for IMID patients and controls with double vaccination. We descriptively analyzed the observed antibody levels over time in cohort participants receiving two vaccinations vs. three vaccinations.

Results

Among 5076 cohort participants, 3147 IMID patients and healthy controls (mean (SD) age 49 (16)) provided 4756 samples for this analysis between December 2020 and 2021, with a median (IQR) 28 (14-31) weeks of follow-up after the first vaccination (Table 1). 2965 (94%) participants had received at least 2 and 223 (7%) participants had received three vaccine doses by the date of their latest sampling. In IMID patients, age and sex-adjusted estimated marginal mean antibody levels waned after week 16 and were substantially reduced at all time points compared to the controls, finally dropping to the borderline range (1.01, 95%CI 0.86 to 1.19) at week 40 (Figure 1A, Table 1). A third dose was given to 128 (7%) of IMID patients with a poor response to 2 vaccine doses after a median 20 weeks of the second dose (IQR 10 to 26 weeks). After the third dose, antibody levels in IMID patients were comparable to those of healthy controls at 40 weeks who had three vaccine doses. These were also higher than that of IMID patients and controls who did not receive a third dose (Figure 1B).

Table 1.

Participant characteristics and antibody levels

Healthy controlsIMID N11991948 Age, mean (SD)40.8 (13.5)54.3 (14.8) Follow-up, weeks, median (IQR)31.1 (23.8-36.6)19.6 (12.3-26.6) Follow-up range, weeks,1.6-46.11.7-46.3Sex, n(%) Female554 (46.2)1136 (58.3)Vaccine intervals, ´median (IQR) 1st to 2nd dose4.6 (3.0-6.0)6.0 (5.0-6.1) 2nd to 3rd dose29.6 (26.9-36.4)19.9 (10.0-26.1)Diagnosis, n (%) Spondyloarthritis-713 (36.6) Rheumatoid arthritis-489 (25.1) Autoimmune disease, systemic+-420 (21.5) Inflammatory bowel disease-219 (11.2) Psoriasis-107 (5.5)Mean* antibody levels after 1st dose Week-84.16 (3.89 to 4.45)2.97 (2.83 to 3.12) Week-168.39 (7.81 to 9.02)5.04 (4.81 to 5.28) Week-325.02 (4.73 to 5.33)2.52 (2.32 to 2.74) Week-402.14 (1.95 to 2.35)1.01 (0.86 to 1.19)

+ Systemic lupus, systemic sclerosis, Sjögren’s syndrome, vasculitis

* Estimated marginal means adjusted for age and sex.

Figure 1.

Conclusion

Humoral response to vaccination against SARS-CoV-2 was weaker in IMID patients compared to controls at all time points after the first vaccine dose and practically disappeared after 1 year. IMID patients can still achieve a good antibody response with a third dose even after a weak response with two doses.

References

[1]Simon D et al Nat Commun 2020

Disclosure of Interests

None declared

POS1263 PRE-EXPOSURE PROPHYLAXIS FOR SARS-CoV-2 INFECTION WITH SUBCUTANEOUS CASIRIVIMAB/IMDEVIMAB IN PATIENTS WITH IMMUNE MEDIATED INFLAMMATORY DISEASES

Background

Patients with immune-mediated inflammatory diseases (IMID), particularly if treated with B-cell depleting therapies, show reduced humoral responses to SARS-CoV-2 vaccines and increased risk of severe COVID-19 (1,2). Since pre-exposure prophylaxis (PrEP) with monoclonal antibodies against SARS-CoV-2 proved effective in preventing infection and COVID-19 (3) in the general population, PrEP could be used for passive immunization of vaccine-refractory patients with IMIDs.

Objectives

To evaluate the persistence of serum and salivary anti-SARS-CoV-2 IgG antibodies in vaccine-refractory patients with IMID after PrEP with casirivimab/imdevimab. Secondary outcomes were safety, SARS-CoV-2 infection, and adverse COVID-19 outcomes.

Methods

We performed a longitudinal analysis on anti-SARS-CoV-2 IgG titers in IMID patients who received a PrEP with 1200 mg of subcutaneous casirivimab/imdevimab due to high infection risk, as they had not developed an adequate humoral response at least 21 days after three COVID-19 vaccinations (Table 1). Serum and salivary anti-SARS-CoV-2 Spike IgG were quantified by ELISA (EUROIMMUN, Lübeck, Germany) before PrEP and after 1, 14, and 30 days. IgG levels are given as antibody ratios by dividing the optical density of the sample by that of the calibrator. A cutoff of ≥1.1 was considered positive. Safety as well as polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection and adverse COVID-19 outcomes (hospitalization, mechanical ventilation, death) after PrEP were recorded.

Table 1.

Baseline characteristics.

N26Age, mean (SD)54 (14)Sex, n (%)Female15 (57.7)Male39 (42.3)Diagnosis, n (%)ANCA-associated vasculitis10 (38.5)Rheumatoid arthritis6 (23.1)Immunoglobulin deficiency4 (15.4)Systemic sclerosis2 (7.7)Psoriatic arthritis1 (3.8)Systemic Lupus Erythematosus1 (3.8)Non-infectious Uveitis1 (3.8)Multiple sclerosis1 (3.8)IgG4-related disease1 (3.8)Autoinflammatory syndrome1 (3.8)CD20-depletionRituximab, n (%)22 (84.6)Other therapies, n (%)Methotrexate6 (23.1)Immunoglobulins4 (15.4)Mycophenolate1 (3.8)Infliximab1 (3.8)CD19+ lymphocytes/mm3, median (IQR)0 (0-9)Serum total IgG, median (IQR)894 (745-987)

SD, standard deviation; IQR, interquartile range; ANCA, anti-neutrophil cytoplasmic antibodies.

Results

We obtained 92 serum and 75 saliva samples from 26 participants at four consecutive timepoints (Figure 1). Anti-SARS-CoV-2 IgG titers were observed in serum and saliva samples of all participants from day 1 and throughout 30 days after PrEP independently of diagnosis, therapy, total IgG, and peripheral CD19+ B-cells. Serum IgG increased rapidly at day 1 and plateaued from day 14 to 30 (Figure 1A), reaching similar levels as seen in healthy subjects after full vaccination (1), while saliva IgG increased steadily from administration up to day 14 and plateaued at day 30 (Figure 1B). No side effects were reported. Five patients (19.2%) had a close contact with a SARS-CoV-2-infected person, after which all but one remained asymptomatic and with a negative PCR test. The patient who tested positive developed mild COVID-19 with fever and cough.

Figure 1.

Temporal pattern and distribution of serum (A) and salivary (B) anti-SARS-CoV-2 IgG levels.

Results from individual participants are represented as line (top) and scatter plots (bottom). Horizontal lines represent median values, the dotted horizontal line represents the positivity cutoff of 1.1.

** p =0.0082; *** p <0.001; **** p <0.0001. mAbs: monoclonal antibodies.

Conclusion

SARS-CoV-2 PrEP induces stable serum and salivary antibody levels in IMID patients who did not respond to COVID-19 vaccination, regardless of pre-existing clinical and serological features. In IMID, PrEP with casirivimab/imdevimab is safe and has the potential to prevent infection and severe COVID-19.

References

[1]Simon D, et al. Ann rheum dis. 2021;80:1312-1316.

[2]Fagni F et al, et al. Lancet Rheumatol. 2021; e724-e736.

[3]Flonza I, et al. MedRxiv. 2021. doi: 10.1101/2021.11.10.21265889

Disclosure of Interests

None declared

POS0699 SIMILAR EFFICACY AND DRUG SURVIVAL RATES OF BARICITINIB MONOTHERAPY AND BARICITINIB/METHOTREXATE COMBINATION THERAPY IN REAL-LIFE TREATMENT OF RHEUMATOID ARTHRITIS - RESULTS FROM A PROSPECTIVE COHORT OF BARICITINIB-TREATED PATIENTS

Background

In clinical trials, baricitinib (BARI), in combination with methotrexate (MTX), demonstrated efficacy in patients with rheumatoid arthritis (RA) who have not responded adequately to conventional (cs)or biologic (b) DMARDs [1]. Since MTX is often not tolerated very well [2], BARI monotherapy may be preferable over BARI/MTX combination in some patients with RA. Therefore, real-life data on BARI mono- vs. combination therapy are needed to support such decisions.

Objectives

The aim of our study was to evaluate the efficacy of BARI as mono- or combination therapy in a prospective, open label cohort of RA patients failing previous cs/bDMARD therapy.

Methods

Patients with active RA (DAS28-ESR >3.2), fulfilling the ACR/EULAR 2010 classification criteria and failing previous cs/bDMARD therapy were included. All patients received BARI either as monotherapy or in combination with MTX based on the judgement of the treating physician. Demographics, medical history, disease activity parameters such as 66/68 TJC/SJC, composite scores such as DAS28-ESR, HAQ-DI, as well as medication were prospectively recorded every 3 months according to a pre-defined protocol. Informed consent and ethics approval (19_18 B) were obtained. To evaluate clinical efficacy, DA28 ESR responses was recorded at respective visit dates (until week 96). We estimated least-square mean DAS-28 scores over time using linear mixed effects models including time-group interactions. Kaplan-Meier method was used to estimate baricitinib survival and probability of remission over time.

Results

139 patients (98 women/41 men; aged 58.4 (12.8) years; mean disease duration of 9.7 years) were included between 4/2017-10/2021. Of these, 46 patients received a combination of BARI with MTX (BARI/MTX) and 93 patients BARI monotherapy. Baseline demographic and disease-specific characteristic were comparable between BARI/MTX and BARI patients (Table 1). Median follow up was 53.1 weeks (IQR 23.0-109.3). Decrease in DAS28-ESR showed a similar dynamics in BARI/MTX (baseline DAS28-ESR: 4.2+/-1.3; 48 weeks: 2.9 (95%CI 2.6 to 3.2)) and BARI (4.3+/-1.3; 48 weeks: 3.0 (95%CI 2.8 to 3.3)) with numerical but no significant differences (Figure 1a). 62% (95%CI 40 to 76%) patients in the BARI/MTX group and 51% (95%CI: 37 to 61%) patients in the BARI attained DAS28ESR remission after 48 weeks. Drug survival was comparable among BARI/MTX and BARI patients. (69 vs.67% at 1 year and 62 vs 56% at 2 years) (Figure 1b).

Conclusion

These data show that BARI monotherapy is efficacious in real life treatment in RA patients with insufficient response to MTX. Clinical efficacy and drug survival is comparable between BARI monotherapy and BARI/MTX combo in a real-life setting.

References

[1]Genovese, M.C., et al., Baricitinib in Patients with Refractory Rheumatoid Arthritis. N Engl J Med, 2016.

[2]Michaud, K., et al., Real-World Adherence to Oral Methotrexate Measured Electronically in Patients With Established Rheumatoid Arthritis. ACR Open Rheumatol, 2019

Acknowledgements

The analysis of the data of this study is partially financially supported by Elli Lilly.

Disclosure of Interests

None declared

AB0385 BARICITINIB LEADS TO RAPID AND PERSISTENT RESOLUTION OF SYNOVITIS AS MEASURED BY HAND MRI IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS (RA) FAILING cs/bDMARD THERAPY

Background

RA is characterized by synovial inflammation resulting in local bone loss [1]. Inhibitors of JAK/Stat pathways, such as baricitinib, demonstrated efficacy in reducing signs and symptoms of RA in clinical trials, however, little is known about their effects on synovitis and bone structure [2]. Preclinical and clinical observations suggest a positive effect JAK inhibitors on bone mass and microstructure, however no prospective, interventional clinical trial has been performed so far [3].

Objectives

The aim of this study is to evaluate the effect of baricitinib on local inflammation (synovitis and osteitis) and bone structure (erosions) in RA patients failing on cs/bDMARD therapy using hand MRI.

Methods

BAREBONE is a prospective, interventional, open label, monocentric single center study (EUDRACT 2018-001164-32 / NCT03701789) to assess the effect of baricitinib (4mg/day) on local MRI inflammation and structure in patients with active RA. Besides demographic and clinical characteristics, hand joint inflammation was assessed by magnetic resonance imaging (MRI) using a 1.5 Tesla scanner (Siemens Magnetom Aera T1w TSE cor, T2w TIRM cor, T2w TSE fat-sat trans, T1w TSE fat-sat trans + cor after KM;). at baseline, week 24 and week 48. Scans were assessed for synovitis, osteitis and bone erosions using the RAMRIS scoring system using two independent blinded readers (SK and SB). Intraclass correlation coefficients were calculated for total RAMRIS and synovitis, erosion and osteitis subscores and in a second step differences between cs and bDMARD failure were elaborated. Variables are summarized descriptively using means and 95% bootstrap confidence intervals for continuous outcomes and as number and percentages for categorical outcomes.

Results

Thirty- two RA patients were screened and 30 patients were included (age: 53.4 [SD 12.6] years; sex: f/m N 24/6; disease duration: 3 [IQR 2.0 – 8.0] years; biologic naïve/bDMARD failure 16/14). 27 patients completed the trial while MRI data was available for 24 patients at week 48. Demographics and clinical characteristics can be seen in Table 1. Total RAMRIS scores slightly decreased from 20.6 (95% CI 14.4 -27.8) at baseline (BL) to 18.3 (11.5 -26.5) at week 48. The synovitis subscore mainly contributed to total RAMRIS reduction by significantly improving from 5.3 (4.0 - 6.8) at BL to 2.7 (1.5 - 4.0) at week 48 with a score change of -2.9 (-4.0 to -1.8). At week 48, 12 patients (44.4%) had no signs of synovitis compared to only 3 patients at BL. In contrast, RAMRIS osteitis subscores only marginally decreased from 4.9 (2.2 - 8.4) at BL to 4.0 (1.9 - 6.7) at week 48. RAMRIS erosion score remained stable over the 48-week observation time. A significant difference in RAMRIS synovitis change for biologic naïve -3.8 (-5.2 to -2.6) vs biologic failure -1.0 (-2.2 to 0.4 could be observed at week 48).

With respect to clinical disease activity, DAS 28 score decreased from 4.8 (4.5 – 5.1) at BL to 2.9 (2.5 – 3.3) at week 48. Detailed results can be found in Table 1 and Figure 1. Intraclass coefficient (95%CI) for RAMRIS scoring was high for both readers 0.997 (0.994 to 0.998).

Table 1.

Demographics, DAS 28 ESR, RAMRIS total score and RAMRIS subset scores at baseline, week 24 and week 48 are shown as well as number of patients with improvement and resolution of synovitis.

BaselineWeek 24Week 48N303027AgeMean [SD]53.5 (12.6)Genderfemalen [%]24 (80.0)malen [%]6 (20.0)Disease duration, yearsMedian (IQR)3.0 (2.0-8.0)DAS-28 ESRMean [95%CI]4.8 (4.5 to 5.1)3.0 (2.7 to 3.3)2.7 (2.4 to 3.0)MRI availablen [%]30 (100.0)28 (93.3)24 (88.9)RAMRIS totalMean [95%CI]20.6 (14.4 to 27.6)18.4 (12.6 to 25.4)18.3 (11.5 to 26.5)RAMRIS total changeMean [95%CI]0.0 (0.0 to 0.0)-2.1 (-4.0 to -0.4)-3.9 (-7.2 to -0.5)RAMRIS synovitisMean [95%CI]5.3 (3.9 to 6.9)3.5 (2.2 to 4.9)2.7 (1.5 to 4.0)RAMRIS synovitis changeMean [95%CI]0.0 (0.0 to 0.0)-1.8 (-2.5 to -1.0)-2.9 (-4.0 to -1.8)RAMRIS synovitis improvedpatients n [%]10 (33.3)13 (48.1)RAMRIS synovitis resolvedpatients n [%]10 (33.3)12 (44.4)RAMRIS osteitisMean [95%CI]4.9 (2.2 to 8.4)3.7 (1.5 to 6.2)4.0 (1.9 to 6.7)RAMRIS osteitis changeMean [95%CI]0.0 (0.0 to 0.0)-0.9 (-3.1 to 1.0)-1.9 (-5.7 to 1.1)RAMRIS osteitis improvedpatients n [%]2 (6.7)4 (14.8)RAMRIS erosionMean [95%CI]10.4 (7.3 to 14.6)11.2 (7.7 to 15.0)11.6 (7.5 to 16.6)RAMRIS erosion changeMean [95%CI]0.0 (0.0 to 0.0)0.6 (0.1 to 1.2)0.9 (0.0 to 2.1)RAMRIS erosion worsenedpatients n [%]2 (6.7)3 (11.1)

Conclusion

Our study shows that baricitinib primarily reduces MRI synovitis in RA patients that have previously failed csDMARD and bDMARD therapy and particularly in patients who are biologic naïve.

References

[1]McInnes, I.B. and G. Schett, The pathogenesis of rheumatoid arthritis. N Engl J Med, 2011.

[2]Genovese, M.C., et al., Baricitinib in Patients with Refractory Rheumatoid Arthritis. N Engl J Med, 2016

[3]Adam, S., et al., JAK inhibition increases bone mass in steady-state conditions and ameliorates pathological bone loss by stimulating osteoblast function. Sci Transl Med, 2020.

Acknowledgements

Lilly Deutschland GmbH funded the Barebone trial

Disclosure of Interests

Stephan Kemenes: None declared, Sara Bayat: None declared, David Simon Speakers bureau: Lilly Pharma Deutschland GmbH, Janssen, Consultant of: BMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, GileaBMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, Gilead, Amgen

d,

, Grant/research support from: Novartis, Gilead, Abbvie, Lilly, Gerhard Krönke Speakers bureau: GSK, Novartis, Consultant of: GSK, Lilly, Novartis, Janssen, Grant/research support from: Lilly, Novartis, BMS, Janssen, Daniela Bohr: None declared, Larissa Valor: None declared, Fabian Hartmann: None declared, Louis Schuster: None declared, Koray Tascilar Speakers bureau: Gilead speaker, Consultant of: UCB, Lilly, Georg Schett Speakers bureau: Janssen, Abbvie, BMS, Lilly, Novartis, Roche, AMGEN, Gilead, UCB, Consultant of: Lilly, Novartis, Abbvie, Grant/research support from: Chugai, Lilly, Novartis, Arnd Kleyer Speakers bureau: Lilly, Novartis, Abbvie, Consultant of: BMS, Pfizer, Sanofi, Abbvie, Janssen, Medac, Novartis,

Lilly Deutschland GmbH, Gilead, Amgen

, Grant/research support from: Novartis, Lilly Deutschland GmbH, Gilead

POS1384 NON-INVASIVE IN VIVO METABOLIC PROFILING OF INFLAMMATION IN JOINTS AND ENTHESES BY OPTOACOUSTIC IMAGING

Background

An in-depth metabolic characterization of joints and entheses at the tissue level can help in the early diagnosis and treatment selection for patients with inflammatory arthritis [1]. However, current knowledge about the metabolic profiles of synovitis and enthesitis is limited. Multispectral optoacoustic tomography (MSOT), a novel metabolic imaging technology, could be used to undertake metabolic profiling of joints and entheses non-invasively using near-infrared multispectral laser to stimulate tissues and detect the emitted acoustic energy, enabling quantification of tissue components in vivo based on differential absorbance at multiple wavelengths [2, 3].

Objectives

To explore the metabolic characteristics of arthritis and enthesitis using MSOT.

Methods

We performed a cross sectional study on healthy controls (HC) and patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) (Table 1). Participants underwent clinical, ultrasound (US), and MSOT examination of metacarpophalangeal joints, wrists, entheses of lateral epicondyles, patellar, quadriceps and Achilles tendons. MSOT-derived hemoglobin, oxygen saturation, collagen and lipid levels were measured. We calculated scaled mean differences (SMD) between affected and unaffected joints and entheses as defined by clinical examination or US using linear mixed effects models.

Table 1.

Baseline characteristics.

OverallHealthyPsARAN87363417Age, mean (SD)47.0 (15.7)34.7 (12.0)52.4 (11.5)62.5 (9.1)Sex, n (%) Female48 (55.2)18 (50.0)17 (50.0)13 (76.5) Male39 (44.8)18 (50.0)17 (50.0)4 (23.5)Tender joints, median (IQR)0 (0-2)0 (0-0)1 (0-5)2 (1-6)Swollen joints, median (IQR)0 (0-1)0 (0-0)0 (0-2)2 (1-6)Tender entheses, median (IQR)0 (0-2)0 (0-0)1 (0-3)0 (0-0)csDMARD, n (%)22 (25.3)-13 (38.3)9 (53.0)b-tsDMARD, n (%)31 (35.6)-20 (58.8)11 (64.7)

SD, standard deviation; IQR, interquartile range; csDMARD, conventional synthetic disease modifying anti-rheumatic drug; b-tsDMARD, biologic or targeted synthetic disease modifying anti-rheumatic drug.

Results

We obtained 1535 MSOT and 982 US scans from 87 participants (36 HC, 34 PsA, 17 RA). Entheseal tenderness was not associated with metabolic changes, whereas US enthesitis was associated with increased total hemoglobin, oxygen saturation and collagen content. In contrast, clinical and US arthritis showed increased hemoglobin levels but reduced oxygen saturation and reduced collagen content. Synovial hypertrophy was associated with increased lipid content in the joints (Figure 1).

Figure 1.

Scaled differences and 95% confidence intervals of MSOT-measured metabolite values by clinical and ultrasonographic findings of enthesitis (A-C) and arthritis (D-F). Two differences are plotted for each metabolite indicating two multispectral processing algorithms used for estimation. P values were adjusted for multiple testing using a false discovery rate of 5%. NS, not significant. sO2, oxygen saturation.

Conclusion

MSOT allows a non-invasive characterization of metabolic changes in arthritis and enthesitis. These findings can be interpreted as a reflection of increased synovial cellularity, collagen degradation, and metabolic demand in synovitis, and of an increased tissue apposition and vascularization in enthesitis. Our results suggest that synovitis and enthesitis do not only differ at the clinical and anatomical-functional level, but also exhibit divergent metabolic changes.

References

[1]Falconer J, et. al. Arthritis Rheumatol. 2018;70(7):984-99.

[2]Regensburger AP, et. al. Biomedicines. 2021;9(5).

[3]Regensburger AP, et al. Nature Medicine. 2019;25(12):1905-15.

Conflict of Interest

AR., FK, MW are co-inventors, together with iThera Medical GmbH, Germany on an EU patent application (no. EP 19 163 304.9) relating to a device and a method for analysis of optoacoustic data, an optoacoustic system and a computer program. All other authors declare no conflict of interest.

Acknowledgements

We thank Ms. Nairouz Al Ahmad, assistant medical technician (Department of Internal Medicine 3), for her assistance in conducting the study and Dr. Yi Qiu, PhD (iThera Medical GmbH) for her assistance in data analysis and interpretation.

Disclosure of Interests

None declared

A phase 1 trial of the bifunctional EGFR/TGFβ fusion protein BCA101 alone and in combination with pembrolizumab in patients with advanced solid tumors

2513

Background: BCA101 is a first-in-class bifunctional fusion protein consisting of an anti-EGFR monoclonal antibody (mAb) and TGFβ receptor 2 extracellular domain (TGFβRII-ECD). Herein, we report the safety, pharmacokinetic (PK), pharmacodynamic (PD), and preliminary efficacy data of BCA101 as monotherapy and in combination with pembrolizumab among patients (pts) with advanced solid tumors refractory to standard therapies. Methods: Pts received BCA101 as a single agent (SA) or in combination with pembrolizumab at escalating doses in a parallel 3+3 design starting at 64 mg intravenously (IV) weekly (qw); and at 240 mg IV qw with pembrolizumab 200 mg IV q3w. Primary endpoint: safety and tolerability (CTCAE v5.0); dose limiting toxicity (DLT) period: 21 days. Secondary endpoints: overall response rate (ORR), PK/PD profile, progression-free survival (PFS), and changes in plasma and intra-tumoral TGFβ signaling assessed by SMAD2 phosphorylation. Results: As of 08-Feb-2022, 60 pts have received BCA101 (part A). Forty-five pts (colorectal, n=14; pancreatic, n=7; head and neck squamous cell carcinoma [HNSCC], n=6) received SA BCA101 at doses up to 1500 mg IV weekly. Fifteen subjects (SCC of the anal canal [SCAC], n=8; HNSCC, n=7) received BCA101 doses ranging from 240 to 1500 mg IV qw in combination with pembrolizumab. Maximum tolerated dose has not been reached. Common adverse events (AEs) attributed to BCA101 include rash (70%), fatigue (23%), pruritis and epistaxis (17% each); all grade (G)2 or less. One DLT was observed at the 1250 mg SA dose (G3 anemia, hematuria). No drug-related G4 AEs or deaths were observed. At data cutoff, best response in the SA arm was stable disease (SD) in 15/39 (39%) evaluable pts. In combination, partial response (PR) was observed in 3/11 (27%) evaluable pts (2 in SCAC, 1 in HNSCC) and a disease control rate (DCR) of 9/11 (82%). Two of 3 responders have been on study >4 months; including 1 confirmed PR in a HNSCC pt refractory to anti-PD-1 therapy and cetuximab. Saturation of the EGFR target was observed at BCA101 doses ≥750 mg. Dose proportional increase in Cmax and AUC were observed with doses of BCA101 750-1500 mg. Prolonged neutralization of plasma TGFβ1 was achieved at all doses ≥500 mg. Among paired tumor biopsies (n=23), pSMAD2 reduction up to 62% was observed at doses ≥500 mg. Conclusions: BCA101 is well tolerated and clinically active as a SA and in combination with PD-1 blockade with a predictable PK/PD profile. A recommended dose of 1500 mg both as SA and in combination has advanced to the part B expansion phase for pts with HNSCC, SCAC, and cutaneous SCC. Clinical trial information: NCT04429542.

First-in-human phase I study of the bifunctional EGFR/TGF fusion protein BCA101 in patients with EGFR-driven advanced solid cancers

3074

Background: Therapeutic targeting of EGFR has demonstrated efficacy in common advanced malignancies such as colorectal cancer (CRC), squamous cell of the head and neck (SCCHN), and non-small cell lung cancer (NSCLC). TGFβ has pro-tumorigenic effects on migration, invasion and tumor-specific immunosuppression, which may enhance the oncogenic effects of activated EGFR. Inhibition of EGFR signaling can lead to TGFβ upregulation as a resistance mechanism. BCA101 is a bifunctional recombinant fusion protein consisting of a chimeric anti-EGFR antibody and an extracellular domain (ECD) of human TGFβRII which demonstrated anti-tumor activity in several preclinical models. Methods: Patients with EGFR-driven advanced solid cancers refractory to standard therapies received BCA101 at escalating doses from 64 mg to 1000 mg intravenously (IV) weekly across 6 dose levels using a 3+3 design to determine dose limiting toxicities (DLT, established within 21 days of initial dosing), maximum tolerated dose (MTD) and/or recommended dose (RD). Secondary endpoints include detailed pharmacokinetic (PK), pharmacodynamic (PD) studies in serial tumor and/or blood samples and assessment of anti-tumor activity. Results: As of 2/11/2021, 21 patients received single agent BCA101 at 64 (n = 3), 240 (n = 7), 500 (n = 2), 750 (n = 3), 800 (n = 3) or 1000 (n = 3) mg IV weekly, including patients with CRC (n = 6), SCCHN (n = 5) uveal melanoma (n = 2), ovarian cancer (n = 2), glioblastoma multiforme (n = 2), conjunctival melanoma, chordoma, pancreatic cancer and anal squamous cell carcinoma (all n = 1). These patients had 1-7 prior lines of antineoplastic therapy (median 4), including 3 patients with prior EGFR inhibitor exposure. Adverse events (AE) related to BCA101 observed in > 1 patient included grade (G) 1-2 rash (n = 9), G 1-2 lipase elevation (n = 2). G3 vitreous hemorrhage at the 240 mg dose level has been the only DLT. The MTD has not been reached and the RD will be based on safety, exposure and pending PD data. Saturation of the clearance was observed at doses above 500mg. Dose proportional increase in Cmax and AUC were observed with doses of 750-1000mg. Best RECISTv1.1 response was stable disease (SD) in 3/10 evaluable patients, with 1 patient on drug ≥4 months. Conclusions: BCA101 is well tolerated at biologically active doses. BCA101 is now being tested in combination with the PD-1 antibody pembrolizumab in patients with SCCHN and anal carcinoma. Clinical trial information: NCT04429542.

AB1346-HPR REAL-WORLD EFFECTIVENESS AND PERCEIVED USEFULNESS OF SYMPTOM CHECKERS IN RHEUMATOLOGY: INTERIM REPORT FROM THE PROSPECTIVE MULTICENTER BETTER STUDY

Background:

Symptom checkers (SC) promise to reduce diagnostic delay, misdiagnosis and effectively guide patients through healthcare systems. They are increasingly used, however little evidence exists about their real-life effectiveness.

Objectives:

The aim of this study was to evaluate the diagnostic accuracy, usage time, usability and perceived usefulness of two promising SC, ADA (www.ada.com) and Rheport (www.rheport.de). Furthermore, symptom duration and previous symptom checking was recorded.

Methods:

Cross-sectional interim clinical data from the first of three recruiting centers from the prospective, real-world, multicenter bETTeR-study (DKRS DRKS00017642) was used. Patients newly presenting to a secondary rheumatology outpatient clinic between September and December 2019 completed the ADA and Rheport SC. The time and answers were recorded and compared to the patient’s actual diagnosis. ADA provides up to 5 disease suggestions, Rheport calculates a risk score for rheumatic musculoskeletal diseases (RMDs) (≥1=RMD). For both SC the sensitivity, specificity was calculated regarding RMDs. Furthermore, patients completed a survey evaluating the SC usability using the system usability scale (SUS), perceived usefulness, previous symptom checking and symptom duration.

Results:

Of the 129 consecutive patients approached, 97 agreed to participate. 38% (37/97) of the presenting patients presented with an RMD (Figure 1). Mean symptom duration was 146 weeks and a mean number of 10 physician contacts occurred previously, to evaluate current symptoms. 56% (54/96) had previously checked their symptoms on the internet using search engines, spending a mean of 6 hours. Rheport showed a sensitivity of 49% (18/37) and specificity of 58% (35/60) concerning RMDs. ADA’s top 1 and top 5 disease suggestions concerning RMD showed a sensitivity of 43% (16/37) and 54% (20/37) and a specificity of 58% (35/60) and 52% (31/60), respectively. ADA listed the correct diagnosis of the patients with RMDs first or within the first 5 disease suggestions in 19% (7/37) and 30% (11/37), respectively. The average perceived usefulness for checking symptoms using ADA, internet search engines and Rheport was 3.0, 3.5 and 3.1 on a visual analog scale from 1-5 (5=very useful). 61% (59/96) and 64% (61/96) would recommend using ADA and Rheport, respectively. The mean SUS score of ADA and Rheport was 72/100 and 73/100. The mean usage time for ADA and Rheport was 8 and 9 minutes, respectively.

Conclusion:

This is the first prospective, real-world, multicenter study evaluating the diagnostic accuracy and other features of two currently used SC in rheumatology. These interim results suggest that diagnostic accuracy is limited, however SC are well accepted among patients and in some cases, correct diagnosis can be provided out of the pocket within few minutes, saving valuable time.

Figure:

Acknowledgments:

This study was supported by an unrestricted research grant from Novartis.

Disclosure of Interests:

Johannes Knitza Grant/research support from: Research Grant: Novartis, Jacob Mohn: None declared, Christina Bergmann: None declared, Eleni Kampylafka Speakers bureau: Novartis, BMS, Janssen, Melanie Hagen: None declared, Daniela Bohr: None declared, Elizabeth Araujo Speakers bureau: Novartis, Lilly, Abbott, Matthias Englbrecht Grant/research support from: Roche Pharma, Chugai Pharma Europe, Consultant of: AbbVie, Roche Pharma, RheumaDatenRhePort GbR, Speakers bureau: AbbVie, Celgene, Chugai Pharma Europe, Lilly, Mundipharma, Novartis, Pfizer, Roche Pharma, UCB, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Timo Meinderink: None declared, Wolfgang Vorbrüggen: None declared, Cay-Benedict von der Decken: None declared, Stefan Kleinert Shareholder of: Morphosys, Grant/research support from: Novartis, Consultant of: Novartis, Speakers bureau: Abbvie, Novartis, Celgene, Roche, Chugai, Janssen, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Peter Bartz-Bazzanella: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, Martin Welcker Grant/research support from: Abbvie, Novartis, UCB, Hexal, BMS, Lilly, Roche, Celgene, Sanofi, Consultant of: Abbvie, Actelion, Aescu, Amgen, Celgene, Hexal, Janssen, Medac, Novartis, Pfizer, Sanofi, UCB, Speakers bureau: Abbvie, Aescu, Amgen, Biogen, Berlin Chemie, Celgene, GSK, Hexal, Mylan, Novartis, Pfizer, UCB

Pharmacodynamic activity of selumetinib to predict radiographic response in advanced uveal melanoma

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Background: Functionally activating mutations (mut) in Gnaq or Gna11, genes that encode for widely expressed G-protein alpha subunits, are early oncogenic events in uveal melanoma (UM) development and result in activation of the MAPK pathway. We previously demonstrated effective pathway inhibition with selumetinib (AZD6244, ARRY-142866) in UM cell lines, with decreased viability associated with pERK and cyclinD1 suppression (Ambrosini, AACR 2010). Methods: Using paired metastatic tumor biopsies from patients (pts) with radiographically progressing UM treated with selumetinib 75 mg BID on a phase II trial (NCT01143402), we correlated MAPK pathway inhibition with radiographic tumor regression and clinical benefit. Biopsies were performed at baseline and after 14 +/-1 days of treatment. Western blotting was performed for pERK and cyclinD1, and quantitated by densitometry. Response (RECIST 1.1) was assessed at baseline, week (wk) 4, wk 8, and q8wks subsequently. Radiographic regression was defined as greatest percentage shrinkage from baseline. Clinical benefit was defined as RECIST response or stable disease ≥16wks. Results: Paired tumor biopsies were assayed from 18 pts: median age 60 (range 47-81), M:F 11:7, median 1 prior therapy (range 0-2), 17 with liver involvement, Gnaq mut:Gna11 mut:wild-type 8:9:1. Radiographic regression was observed in 5 pts, with 2 achieving partial responses. 4 pts were on study ≥16wks (16+, 20, 25, 31 wks), with one currently on study at 11+ wks. Median pERK and cyclinD1 as measured by densitometry decreased by 48% (p=.03) and 76% (p=.03), respectively. Radiographic regression correlated with suppression of pERK (Spearmen’s rank correlation; p=0.04) but not cyclinD1 (p=0.38). A trend towards pERK suppression correlating with clinical benefit was observed (p=.07) with each of the 5 pts achieving PR or SD ≥16wks having a decrease of ≥30% in pERK from baseline. Conclusions: Selumetinib can inhibit pERK and cyclinD1 in UM and can result in tumor shrinkage. Sustained inhibition of pERK inhibition at day 14 may be predictive of benefit. Further evaluation of MEK inhibition in this disease is warranted.

Inducible L-arginine/nitric oxide pathway in human internal mammary artery and saphenous vein

To characterize the L-arginine/nitric oxide (NO) pathway in human vascular smooth muscle (VSM), contractile responses of isolated internal mammary arteries (IMA) and saphenous veins (SV) were observed after induction of NO synthase by interleukin-1 beta (IL-1 beta) or by lipopolysaccharide (LPS). In IL-1 beta-treated endothelium-denuded rings, contractile responses to phenylephrine were reduced in SV rings only. Maximum phenylephrine-induced contraction was depressed by approximately 50%. This was not modified by the presence of indomethacin, NG-nitro-L-arginine methyl ester (L-NAME), or methylene blue (MeB). In LPS-treated vessels, contractile responses were depressed in both SV and IMA rings (40%), and this was not affected by indomethacin. In SV, L-NAME, NG-monomethyl-L-arginine, or MeB did not affect the inhibitory effect of LPS, whereas the effect was reversed in IMA by these inhibitors. In LPS-treated IMA, but not in SV, exogenous L-arginine evoked significant vasodilation (20%). We conclude that VSM of the human IMA possesses an L-arginine/NO pathway inducible by LPS. In SV, LPS or IL-1 beta treatment inhibits contraction by an unidentified system that is not dependent on NO synthase or on guanylate cyclase activities.

The role of nitric oxide in the central control of blood pressure

In these studies blood pressure responses to intracerebroventricular (i.c.v.) infusions were recorded in anesthetized rats. NO donors caused a fall in blood pressure, whereas L-NAME, which blocks the enzyme (NOS) that produces NO, caused a rise in blood pressure. Calcium, i.c.v., stimulates NOS to lower blood pressure. The depressor action of NO is reduced by blocking the action of cGMP. This central NO/cGMP system is tonically active to maintain blood pressure at a normal level.

Light-activated release of nitric oxide from vascular smooth muscle of normotensive and hypertensive rats

A porphyrinic sensor was used to monitor nitric oxide release from vascular smooth muscle in response to exposure to ultraviolet light. Aortic rings exposed to UV light relaxed with a time course that parallels this observed NO release. With repeated UV light treatments, the magnitude of the relaxations diminished, suggesting that a store of NO was being exhausted. Photorelaxation in response to UV light was studied in aortic ring from two types of hypertensive rats, genetic (SHRSP) and nitroarginine-induced. These aortic rings showed greater photorelaxation and evidenced less tolerance than did aortic rings from control normotensive rats. Since NO synthase activity is depressed in both types of hypertension, it appears, paradoxically, that the UV light-releasable store of NO is augmented when NO synthase activity is depressed.

Nitric oxide synthase activity in genetic hypertension

A porphyrinic sensor was used to monitor nitric oxide released from cultured endothelial and vascular smooth muscle cells obtained from genetically hypertensive rats and from a normotensive reference strain of rats. Endothelial cell nitric oxide synthase (the constitutive enzyme) was stimulated with bradykinin, and vascular smooth muscle cell nitric oxide synthase (the inducible enzyme) was induced with interleukin-1 beta. Both types of cells from hypertensive rats released less nitric oxide than did cells from normotensive rats. The observed deficient nitric oxide release from endothelial and smooth muscle cells may contribute to the elevated vascular tone and increased cell growth described in hypertension.

Endothelium-mediated spontaneous response in aortic rings of deoxycorticosterone acetate-hypertensive rats

Aortic rings isolated from normotensive Sprague-Dawley rats (CONT) exhibited spontaneous tone when the preparations were stretched. After administering deoxycorticosterone acetate (DOCA), the rats became hypertensive, and this spontaneous tone increased remarkably. The spontaneous tone was dependent on the extracellular calcium concentration. Incubation with the calcium entry blocker D-600 attenuated the spontaneous response to a greater degree in rings from DOCA rats than in rings from CONT rats. Nifedipine relaxed the already developed spontaneous tone. Removal of the endothelium greatly depressed spontaneous tone, but did not diminish the contraction caused by norepinephrine. On the basis of our findings, we conclude that 1) spontaneous tone depends on calcium influx, presumably through specific stretch-operated membrane channels, 2) these stretch-dependent channels are blocked by D-600 and nifedipine, 3) spontaneous tone is enhanced in DOCA hypertension, and 4) the endothelium appears to act as a receptor for stretch, mediating--at least in part--the spontaneous contractile response by releasing a constrictor agent.

Plasma membrane and its abnormalities in hypertension

The plasma membrane is composed of proteins embedded in a discontinuous fashion in a lipid bilayer. These proteins maintain the integrity of the membrane and play fundamental roles as ion transport channels and as receptors for agents that regulate cell function. The membrane is therefore an important regulator of vascular smooth muscle contraction. The plasma membrane in the hypertensive animal exhibits abnormal permeability for monovalent ions and defective calcium handling. This is reflected in fewer calcium-binding sites and, as a result, in deficient membrane stabilization. These defects have been identified in several cell types, including lymphocytes, red blood cells, adipocytes, and vascular smooth muscle cells. Evidence presented in the current review suggests that hypertension is associated with a generalized membrane defect. Abnormalities in ion transport in vascular smooth muscle cells are the most relevant to the pathogenesis of hypertension since they could be directly responsible for the rise in blood pressure. We hypothesize that the impaired stabilizing effect of calcium in vascular smooth muscle cells of hypertensive subjects renders the membrane more excitable and that this in turn leads to increased vascular reactivity and higher peripheral resistance. Peripheral vascular reactivity usually is increased in hypertension, suggesting increased responsiveness of the smooth muscle cells. Possible abnormalities of the several components of the contractile process of these cells have been investigated for the role they might play in this altered response. Abnormalities in the plasma membrane have been most clearly defined and are emphasized in this review.