Cancer Immunotherapy Trials Research Articles

Cancer Immunotherapy Trials Network 12: Pembrolizumab in HIV-Associated Kaposi Sarcoma.

Cancer Immunotherapy Trials Network 12 demonstrated safety of pembrolizumab in treating advanced cancer in people with HIV. Here, we report results of the Kaposi sarcoma (KS) cohort. In this multicenter phase I trial, we enrolled participants with HIV-associated KS on antiretroviral therapy with CD4+ ≥50 cells/μL and HIV plasma RNA <200 copies/mL. Pembrolizumab 200 mg intravenously was administered once every 3 weeks for up to 35 cycles. The primary end point was safety, and the secondary end point was KS response by modified AIDS Clinical Trials Group Criteria. Thirty-two cisgender men enrolled with baseline median CD4+ T-cell count of 274 cells/µL. All but nine participants had received previous systemic KS therapy. Participants received a median of 11 cycles of pembrolizumab (range, 1-35). Sixty-six percent had grade ≥1 treatment-emergent adverse events, including one death from polyclonal KS herpesvirus-related B-cell lymphoproliferation. Thirty-one percent had ≥one immune-mediated AEs (imAEs) with 25% requiring systemic steroids. In 29 participants with evaluable KS, the overall response rate (ORR) was 62.1% (95% CI, 42.3 to 79.3) and did not differ by CD4+ T-cell count. ORR in the eight participants with evaluable disease without previous KS therapy was 87.5% (95% CI, 47.3 to 99.7). Median duration of response (DOR) was not reached, and the Kaplan-Meier estimate of DOR of ≥12 months was 92.3% (95% CI, 56.6 to 98.8). Median progression-free survival was 28.2 months (95% CI, 4.2 to noncalculable). Pembrolizumab yielded a high rate of durable responses in HIV-associated KS. imAEs were successfully managed with standard guidelines.

158P Patterns of immune-related adverse events in early-phase cancer immunotherapy trials

158P Patterns of immune-related adverse events in early-phase cancer immunotherapy trials

160P Predicting immune-related adverse events using biomarkers in early-phase cancer immunotherapy trials

160P Predicting immune-related adverse events using biomarkers in early-phase cancer immunotherapy trials

Placebo immune-related adverse events (irAEs): A neglected phenomenon in cancer immunotherapy trials

PurposeThis study aims to investigate the underexplored prevalence of placebo-reported immune-related adverse events (irAEs) in immune checkpoint inhibitor (ICI) trials. MethodsWe searched public databases for randomized clinical trials (RCTs) involving ICI versus placebo treatments in patients with malignancies. Study characteristics and irAEs occurrences were extracted for meta-analyses using a random-effects model. Main OutcomesProportions of patients reported to experience any grade and grade 3 to 5 placebo irAEs; the risk ratio (RR) of reporting 'false' irAEs in the experiment arm (defined as 'false-irAE ratio', calculated by dividing the proportion of patients documented with irAEs in the placebo arm by that in the experimental arm). Results47 RCTs with 30,119 patients were analyzed. The pooled proportion of patients reported to experience any grade and grade 3 to 5 irAEs among placebo participants was 22.85 % (17.33 %−29.50 %) and 3.40 % (2.35 %−4.63 %), respectively. The pooled proportion of placebo-treated patients who experienced serious irAEs was 0.67 % (0.03 %−1.91 %). Treatment discontinuation and death due to placebo irAEs occurred in 0.69 % (<0.01 %−1.30 %) and 0.12 % (<0.01 %−0.40 %) of patients, respectively. The false-irAE ratio for any grade and grade 3 to 5 irAEs were 0.49 and 0.28. The false-irAE ratio was significantly higher in RCTs with control arms of placebo plus non-immunotherapy than in those with placebo alone (any grade: 0.57 vs. 0.32, P < 0.001; grade 3 to 5: 0.36 vs. 0.12, P = 0.009). ConclusionOur analyses of placebo-treated participants in ICI RCTs document the common occurrence of placebo irAEs. These findings are important for interpreting irAE profiles, avoiding inappropriate therapeutic interventions.

Completion Rate and Positive Results Reporting Among Immunotherapy Trials in Breast Cancer, 2004-2023

Clinical trials are the path to test and introduce new therapies in the clinic. Trials that are unable to produce results represent inefficiency in the system and may also undermine patient confidence in the new drug development process. To survey the immunotherapy clinical trial landscape of breast cancer between January 2004 and April 2023 and examine what fraction of trials with primary completion date up to November 30, 2022, failed to report outcome, assessing the proportion of trials that yielded positive results and describing trial features associated with these 2 outcomes. This cross-sectional study included breast cancer immunotherapy trials identified in ClinicalTrials.gov. Trial details and results were retrieved in December 2023. Google Scholar, PubMed, and LARVOL CLIN websites were also searched for reports. Trial outcome reported as abstract or manuscript. Reported trials were categorized as positive (ie, met its end point) or negative. Association between reporting and trial features were tested using Fisher exact test. A total of 331 immuno-oncology trials were initiated in breast cancer by April 2023; 242 trials were phase II, 47 were phase I, and 42 phase III. By setting, 212 studies (64.0%) were conducted in metastatic, 94 (28.4%) in neoadjuvant, and 25 (7.6%) in adjuvant settings. Among phase II and III trials, 168 (59.2%) were nonrandomized. One hundred twenty trials had primary completion dates up to November 30, 2022, of which 30 (25.0%; enrolling a combined 2428 patients) failed to report their outcomes; 7 phase I trials (31.8%), 21 phase II trials (23.6%), and 2 phase III trials (22.2%) were unreported. Single-center studies were significantly more likely to be unreported than multicenter studies (19 of 54 [35.2%] vs 9 of 60 [15.0%]; P = .02). Of the 90 reported trials, 47 (52.2%) and 43 (47.8%) were positive and negative, respectively. Seventeen of 19 (89.5%) of the reported randomized trials (accruing a total of 4189 patients) were negative. In this cross-sectional study of immunotherapy breast cancer trials, the large number of trials yielded modest clinical impact. Single-center trials commonly failed to report their outcomes and many phase II studies have not translated into corresponding successful phase III trials.

Anticancer Mechanism of Astragalus Polysaccharide and Its Application in Cancer Immunotherapy.

Astragalus polysaccharide (APS) derived from A. membranaceus plays a crucial role in traditional Chinese medicine. These polysaccharides have shown antitumor effects and are considered safe. Thus, they have become increasingly important in cancer immunotherapy. APS can limit the spread of cancer by influencing immune cells, promoting cell death, triggering cancer cell autophagy, and impacting the tumor microenvironment. When used in combination with other therapies, APS can enhance treatment outcomes and reduce toxicity and side effects. APS combined with immune checkpoint inhibitors, relay cellular immunotherapy, and cancer vaccines have broadened the application of cancer immunotherapy and enhanced treatment effectiveness. By summarizing the research on APS in cancer immunotherapy over the past two decades, this review elaborates on the anticancer mechanism of APS and its use in cancer immunotherapy and clinical trials. Considering the multiple roles of APS, this review emphasizes the importance of using APS as an adjunct to cancer immunotherapy and compares other polysaccharides with APS. This discussion provides insights into the specific mechanism of action of APS, reveals the molecular targets of APS for developing effective clinical strategies, and highlights the wide application of APS in clinical cancer therapy in the future.

Adaptive promising zone design for cancer immunotherapy with heterogeneous delayed treatment effect

ABSTRACT Indirect mechanisms of cancer immunotherapies result in delayed treatment effects that vary among patients. Consequently, the use of the log-rank test in trial design and analysis can lead to significant power loss and pose additional challenges for interim decisions in adaptive designs. In this paper, we describe patients’ survival using a piecewise proportional hazard model with random lag time and propose an adaptive promising zone design for cancer immunotherapy with heterogeneous delayed effects. We provide solutions for calculating conditional power and adjusting the critical value for the log-rank test with interim data. We divide the sample space into three zones – unfavourable, promising, and favourable –based on re-estimations of the survival parameters, the log-rank test statistic at the interim analysis, and the initial and maximum sample sizes. If the interim results fall into the promising zone, the sample size is increased; otherwise, it remains unchanged. We show through simulations that our proposed approach has greater overall power than the fixed sample design and similar power to the matched group sequential trial. Furthermore, we confirm that critical value adjustment effectively controls the type I error rate inflation. Finally, we provide recommendations on the implementation of our proposed method in cancer immunotherapy trials.

CD155-TIGIT Axis as a Therapeutic Target for Cancer Immunotherapy.

Immune checkpoint inhibitors (ICIs) have shown unprecedented efficacy in treating many advanced cancers. Although FDA-approved ICIs have shown promising efficacy in treating many advanced cancers, their application is greatly limited by the low response rate, immune-related adverse events (irAE), and drug resistance. Developing novel ICIs holds great promise to improve the survival and prognosis of advanced cancer patients. T-Cell immunoglobulin and ITIM domain (TIGIT) is an inhibitory receptor expressed on T cells, natural killer (NK) cells, and T regulatory cells. Increasing reports have shown that the disrupting CD155-TIGIT axis could activate the immune system and restore antitumor immune response. This review briefly summarized the role of TIGIT in tumor immune escape and targeting CD155-TIGIT axis drugs in preclinical and clinical trials for cancer immunotherapy.

Decision-making and autonomy among participants in early-phase cancer immunotherapy trials: a qualitative study

BackgroundParticipants considering early-phase cancer clinical trials (CTs) need to understand the unique risks and benefits prior to providing informed consent. This qualitative study explored the factors that influence patients’ decisions about participating in early-phase cancer immunotherapy CTs through the ethical lens of relational autonomy.MethodsUsing an interpretive descriptive design, interviews were conducted with 21 adult patients with advanced cancer who had enrolled in an early-phase CT. Data was analyzed using relational autonomy ethical theory and constant comparative analysis.ResultsThe extent to which participants perceived themselves as having a choice to participate in early-phase cancer immunotherapy CTs was a central construct. Perceptions of choice varied according to whether participants characterized their experience as an act of desperation or as an opportunity to receive a novel treatment. Intersecting psychosocial and structural factors influenced participants’ decision making about participating in early-phase cancer immunotherapy trials. These relational factors included: (1) being provided with hope; (2) having trust; (3) having the ability to withdraw; and (4) timing constraints.ConclusionsFindings highlight the continuum of perceived choice that exists among patients with cancer when considering participation in early-phase cancer immunotherapy CTs. All participants were interpreted as exhibiting some degree of relational autonomy within the psychosocial and structural context of early-phase CT decision making. This study offers insights into the intersection of cancer care delivery, personal beliefs and values, and established CT processes and structures that can inform future practices and policies associated with early-phase cancer immunotherapy CTs to better support patients in making informed decisions.

Exhausted Tumor-infiltrating CD39+CD103+ CD8+ T Cells Unveil Potential for Increased Survival in Human Pancreatic Cancer.

Patients with pancreatic cancer with a high proportion of CD39+CD103+ CD8+ T cells exhibiting a tumor-reactive phenotype have improved survival rates, suggesting their potential utility in selecting candidates for immunotherapy trials.

Examining crossover and postprotocol therapies in first-line immunotherapy trials in non-small cell lung cancer.

Immune checkpoint inhibitor (ICI) therapy has led to significant improvement in outcomes for patients with nononcogene-driven advanced non-small cell lung cancer (NSCLC). The rate of crossover and receipt of postprotocol ICI in frontline trials for advanced NSCLC has not been systematically evaluated. ClinicalTrials.gov was used to identify phase 3 studies evaluating the use of immunotherapy or combination chemoimmunotherapy against chemotherapy alone in the frontline management of advanced NSCLC. Data on outcomes, rate of crossover and/or subsequent post-protocol receipt of immunotherapy, and the start dates of these clinical trials were then extracted. Twenty-three frontline trials in nononcogene-driven advanced NSCLC were identified. Six trials with ICI monotherapy/dual ICI therapy and 17 trials evaluating chemotherapy/ICI in first-line advanced NSCLC were included in the analysis. The crossover rate ranged 0% to 54% in ICI monotherapy/dual ICI trials and 0% to 52% in chemotherapy/ICI trials. Nineteen of 23 trials provided information on subsequent postprotocol therapies. Among the trials not allowing crossover, postprotocol ICI was administered to 17% to 45.8% of patients. Information regarding the eventual receipt of ICI therapy was available for 22 of 23 trials. Of 6631 patients, 2507 (37.8%) randomized to the control arm eventually received ICI therapy. The rate of crossover and postprotocol ICI use was low in frontline trials for first-line NSCLC incorporating ICI. Given the proven improved overall survival of ICI in a broad population, there is a need to ensure availability of this life-prolonging therapy in future trials, either by crossover treatment or postprotocol administration.

Sequential monitoring of cancer immunotherapy trial with random delayed treatment effect

ABSTRACT Cancer immunotherapy trials are frequently characterized by a delayed treatment effect that violates the proportional hazards assumption. The log-rank test (LRT) suffers a substantial loss of statistical power under the nonproportional hazards model. Various group sequential designs using weighted LRTs (WLRTs) have been proposed under the fixed delayed treatment effect model. However, patients enrolled in immunotherapy trials are often heterogeneous, and the duration of the delayed treatment effect is a random variable. Therefore, we propose group sequential designs under the random delayed effect model using the random delayed distribution WLRT. The proposed group sequential designs are developed for monitoring the efficacy of the trial using the method of Lan-DeMets alpha-spending function with O’Brien-Fleming stopping boundaries or a gamma family alpha-spending function. The maximum sample size for the group sequential design is obtained by multiplying an inflation factor with the sample size for the fixed sample design. Simulations are conducted to study the operating characteristics of the proposed group sequential designs. The robustness of the proposed group sequential designs for misspecifying random delay time distribution and domain is studied via simulations.

Assessing surrogacy using restricted mean survival time ratio for overall survival in liver cancer: a narrative review.

The application of immunotherapy in cancers, including liver cancer, has been increasing. However, non-proportional hazard (NPH) is often observed in cancer immunotherapy trials. In presence of violation of proportional hazard (PH) assumption, restricted mean survival time (RMST) ratio was proposed as an alternative to hazard ratio (HR) for evaluating the treatment effects of such trials. To shorten the total study duration, an intermediate endpoint with shorter follow-up such as progressionfree survival (PFS) is used as the primary endpoint. Our aim is to evaluate the applicability of RMST ratio in addition to the HR in assessing the level of PFS serving as a surrogacy of overall survival (OS). Phase II or phase III hepatocellular carcinoma (HCC) immunotherapy studies that were published between January 2013 and August 2022 were identified via the search in PubMed. Weighted leastsquare regression (WLSR) was applied to analyze the trial level data with the sample size of study being set as the weight. The evaluation was conducted twice with RMST ratio and HR being applied in respective evaluation to examine the level of PFS as a surrogacy for OS. Based on the results of eight included trials, the R-square values of WLSR with either HR or RMST ratio being applied were 0.31 and 0.16 separately, indicating a moderate and low correlation between PFS and OS respectively. In this study, our results demonstrated the potential of RMST ratio in addition to HR for evaluating the level of surrogacy in immunotherapy trials. Furthermore, including more large scale and homogeneous studies into the research may help better understand the level of surrogacy in liver cancer.

Development of a prognostic signature for immune-associated genes in bladder cancer and exploring potential drug findings.

Bladder cancer, predominantly affecting men, is a prevalent malignancy of the urinary system. Although platinum-based chemotherapy has demonstrated certain enhancements in overall survival when compared to surgery alone, the efficacy of treatments is impeded by the unfavorable side effects of conventional chemotherapy medications. Nonetheless, immunotherapy exhibits potential in the treatment of bladder cancer. To create an immune-associated prognostic signature for bladder cancer, bioinformatics analyses were performed utilizing The Cancer Genome Atlas (TCGA) database in this study. By identifying differential gene expressions between the high-risk and low-risk groups, a potential therapeutic drug was predicted using the Connectivity Map database. Subsequently, the impact of this drug on the growth of T24 cells was validated through MTT assay and 3D cell culture techniques. The signature included 1 immune-associated LncRNA (NR2F1-AS1) and 16 immune-associated mRNAs (DEFB133, RBP7, PDGFRA, CGB3, PDGFD, SCG2, ADCYAP1R1, OPRL1, PGR, PSMD1, TANK, PRDX1, ADIPOR2, S100A8, AHNAK, EGFR). Based on the assessment of risk scores, the patients were classified into cohorts of low-risk and high-risk individuals. The cohort with low risk demonstrated a considerably higher likelihood of survival in comparison to the group with high risk. Furthermore, variations in immune infiltration were noted among the two categories. Cephaeline, a possible medication, was discovered by analyzing variations in gene expression. It exhibited promise in suppressing the viability and growth of T24 bladder cancer cells. The novel predictive pattern allows for efficient categorization of patients with bladder cancer, enabling focused and rigorous treatment for those expected to have a worse prognosis. The discovery of a possible curative medication establishes a basis for forthcoming immunotherapy trials in bladder cancer.

Efficacy and safety of immune checkpoint inhibitors for advanced non-small cell lung cancer with or without PD-L1 selection: A systematic review and network meta-analysis.

Immune checkpoint inhibitors (ICIs) are standard treatments for advanced non-small cell lung cancer (NSCLC); however, evidence regarding their relative efficacy and safety is lacking. This study compared the efficacy and safety of all currently available ICI treatments in patients with advanced NSCLC to identify optimal treatment regimens. PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase databases were systematically searched for randomized controlled trials (RCTs) published up to August 8, 2022. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Secondary outcomes included objective response rate (ORR) and adverse events (AEs). Forty RCTs involving 22,526 patients were selected, and a total of 26 treatment regimens were identified. Treatment with anti-programmed cell death protein-1 (anti-PD-1) provided superior OS compared with anti-programmed death ligand 1 (anti-PD-L1) treatment. ICIs plus platinum-based chemotherapy (PBC) were superior to ICIs treatment alone, although the addition of PBC increased treatment toxicity. Cemiplimab ranked first for OS and lowest for any-grade AEs in advanced NSCLC patients without PD-L1 selection. Regarding grade ≥3 AEs, the toxicity of ICI monotherapy or ICI-ICI combination was consistently lower than that of the other treatments. For patients without PD-L1 selection, cemiplimab showed the best OS, pembrolizumab plus docetaxel (Pem-DXT) showed the best PFS, and atezolizumab plus bevacizumab and PBC (Atezo-Beva-PBC) showed the best ORR. Pembrolizumab plus PBC and Atezo-Beva-PBC were the most likely optimal treatments for OS and PFS in patients with PD-L1 expression <1%, respectively. In patients with PD-L1 expression ≥1%, treatment regimens containing anti-PD-1 provided superior OS benefits compared with those of anti-PD-L1 treatment, and sintilimab plus PBC (Sint-PBC) provided the best OS benefit; as for PFS, ICI plus PBC consistently showed greater PFS benefits than ICI or PBC alone. For patients with anti-PD-L1 expression of 1-49%, camrelizumab plus PBC provided the best benefit for OS and PFS among included treatment. Durvalumab-tremelimumab-PBC and Atezo-Beva-PBC respectively presented the highest OS and PFS for patients with PD-L1 expression ≥50%. Moreover, cemiplimab and Atezo-Beva-PBC yielded the best OS and PFS benefits as first-line treatments for patients with advanced NSCLC, respectively. Although ICI plus PBC likely resulted in superior survival outcomes compared to ICI treatment alone, it did increase toxicity. Cemiplimab presented a well-balanced efficacy and safety profile in advanced NSCLC treatment. Our findings with the current ICIs comparisons will aid future trials for cancer immunotherapy. PROSPERO, https://www.crd.york.ac.uk/PROSPERO/ , CRD42022323879.

Vinylphosphonate-based cyclic dinucleotides enhance STING-mediated cancer immunotherapy

Cyclic dinucleotides (CDNs) trigger the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which plays a key role in cytosolic DNA sensing and thus in immunomodulation against infections, cell damage and cancer. However, cancer immunotherapy trials with CDNs have shown immune activation, but not complete tumor regression. Nevertheless, we designed a novel class of CDNs containing vinylphosphonate based on a STING-affinity screening assay. In vitro, acyloxymethyl phosphate/phosphonate prodrugs of these vinylphosphonate CDNs were up to 1000-fold more potent than the clinical candidate ADU-S100. In vivo, the lead prodrug induced tumor-specific T cell priming and facilitated tumor regression in the 4T1 syngeneic mouse model of breast cancer. Moreover, we solved the crystal structure of this ligand bound to the STING protein. Therefore, our findings not only validate the therapeutic potential of vinylphosphonate CDNs but also open up opportunities for drug development in cancer immunotherapy bridging innate and adaptive immunity.

Early Adverse Event Derived Biomarkers in Predicting Clinical Outcomes in Patients with Advanced Non-Small Cell Lung Cancer Treated with Immunotherapy.

Adverse events (AEs) have been shown to have clinical associations, in addition to patient safety assessments of drugs of interest. However, due to their complex content and associated data structure, AE evaluation has been restricted to descriptive statistics and small AE subset for efficacy analysis, limiting the opportunity for global discovery. This study takes a unique approach to utilize AE-associated parameters to derive a set of innovative AE metrics. Comprehensive analysis of the AE-derived biomarkers enhances the chance of discovering new predictive AE biomarkers of clinical outcomes. We utilized a set of AE-associated parameters (grade, treatment relatedness, occurrence, frequency, and duration) to derive 24 AE biomarkers. We further innovatively defined early AE biomarkers by landmark analysis at an early time point to assess the predictive value. Statistical methods included the Cox proportional hazards model for progression-free survival (PFS) and overall survival (OS), two-sample t-test for mean difference of AE frequency and duration between disease control (DC: complete response (CR) + partial response (PR) + stable disease (SD)) versus progressive disease (PD), and Pearson correlation analysis for relationship of AE frequency and duration versus treatment duration. Two study cohorts (Cohort A: vorinostat + pembrolizumab, and B: Taminadenant) from two immunotherapy trials in late-stage non-small cell lung cancer were used to test the potential predictiveness of AE-derived biomarkers. Data from over 800 AEs were collected per standard operating procedure in a clinical trial using the Common Terminology Criteria for Adverse Events v5 (CTCAE). Clinical outcomes for statistical analysis included PFS, OS, and DC. An early AE was defined as event occurrence at or prior to day 30 from initial treatment date. The early AEs were then used to calculate the 24 early AE biomarkers to assess overall AE, each toxicity category, and each individual AE. These early AE-derived biomarkers were evaluated for global discovery of clinical association. Both cohorts showed that early AE biomarkers were associated with clinical outcomes. Patients previously experienced with low-grade AEs (including treatment related AEs (TrAE)) had improved PFS, OS, and were associated with DC. The significant early AEs included low-grade TrAE in overall AE, endocrine disorders, hypothyroidism (pembrolizumab's immune-related adverse event (irAE)), and platelet count decreased (vorinostat related TrAE) for Cohort A and low-grade AE in overall AE, gastrointestinal disorders, and nausea for Cohort B. In contrast, patients with early development of high-grade AEs tended to have poorer PFS, OS, and correlated with PD. The associated early AEs included high-grade TrAE in overall AE, gastrointestinal disorders with two members, diarrhea and vomiting, for Cohort A and high-grade AE in overall AE, three toxicity categories, and five related individual AEs for Cohort B. One low-grade TrAE, alanine aminotransferase increased (vorinostat + pembrolizumab related), was an irAE and correlated with worse OS in Cohort A. The study demonstrated the potential clinical utility of early AE-derived biomarkers in predicting positive and negative clinical outcomes. It could be TrAEs or combination of TrAEs and nonTrAEs from overall AEs, toxicity category AEs, to individual AEs with low-grade event leaning to encouraging effect and high-grade event to undesirable impact. Moreover, the methodology of the AE-derived biomarkers could change current AE analysis practice from a descriptive summary into modern informative statistics. It modernizes AE data analysis by helping clinicians discover novel AE biomarkers to predict clinical outcomes and facilitate the generation of vast clinically meaningful research hypotheses in a new AE content to fulfill the demands of precision medicine.

In silico cancer immunotherapy trials uncover the consequences of therapy-specific response patterns for clinical trial design and outcome

Late-stage cancer immunotherapy trials often lead to unusual survival curve shapes, like delayed curve separation or a plateauing curve in the treatment arm. It is critical for trial success to anticipate such effects in advance and adjust the design accordingly. Here, we use in silico cancer immunotherapy trials – simulated trials based on three different mathematical models – to assemble virtual patient cohorts undergoing late-stage immunotherapy, chemotherapy, or combination therapies. We find that all three simulation models predict the distinctive survival curve shapes commonly associated with immunotherapies. Considering four aspects of clinical trial design – sample size, endpoint, randomization rate, and interim analyses – we demonstrate how, by simulating various possible scenarios, the robustness of trial design choices can be scrutinized, and possible pitfalls can be identified in advance. We provide readily usable, web-based implementations of our three trial simulation models to facilitate their use by biomedical researchers, doctors, and trialists.

Abstract 987: Seamless statistical analysis of adverse event data for clinical association

Abstract Purpose: Adverse event (AE) is a critical element in clinical trial to evaluate patient safety profile of the drug for benefit-risk assessment. AE is also shown to have clinical association. However, due to its complexity, utilization of AE data has been suboptimal. This study takes a unique approach to utilize AE parameters and to derive a set of innovative AE metrics which could have the potential as a predictive biomarker of treatment response and survival outcomes. Methods: The AE-derived biomarkers integrated toxicity severity level (grade) and treatment relatedness, with further tune-up by AE occurrence, frequency, and duration. Implementation of AE-derived biomarkers was performed in a comprehensive strategy starting from overall AE, toxicity category, down to individual AE. Landmark analysis at day 30 from initial treatment date was used to define early AE biomarkers. Two study cohorts (Cohort A and B) from two immunotherapy trials in late-stage non-small cell lung cancer were used to evaluate the potential of AE-derived biomarkers. Clinical outcomes for statistical analysis included progression-free survival, overall survival, disease control, and duration of treatment. Results: Both cohorts showed that early AEs were associated with clinical outcomes. Patients experienced with low-grade AEs (including treatment related AEs) at early time point had improved PFS, OS, and were associated with disease control. The significant early AEs included treatment related low-grade AE in overall AE, endocrine disorders, hypothyroidism (immune-related adverse event (irAE)), and platelet count decreased for Cohort A and low-grade AE in overall AE, gastrointestinal disorders, and nausea for Cohort B. In contrast, patients with early development of higher-grade AEs tended to have poorer PFS, OS, and correlated with PD. The associated early AEs included treatment related high-grade AE in overall AE, gastrointestinal disorders with two members, diarrhea and vomiting, for Cohort A and high-grade AE in overall AE, 3 toxicity categories, and 5 related individual AEs for Cohort B. One treatment related low-grade AE, alanine aminotransferase increased, was irAE and correlated with worse OS in Cohort A. Conclusions: The study demonstrated evidence of AE utility in predicting positive and negative clinical outcomes. It could be treatment related AEs or combination of treatment related and not related AEs. Grade level played a key role in determining direction of clinical outcomes with low-grade leaning to positive effect and high-grade to negative impact. Significant AEs covering overall AEs, toxicity category AEs, to individual AEs provided relatively comprehensive view of AE results for clinical relevance. Citation Format: Dung-Tsa Chen, Jhanelle Gray, Andreas Saltos, Trevor A Rose, Alberto Chiappori, Zachary Thompson, Ram Thapa. Seamless statistical analysis of adverse event data for clinical association [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 987.

Abstract 6245: Selective HDAC6 inhibition by ITF3756 modifies the landscape of gene and protein expression in human monocytes: Possible identification of a specific biomarker signature

Abstract Histone deacetylase 6 (HDAC6) modulates tumor immunogenicity through several pathways, such as the control of PD-L1 expression on tumor and on lymphoid cells. Thus, HDAC6 is a potential pharmacological target for cancer treatment. In humans, HDAC6 inhibition can be monitored by measuring the ratio between tubulin and histone acetylation. However, the identification of biomarkers to be used as a signature for patient stratification that correlates with the treatment efficacy is missing. Since we have previously demonstrated that the activity of the selective HDAC6 inhibitor ITF3756 on myeloid cells plays a role in the antitumor immune response in the TME, we reasoned that an ITF3756-specific signature could be identified in unstimulated monocytes treated with the compound. Monocytes were purified from healthy donors, treated with ITF3756 and RNAseq and proteomic analyses were performed. Gene Ontology analysis shows that ITF3756 has a widespread effect on monocyte transcriptome and proteome. We observed the down-modulation of genes and proteins involved in inflammatory pathways and in transcription regulation. Up-regulation of neutrophil-mediated immunity, metabolic pathways and protein phosphorylation was also identified. Focusing on genes that could be relevant in the tumor context, we selected a panel of genes from the most up- (SCL27A1, ANXA6 and IRF6) and down-modulated (CD84, RANK, CXCL2, CXCL3, STAB-1, CD163, PD-L1, CD206 and ADA). Interestingly, we found among the downmodulated genes markers of M2 macrophages, genes related to the tumor associated macrophages, and STAB-1, whose targeting is currently in clinical trials for cancer immunotherapy. Peripheral Blood Mononuclear Cells (PBMCs) could be a less expensive starting material for biomarker identification to be collected during a clinical trial when compared to purified monocytes. Thus, to ascertain whether the regulation by ITF3756 of our selected genes was detectable also in PBMCs we performed gene expression analysis after ITF3756 treatment and we confirmed that all selected genes were reproducibly modulated. Surface protein expression of M2 macrophages biomarkers in our panel, were determined by flow cytometry and all of them were significantly modulated in PBMCs. These data show how our approach successfully led both to the identification of a biomarker signature that could be used in clinical trials to monitor the pharmacodynamic effect of ITF3756, and to the discovery of previously unknown targets of HDAC6 inhibition. Citation Format: Chiara Ripamonti, Valeria Spadotto, Monica Forino, Christian Steinkuhler, Gianluca Fossati. Selective HDAC6 inhibition by ITF3756 modifies the landscape of gene and protein expression in human monocytes: Possible identification of a specific biomarker signature. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6245.