BACKGROUND:Eftilagimod alpha (efti) is a major histocompatibility complex class II agonist activating antigen-presenting cells which leads to greater systemic type 1 T helper response and more cytotoxic CD8+ T-cell activation. This phase I trial evaluated the administration of efti, a soluble lymphocyte activation gene-3 (LAG-3) protein, combined with the anti-programmed death-ligand 1 (PD-L1) antibody avelumab in advanced solid tumors.PATIENTS AND METHODS:Patients with heavily pretreated metastatic solid tumors received intravenous avelumab (800 mg) combined with subcutaneously administered efti (6 or 30 mg) for up to 12 cycles, followed by avelumab monotherapy. The primary endpoint was the assessment of the recommended phase II dose (RP2D) of efti in combination with avelumab.RESULTS:Twelve patients with different tumor entities were enrolled (six patients in each cohort). During treatment, no dose-limiting toxicities occurred, and the severity of most adverse events was grade 1 or 2. In total, nine serious adverse events were documented, resulting in a fatal outcome in two cases, but none of them were assessed to be treatment related. Five patients (42%) achieved partial response. The median progression-free survival was 1.96 months and the median overall survival was not reached, with a 12-month survival rate of 75%.CONCLUSION:Subcutaneously administered efti plus avelumab was well tolerated, and efti of 30 mg was determined to be RP2D. The activity is promising and warrants further investigation in future phase II trials.

Immune checkpoint inhibitor (ICI)-related pneumonitis is a common and serious immune-related adverse event (irAE) in patients with non-small cell lung cancer (NSCLC). The factors driving the development of ICI-related pneumonitis in some patients and not others are poorly understood. A prospective cohort of patients with stage IV NSCLC and stage IV melanoma who received ICI treatment was established across four clinical centers in Switzerland. Patient blood was drawn pre-treatment, at every cycle of treatment and, where possible, at the time point of irAE onset. Lung tumor/pneumonitis biopsies were available from some patients. Serum samples were used to perform a high-throughput proteomics analysis as well as ELISAs. Biopsies were used to perform immunohistochemistry and mass spectrometry-based HLA immunopeptidomics analyses. PBMCs were isolated from blood and used to perform in vitro T cell stimulation assays followed by flow cytometric cell acquisition. Lastly, PBMCs were also used to perform cell sorting and single cell RNA sequencing. Using longitudinal samples from a prospective cohort of 144 ICI-treated patients with NSCLC we uncovered important differences between patients with pneumonitis and those without: pre-treatment, patients with pneumonitis showed significantly higher levels of IgG autoantibodies targeting surfactant protein B (SP-B); while, at the onset of pneumonitis, these patients exhibited significantly higher frequencies of CD4+ IFN-γ+ SP-B-specific T cells in their blood. At the onset of pneumonitis patients also expressed a distinct serum proteomic profile including well-known inflammation-associated immune mediators. Finally, they harbored higher frequencies of T cell clonotypes likely to recognize SP-B in their blood than control patients without pneumonitis. Our data suggest that the co-occurrence of SP-B-specific IgG autoantibodies and SP-B-specific CD4+ T cells leads to the development of ICI-related pneumonitis in patients with NSCLC. Our data also indicate that the pre-treatment level of SP-B-specific IgG may be used as a potential biomarker to identify patients at higher risk of developing ICI-related pneumonitis.

There is an ongoing need for high-precision serological assays for the quantitation of anti-SARS-CoV-2 antibodies. Here, a trimeric SARS-CoV-2 spike (S) protein was used to develop an ELISA to quantify specific IgG antibodies present in serum, plasma, and dried blood spots (DBS) collected from infected patients or vaccine recipients. The quantitative S-ELISA was calibrated with international anti-SARS-CoV-2 immunoglobulin standards to provide test results in binding antibody units per mL (BAU/mL). The assay showed excellent linearity, precision, and accuracy. A sensitivity of 100% was shown for samples collected from 54 patients with confirmed SARS-CoV-2 infection more than 14 days after symptom onset or disease confirmation by RT-PCR and 58 vaccine recipients more than 14 days after vaccination. The assay specificity was 98.3%. Furthermore, antibody responses were measured in follow-up samples from vaccine recipients and infected patients. Most mRNA vaccine recipients had a similar response, with antibody generation starting 2–3 weeks after the first vaccination and maintaining positive for at least six months after a second vaccination. For most infected patients, the antibody titers increased during the second week after PCR confirmation. This S-ELISA can be used to quantify the seroprevalence of SARS-CoV-2 in the population exposed to the virus or vaccinated.

Background Eftilagimod alpha (efti; IMP321) is a MHC II class agonist (soluble LAG-3 protein) which activates antigen-presenting cells followed by T-cell (CD4/CD8) activation. Data from the TACTI-002–trial (NCT03625323) and INSIGHT–004 of the current multiple-strata INSIGHT phase-I platform-study revealed that the combination of 30 mg efti subcutaneous (s.c.) with anti-PD-(L)1–checkpoint–inhibitor is well tolerated with encouraging efficacy especially in NSCLC. Stratum–C (INSIGHT-003) of the INSIGHT–study aims to evaluate the feasibility and tolerability of s.c. injections with efti combined with Standard-of-Care (SOC) chemo- and immuno-therapy in 1st-line NSCLC-patients (pts). Methods In Stratum–C, pts with metastatic NSCLC adenocarcinomas are treated with: SOC–chemotherapy (carboplatin AUC5 / pemetrexed 500 mg/m2 q3w for 4 cycles + 500 mg/m2 q3w for maintenance) plus pembrolizumab 200 mg q3w combined with s.c. injections of efti (30 mg) (q2w for 24 weeks; thereafter q3w till week 52). Imaging is performed every 8 weeks and assessed locally. The primary endpoint is feasibility (defined by safety & tolerability) while secondary endpoints include objective response acc. to RECIST 1.1 and other efficacy parameters. In total 20 pts will be enrolled. Results From 02Aug2021 till 22Jul2022, 14 pts have been enrolled. Median age is 66 years and 71.4% are male. Eleven (78.6 %) pts had PD-L1 TPS <50%. No occurrence of unacceptable toxicities (i.e., causally related to efti AND resulting in permanent discontinuation of combination-treatment before administration of two complete cycles). Two serious adverse events (1 thromboembolic event, grade 3; 1 bronchial infection grade, 3) were reported, both unrelated to efti. In total, 69 adverse events (grade 1-2: 29; grade 3: 38; grade 4: 2) were documented. The most frequent AEs were platelet-count decreased in three pts (21.4%, grade 1-3) and anemia (grade 2-3), white-blood-cell decreased (grade 3), and neutrophil-count decreased (grade 3-4) in four pts (28.6%). One grade 3 AE was considered related to efti (insomnia). 10/14 pts are currently evaluable for efficacy (four did not yet have any on-treatment tumor-staging): Seven (70 %) partial responses, two (20%) stable diseases, one (10%) progressive disease as best overall response acc to RECIST 1.1. Conclusions To date, 30 mg efti combined with SOC appears to be feasible and safe with first promising signals of efficacy. Acknowledgements We thank all the participating patients & their families. We thank the dedicated clinical trial investigators & their team members. Immutep, Berlin, Germany provided eftilagimod alpha and funding support for the study. Ethics Approval The study was approved by 9Ethik-Kommission bei der Landesärztekammer Hessen9 institution9s Ethics Board, approval number 2019-1267-fAM. Participants gave informed consent before taking part.

Treatment beyond progression (TBP) during systemic anticancer drug therapy is a commonly used strategy in patients (pts) with different metastatic cancers when oligoprogression is observed and additional local treatment is feasible. There is only limited data whether this approach is also useful in metastatic non-small cell lung cancer (NSCLC) and progressive disease during immune-checkpoint inhibitor (ICI) therapy receiving additional local treatment.

We studied the suitability of commercially available monoclonal antibodies (mAbs) for the immunohistochemical (IHC) detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in standard archival specimens. Antibodies were screened on HEK293 cells transfected with viral nucleoprotein, S1 subunit and S2 subunit of spike protein and on untransfected cells, as well as a panel of normal tissue. Lung tissue with presence of SARS-CoV2 confirmed by in situ hybridization (ISH) was also used. A total of 7 mAbs were tested: (1) mAb 001 (Sino Biological, 40143-R001), (2) mAb 007 (Sino Biological, 40150-R007), (3) mAb 019 (Sino Biological, 40143-R019), (4) mAb 1A9 (GeneTex, GTX632604), (5) mAb ABM19C9 (Abeomics, 10-10007), (6) FIPV3-70 (Santa Cruz, SC-65653), and (7) mAb 6F10 (BioVision, A2060). Only 2 mAbs, clone 001 to the nucleoprotein and clone 1A9 to the S2 subunit spike protein displayed specific immunoreactivity. Both clones showed strong staining in the acute phase of COVID-19 pneumonia, mostly in areas of acute diffuse alveolar damage, but were not completely congruent. Viral protein was also found in kidney tubules, endothelia of multiple organs and a nasal swab of a patient with persistent SARS-CoV2 infection. The other tested reagents were either poorly reactive or demonstrated nonspecific staining in tissues and lesions not infected by SARS-CoV2. Our study demonstrates that rigid specificity testing is mandatory for the evaluation of mAbs to SARS-CoV2 and that clones 001 to nucleoprotein and 1A9 to S2 subunit spike protein are useful for the in situ detection of SARS-CoV2.

Strata (St) A / B of the INSIGHT study evaluate feasibility of intratumoral (i.t.) and intraperitoneal (i.p.) IMP321 monotherapy in advanced solid tumors. The MHC class II agonist activates antigen presenting cells followed by CD8 T cell activation. This is an investigator-initiated study with currently 4 St: i.t. (A) or i.p. IMP321 (B); s.c. IMP321 with SOC (C) or combined with avelumab (D). Here we focused on St A / B. In St A, patients (pts) received i.t. injections (inj) with IMP321 escalation 6-12-24-30mg in cohort (coh) 1 and the max. tolerated dose (MTD) in coh 2. In St B, pts with peritoneal carcinomatosis received i.p. IMP321 (dose escalation 1-3-6-12-30mg in coh 1 and MTD in coh 2). In both St pts with a benefit after the last inj. were offered s.c. IMP321 for up to 52 weeks. Main endpoint was safety. Recruitment has been completed with 8 pts treated in St A (coh 1: 3 pts. [2 gastric cancer, 1 peritoneal mesothelioma]; coh 2: 5 pts [cancer of head & neck, colon {2}, papilla, lung]) and 4 pts in St B coh 1 (2 gastric, 2 colon cancer). No dose limiting toxicities occurred. 14 serious adverse events (SAEs) have been reported: 8 in St A (2 in 1 pt of coh 1, 6 in 4 pts of coh 2) and 6 in 3 pts of St B coh 1. 1 SAE in coh 2 of St A was related to study procedure (sudden death NOS grade 5). 1 AESI (St A coh 1) probably related to IMP321 (chills grade 3). Of the heavily pretreated pts, 5 had stable disease (SD) (3 gastric, 2 colon cancer), 5 progressive disease (RECIST) and 2 clinical progression. 2 of the SD pts. had PFS of 3mo (1 gastric St A; 1 colon St B) and 2 SD pts. had PFS of 4mo (2 gastric St B). The SD gastric cancer pt of St A with PFS of 3 mo had an OS of 28 mo with increase of PD-L1 in the immune cells from 20% at baseline (BL) to 30% (D29 + D71). 3 SD pts with gastric cancer showed high CD45, CD163 expression at BL (tissue). Blood cytokine profile: 1 SD St B pt showed a significant increase in CXCL10, 4h - 24h after inj. measured on D1/D29, with similar peaks for IFN ɣ, combined with a moderate increase in CD4 and CD8 cells. Increase in IFN ɣ with additional Nk-cells was also seen in 1 SD St A pt. Intratumoral and intraperitoneal IMP321 can be safely administered up to 30 mg with signals of clinical and cytokine activity.

3099 Background: Stratum D of the INSIGHT study investigates the feasibility and safety of s.c. application of IMP321 (eftilagimod alpha) combined with the PD-L1 inhibitor avelumab in advanced stage solid tumors. The MHC class II agonist IMP321 activates antigen-presenting cells followed by CD8 T-cell activation. The addition of avelumab aims at enhancing activity by combining IMP321’s activating effects on immune cells with the release of immune inhibitory effects caused by interruption of the PD-1/PD-L1 axis. Methods: This investigator-initiated phase I trial consists of four strata: intratumoral (A) or intraperitoneal IMP321 (B); s.c. IMP321 with SOC (C) or with PD-L1 inhibition (D). This abstract focuses on Stratum D. Patients (pts) receive 800mg avelumab i.v. q2w along with s.c. IMP321 injections (6mg IMP321 in cohort 1 and 30mg IMP321 in cohort 2). 12 pts are planned in stratum D : 6 pts in cohort 1 and 6 pts in cohort 2. Primary endpoint is safety. Results: So far, 8 pts have been enrolled (6 in cohort 1 and 2 in cohort 2). In 6 pts (cohort 1) treated for different tumor indications (gastric, gallbladder, colon cancer, pleural mesothelioma), no dose limiting toxicities occurred. 3 serious adverse events (SAEs) (1 acute kidney injury grade 5 in 1 pt, 2 preileus grade 3 in 1 pt) were reported, none of them was related to any of the study drugs. In total, 34 adverse events (AEs; grade 1-2, 21; grade 3, 12; no grade 4; grade 5, 1) have been documented in 5 pts. Most common grade 1-2 AEs were pain, nausea, and injection site reaction in 50%, 33%, and 17% of the pts. Most common grade 3 AEs were nausea/vomiting, preileus/ileus, and ascites in 33%, 33%, and 17% of the pts. One AE grade 5 (acute kidney injury) was reported. 4 AEs grade 1-2 were possibly or definitely related to IMP321 (injection site reaction 2x; fever; lipohypertrophy), 6 AEs grade 1-2 were possibly or definitely related to avelumab (nausea 2x; chills; fever; dyspnea; lipohypertrophy). All AEs grade 3-5 were unrelated to any of the study drugs. Of the 8 pts enrolled so far, 4 had disease progression (acc. to RECIST 1.1), 1 partial response, 1 stable disease with some extent of tumor shrinkage, and 2 have not had tumor assessment yet. Conclusions: Combination treatment with avelumab 800mg and IMP321 6mg is safe and well tolerated. Cohort 2 will be presented at the meeting. Clinical trial information: NCT03252938 .

PURPOSE: Exercise therapy programs are increasingly incorporated into oncological clinics, but it is largely unknown if this facilitates information availability or patients’ exercise readiness. This survey compares the knowledge and barriers regarding exercise in cancer patients treated in an oncological clinic with an established exercise therapy and counseling program versus an oncological clinic without any exercise offers. METHODS: Participants were recruited in an oncological outpatient clinic that provides an exercise therapy and counseling program (OC+Ex) and an oncological outpatient clinic without any exercise offers (OC). Information status concerning cancer diagnosis, treatment, exercise, and exercise-related barriers were assessed with an extended version of the EORTC QLQ-INFO-25 questionnaire and the Perceived Physical Activity Barriers (PPAB) scale. Results were compared using contingency tables and chi-square tests. RESULTS: Out of 215 patients 200 returned the questionnaire (OC+Ex: n = 109; 64±13 yrs.; 85% during treatment; OC: n = 91; 60±11 yrs.; 96% during treatment). A comparable proportion of the patients of the OC+Ex and the OC felt moderately to well informed concerning cancer treatment (90% vs. 88%) and side effects (81% vs. 79%). Regarding exercise 31% vs. 15% and 23% vs. 29% of the patients in the OC+Ex versus the OC reported a high or moderate information status, while 18% (OC+Ex) or 27% (OC) stated to not have received any information (p < .05). Patients in the OC+Ex documented receiving specific exercise recommendations more often than patients in the OC (41% vs. 16%; p < .001), 25% (OC+Ex) or 3% (OC) reported a direct referral to a concrete exercise course/program (p < .001). 53% (OC+Ex) and 60% (OC) asked for more information about exercise. Perceived exercise barriers included fatigue (39%), physical weakness (31%), nausea (24%), pain/discomfort (23%), and lack of exercise routine (25%). CONCLUSIONS: Our results indicate that an exercise program at an oncological clinic supports patients’ knowledge about exercise. Further targeted triage and information activities including a stronger collaboration between oncologists and exercise specialists might contribute to further enhance patients’ knowledge, to diminish perceived barriers and to improve exercise behavior.