anti-PD1 Monoclonal Antibodies Research Articles

Combining a WT1 Vaccine (Galinpepimut-S) With Checkpoint Inhibition (Nivolumab) in Patients With WT1–Expressing Diffuse Pleural Mesothelioma: A Phase 1 Study

IntroductionWT1 often presents on the surface of diffuse pleural mesotheliomas (DPMs) and is an ideal therapeutic target. Galinpepimut-S (GPS), a tetravalent, non–human leukocyte antigen–restricted, heteroclitic WT1–specific peptide vaccine was safe and effective in early phase clinical trials and upregulates T-cell suppressive programmed death-ligand 1 in the tumor microenvironment of other malignancies. A randomized phase 2 study of adjuvant GPS in patients with DPM trended toward improved median overall survival. MethodsTo further enhance immunogenicity, we combined GPS with nivolumab, an anti-PD1 monoclonal antibody, in an open-label, single-center phase 1 study, examining tolerability and immunogenicity in patients with previously treated DPM. We enrolled patients with progressive or recurrent DPM treated with at least one course of pemetrexed-based chemotherapy. Patients received two doses of GPS followed by six doses of GPS with intravenous nivolumab every 2 weeks, and up to six additional cycles until disease progression or unacceptable toxicity. ResultsTen patients were treated; 70% experienced mostly mild treatment-related adverse events; two experienced a grade 3 or higher adverse event. Three of the 10 patients (30%) reported vaccine-specific T-cell responses. There were no partial responses; three patients had prolonged stable disease with up to 17% decrease in tumor volume. Median progression-free survival was 3.9 months and the median overall survival was 7.4 months. ConclusionsCoadministration of GPS and nivolumab reported a tolerable toxicity profile and induced immune responses in a subset of patients, but initial response and survival benefit were limited possibly owing to the small sample size.

A novel biomimetic nanoplasmonic sensor for rapid and accurate evaluation of checkpoint inhibitor immunotherapy.

Immune checkpoint inhibitors (ICIs) emerged as promising immunotherapies for cancer treatment, harnessing the patient's immune system to fight and eliminate tumor cells. However, despite their potential and proven efficacies, checkpoint inhibitors still face important challenges such as the tumor heterogeneity and resistance mechanisms, and the complex in vitro testing, which limits their widespread applicability and implementation to treat cancer. To address these challenges, we propose a novel analytical technique utilizing biomimetic label-free nanoplasmonic biosensors for rapid and reliable screening and evaluation of checkpoint inhibitors. We have designed and fabricated a low-density nanostructured plasmonic sensor based on gold nanodisks that enables the direct formation of a functional supported lipid bilayer, which acts as an artificial cell membrane for tumor ligand immobilization. With this biomimetic scaffold, our biosensing approach provides real-time, highly sensitive analysis of immune checkpoint pathways and direct assessment of the blocking effects of monoclonal antibodies in less than 20min/test. We demonstrate the accuracy of our biomimetic sensor for the study of the programmed cell death protein 1 (PD1) checkpoint pathway, achieving a limit of detection of 6.7ng/mL for direct PD1/PD-L1 interaction monitoring. Besides, we have performed dose-response inhibition curves for an anti-PD1 monoclonal antibody, obtaining a half maximal inhibitory concentration (IC50) of 0.43nM, within the same range than those obtained with conventional techniques. Our biomimetic sensor platform combines the potential of plasmonic technologies for rapid label-free analysis with the reliability of cell-based assay in terms of ligand mobility. The biosensor is integrated in a compact user-friendly device for the straightforward implementation in biomedical and pharmaceutical laboratories.

Effect of anti CTLA-4 and PD-1 monoclonal antibodies on systemic SDF-1 and galectin-3 levels through NLRP3 and MyD-88 pathways in preclinical models.

Effect of anti CTLA-4 and PD-1 monoclonal antibodies on systemic SDF-1 and galectin-3 levels through NLRP3 and MyD-88 pathways in preclinical models.

The efficacy and safety of toripalimab combined with anlotinib in the first-line treatment of Chinese patients with metastatic melanoma.

9560 Background: Acral, mucosal and non-CSD melanoma are the major subtypes in Chinese melanoma patients, with poor response to antiprogrammed cell death-1 (PD-1) monotherapy. Anti PD-1 monoclonal antibodies combined with anti-angiogenesis agent have showed synergistic effects mechanically and a promising response rate. Here, we report efficacy and safety of toripalimab combined with anlotinib in Chinese patients with metastatic melanoma. Methods: Patients with metastatic acral, mucosal and non-CSD melanoma received toripalimab 240mg intravenously every 3 weeks combined with anlotinib 12 mg orally once a day for first 2 weeks every 3 weeks as first-line treatment, until disease progression or unacceptable toxicity. All patients were enrolled from the Cancer Center of Union Hospital, affiliated to Tongji Medical College of Huazhong University of Science and Technology and Hunan Cancer Hospital. Results: From January 2021 to January 2024, a total of 47 patients were enrolled in this study. Subtypes were 16 patients with acral melanoma, 21 patients with mucosal melanoma, and 10 patients with non-CSD melanoma. Average age was 59.7 ±10.1 years old. The median follow-up was 26.5 months (95% CI: 20.6, 32.4 months). Among the 46 efficacy evaluable patients, the objective response rate (ORR) and disease control rate (DCR) were 23.9% and 80.4%, respectively. Median duration of response was 14.4 months (95% CI: 7.5, 21.3). The median progression-free survival (PFS) of all 47 patients was 5.7 months (95% CI 4.2 to 7.2 months); and the median OS was 14.4 months (95% CI 7.3 to 21.5 months). The median PFS of patients with M1a stage is 24.4 months, statistically longer than M1b (5.1 months), M1c (6.6 months) and M1d (4.0 months). The median PFS of acral, mucosal and non-CSD melanoma were 6.6m, 5.1m, 5.2m respectively with no statistical difference, and these is no difference of PFS between gender and age. In terms of safety, treatment-related adverse events (TRAEs) for all grades occurred in 76.6% (36/47) of patients, and grade 3 or 4 occurred in 4.3% (2/47) of patients. The incidence of immune-related adverse reactions (irAE) was 23.4% (11/47) for all grades, the most common irAEs (≥2%) included hypothyroidism, immune-associated hepatitis and rash. Conclusions: Toripalimab combined with anlotinib displays good efficacy and well-tolerant safety profiles in the treatment of patients with metastatic melanoma. Further biomarker analysis was ongoing.

PD1 blockade improves survival and CD8+ cytotoxic capacity, without increasing inflammation, during normal microbial experience in old mice

Abstract The elderly and those with chronic diseases face a 2 to 10-fold higher risk of hospitalization and mortality post-infection compared with healthy adults. Disease severity in the elderly is often attributed to the aging of the immune system, including an expansion of exhausted T cells that contribute to inflammation and have impaired activation and function. It is unclear how exhausted T cells from aged individuals respond to infection and the impact of acute restoration of T cell activation produces functional cells that contribute to excessive inflammation. In a mouse model of normal microbial exposure (NME), old specific pathogen-free (SPF) mice exhibit 100% mortality when exposed to microbes ordinarily found in pet store mice. We show that old mice exposed to NME show increased expression of inflammatory pathways and elevated frequencies of a heterogenous exhausted CD8+ T cell pool that express different levels of PD1, TOX, and CXCR5. Treatment with an anti-PD1 monoclonal blocking antibody in old mice during NME significantly improves survival without altering the acute inflammatory response despite the potential for adverse events following checkpoint blockade. Anti-PD1-mediated survival depends on CD8+ but not CD4+ T cells. CD8+ PD1+ T cells from old mice given anti-PD1 have increased GzmB production. These data suggest a novel approach for reducing infection vulnerability in the aged by targeting CD8+ T cell exhaustion through checkpoint blockade immunotherapy.

Abstract 2733: NB202: A bispecific anti-PD1/TIM-3 antibody for cancer immunotherapy

Abstract Despite the remarkable efficacy of PD-(L)1 therapy, a significant proportion of cancer patients fail to respond or develop resistance over time. Co-expression of T-cell immunoglobulin and mucin domain containing-3 (TIM-3) with PD-1 on primed T cells has been observed in patients exhibiting resistance to PD-1 blockade. Moreover, TIM-3 is also expressed on other immune cells, including NK and DC, and plays a negative regulatory role in these immune cells. Therefore, the dual blockade of PD-1 and TIM-3 holds potential for enhanced clinical benefits. NB202 is a bispecific anti-PD1/TIM-3 antibody that has been designed to optimize the therapeutic response of anti-PD1 therapy by maximizing TIM-3 blockade on antigen-experienced T cells, enhancing NK cell activity, and improving antigen presentation ability of antigen-presenting cells (APC). NB202 has demonstrated high affinity binding to human TIM3 and PD-1 in the low nanomolar range. Moreover, it can simultaneously bind to TIM-3 and PD-1 receptors through a trans-manner, suggesting its potent capacity to enhance the interaction between T cells and dendritic cells (DCs). In classic MLR (mixed lymphocyte reaction) and T cell stimulation assays, NB202 has exhibited superior efficacy compared to the combination of anti-PD1 mAb and anti-TIM3 monoclonal antibodies as it significantly enhances the secretion level of interferon-gamma (IFN-gamma), and particularly interleukin-2 (IL-2). Moreover, in an anti-PD1 resistant mouse model, NB202 has shown promising efficacy results. Citation Format: Jinyu Dong, Yu Zhang, Binbin Wang, Dong Wang, Tingting Bu, Jie Ni, Bishnu Nayak, Xin Dong. NB202: A bispecific anti-PD1/TIM-3 antibody for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2733.

'Immunotherapeutic Strategies for Intra-cranial Metastatic Melanoma - a Meta-analysis and Systematic Review'.

Immune-activating anti-CTLA4 and anti-PD1 monoclonal antibodies (alone or in combination) are being used to treat advanced melanoma patients and can lead to durable remissions, and long-term overall survival may be achieved in between 50-60% of patients. Although intracranial metastases are very common in melanoma (about 50-75% of all patients with advanced disease), most of the pivotal prospective clinical trials exclude patients with intra-cranial metastases, certainly if their lesions are symptomatic and steroid-requiring and the degree of sensitivity of intra-cranial melanoma to immunotherapy remains uncertain, and requires further investigation especially in view of the demonstrable activity of RAF-MEK inhibitors in this clinical setting and the emergence of stereotactic radiotherapy. Our study aimed to evaluate the efficacy and toxicity of immunotherapy against advanced melanoma patients with brain metastases. In terms of comparative studies, only retrospective analyses could be identified. Based on 3 retrospective studies, treatment of patients with melanoma brain metastases with immunotherapeutic approaches improves overall survival substantially compared with supportive measures alone (no active anticancer treatment). The efficacy of targeted therapy appeared to be comparable to that of immune therapy in terms of overall survival, based on a small number of patients. The combination of concurrent radiation therapy to the brain and systemic immunotherapy led to improved overall survival compared to radiotherapy alone, suggesting potential synergism between the approaches, and combination treatment could be delivered safely. Our review supports the use of immunotherapeutic strategies for these patients although treatment efficacy appears to be lower for symptomatic lesions. In view of the extremely high efficacy of stereotactic radiotherapy approaches in the brain, understanding the interaction between radiotherapy and immunotherapy is vital and should be an area of active investigation.

10195-MET-11 THE PREDICTIVE FACTORS OF EFFICACY OF PEMBROLIZUMAB IN BRAIN METASTASES OF LUNG CANER

Abstract The main treatment for metastatic brain tumors is radiation therapy or surgical removal. Since the pembrolizumab, an anti-PD1 monoclonal antibody, was revealed to be effective for brain metastases of lung cancer, it has been used as a therapeutic option. However, the predictive factors of its efficacy have been unclear. If the efficacy of pembrolizumab can be predicted prior to the treatment of metastatic brain tumors, it will have a significant impact on subsequent treatment strategies. In this study, we performed a retrospective analysis of patients with metastatic brain tumors from lung cancer treated with pembrolizumab to investigate predictive factors of pembrolizumab efficacy. From January 2018 to July 2023, 73 patients were treated with pembrolizumab for brain metastases of lung cancer at our institution. Among them, 16 patients who had received pembrolizumab for at least 1 year were included. Median age was 68 years (45-86), 10 were male (63%), and median period of pembrolizumab treatment was 105 months (49-319). Patients with brain metastasis which was well controlled for at least 2 years after starting pembrolizumab were defined as effective, and those who required new treatment were defined as invalid. There were 11 effective cases and 5 invalid cases. We compared clinical characteristics, genetic characteristics of the primary tumor, and imaging characteristics of metastatic brain tumors between the effective and ineffective cases, and identified predictive factors for efficacy of pembrolizumab.

Abstract C104: Targeted epigenomic inhibition of MYC enhances responses to immune checkpoint and EGFR inhibitors in preclinical models of NSCLC

Abstract Aberrant expression of the transcription factor MYC is found in most cancers including non-small cell lung cancer (NSCLC) and has critical roles in a wide range of oncogenic processes including immune evasion and EGFR inhibitor resistance. Despite MYC’s therapeutic attractiveness, potent inhibitors of MYC activity have been elusive, due to its intrinsically disordered protein structure and tightly autoregulated expression. We have developed NSCLC-specific programmable epigenomic mRNA therapy, termed a MYC Omega epigenomic controller (NSCLC MYC-OEC) that is designed to target the insulated genomic domain of MYC. We have previously shown that NSCLC MYC-OEC effectively downregulates MYC expression pre-transcriptionally and have demonstrated that NSCLC MYC-OEC inhibits NSCLC patient-derived organoid viability in vitro and abrogates xenograft tumor growth in vivo. To identify combination treatments with NSCLC MYC-OEC, we retrospectively evaluated baseline MYC expression and real-world progression-free survival (PFS) in a cohort of 283 NSCLC patients treated with pembrolizumab, an anti-PD1 monoclonal antibody. This analysis revealed that NSCLC patients with MYC-overexpressing tumors exhibited shorter PFS when treated with pembrolizumab. Moreover, analysis of PD1 or PD-L1 transcript levels in tumors from 13,230 lung adenocarcinoma patients revealed a significant positive correlation between PD1 or PD-L1 and MYC mRNA levels, consistent with a role for MYC in regulation of the immune response. In vivo evaluation of NSCLC MYC-OEC activity and immune checkpoint immunotherapy (ICI) treatment of preclinical Lewis lung carcinoma syngeneic tumor models demonstrated that the combination of NSCLC MYC-OEC with anti-PD-L1 antibody enhanced inhibition of tumor growth and prolonged survival over administration when compared to either NSCLC MYC-OEC or anti-PD-L1 antibody monotherapy. Retrospective analysis of a cohort of 301 NSCLC patients also showed that patients with MYC-overexpressing tumors exhibited significantly shorter PFS when treated with osimertinib, a third generation EGFR inhibitor. To further understand this, we investigated the effects of NSCLC MYC-OEC and osimertinib treatment alone or in combination in EGFR mutant cells, H1975 and PC9. While NSCLC MYC-OEC and osimertinib monotherapy treatments resulted in downregulation of MYC protein expression in both cell lines, combination treatment led to a significantly greater decrease in MYC expression. Furthermore, the combination synergistically reduced H1975 and PC9 cell viability in vitro and led to a significantly greater inhibition of H1975 xenograft growth relative to each single agent in vivo. Together, these data provide preclinical proof-of-concept in NSCLC for development of OEC-mediated pre-transcriptional epigenomic inhibition of MYC expression in combination with immune checkpoint and EGFR inhibitors. Furthermore, these findings suggest that NSCLC MYC-OEC combination with ICI or EGFR-targeted therapy may improve patient outcomes. Citation Format: Defne Yarar, Eugine Lee, Padraich Flahardy, Cameron Vergato, Graeme Hodgson, Thomas McCauley. Targeted epigenomic inhibition of MYC enhances responses to immune checkpoint and EGFR inhibitors in preclinical models of NSCLC [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C104.

Isatuximab and Cemiplimab in Relapsed or Refractory Extranodal Natural Killer/T-Cell Lymphoma: A Multi-Center, Open-Labeled Phase II Study (CISL2102/ICING study)

Introduction Extranodal NK/T-cell lymphoma (ENKTL), an Epstein-Barr virus (EBV) associated lymphoid malignancy is a rare but aggressive non-Hodgkin lymphoma (NHL). The prognoses of patients with relapsed or refractory (R/R) ENKTL are still poor because there is limited treatment option for R/R ENKTL. The expression of PD-L1 (Programmed Death Ligand-1) is common in ENKTL because EBV could induce the PD-L1 expression. Thus, PD1 and PD-L1 inhibitors have been tried as salvage treatments, but their single-agent activities in previous studies were not satisfactory. CD38 has been considered as another potential therapeutic target in ENKTL because tumor cells of ENKTL could express CD38. CD38 expression was also reported to be related with the resistance to PD1 inhibitors. Thus, we conducted a phase II study with the combination of cemiplimab (PD1 inhibitor) and isatuximab (monoclonal anti-CD38 antibody) in patients with R/R ENKTL. Methods We aimed to analyze the efficacy of isatuximab (anti-CD38 monoclonal antibody) and cemiplimab (anti-PD1 monoclonal antibody) in patients with R/R ENKTL. Patients eligible for this study had relapsed or refractory disease at least one line of treatment. The induction treatment consisted of cemiplimab 250mg (day 1 and 15) and isatuximab 10mg/kg (day 2 and 16) intravenous administration every 4 weeks for 6 cycles. After that, responders received cemiplimab 250mg and isatuximab 10mg/kg once every 3 weeks up to 24 months or until progression, death, or study withdrawal. The primary end point was complete response (CR) rate and secondary end points were objective response rate (ORR) consisting of CR and partial response (PR), progression-free survival (PFS), and safety. The target CR rate was designated as 40% (P1). Considering 20% (P0) of CR rate after conventional salvage therapies and 10% of drop-out rate, 37 patients were planned to be enrolled. Results Between June 2021 and May 2023, we enrolled 37 patients. At enrollment, 29 (78%) patients had stage IV disease and 26 (70%) belonged to the high-risk of prognostic index of NK lymphoma (PINK-E, Table 1). Prior to the participating in the study, 19 (51%) patients had received ≥ 2 lines of systemic therapy. At the time of enrollment, 10 (27%) patients were refractory to their previous treatments whereas the remaining patients had relapsed diseases. After the first day of first cycle, all patients completed at least one cycle of treatment. The response rate was determined by the best response during treatment. As 16 patients achieved CR, the CR rate was 43% (16/37). Thus, the primary end point was met in the study. The ORR was 65% (24/37) consisting of 16 CR and 8 PR. The responders could maintain their treatments up to 32 cycles, and the median PFS of responders was 21.0 months (95% CI: 7.8-34.2 months, Figure 1). The comparison of characteristics between responders and non-responders showed stage at enrollment was significantly associated with response (P = 0.032, Table 1). Thus, eight patients with stage I/II at enrollment responded to the treatment (100%, 8/8) whereas 55% (16/29) patients in stage III/IV responded to the treatment. The risk of PINK-E and other unfavorable parameters were not related with treatment response. Furthermore, the PD-L1 expression showed an association with response (Table 1), thus, 83% of patients (15/18) achieved CR or PR. Most treatment-emergent adverse events were grade 1-2 in severity. Only one patient with CR withdrew from the study due to neuropathic pain that was related with the patient's previous treatments. The hematologic and non-hematologic grade ≥ 3 events were reported in 12 (32%) patients including pneumonia. However, they were manageable, and there was no treatment-related death. Conclusions The combination of isatuximab with cemiplimab showed durable antitumor activity and manageable safety profiles in R/R ENKTL. Especially, patients with PD-L1 expression showed better outcomes than patients with low PD-L1 expression. Further study with a larger study population should be warranted to confirm our findings.

Anti CTLA-4 and PD-1 monoclonal antibodies increases systemic SDF-1 and galectin-3 levels and reduces myocardial strain through NLRP3 and MyD-88 pathways

Abstract Background Immune checkpoint inhibitors (ICIs) have significantly changed the oncology clinic in recent years, improving survival expectations in cancer patients. ICI therapy have a broad spectrum of side effects from endocrinopathies to cardiovascular diseases. Purpose In this study, pro-inflammatory and pro-fibrotic effects of short-term ICIs therapy in preclinical models were analyzed. Methods Firstly, in a human in vitro model, human cardiomyocytes co-cultured with hPBMC were exposed to ICIs (with CTLA-4 or PD-1 blocking agents, at 200 nM) for 72h. After treatment, production of DAMPs and 12 cytokines were analyzed in the supernatant through colorimetric and enzymatic assays. C57/Bl6 mice were treated with CTLA-4 or PD-1 blocking agents (15 mg/kg) for 10 days. Before (T0), after three days (T3) and after treatments (T10), ejection fraction, fractional shortening, radial and longitudinal strain were calculated by using bidimensional echocardiography (Vevo 2100,Fujfilm). Fibrosis, necrosis, hypertrophy and vascular NF-kB expression were analyzed through Immunohistochemistry. Myocardial expression of DAMPs (S100- Calgranulin, Fibronectin and Galectine-3), MyD88, NLRP3 and twelve cytokines have been analyzed. Systemic levels of SDF-1, IL-1β and IL-6 were analyzed before, during and after ICIs therapy. Results Radial and longitudinal strain were decreased after 10 days of ICIs therapy. Histological analysis of NF-kB expression shows that short-term anti-CTLA-4 or anti-PD-1 treatment increased vascular and myocardial inflammation. No myocardial hypertrophy was seen with the exception of the pembrolizumab group. Myocardial fibrosis and expression of galectin-3, pro-collagen 1-α and MMP-9 were increased after treatment with all ICIs. Both anti-CTLA-4 or anti-PD-1 treatments increased the expression of DAMPs, NLRP3 inflammasome and MyD88 and induced both in vitro and in vivo the secretion of IL-1β, TNF-α and IL-6. Systemic levels of SDF-1, IL-1β and IL-6 were increased during and after treatment with ICIs. Conclusions Short therapy with PD-1 and CTLA-4 blocking agents increases vascular expression of NF-kB, systemic SDF-1, IL-1β, IL-6 levels and myocardial NLRP3, MyD88 and DAMPs expression in preclinical models. A pro-inflammatory cytokine storm was induced in myocardial tissues and in cultured cardiac cells after ICIs therapy. The overall picture of the study suggests new putative biomarkers of ICIs-mediated systemic and myocardial damages potentially useful in clinical cardioncology.

Abstract 15045: Anti CTLA-4 and PD-1 Monoclonal Antibodies Increases Systemic SDF-1 and Galectin-3 Levels and Reduces Myocardial Strain Through NLRP3 and MyD-88 Pathways

Background: Immune checkpoint inhibitors (ICIs) have significantly changed the oncology clinic in recent years, improving survival expectations in cancer patients. ICI therapy have a broad spectrum of side effects from endocrinopathies to cardiovascular diseases. In this study, pro-inflammatory and pro-fibrotic effects of short-term ICIs therapy in preclinical models were analyzed. Methods: Firstly, human cardiomyocytes co-cultured with hPBMC were exposed to ICIs (with CTLA-4 or PD-1 blocking agents, at 200 nM) for 72h. After treatment, production of DAMPs and 12 cytokines were analyzed in the supernatant through enzymatic assays. C57/Bl6 mice were treated with CTLA-4 or PD-1 blocking agents (15 mg/kg) for 10 days. Before (T0), after three days (T3) and after treatments (T10), ejection fraction, fractional shortening, radial and longitudinal strain were calculated by using bidimensional echocardiography (Vevo 2100,Fujfilm). Fibrosis, necrosis, hypertrophy and vascular NF-kB expression were analyzed through Immunohistochemistry. Myocardial expression of DAMPs, MyD88, NLRP3 and twelve cytokines have been analyzed. Systemic levels of SDF-1, IL-1β and IL-6 were analyzed before, during and after ICIs therapy. Results: Radial and longitudinal strain were decreased after 10 days of ICIs therapy. Histological analysis of NF-kB expression shows that short-term anti-CTLA-4 or anti-PD-1 treatment increased vascular and myocardial inflammation. No myocardial hypertrophy was seen with the exception of the pembrolizumab group. Myocardial fibrosis and expression of galectin-3, pro-collagen 1-α and MMP-9 were increased after treatment with all ICIs. Both anti-CTLA-4 or anti-PD-1 treatments increased the expression of DAMPs, NLRP3 and MyD88 and induced both in vitro and in vivo the secretion of IL-1β, TNF-α and IL-6. Systemic levels of SDF-1, IL-1β and IL-6 were increased during and after treatment with ICIs. Conclusions: Short therapy with PD-1 and CTLA-4 blocking agents increases vascular expression of NF-kB, systemic SDF-1, IL-1β, IL-6 levels and myocardial NLRP3, MyD88 and DAMPs expression in preclinical models. A pro-inflammatory cytokine storm was induced in myocardial tissues after ICIs therapy.

2244P Anti CTLA-4 and PD-1 monoclonal antibodies increases systemic SDF-1 and galectin-3 levels through NLRP3 and MyD-88 pathways in preclinical models

2244P Anti CTLA-4 and PD-1 monoclonal antibodies increases systemic SDF-1 and galectin-3 levels through NLRP3 and MyD-88 pathways in preclinical models

Abstract PO-089: Opioid-mediated suppression of anti-tumor immunity via peripheral OPRM1 signaling in head and neck squamous cell carcinoma

Abstract Head and Neck squamous cell carcinoma (HNSCC) causes severe pain, beyond what is reported in other cancer types. Opioids are the current backbone of HNSCC pain treatment but may have an immunomodulatory effect in the presence of cancer; T cells express opioid receptors. We recently demonstrated that opioids may affect the efficacy of anti-PD1 monoclonal antibody (mAb) treatment in recurrent/metastastic HNSCC patients; opioid usage was associated with significantly lower progression free survival and overall survival as well as decreased CD8 T cells in the tumor microenvironment. We hypothesized that cancer immunosurveillance is impaired by the immunosuppressive actions of exogenous opioids via peripheral mu-opioid receptor (OPRM1) signaling. A syngeneic mouse oral cancer model was used to determine if analgesic morphine impacted the tumor-associated immune response during tumor progression and in response to anti-PD1 mAb; mouse oral cancer cell line 1 (MOC1) tumor-bearing mice were treated with vehicle or morphine (10mg/kg i.p., 2x daily for 4.5 days) and the tumor-associated immune infiltrate was assessed between groups using flow cytometry. Anti-PD1 mAb (250µg/mouse, 3 × 2 day interval) was initiated directly following morphine treatment. Co-administration of methylnaltrexone (MNTX), a peripheral OPRM1 antagonist used to confirm specificity and site of action of the morphine-induced effects. Finally, any direct effects of morphine on tumor cells were investigated in oral cancer cell lines using quantitative PCR and colorimetric proliferation assays. Morphine induced a 75±5% reduction in CD8+ T cells and a 90±3% reduction in CD19+ B cells in MOC1 compared to sham mice (n=6/group); morphine-induced immunosuppression was completely blocked with co-treatment of MNTX. Studies involving morphine administration prior to anti-PD1 treatment are currently underway but given the substantial suppression in infiltrating lymphocyte populations, efficacy is expected to be lessened. Lastly, Oprm1 expression was not detected at the mRNA level in mouse oral cancer cell lines. In vitro, 10µM morphine did not induce cell proliferation (proliferation relative to vehicle after 48hr; vehicle=100±8.3%, morphine=115.7±9.6%) or improve wound healing (wound closure after 24hr; vehicle=76.2±11.6%, morphine=78.5±11.4%). Taken together, our data suggest that morphine suppresses anti-tumor immunity via peripheral OPRM1 signaling in immune cells but not tumor cells. Further investigation is warranted to determine whether peripheral opioid blockade (i.e. MNTX) can slow tumor progression and improve response to cancer treatments while preserving centrally-mediated analgesia. Citation Format: Lisa A. McIlvried, Mona Yuan, Nicole L. Horan, Megan A. Atherton, Marci L. Nilsen, Dan P. Zandberg, Nicole N. Scheff. Opioid-mediated suppression of anti-tumor immunity via peripheral OPRM1 signaling in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-089.

A versatile genomic transgenesis platform with enhanced λ integrase for human Expi293F cells.

Reliable cell-based platforms to test and/or produce biologics in a sustainable manner are important for the biotech industry. Utilizing enhanced λ integrase, a sequence-specific DNA recombinase, we developed a novel transgenesis platform involving a fully characterized single genomic locus as an artificial landing pad for transgene insertion in human Expi293F cells. Importantly, transgene instability and variation in expression were not observed in the absence of selection pressure, thus enabling reliable long-term biotherapeutics testing or production. The artificial landing pad for λ integrase can be targeted with multi-transgene constructs and offers future modularity involving additional genome manipulation tools to generate sequential or nearly seamless insertions. We demonstrated broad utility with expression constructs for anti PD-1 monoclonal antibodies and showed that the orientation of heavy and light chain transcription units profoundly affected antibody expression levels. In addition, we demonstrated encapsulation of our PD-1 platform cells into bio-compatible mini-bioreactors and the continued secretion of antibodies, thus providing a basis for future cell-based applications for more effective and affordable therapies.

A phase 2 study of pembrolizumab after autologous stem cell transplantation in patients with T-cell non-Hodgkin lymphoma

AbstractAutologous stem cell transplantation (ASCT) is often used as consolidation for several subtypes of peripheral T-cell lymphoma (PTCL) in first remission. However, many patients relapse after ASCT and have a very poor prognosis. There are no approved treatment options for posttransplantation maintenance or consolidation in PTCL. PD-1 blockade has demonstrated some efficacy for patients with PTCL. We, therefore, conducted a phase 2 multicenter study of the anti–PD-1 monoclonal antibody pembrolizumab after ASCT in patients with PTCL in first remission. Pembrolizumab was administered at 200 mg IV every 3 weeks for up to 8 cycles within 21 days from post-ASCT discharge (and within 60 days of stem cell infusion). The primary end point was progression-free survival (PFS) at 18 months after ASCT. Twenty-one patients were treated in this study and 67% (n = 14) completed 8 cycles of treatment. Among all patients who were evaluable, 13 of 21 were alive and achieved PFS at 18 months after ASCT, meeting the study’s primary end point. The estimated 18-month PFS was 83.6% (95% confidence interval [CI], 68-100), and overall survival 94.4% (95% CI, 84-100). The toxicity profile was consistent with the known toxicity profile of pembrolizumab, with no grade 5 toxicities. In conclusion, PD-1 blockade after ASCT with pembrolizumab is feasible with a favorable safety profile and promising activity, supporting further confirmatory studies. This trial was registered at www.clinicaltrials.gov as #NCT02362997.

Efficacy and safety of donafenib combined with transcatheter arterial chemoembolization (TACE) and anti-PD1 antibody for the treatment of unresectable hepatocellular carcinoma (uHCC): A retrospective study.

e16120 Background: For unresectable hepatocellular carcinoma (uHCC), the efficacy of TACE monotherapy is not satisfactory. It has recently been reported that molecular targeted drugs combined with anti-PD1 antibody and TACE exhibit improved anti-tumor efficacy compared with monotherapy. Donafenib is a new generation of multi-kinase inhibitor which is approved as the first-line treatment for uHCC. This study aimed to explore the efficacy and safety of the combination therapy of donafenib, anti-PD1 monoclonal antibody and TACE in patients with uHCC. Methods: This was a single-center retrospective study, and involved patients with uHCC who received donafenib (200 mg po bid) combined with TACE and anti-PD1 monoclonal antibody or donafenib (200 mg po bid) combined with TACE at Shanghai Eastern Hepatobiliary Surgery Hospital from September 2021 to September 2022. All patients had at least one measurable lesion defined by mRECIST criteria. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) data of patients were collected and analyzed. Results: A total of 34 patients with uHCC were included and had a median age of 56 years (32–81 years). Of these patients, 3 (9%) were classed as BCLC stage B, 31 (91%) were BCLC stage C. All 34 patients were complicated with HBV infection. First-line treatment was administered to 24 patients (71%), among which 21 patients received donafenib combined with TACE and anti-PD1 antibody. 3 patients were treated with donafenib combined with TACE. The remaining 10 patients (19%) received second-line treatment, among which 7 patients were treated with donafenib combined with TACE and anti-PD1 antibody. 3 patients received donafenib combined with TACE. There were 14 patients (41%) with baseline AFP ≥400 ng/mL. At data cut-off, the median follow-up time was 5 months [95% CI: 3.42-6.58]. The best overall response rate (BOR) was complete response in 5 patients (14.7%), partial response in 13 patients (38.2%), stable disease in 10 patients (29.4%), and progressive disease in 6 patients (17.6%). The ORR was 52.9% (95%CI: 36.7–68.6%) and DCR was 82.4% (95%CI: 66.5–91.7%). The median PFS and median OS were not reached, the one-year PFS rate was 61.6% (95%CI: 38–78.7%), and the one-year OS rate was 83.1% (95%CI: 56.1–95.2%). The ORR (58%) and DCR (87.5%) of patients receiving first-line treatment were better compared with those of patients receiving second-line treatment (40% and 70%, respectively). Treatment-related adverse events (TRAE) were reported by 30 patients (88.2%), of which 7 patients (20.6%) had grade 3 TRAE. No grade 4 or 5 TRAE was reported. Conclusions: Donafenib combined with TACE and anti-PD-1 antibody exhibited encouraging efficacy and favorable safety profile in patients with uHCC.

Ribociclib (RIB) vs. palbociclib (PAL) in patients (pts) with hormone receptor-positive/HER2-negative/HER2-enriched (HR+/HER2-/HER2-E) advanced breast cancer (ABC): A head-to-head phase III study—HARMONIA SOLTI-2101/AFT-58.

TPS1125 Background: RIB and PAL are CDK4/6 inhibitors with demonstrated efficacy in terms of progression-free survival (PFS) and similar tolerability in pts with HR+/HER2- ABC when combined with endocrine therapy (ET). Only RIB has demonstrated a consistent, statistically significant, and clinically meaningful overall survival (OS) benefit across the MONALEESA (ML) phase III trials, while PALOMA trials failed to achieve similar outcome. Given effective treatments (Tx) may change underlying tumor biology (TB), it is hypothesized that RIB changes TB, enabling a better response to subsequent therapy and thus improving OS. RNA-based intrinsic subtyping reflects differences in TB and has strong prognostic and predictive value in HR+/HER2- ABC. Non-Luminal subtypes, as HER2-E and basal-like (BL), are relatively endocrine-resistant and have poorer prognosis than luminal. Tumors can switch subtypes over time to a more aggressive and less endocrine-responsive biology, which may also be reversed by effective Tx. A retrospective analysis of pooled data from ML 2/3/7 trials showed that HER2-E tumors had surprising benefit from RIB, while BL tumors did not. Pre/clinical data and indirect comparisons suggest that RIB may outperform PAL in HER2-E. Thus, choosing pts with HER2-E tumors as a means of a well defined TB with relative endocrine resistance provides the right setup for HARMONIA study to explore likely differential re-sensitization to endocrine therapy with RIB vs. PAL and ultimately testing which CDK4/6i prepares best for continued response and OS benefit. In addition, HARMONIA explores the value of earlier Tx with chemotherapy (paclitaxel) + anti PD-1 (tislelizumab) in pts with BL tumors to leverage learnings from treating ET-insensitive triple-negative BC. Methods: This is an international, multicenter, randomized, open-label, phase III study, using prospective pre-selection based on TB in pts with HR+/HER2- ABC, with HER2-E tumors (main cohort) and with BL tumors (exploratory cohort). HER2-E cohort will randomized pts 1:1 to RIB+ET (letrozole or fulvestrant) or PAL+ET. As per recent protocol amendment, BL cohort pts will be treated with paclitaxel plus tislelizumab, an anti PD-1 monoclonal antibody, pts may be offered to try RIB + ET first, and will remain eligible for paclitaxel + tislelizumab upon progression. Primary endpoint (EP): PFS per RECIST v1.1. Secondary EP: OS, PFS2, clinical benefit rate, duration and time to response, quality of life, and exploratory EP, including subtype switching between primary and metastatic tumor, and after trial Tx. Interim and primary EP analysis will be performed after 224 and 310 PFS events are observed (~80% power using one-sided 5% α). HARMONIA will recruit in Spain (55 sites), Portugal (5), and US (35) within SOLTI & AFT network. Clinical trial information: NCT05207709 .

KontRASt-01 update: Safety and efficacy of JDQ443 in KRAS G12C-mutated solid tumors including non-small cell lung cancer (NSCLC).

9007 Background: KRAS G12C oncogenic mutations occur in ~13% of NSCLCs and up to 4% of other solid tumors. JDQ443 is a selective, covalent, orally bioavailable KRASG12C inhibitor that irreversibly traps KRASG12C in the inactive, GDP-bound state. Clinical activity was seen in initial cohorts of patients (pts) treated with JDQ443 monotherapy, and 200 mg twice daily (BID) was selected as the recommended dose (RD) for expansion (Tan DS, et al. AACR 2022; Abstract CT033). Methods: KontRASt-01 (NCT04699188) is a Phase Ib/II, open-label, multicenter, dose-escalation (DEs), and dose-expansion (DEx) trial of JDQ443 as a monotherapy or in combination with TNO155 (SHP2 inhibitor) and/or tislelizumab (anti–PD-1 monoclonal antibody). Primary objectives of DEs are to assess safety/tolerability and identify the RD and regimens for future studies. The primary objective of DEx is to assess efficacy. Key inclusion criteria: advanced, KRAS G12C-mutated solid tumors; previous standard-of-care treatment; age ≥18 years; and ECOG PS 0–1. Prior KRASG12C inhibitor treatment is not permitted for the JDQ443 monotherapy arm and is allowed for the JDQ443 + TNO155 and JDQ443 + tislelizumab DEs arms. Results: As of Oct 28, 2022, 84 pts were treated with JDQ443 monotherapy, orally, continuously, in DEs, DEx, and food effect (FE) cohorts at 200 mg once daily (QD; n=10), 400 mg QD (n=11), 200 mg BID (n=56), and 300 mg BID (n=7). Median age was 61 years (range 26–83); median prior lines of therapy was 3 (range 1–7); and indications included NSCLC (n=38), colorectal cancer (n=42), and others (n=4). Median duration of exposure was 14.6 weeks (range 0.1–68.4) for all pts and 15.1 weeks (0.1–68.1) for pts treated at 200 mg BID. Among pts treated at 200 mg BID, 40 (71.4%) and 4 (7.1%) experienced treatment-related adverse events (TRAEs) of any grade (Gr) and of Gr 3, respectively. There were no Gr 4–5 TRAEs at any dose level. The most common TRAEs (any Gr, occurring in ≥10% of pts) at 200 mg BID were fatigue (17.9%), edema (14.3%), diarrhea (16.1%), nausea (16.1%), vomiting (10.7%), and peripheral neuropathy (10.7%). Gr 3 TRAEs were neutropenia in 2 pts, ALT and AST increase in 1 pt, and myalgia in 1 pt. One pt receiving 200 mg BID required a dose reduction due to a TRAE of Gr 2 peripheral neuropathy. Among response evaluable pts with NSCLC treated in DEs and FE cohorts, the confirmed overall response rate was 41.7% (10/24 pts) across dose levels and 54.5% (6/11 pts) at the RD of 200 mg BID. Combination JDQ443 + TNO155 and JDQ443 + tislelizumab arms are enrolling. Additional data will be available at the time of presentation. Conclusions: JDQ443 demonstrates an acceptable safety and tolerability profile at 200 mg BID, with clinical activity in pts with NSCLC. Enrollment is ongoing to the JDQ443 monotherapy DEx and the JDQ443 + TNO155 and JDQ443 + tislelizumab combination arms. Clinical trial information: NCT04699188 .

Efficacy and final safety analysis of pre- and co-administration of nivolumab (Nivo) with concurrent chemoradiation (CCRT) followed by Nivo maintenance therapy in patients (pts) with locally advanced cervical carcinoma (LACvCa): Results from the phase I trial, GOTIC-018.

5519 Background: LACvCa is associated with a poor prognosis, and CCRT is the standard treatment for LACvCa pts. Anti-PD1 monoclonal antibodies are associated with increased survival in recurrent or persistent CVCa pts; thus, Nivo may enhance antitumor immune responses. We previously reported that the addition of pre- and co-administration of Nivo was safe and feasible in the acute phase in pts with LACvCa who were treated with CCRT (GOTIC-018; JMA-IIA00425). Herein, we report the efficacy and final safety of GOTIC-018. Methods: The GOTIC-018 study was a multicenter, multi-cohort phase I study of Nivo plus CCRT in pts with LACvCa. The treatment plan in cohort A was co-administration of Nivo (240 mg/body once every 2 weeks) with CCRT followed by Nivo maintenance therapy for 52 weeks. The treatment plan in cohort B was pre-CCRT (two doses of Nivo before CCRT) followed by co-administration of Nivo with CCRT followed by Nivo maintenance therapy. Efficacy was evaluated using the RECIST v1.1. Tumor biopsies were obtained before treatment in each cohort and after two doses of Nivo in cohort B. Results: 30 pts (15 in each cohort) were enrolled between May 2019 and June 2021. There were one stage IVA, 11 stage IIIB, 16 stage II, and two stage IB2 tumors based on FIGO 2008. 28 squamous cell and 2 adenocarcinomas were included. 27 of the 30 tumors were positive for high-risk HPV, 14 were positive for PD-L1 TPS, and all tumors were microsatellite stable. The median follow-up was 15.2 months. The median number of Nivo cycles was 30 and 32 for cohorts A and B, respectively. 26 pts completed the study protocol, two discontinued Nivo due to AEs, and two withdrew their consent during the maintenance phase. Ten and eight pts in cohorts A and B, respectively, required Nivo interruption. The best overall response rates were 100% and 93.3% in cohorts A and B, respectively. A total of 73.3% of the pts achieved a complete response in each cohort. The 12-months progression-free survival rate was 100% of the evaluable 29 pts for each cohort. The most common grade ≥ 3 AEs were neutropenia (60.0 and 26.7% in cohorts A and B, respectively), followed by diarrhea (13.3 and 26.7%, respectively), and anemia (13.3 and 16.7%, respectively). Grade ≥ 3 irAEs were observed in two (13.3%) and one (6.7%) pts in cohorts A and B, respectively. The most common grade ≥ 3 irAEs were increased serum lipase levels in two pts. In addition, 6 of the 12 tumors that were PD-L1 TPS negative turned positive after two doses of Nivo in cohort B. Conclusions: The addition of pre- and co-administration of Nivo followed by Nivo maintenance therapy appears safe and shows encouraging efficacy in pts with LACvCa treated with CCRT. Pre-CCRT administration of Nivo may affect the tumor microenvironment. Clinical trial information: JMA-IIA00425 .