Efficacy Of Combination Therapy Research Articles

#1206 Combination therapy with Lisinopril and Dapagliflozin rescues GFR decline and glomerular damage in the KKAy mouse model of diabetic kidney disease

Abstract Background and Aims Male KKAy mice develop diabetic kidney disease (DKD) with progressive decline of GFR upon high fat diet feeding which is accelerated by the vasoconstrictor LNNA. In this study, efficacy of combination therapy with clinical relevant therapeutics in the form of an ACE-inhibitor (Lisinopril) and SGLT2-inhibitor (Dapagliflozin) on renal function and histopathology was investigated. Method Male KKAy mice underwent uninephrectomy (UNX). After recovery mice received high fat diet (45% LARD) and 50 mg/L LNNA in drinking water (wk0). At week 4, Lisinopril (2.5 mg/kg/day in drinking water) and at week 8 Dapagliflozin (5 and 20 mg/kg/day in diet) were started. Body weight, blood glucose, food and water intake and albuminuria were determined regularly. GFR was measured transdermally by FITC-sinistrin clearance. Mice were terminated at week 16 and renal histology was scored by a team of renal histopathologists. Non-induced and induced non-treated mice were used as controls. Results Treatment of KKAy mice on HFD+LNNA with Dapagliflozin reduced blood glucose immediately. Combination therapy with Lisinopril and Dapagliflozin (5 mg/kg/day) rescued the progressive GFR decline to levels seen in non-induced chow-controls (p < 0.05 vs UNX+HFD+LNNA). Pathology showed that the percentage of healthy glomeruli increased from 14% to 26% after combination therapy (Dapa 5). Interstitial fibrosis and tubular atrophy were significantly reduced by combination therapy (p < 0.05 vs UNX+HFD+LNNA). Conclusion Male KKAy mice on a HFD and LNNA developed DKD resulting in CKD. Combination therapy with Lisinopril and Dapagliflozin rescued GFR decline and reduced glomerular damage and interstitial fibrosis and tubular atrophy This indicates the clinical relevance of the model which can be used to study compound efficacy in both early and more advanced stages of DKD.

#1311 Cardiac damage in a multifactorial DKD/CKD mouse model resembles HFpEF and can be reduced by standard-of-care treatment

Abstract Background and Aims We developed a diet-induced hypertension-accelerated mouse model of diabetic kidney disease characterized by progressive loss of GFR resulting in chronic kidney disease. Since cardiovascular disease is the major cause of death in CKD, we characterized the functional and structural cardiac damage in this model. Additionally, we studied the efficacy of combination therapy with an ACE-inhibitor (Lisinopril) and SGLT2-inhibitor (Dapagliflozin) on cardiac histopathology. Method Male KKAy mice underwent uninephrectomy. After recovery mice received high fat diet (45% LARD) and drinking water with or without 50 mg/L LNNA (wk0). At 12 weeks, imaging was performed to study cardiac function and mice were terminated at week 13. In the intervention study, at week 4, lisinopril (2.5 mg/kg/day; drinking water) and at week 8 dapagliflozin (5 and 20 mg/kg/day; foodadmix) treatment were started. At week 16 mice were terminated and lung and heart weight and cardiac histology were determined. Results Upon termination, macroscopic evaluation of the hearts showed extensive scar tissue formation on the outside of the left ventricle. Histological evaluation showed the presence left ventricular hypertrophy, coronary calcification and myocardial fibrosis in male KKAy mice with UNX, HFD and LNNA. KKAy mice with UNX and HFD but without LNNA also showed myocardial fibrosis, monocyte infiltration and focal mineralization. Imaging showed preserved ejection fraction, a significant reduction, increased left ventricle posterior wall thickness and decrease left ventricle inner diameter. Treatment with combination therapy reduced lung wet weight, significantly reduced heart weight and significantly decreased cardiac fibrosis. Macroscopically, less scar tissue was observed after treatment. Conclusion This multifactorial mouse model shows cardiac damage on a background of hypertension, diabetes, renal dysfunction and obesity. Functional measurement including preserved ejection fraction, left ventricle hypertrophy, diastolic dysfunction and increased fibrosis resembling the clinical HFpEF phenotype. Combination therapy with Lisinopril and Dapagliflozin reduced cardiac weight and cardiac fibrosis. This indicates cardiac involvement in the DKD mouse model which confirms that this multifactorial model is clinically relevant.

Abstract B011: Predictable successes: drug additivity explains the efficacy of combination therapies for metastatic urothelial cancer

Abstract Objective: Combination drug regimens have changed the treatment landscape of metastatic urothelial cancer (mUC) and other cancers and are integrated into routine clinical practice. Combination drug regimens may impact cancer outcomes via three major pharmacologic principles: less-than-additive, additive, or more-than-additive efficacy (i.e., synergy). Despite the profound implications of these types of interactions on future drug and biomarker development, as well as on treatment sequencing, these principles have been underexplored in contemporary clinical trials. Here we analyze recent phase 3 trials in locally advanced or metastatic UC to assess whether progression-free survival (PFS) distributions of combination therapies with immune checkpoint inhibitors (ICIs) are lesser than, greater than, or equal to the additive effect expected based on single-agent efficacies. Methods: We analyzed phase 3 trials in locally advanced or metastatic UC including EV302, CheckMate 901, KEYNOTE-361, DANUBE, and IMvigor130. When one monotherapy was not included as an arm in the phase 3 trial, we utilized monotherapy PFS distributions from trials in patients with metastatic UC including EV103, KEYNOTE-045, CheckMate 275, and HCRN-GU17-294. The expected additive effect of a drug combination was calculated by adding the PFS durations of individual drugs, sampled from monotherapy distributions, as recently described for other approved oncology drug combinations (Hwangbo et al, Nature Cancer, 2023). Results: Combination therapies with ICIs were as clinically effective as predicted by additivity, or less so in one case. Specifically, Pembrolizumab plus Enfortumab vedotin (EV302), Nivolumab plus Gemcitabine/Cisplatin (CheckMate 901), Pembrolizumab plus chemotherapy (KEYNOTE-361), and Durvalumab plus Tremelimumab (DANUBE) each exhibited PFS distributions that were statistically indistinguishable from PFS predicted by the additivity model (Cox Proportional Hazards). Atezolizumab plus chemotherapy (IMvigor130) was inferior to additivity. Subgroup analyses by PD-L1 expression and by cisplatin versus carboplatin will be presented. Conclusions: Life-prolonging treatments for mUC have been the result of additive combination therapies, wherein the efficacy of the drug combination is quantitatively explained by the individual efficacies of the component drugs. Additivity in this setting has several potential implications: (1) when a single-agent is principally active in a biomarker-defined subpopulation, the use of that agent in a combination will also principally improve outcomes in that subpopulation; (2) net duration of disease control may be similar between up-front combination and sequential use of the same drugs; assuming that the biology of disease at progression does not preclude the ability to receive subsequent lines of therapy, and (3) future drug development should prioritize combinations based on highly active single agents rather than solely based on hypothesized mechanistic rationale. Citation Format: Noah M. Schlachter, Eric J. Miller, Jonathan F. Anker, Matthew D. Galsky, Adam C. Palmer. Predictable successes: drug additivity explains the efficacy of combination therapies for metastatic urothelial cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B011.

Protein tyrosine phosphatases: emerging role in cancer therapy resistance.

Tyrosine phosphorylation of intracellular proteins is a post-translational modification that plays a regulatory role in signal transduction during cellular events. Dephosphorylation of signal transduction proteins caused by protein tyrosine phosphatases (PTPs) contributed their role as a convergent node to mediate cross-talk between signaling pathways. In the context of cancer, PTP-mediated pathways have been identified as signaling hubs that enabled cancer cells to mitigate stress induced by clinical therapy. This is achieved by the promotion of constitutive activation of growth-stimulatory signaling pathways or modulation of the immune-suppressive tumor microenvironment. Preclinical evidences suggested that anticancer drugs will release their greatest therapeutic potency when combined with PTP inhibitors, reversing drug resistance that was responsible for clinical failures during cancer therapy. This review aimed to elaborate recent insights that supported the involvement of PTP-mediated pathways in the development of resistance to targeted therapy and immune-checkpoint therapy. This review proposed the notion of PTP inhibition in anticancer combination therapy as a potential strategy in clinic to achieve long-term tumor regression. Ongoing clinical trials are currently underway to assess the safety and efficacy of combination therapy in advanced-stage tumors.

Safety and Efficacy of Combination Therapy of Upadacitinib and Biologic Agents for Treatment-Resistant Psoriasis and Psoriatic Arthritis

Importance: Although there are many available treatments for psoriasis and psoriatic arthritis (PsA), there are patients resistant to standard conventional therapy. For these patients, combination therapy of biologic agents and upadacitinib may be a viable alternative option; however, there is limited data on concomitant usage. Objective: To evaluate the safety and efficacy of combination therapy of upadacitinib and biologic agents for the treatment of refractory psoriasis and psoriatic arthritis. Design: We report the results of a retrospective chart review of 3 patients in a single practice treated with a combination of upadacitinib and biologics for psoriasis and PsA. The risks, benefits, and safety warnings of combination therapy of upadacitinib and biologic agents were discussed before initiation. After shared decision-making with the provider, patients were placed on a trial of combination therapy. Results: All three patients, previously refractory to monotherapy, experienced significant improvement of their symptoms while on combination therapy. No adverse reactions (malignancy, cardiovascular events, venous thromboembolism) occurred during treatment. However, one patient experienced a shingles outbreak and diverticulitis while on combination treatment. Further studies are needed to determine long-term efficacy with a larger sample size.

Prediction of combination therapy efficacy in patients with locally advanced squamous cell oropharyngeal carcinoma

Background. Oropharyngeal squamous cell carcinoma (OPSCC) is characterized by late-stage diagnosis and high rate of mortality. Combined modality treatment including preoperative chemoradiotherapy (CRT) is the standard of care for OPSCC. The search for criteria for predicting the efficacy of preoperative chemoradiotherapy with a view to prescribe it to those patients for whom it is really indicated and will be effective remains challenging. The aim of the study was to identify serum actin-binding proteins that can predict preoperative therapy efficacy in patients with OPSCC. Material and methods. Blood serum from 45 patients with stage II–IV OPSCC was studied. all patients received preoperative chemotherapy with paclitaxel and carboplatin. Radiation therapy in a standard mode was given 2 weeks after chemothetapy. serum levels of actin-binding proteins (CAP1, fascin, ezrin, gelsolin, and profiling) were determined before treatment using ELISA. Results. complete or partial response to preoperative CRT was achieved in 27 patients. Disease progression or stabilization was observed in 18 patients. A comparison of the serum levels of actin-binding proteins before treatment with those obtained after preoperative CRT showed that the serum level of ezrin was lower in patients who did not respond to preoperative CRT than in patients with partial or complete response to therapy. ROC-analysis showed that the serum level of ezrin of less than 2.50 ng/ml can predict the tumor response to CRT as unfavorable (less than 75 % according to the RECIST scale). The sensitivity was 72 % and the specificity was 71 %. Conclusion. Determination of the serum level of ezrin in patients with OPSCC has a predictive value in relation to preoperative chemoradiotherapy.

Recurrent cystitis: how to achieve perfection in treatment?

Introduction. Urinary tract infections are the second most common type of bacterial infections worldwide. Treatment of patients with chronic (recurrent) cystitis remains challenging and requires an individual approach.Aim. To assess the efficacy of combined therapy for exacerbation of chronic cystitis.Materials and methods. A total of 65 women aged 18–48 years were enrolled in an open comparative bidirectional study. All participants received antibacterial therapy for exacerbation of chronic cystitis in accordance with the clinical guidelines for the treatment of cystitis in women. After the therapy was completed, the comparison group (35 patients) did not receive any drugs, whereas 30 patients from the treatment group were prescribed Cystenium II biologically active dietary supplement at a dose of 1 orally disintegrating tablet twice daily for 2 weeks. The examination included a measurement of the severity of complaints using the Acute Cystitis Symptom Score (ACSS), a clinical urinalysis and urine culture + sensitivity test. The efficacy of treatment was assessed following completion of antibiotic therapy and two weeks after the therapy.Results. After finishing antibiotic treatment, no patient has achieved full recovery (improvement of urinalyses, no growth of pathogenic microbial flora, no complaints). Both groups showed statistically significant decreases in ACSS scores on Visit 2. Over the following two weeks, the symptoms in the comparison group did not change (p > 0.05), and in the treatment group the sum of scores continued to decrease, reaching an average of 3.62 ± 0.42, which is 5.5 times less than the baseline level and almost 3 times less than the sum of scores following completion of antibacterial therapy (p < 0.05). The positive changes in leukocyturia and bacteriuria were also more pronounced in the treatment group.Conclusion. After completion of antibiotic therapy for relapse of chronic (recurrent) cystitis, the patients usually have residual effects that cannot be regarded as presentations of an active disease, but they disturb patients. A two-week course of pathogenetic therapy with a combination drug containing A-type Vaccinium macrocarpon proanthocyanidins, vitamin C and D-mannose to be received as the second step can increase the efficacy of treatment.

Bibliometric analysis of artemisinin combination therapy efficacy publications on SCOPUS and PUBMED databases

In line with research efforts towards malaria control and eradication, this study was proposed to provide a bibliometric summary of research output on ACT resistance/ therapeutic efficacy. Keywords related to ACT efficacy were used to retrieve literature using the PUBMED and SCOPUS databases. In total we obtained 7082 and 3031 journal articles were retrieved from the databases respectively. The number of publications on SCOPUS was within the same range of 310-370 except for 2023 which recorded only 207 publications, while for PUBMED, publications showed a noticeable increase between 2006 and 2015. The malaria journal was well represented in both databases with 195, 2.7% appearance in PUBMED and 588, 19.4% in SCOPUS. Although it was the most productive journal in SCOPUS, in PUBMED we had BMC medicine (333, 4.7%). Publications in SCOPUS recorded an average yearly citation of 13.8, further individual analysis showed that 533, 7.5% of publications were cited eleven to twenty times, followed closely by 525,7.4% of the publications with six to 10 citations. Analysis of Author contribution showed majority of publications in the authorship of 6 and above.

A retrospective study of combination therapy with glucocorticoids and pirfenidone for PD-1 inhibitor-related immune pneumonitis.

Immune checkpoint inhibitor pneumonitis (ICIP) is thought to be a self-limiting disease; however, an effective treatment option does not currently exist. This study aimed to determine the clinical efficacy of combination therapy with glucocorticoids and pirfenidone for ICIP related to programmed cell death protein-1 (PD-1) inhibitors. We conducted a retrospective analysis of 45 patients with advanced non-small cell lung cancer who developed ICIP following PD-1 inhibitor and albumin-bound paclitaxel or carboplatin treatment at our hospital. The PD-1 inhibitor was discontinued, and glucocorticoids were used alone or in combination with pirfenidone to treat ICIP. The relevant clinical data of these patients were collected and analyzed. Compared with the glucocorticoid alone group, the glucocorticoid-pirfenidone group showed significant improvement in forced vital capacity (FVC), carbon monoxide diffusing capacity [%], peripheral capillary oxygen saturation, and 6-minute walk distance (P < .05). There were benefits with respect to the St. George's Respiratory Questionnaire score and the recurrence rate of ICIP, but there was no significant difference between the 2 groups (P > .05). Adding pirfenidone to glucocorticoid treatment was shown to be safe and may be more beneficial than glucocorticoids alone for improving pulmonary interstitial lesions, reversing ICIP, and preventing its recurrence.

Fcγ-Receptor-Independent Controlled Activation of CD40 Canonical Signaling by Novel Therapeutic Antibodies for Cancer Therapy.

The activation of CD40-mediated signaling in antigen-presenting cells is a promising therapeutic strategy to promote immune responses against tumors. Most agonistic anti-CD40 antibodies currently in development require the Fcγ-receptor (FcγR)-mediated crosslinking of CD40 molecules for a meaningful activation of CD40 signaling but have limitations due to dose-limiting toxicities. Here we describe the identification of CD40 antibodies which strongly stimulate antigen-presenting cells in an entirely FcγR-independent manner. These Fc-silenced anti-CD40 antibodies induce an efficient upregulation of costimulatory receptors and cytokine release by dendritic cells. Finally, the most active identified anti-CD40 antibody shows activity in humanized mice. More importantly, there are no signs of obvious toxicities. These studies thus demonstrate the potent activation of antigen-presenting cells with anti-CD40 antibodies lacking FcγR-binding activity and open the possibility for an efficacious and safe combination therapy for cancer patients.

Association of metabolomics with PD-1 inhibitor plus chemotherapy outcomes in patients with advanced non-small-cell lung cancer

BackgroundCombining immune checkpoint inhibitors (ICIs) with chemotherapy has become a standard treatment for patients with non-small cell lung cancer (NSCLC) lacking driver gene mutations. Reliable biomarkers are essential for predicting...

Combination of the Topical Photodynamic Therapy of Chloroaluminum Phthalocyanine Liposomes with Fexinidazole Oral Self-Emulsifying System as a New Strategy for Cutaneous Leishmaniasis Treatment.

Cutaneous leishmaniasis (CL) is a neglected tropical disease. The treatment is restricted to drugs, such as meglumine antimoniate and amphotericin B, that exhibit toxic effects, high cost, long-term treatment, and limited efficacy. The development of new alternative therapies, including the identification of effective drugs for the topical and oral treatment of CL, is of great interest. In this sense, a combination of topical photodynamic therapy (PDT) with chloroaluminum phthalocyanine liposomes (Lip-ClAlPc) and the oral administration of a self-emulsifying drug delivery system containing fexinidazole (SEDDS-FEX) emerges as a new strategy. The aim of the present study was to prepare, characterize, and evaluate the efficacy of combined therapy with Lip-ClAlPc and SEDDS-FEX in the experimental treatment of Leishmania (Leishmania) major. Lip-ClAlPc and SEDDS-FEX were prepared, and the antileishmanial efficacy study was conducted with the following groups: 1. Lip-ClAlPc (0.05 mL); 2. SEDDS-FEX (50 mg/kg/day); 3. Lip-ClAlPc (0.05 mL)+SEDDS-FEX (50 mg/kg/day) combination; 4. FEX suspension (50 mg/kg/day); and 5. control (untreated). BALB/c mice received 10 sessions of topical Lip-ClAlPc on alternate days and 20 consecutive days of SEDDS-FEX or FEX oral suspension. Therapeutical efficacy was evaluated via the parasite burden (limiting-dilution assay), lesion size (mm), healing of the lesion, and histological analyses. Lip-ClAlPc and SEDDS-FEX presented physicochemical characteristics that are compatible with the administration routes used in the treatments. Lip-ClAlPc+SEDDS-FEX led to a significant reduction in the parasitic burden in the lesion and spleen when compared to the control group (p < 0.05) and the complete healing of the lesion in 43% of animals. The Lip-ClAlPc+SEDDS-FEX combination may be promising for the treatment of CL caused by L. major.

Comparison of Efficacy and Safety of Different Second-line Therapies for Patients With Advanced Thymic Carcinoma

AimsThymic carcinoma (TC) is a rare form of highly invasive tumors. Currently, the standard first-line therapy involves paclitaxel plus carboplatin treatment, while the recommended regimen for second-line therapy remains uncertain. The purpose of this study is to explore the second-line mode of TC patients. Materials and methodsWe evaluated the outcome of subjects with advanced TC between 2009 and 2023 in three medical centers, retrospectively. Tumor response was evaluated according to the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). Kaplan-Meier was used for calculating Progression-free survival (PFS) and overall survival (OS). The factors affecting survival in the real world were evaluated by Cox analysis. ResultsTotally 136 patients were included in this study, the median PFS (mPFS) for all subjects was 5.97 months, and the median OS (mOS) was 25.03 months. According to patient's treatment modes, they are divided into monotherapy (n = 95) and combination therapy (n = 41), PFS manifested the difference between two groups (5.17 vs. 9.00 months, P = 0.043). OS also indicated a significant distinction (22.50 vs. 38.00 months, P = 0.017). Furthermore, there was a significant difference in PFS between patients using immunotherapy combined with chemotherapy and those with antivascular therapy (8.57 vs. 13.10 months, P = 0.047). ConclusionIn the second-line therapy for advanced TC, the efficacy of combination therapy was better than monotherapy, especially for immunotherapy combined with antivascular therapy.

Levodopa And Pramipexole Combination Therapy Efficacy In Vietnamese Patients With Parkinson’s Disease: A Randomized Controlled Trial

Early diagnosis and appropriate treatment of Parkinson's disease to minimize the adverse effects of the disease and drug side effects on the patient. Using levodopa combined with pramipexole is an effective therapy for treating Parkinson's disease. Objectives — This study aims to evaluate the treatment outcome of combination therapy with levodopa and pramipexole compared to levodopa monotherapy in Vietnamese Parkinson's patients. Material and Methods — A randomized controlled clinical trial with a 1:1 randomized ratio of 80 individuals with Parkinson's disease. The intervention group received a combination therapy with levodopa/benserazide and pramipexole, and the control group received a monotherapy with levodopa/benserazide. Motor symptoms, non-motor symptoms, The Unified Parkinson's Disease Rating (UPDRS), and The Parkinson's Disease Questionnaire (PDQ-39) scores were assessed before, after, and a follow-up period of 1 and 4 weeks after discharge to evaluate the treatment outcome. Results — Combining therapy with levodopa and pramipexole led to statistically significant improvements in UPDRS and PDQ-39 scores (p&lt;0.05). The mean difference in UPDRS parts I, II, and III after 4 weeks of discharge was -0.5 (p=0.014), -1.68 (p=0.005), and -2.52 (p=0.010) respectively. The quality of life was also enhanced by combining therapy due to a better reduction of PDQ-39 score: 26.0±6.3 versus 32.7±6.4 (p&lt;0.001). The most common side effects were headache, nausea/vomiting, and somnolence. Conclusions — Treatment with levodopa combined with pramipexole improves clinical symptoms and quality of life in patients with Parkinson's, as evidenced by improvements in UPDRS and PDQ-39 scores.

Abstract 721: Novel and distinctive anti-HLA-G antibody, IMB-201, inhibits tumor progression by breaking immune escape mechanism and enhancing cytotoxicity

Abstract Human leukocyte antigen-G (HLA-G), a type of MHC class I, is known to be expressed only in the placenta and acts as an immune suppressor to protect the fetus from maternal immunity. Recent studies have revealed that HLA-G suppresses various tumor-infiltrated immune cells, such as T cells, NK cells, and macrophages, through interaction with inhibitory receptors Ig-like transcript 2 (ILT2). HLA-G has recently emerged as an attractive anticancer target because HLA-G is a highly specific tumor antigen and has a role in immune evasion of cancer cells. Additionally, the expression pattern of ILT2 differs from that of PD-1 in tumor-infiltrated CD8+ T cells. Therefore, an HLA-G targeting strategy is expected to be an alternative to address unmet medical needs for those not responding to anti-PD(L)1 therapies. In this study, we screened the novel anti-HLA-G antibody, IMB-201, using phage display technique and confirmed that IMB-201 selectively bound to the membrane HLA-G of cancer cells. It exhibited superior activities in ILT2 blockade, NK cell activation, and antibody-dependent cellular cytotoxicity (ADCC) compared to the reference antibody. Furthermore, IMB-201 demonstrated more efficient suppression of tumor growth compared to the reference antibody in subcutaneous gastric cancer xenograft model. Notably, the group administered IMB-201 with NK92MI cells (CD16-negative NK cells) in the ovarian cancer xenograft model showed stronger tumor growth inhibition compared to the group treated only IMB-201, indicating that NK92MI cells were activated by IMB-201. This result indicates that one of the mechanisms of action (MoA) of IMB-201 worked effectively in vivo. In addition, to maximize the efficacy of IMB-201 and differentiate it from competitors, various efficacy enhancing modality could be applicable. We aim to develop biopharmaceuticals by selecting the optimized modality. Based on these results, IMB-201 could overcome the limitations of existing cancer immunotherapy, potentially becoming highly influential in cancer treatment as a novel immune checkpoint inhibitor. It is also expected to exhibit higher anticancer efficacy in combination therapy with immune checkpoint inhibitors. Citation Format: Hyeonju Kang, Seungil Baek, Inyoung Lee, Manseok Ju, Seonggu Han, Eunjung Han, Sungmuk Kang, Jihye Koo, Yoojin Kim, Suho Park, Eunyoung Cho, Chungmin Lee, Gyongsik Ha. Novel and distinctive anti-HLA-G antibody, IMB-201, inhibits tumor progression by breaking immune escape mechanism and enhancing cytotoxicity [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 721.

Abstract 5306: PTPN22 targeting partners with 41BB/OX40 costimulation to overcome anti-PD1 resistance in pancreatic ductal adenocarcinoma

Abstract Background: The pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment (TME) is notable for a scarcity of cytotoxic T cells and an overabundance of immunosuppressive myeloid and regulatory T cells. Checkpoint immunotherapies targeting PD/L1 or CTLA4 have shown efficacy in immunogenic cancers but remain ineffective in PDAC, highlighting a need for novel approaches. Abrogating protein tyrosine phosphatase non-receptor type 22 (PTPN22), a phosphatase in the TCR signaling cascade, has been shown to modulate multiple mechanisms of immune resistance. Furthermore, 41BB costimulatory pathway has recently been investigated as a potential strategy to enhance immunotherapy against PDAC. Using immune-resistant murine models of PDAC, we investigated PTPN22 as an immunotherapeutic target in combination with 41BB co-stimulation and PD1 inhibition against PDAC. Methods: We employed a well-characterized murine PDAC cell line expressing mutant KrasG12D and Trp53R172H under the Pdx1-cre promoter (KPCY 6419c5). This tumor line is resistant to combination immuno- and chemotherapies. To determine treatment efficacy, PTPN22 deficient mice (KO) were inoculated with KPCY6419c5 cells either subcutaneously or orthotopically into the pancreas. To extend the translatability of PTPN22 targeting, we also injected PTPN22 competent mice with the same tumor cells and treated them with our novel PTPN22 inhibitor L1. Harvested tumors were processed for FFPE and mass cytometry (CyTOF) analysis to track changes in the immune compartment. Results: When PTPN22 was abrogated, treatment with anti-PD1 and 41BB agonism led to a 10-day delay in substantial tumor formation and roughly 75% reduction in tumor volume by 21-days post treatment. These tumors showed elevated levels of OX40 and OX40L primarily in the setting of PTPN22 KO/PD1/41BB therapy. In a subsequent in vivo experiment using an OX40L neutralizing antibody, we found that OX40 signaling is essential for the efficacy of PTPN22 KO/PD1/41BB therapy. Furthermore, combining OX40 agonist with anti-PD1 in PTPN22 KO sufficiently mimicked the efficacy seen with the anti-PD-1 and 41BB combination. CyTOF analysis indicated that OX40 expression is enriched in Tregs and OX40L is enriched in myeloid derived suppressor cells (MDSCs). Moreover, combination therapy efficacy was reproduced using the PTPN22 inhibitor L1. Conclusions: PTPN22 abrogation enhances the success of PD-1 inhibition given with either OX-40 or 41BB agonist therapies. In addition, PTPN22 abrogation together with PD1 inhibition and 41BB costimulation reduces MDSC and Treg suppression of effector T cells via the OX40L-OX40 axis. Finally, PTPN22 can be blocked by a small molecule inhibitor strengthening its candidacy as a therapeutic target. Citation Format: Soren Charmsaz, Nicole E. Gross, Jae W. Lee, Jianping Lin, Alexei G. Hernandez, Erin M. Coyne, Sarah M. Shin, Courtney Cannon, Xuan Yuan, Zhong-Yin Zhang, Elizabeth M. Jaffee, Won Jin Ho. PTPN22 targeting partners with 41BB/OX40 costimulation to overcome anti-PD1 resistance in pancreatic ductal adenocarcinoma [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 5306.

Abstract 167: Modulation of PD-1/PD-L1 by simvastatin in TNBC and macrophages and its impact on the efficacy of immunotherapy

Abstract Introduction: Statins, known as inhibitors of HMG-CoA, not only reduce cholesterol but also exhibit pleiotropic effects which include anti-tumor activities by targeting tumor microenvironments. They inhibit the synthesis of FPP and GGPP, which is important for prenylation of signaling proteins. Although PD-1/PD-L1 inhibitors has been approved for treatment for TNBC patients with PD-L1 positive, the response remains unsatisfactory. Also, it has been reported that statins affect PD-L1 expression in other tumors, but it is still uncertain in TNBC. Therefore, we aimed to identify the effect of statins on the expression of PD-L1 in TNBC and to verify the efficacy of combination therapy with statins and immune checkpoint inhibitors. Methods: Human and mouse TNBC cell lines, mouse macrophage cell line (RAW 264.7), and clinically approved simvastatin were used. Flow cytometry, western blot, proliferation assay, qRT-PCR, immune phenotyping and immunohistochemistry were conducted. A co-culture of macrophages and cancer cells was performed. An orthotopic syngeneic mouse model by injection of EMT6 cells into mammary gland fat pad were produced. Mice were treated with simvastatin(20mg/kg) by oral gavage daily and anti-PD-1(200μg) by intraperitoneal injection two times per week. Results: Among thirteen human TNBC cell lines, we confirmed that TNBC cell lines showed various PD-L1 expression, and especially MDA-MB-231 and HCC38 highly expressed endogenous/constitutive PD-L1. Statins reduced PD-L1 expression and exerted anti-proliferative effects in MDA-MB-231, HCC38, and EMT6 in a dose- and time-dependent manner. Phosphorylation of AKT and STAT3 was reduced when simvastatin was treated. Mice with combination therapy of anti-PD-1 and simvastatin had less effective inhibitory effect on tumor growth than mice with anti-PD-1 monotherapy, which showed the highest tumor suppression effect. In immune phenotyping, tumor-infiltrated T cells did not have significant differences among groups. However, M1:M2 macrophage ratio was highest in anti-PD-1 group but decreased in combination therapy group with simvastatin. To determine the effect of simvastatin on macrophages, RAW264.7 cells were stimulated with MDA-MB-231 conditioned medium, revealing an upregulation of PD-1 expression. Conclusions: Our findings show that simvastatin has an anti-tumor effect, which reduces Pd-L1 expression and kills breast cancer cells, reducing phosphorylation of STAT3 and AKT. However, when combined with PD-1 checkpoint inhibitor, it reduces the anti-tumor effect by increasing PD-1 expression in macrophages and promoting M1 to M2 polarization. Further study is needed to demonstrate the mechanism by which simvastatin regulate polarization of macrophages and to confirm the polarization of macrophages in samples of TNBC patients who had been taking simvastatin. Citation Format: Sangeun Lee, Ju Hee Kim, A Young Park, Jihong Baik, Ji-Jung Jung, Han-Byoel Lee, Wonshik Han. Modulation of PD-1/PD-L1 by simvastatin in TNBC and macrophages and its impact on the efficacy of 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 167.

Abstract 5340: NK-humanized mouse models for the in vivo evaluation of NK cell-based therapies in solid tumors

Abstract Novel immunotherapeutic strategies targeting Natural Killer (NK) cells using monoclonal or multi-specific antibodies and immune modulator molecules are under development and suitable mouse models are needed to evaluate these therapeutics. We developed and characterized robust in vivo models that allow the engraftment and long-term maintenance of fully functional human NK (huNK) cells in immunodeficient transgenic mice for human cytokines (IL15). In efficacy studies, we confirmed that huNK cells are recruitable by NK cell-based therapies including therapeutic antibodies or multi-specific biologics and able to control tumor growth in these models.To establish a more relevant model for better clinical translatability for Fc-competent therapeutics evaluation, we optimized the model by validating a mouse strain with a functional knock-out of murine Fcγ receptors (FcgR-KO) to minimize the confounding impact of mouse immune cells. We characterized huNK cells kinetics and profile by flow cytometry compared to NOG-huIL15 mice. In efficacy studies with the FcgR-KO strain, therapeutic antibodies are inactive in non-NK-humanized mice, whereas in NK-humanized mice huNK cells can be recruited by the therapeutic antibody to control tumor growth by ADCC, in B cell lymphoma or multiple myeloma bearing mice.We also report the development of NK-humanized models for the evaluation of NK-based therapies in solid tumors. We characterized huNK intratumoral infiltration in several subcutaneous tumor xenograft models and evaluated the impact of tumor environment on the expression of functional NK markers (NKp46, NKG2D, Tim3, CD69) by flow cytometry and IHC studies.In summary, we have developed and optimized robust murine models sustaining fully functional huNK cells that can be proficiently recruited in vivo by various NK-based therapeutics. These models can also be used to evaluate the efficacy of combination therapies. Citation Format: Pauline Rettman, Samira Benhamouche-Trouillet, Michel Pelat, Katarzyna Franciszkiewicz, Georges Azar, Lydia Blot, Loreley Calvet, Sukhvinder Sidhu, Céline Nicolazzi. NK-humanized mouse models for the in vivo evaluation of NK cell-based therapies in solid tumors [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 5340.

Abstract 2534: Single-cell dissection of heterogeneity and dynamics of tumor ecosystem upon immune-checkpoint blockade in hepatocellular carcinoma

Abstract Background: Therapy-induced alteration of tumor ecosystem poses a major barrier for cancer regression. As the majority of patients with hepatocellular carcinoma (HCC) develops resistance to immune checkpoint blockade (ICB) therapy, we aimed to characterize heterogeneity and dynamics of multicellular tumor ecosystem following anti-PD-1 treatment using scRNA-seq. Methods: In a phase II clinical trial of pembrolizumab on advanced hepatitis B virus-related HCC patients (NCT03419481), we performed a comprehensive single-cell transcriptomic profiling of biopsy samples from 26 patients before and during treatment. The composition and distribution of immune aggregates in responsive tumors was characterized by scRNA-seq and spatial transcriptome analyses. The anti-tumor efficacy of combined therapy with anti-PD-1 and inhibition of immunosuppressive macrophage were further determined in RIL-175-derived PD-1-resistant mouse model. Results: After initial data processing and quality control, we obtained 353,329 high-quality cells that included tumor cells, myeloid cells, lymphoid cells, endothelial cells and fibroblasts. Our analysis revealed that baseline tumor-reactive CD8+T cells exhibited a strong association with improved prognosis. Notably, treatment-induced expansion and differentiation of tumor-reactive CD8+T cells with memory-like phenotype highly correlated with durable ICB response. Moreover, we observed a co-occurrence pattern of key anti-tumor immune subsets in the tumor microenvironment (TME), which associated with ligand-receptor pair interactions. Spatial transcriptome analysis further validated the presence of immune aggregates in responsive tumors. Importantly, we derived an responsive signature from immune aggregates, which showed a strong association with improved prognosis in pan-cancer ICB datasets. Paired comparisons of pre- and on-treatment macrophage percentages in non-responders revealed a specific expansion of an immunosuppressive macrophage subset. Inhibition of this macrophage subset could overcome ICB resistance by enhancing T cell function in our PD-1 resistant model. We further observed that a tumorous epithelial-mesenchymal transition (EMT) program might contribute to therapeutic resistance via TME remodeling. Conclusions: Our study suggests that tumor-reactive CD8+T cells and immune aggregates may be associated with durable ICB response, while ICB-induced upregulation of immunosuppressive macrophages and EMThi tumor cells contributed to therapeutic evasion. These findings provide valuable insights for identification of predictive biomarkers and therapeutic strategies for ICB therapy of HCC. This project is supported by the General Research Fund (14119023, 14120621 and 14115820), the Li Ka Shing Foundation, and the CUHK Strategic Seed Funding for Collaborative Research Scheme. Citation Format: Alfred S. L. Cheng, Zhewen Xiong, Haoran Wu, Jianquan Cao, Zhixian Liang, Jingying Zhou, Joseph Jao-Yiu Sung, Kevin Yip, Stephen Chan. Single-cell dissection of heterogeneity and dynamics of tumor ecosystem upon immune-checkpoint blockade in hepatocellular carcinoma [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 2534.

Abstract 2640: HBI-2375, a first-in-class IND ready selective MLL1-WDR5 inhibitor, retains desirable preclinical characteristics in solid tumors and in leukemias to be pursued in clinical studies

Abstract MLL1 (mixed lineage leukemia1) interaction with WDR5 (WD repeat domain 5) is critical for its histone methyl transferase (HMT) activity leading to transcriptional regulation of gene expression. MLL1 dysregulation such as its translocation at chromosome 11q23 results in generation of MLL1 fusion genes and leukemia development. Additionally, recent studies indicated a role for MLL1-WDR5 interaction in solid tumors progression via directly affecting cancer cells or by suppression of tumor immunity. Therefore, MLL1-WDR5 interaction is an important target in the discovery of anti-cancer drugs for both leukemia and solid tumors. We recently identified HBI-2375 as a selective inhibitor of MLL1-WDR5 interaction. HBI-2375 showed potent inhibition of WDR5 (IC50: 4.48nM) in biochemical assay and inhibited MV4-11 cellular proliferation (average IC50: 3.17µM) in CTG assays. In addition, HBI-2375 was stable in liver S9 and whole blood, with moderate to high plasma protein binding rates in multiple species, and acceptable hERG (IC50: 17µM). Furthermore, HBI-2375 displayed reasonable oral PK properties (Cmax, T1/2, AUC, and F%) in mouse, rat and dog and showed good safety profile in GLP tox studies. In pharmacology studies HBI-2375 showed significant dose dependent anti-tumor activity in MV4-11 AML model along with reduction in methylation of H3K4 in the tumors harvested from the treated animals demonstrating the targeted disruption of HMT activity in cancer cells by HBI-2375. Furthermore HBI-2375 in combination with PD-1 mAb significantly inhibited tumor growth in MC38, colorectal tumor model, and in 3LL lung carcinoma syngeneic tumor models. Flow cytometry and IHC showed significant increase in the infiltration of CD8+ CTLs in the combination group further providing immune-driven mechanisms for greater efficacy of combination therapy. Gene expression analysis also identified genes that are involved in promoting immune system activity in the combination group. Tissue distribution studies also showed greater accumulation of HBI-2375 in brain tissue indicative of a potential to target glioma and glioblastoma in clinical studies. Therefore, HBI-2375 represents a first-in-class MLL1-WDR5 inhibitor with promising characteristics for future testing in the clinic. Citation Format: Farbod Shojaei, Che Fang, Jill M. Ricono, Mireille Gillings. HBI-2375, a first-in-class IND ready selective MLL1-WDR5 inhibitor, retains desirable preclinical characteristics in solid tumors and in leukemias to be pursued in clinical studies [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 2640.