Secondary Resistance Research Articles

Update on the treatment of BRAFmut metastatic melanoma and future perspectives

Abstractv‐Raf murine sarcoma viral oncogene homolog B (BRAF) mutations were first identified in melanoma in 2002, leading to increased cell division and proliferation, and resultant tumour growth. The identification and characterisation of BRAF mutations (BRAFmut) led to the development of several highly specific, BRAF‐, then mitogen‐activated kinase enzyme (MEK)‐targeted therapies that have enabled rapid tumour responses and improved treatment outcomes in most patients with metastatic BRAFmut melanoma. The combination of these two drug classes (BRAF inhibitors and MEK inhibitors) has demonstrated improved response rates, progression‐free survival, and overall survival (OS), along with a more tolerable safety profile, compared with BRAF inhibition alone. In parallel, improved knowledge of the immune system has enabled the development of immune checkpoint inhibitors (ICIs), although immune‐related adverse events with ICIs may prove to be problematic in some patients and require careful management. While targeted therapy appears to provide rapid disease control in a relatively high proportion of patients, the development of secondary resistance may limit the overall duration of responses. Acquired resistance, along with primary resistance, has also been reported for ICIs, with a lower overall response rate to that with targeted therapy, although durable responses have been reported in some responding patients. A combination strategy of targeted therapy with ICIs has demonstrated modest increases in efficacy compared with targeted therapy combinations, although data significance varies across studies, there is increased risk of toxicity, and triple combination therapy has not yet received clinical approval in Europe. Thus, there is an ongoing need to establish optimal sequencing of these treatments in patients with advanced BRAFmut melanoma, and this has become the focus of current research. The aim of this narrative review was to provide an update on the treatment of BRAFmut metastatic melanoma, current guideline recommendations, and future clinical perspectives.

Hepatocellular Carcinoma Immunotherapy: Predictors of Response, Issues, and Challenges

Immune checkpoint inhibitors (ICIs), such as durvalumab, tremelimumab, and atezolizumab, have emerged as a significant therapeutic option for the treatment of hepatocellular carcinoma (HCC). In fact, the efficacy of ICIs as single agents or as part of combination therapies has been demonstrated in practice-changing phase III clinical trials. However, ICIs confront several difficulties, including the lack of predictive biomarkers, primary and secondary drug resistance, and treatment-related side effects. Herein, we provide an overview of current issues and future challenges in this setting.

Modern approaches to the eradication of <i>Helicobacter pylori</i>: a spectrum of perspectives

Helicobacter pylori is one of the most widespread infections, affecting approximately 50% of the global population, with the Russian Federation ranking among the regions with a relatively high prevalence. Eradication therapy remains the primary strategy, not only for the treatment and prevention of gastrointestinal diseases but also for reducing the risk of stomach cancer, highlighting the medical and social impact of this infection. A key factor contributing to the reduced effectiveness of eradication therapy is the microorganism’s primary or secondary resistance to antibacterial drugs, a problem recognized worldwide. It is widely acknowledged that national treatment regimens for Helicobacter pylori infection must be adapted based on systematic antimicrobial sensitivity testing to curb the rise of global antibiotic resistance. Despite decades of research and clinical practice, identifying the most effective, safe, and straightforward therapy remains a significant challenge for clinicians. This review provides a comparative analysis of current treatment recommendations for Helicobacter pylori infection, as presented by various national and regional gastroenterological societies, including those relevant in the Russian Federation.

Discovery of Oral Degraders of the ROS1 Fusion Protein with Potent Activity against Secondary Resistance Mutations.

The development of therapeutic resistance in the majority of patients limits the long-term benefit of ROS1 inhibitor treatment. On-target mutations of the ROS1 kinase domain confer resistance to crizotinib and lorlatinib in more than one-third of acquired resistance cases with no current effective treatment option. As an alternative to stoichiometric inhibition, proteolytic degradation of ROS1 could provide an effective tool to combat resistance generated by these mutations. Our study has identified a potent, orally active ROS1 degrader with an excellent pharmacokinetics profile. The degrader can effectively inhibit ROS1-dependent cell proliferation and tumor growth by degrading the ROS1 kinase, thereby eliminating the active phospho-ROS1. More importantly, the degradation-based therapeutic modality can overcome on-target mutation resistance to tyrosine kinase inhibitors by efficient degradation of the mutated kinase to achieve greater potency than inhibition.

P4.11D.12 Phase 3 Trial of OSE2101 Versus Docetaxel in Patients with Non-Small Cell Lung Cancer & Secondary Resistance to Immunotherapy

P4.11D.12 Phase 3 Trial of OSE2101 Versus Docetaxel in Patients with Non-Small Cell Lung Cancer & Secondary Resistance to Immunotherapy

Weekly carboplatin plus paclitaxel chemotherapy in advanced melanoma patients resistant to anti-PD-1 inhibitors: a retrospective, monocentric experience

Immunotherapy with anti-PD-1 antibodies significantly improved the prognosis in advanced melanoma patients, but most of them develop primary or secondary resistance to the treatment. In this study, we evaluated efficacy and safety of a chemotherapy regimen with weekly carboplatin plus paclitaxel (wCP) in patients previously treated with anti-PD-1 antibodies. We retrospectively identified 30 patients with advanced melanoma treated at our Institute over the last eight years with wCP. The co-primary endpoints of the study were overall survival (OS) and progression-free survival (PFS). In addition, we evaluated treatment tolerability. For this patient cohort, median PFS and OS were 3.25 and 7.69 months, respectively. All included patients had previously received anti-PD-1 immunotherapy, most of them had ECOG PS 0–1, and only 5 patients had a BRAF V600 mutation. In univariable analysis, we observed shorter OS in patients with > 2 involved metastatic sites, superficial spreading histology, and serum lactate dehydrogenase (LDH) values above the median. Liver metastases were associated with worse outcomes, while radiotherapy treatment of brain metastases was associated with improved OS. However, in a multivariable Cox regression model, only LDH above the median, superficial spreading histology, and female sex were significantly associated with worse OS. We reported grade 3 and 4 treatment-related toxicities in 4 and 0 patients, respectively. In conclusion, chemotherapy with wCP is a valid palliative treatment in advanced melanoma who progressed with anti-PD-1 antibodies.

EGFR T790M mutation detection in NSCLC patients resistant to tyrosine kinase inhibitor therapy.

The finding of mutations that activate epidermal growth factor receptor (EGFR) in people with lung adenocarcinoma resulted in the creation of a new class of biological treatments called tyrosine kinase inhibitors (TKI). These medications have changed how patients with EGFR mutations are clinically managed, nearly doubling their survival rate compared to standard chemotherapy. Though 1st and 2nd generation EGFR TKIs are initially highly effective, typically within 9-14 months all tumors with the mutation progress due to secondary resistance mutations involving alternative molecular pathways. In most cases (up to 60%), this is due to the T790M mutation emerging in the EGFR gene. The study included 85 patients with NSCLC with progression of the disease after treatment with TKI 1st and 2nd generation. The T790M mutation was determined by digital polymerase chain reaction (PCR) on the QIAcuity One 5plex digital PCR system and traditional real-time PCR. Real-time PCR analysis of the presence of the T790M mutation was performed using the Therascreen EGFR Plasma RGQ PCR Kit (Qiagen). Using a digital PCR system in QIAcuity One (Qiagen) nanoplanets, the T790M mutation was analysed by digital PCR. The age of the patients ranged from 37 to 85 years. Of 85 patients with NSCLC with disease progression after TKI treatment, T790M mutations were detected during digital PCR in 30 of 85 patients, which is 35.2% of the sample, and with traditional real-time PCR, positive mutations came out only in 3 out of 85 patients.

Abstract B049: Oncolytic virotherapy as an effective tool to synergistically enhance therapeutic efficacy of standard systemic treatments for pancreatic cancer

Abstract Background: Standard therapies provide marginal benefits in overall survival and leading immunologic agents have proven ineffective in the immunologically cold environment of pancreatic ductal adenocarcinoma (PDAC). Current standard of care chemotherapies experience demonstrable resistance in the clinical setting with primary and secondary resistance frequently leading to poor outcomes. Oncolytic virus (OV) therapies are emerging as an avenue of therapeutic potential with vesicular stomatitis virus (VSV) providing an onco- selective platform with potential for rapid replication and minimal outside virulence. The aim of this project is to determine if the addition of OV to the standard systemic treatments would result in a synergistic improvement of the therapeutic efficacy, and investigate the potential mechanisms involved. Methods: A VSV variant containing the Morreton G protein inserted into a wild-type VSV backbone (VMG)was propagated and purified for in vitro and in vivo studies. In vitro studies investigating oncolytic potential and viral kinetics of VSV in combination with FOLFIRINOX (FFX) and Gemcitabine Paclitaxel (GP) therapies were compared to monotherapy in multiple cell culture formats including 2D Monolayer, 3D Spheroid, and ongoing investigation into patient derived organoids. Proteomics analysis of monotherapies along with combination therapy was performed on in vitro cultures. Ongoing in vivo studies are investigating the therapeutic potential of concurrent treatments. Results: Cytotoxicity assay studies of equivalent multiplicities of infection (MOI) demonstrated increased cytotoxicity of combination therapy (Percent viable 10.2% ± 1.3%) compared to virus alone (30.7% ± 1.9%) or FFX alone (84.4% ± 6.6%) in Hs766T PDAC cell lineAsPC-1 cell line demonstrated similar effects with minimal cytotoxicity from FFX alone (100% ± 5%) with comparable resistance to virus alone (69.9% ± 1.8%) in comparison to combination therapy (40.3% ± 1.0%). Additional cell lines including Panc-01 and MiaPaCa2 provided similar results. Treatment of formed spheroids with combination therapy resulted in reduction in overall size of spheroid along with increased Viral GFP marker fluorescence, in combination group, compared to monotherapy with each treatment. Proteomic analysis investigating concomitant treatment with both standards of care produced unique expression profiles. Multiple pathways including cell cycle regulation, apoptosis, MAPK signaling, PI3K-Akt signaling, ErbB signaling showed significant regulatory changes in protein expression across all treatment groups. Conclusion: VSV oncolytic virus in conjunction with standard of care therapy demonstrates a potentially effective approach for synergistic enhancement of the therapeutic efficacy against PDAC. Ongoing research is investigating the immunomodulatory and metabolic effects of both monotherapies in conjunction with combination therapy to further determine the synergistic mechanisms involved and how they can be further utilized to overcome treatment resistance in PDAC. Citation Format: Conner Hartupee, Amirsalar Mansouri, Joycelynn Coleman-Barnett, Dana Adamcova, Dorota Wyczechowska, Bolni Marius Nagalo, Mulu Tesfay, Jovanny Zabaleta, Luis Del Valle, John West, Jiri Adamec, Omeed Moaven. Oncolytic virotherapy as an effective tool to synergistically enhance therapeutic efficacy of standard systemic treatments for pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B049.

Continued decitabine/all-trans retinoic acid treatment: extended complete remission in an elderly AML patient with multi-hit TP53 lesions and complex-monosomal karyotype

DNA-hypomethylating agents (HMAs) induce notable remission rates in AML/MDS patients with TP53 mutations; however, secondary resistance often develops rapidly. In the DECIDER trial (NCT00867672), elderly AML patients (also those with adverse genetics) randomized to all-trans retinoic acid (ATRA) added to decitabine (DEC) attained significantly delayed time-to-resistance. An 82-year-old patient with a non-disruptive, in-frame TP53 mutation (p.Cys238_Asn239delinsTyr, VAF 90%) and complex-monosomal karyotype attained a complete hematologic and cytogenetic remission with DEC + ATRA, with 3.7 years survival after 30 treatment cycles that were well-tolerated. Further HMA + ATRA studies appear warranted in AML/MDS patients of different genetic risk groups ineligible for more intensive treatment.Trial registration: This trial was registered at ClinicalTrials.gov identifier: NCT00867672

Antibiotic Resistance of Helicobacter pylori in Mainland China: A Focus on Geographic Differences Through Systematic Review and Meta-Analysis

BackgroundEmpirical treatment needs to be supported by regional data, but knowledge of interregional differences is currently lacking in China. This study aimed to summarize and map the primary and secondary antibiotic resistance of H. pylori in different regions of mainland China. MethodsPubMed, EMBASE, Web of Science, China National Knowledge Infrastructure and Wanfang databases were systematically reviewed for studies published between January 1st, 2000 and July 15th, 2023. Data related to primary and secondary H. pylori antibiotic resistance rates were included. Random-effects models were used to synthesize the pooled resistance rates. ResultsUltimately, 74 studies were included in the final analysis. Sixteen provinces reported resistance data. The overall resistance rates of H. pylori in mainland China were 30.72% (95% CI 27.53%–33.99%) to clarithromycin, 70.14% (95% CI 29.53%–37.46%) to metronidazole, and 32.98% (95% CI 28.73%–37.37%) to levofloxacin; for amoxicillin, tetracycline, and furazolidone, the rates were 2.41% (95% CI 1.43%–3.60%), 2.53% (95% CI 1.19%–4.28%) and 1.54% (95% CI 0.28%–3.62%), respectively. Spatial and temporal differences were observed. The resistance rates increased after treatment failure, however, secondary resistance to amoxicillin, tetracycline, and furazolidone were still low across the vast majority of study regions. ConclusionSurveillance of the updated prevalence of antibiotic resistance of H. pylori for different regions is warranted, which should factor into clinical decision making and guideline recommendations.

The INSIGHT study: a randomized, Phase III study of ripretinib versus sunitinib for advanced gastrointestinal stromal tumor with KIT exon 11+17/18mutations.

Somatic KIT activating mutations drive most gastrointestinal stromal tumors (GISTs). Disease progression eventually develops with first-line imatinib, commonly due to KIT secondary mutations, and different kinase inhibitors have various levels of treatment efficacy dependent on specific acquired resistance mutations. Ripretinib is a broad-spectrum switch-control KIT/PDGFRA tyrosine kinase inhibitor for patients with advanced GIST who received prior treatment with threeor more kinase inhibitors, including imatinib. Exploratory baseline circulating tumor DNA analysis from the second-line INTRIGUE trial determined that patients with advanced GIST previously treated with imatinib harboring primary KIT exon 11mutations and secondary resistance mutations restricted to KIT exons 17/18 had greater clinical benefit with ripretinib versus sunitinib. We describe the rationale and design of INSIGHT (NCT05734105), an ongoing Phase III open-label study of ripretinib versus sunitinib in patients with advanced GIST previously treated with imatinib exclusively harboring KIT exon 11+17/18mutations detected by circulating tumor DNA.Clinical Trial Registration: NCT05734105 (ClinicalTrials.gov).

1397TiP Phase III trial of the therapeutic cancer vaccine OSE2101 versus docetaxel in patients with metastatic non-small cell lung cancer and secondary resistance to immunotherapy

1397TiP Phase III trial of the therapeutic cancer vaccine OSE2101 versus docetaxel in patients with metastatic non-small cell lung cancer and secondary resistance to immunotherapy

The effect of ribociclib on the expression levels of miR-141 and CDK4/6-USP51 signaling pathway genes in MCF-7 and MDA-MB-231 cells.

Patients with breast cancer, especially triple-negative breast cancer, have a poor prognosis. There is still no effective treatment for this disease. Due to resistance to traditional treatments such as chemotherapy and radiation therapy, there is a need to discover novel treatment strategies to treat this disease. Ribociclib is a selective CDK4/6 inhibitor. Approximately 20% of patients with HR+ breast cancer developed primary resistance to CDK4/6 inhibitors, and more than 30% experienced secondary resistance. Since most patients experience resistance during CDK4/6 inhibitor treatment, managing this disease is becoming more challenging. Many malignant tumors abnormally express microRNA (miR)-141, which participates in several cellular processes, including drug resistance, proliferation, epithelial-mesenchymal transition, migration, and invasion. In the present study, we cultured MDA-MB-231 and MCF-7 cells in DMEM-F12 medium. By performing MTT assay we determined the cytotoxic effects of ribociclib on breast cancer cells, as well as determining the IC50 of it. Then, we treated the cells with ribociclib at two time points: 24 h and 72 h. After that, RNA was isolated and reverse transcribed to cDNA. Finally, we performed qRT‒PCR to evaluate how ribociclib affects the expression level of desired genes. We found that ribociclib can inhibit cell growth in a dose- and time-dependent manner. We examined the mRNA expression of 4 genes. After ribociclib treatment, the mRNA expression of CDK6 and MYH10 decreased (p < 0.01, p < 0.05). The mRNA expression of CDON increased (p<0.05), but no significant changes were observed in ZEB1 mRNA expression. Furthermore, the qRT‒PCR results for miR-141 showed that the expression of miR-141 increased (p<0.01) after 72 h of treatment with ribociclib.

Sialylation Inhibition Can Partially Revert Acquired Resistance to Enzalutamide in Prostate Cancer Cells.

Prostate cancer is a lethal solid malignancy and a leading cause of cancer-related deaths in males worldwide. Treatments, including radical prostatectomy, radiotherapy, and hormone therapy, are available and have improved patient survival; however, recurrence remains a huge clinical challenge. Enzalutamide is a second-generation androgen receptor antagonist that is used to treat castrate-resistant prostate cancer. Among patients who initially respond to enzalutamide, virtually all acquire secondary resistance, and an improved understanding of the mechanisms involved is urgently needed. Aberrant glycosylation, and, in particular, alterations to sialylated glycans, have been reported as mediators of therapy resistance in cancer, but a link between tumour-associated glycans and resistance to therapy in prostate cancer has not yet been investigated. Here, using cell line models, we show that prostate cancer cells with acquired resistance to enzalutamide therapy have an upregulation of the sialyltransferase ST6 beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1) and increased levels of α2,6-sialylated N-glycans. Furthermore, using the sialyltransferase inhibitor P-SiaFNEtoc, we discover that acquired resistance to enzalutamide can be partially reversed by combining enzalutamide therapy with sialic acid blockade. Our findings identify a potential role for ST6GAL1-mediated aberrant sialylation in acquired resistance to enzalutamide therapy for prostate cancer and suggest that sialic acid blockade in combination with enzalutamide may represent a novel therapeutic approach in patients with advanced disease. Our study also highlights the potential to bridge the fields of cancer biology and glycobiology to develop novel combination therapies for prostate cancer.

BRAF + EGFR +/- MEK inhibitors after immune checkpoint inhibitors in BRAF V600E mutated and deficient mismatch repair or microsatellite instability high metastatic colorectal cancer

BackgroundImmune checkpoint inhibitors (ICIs) are the guideline endorsed first choice for patients with deficient mismatch repair or microsatellite instability high (dMMR/MSI-H) mCRC, however a significant proportion experience primary or secondary resistance. BRAF V600E mutated (BRAFm) and dMMR/MSI-H mCRC can be treated with BRAF + EGFR inhibitors but specific data on the efficacy after progression to ICIs are missing. MethodsWe collected consecutive patients with BRAFm dMMR/MSI-H mCRC treated from 2017 to 2024 with a combination of BRAFi+EGFRi+/-MEKi, after disease progression on ICIs. A control cohort of BRAFm pMMR/MSS mCRC patients treated with encorafenib+cetuximab+/-binimetinib from 2nd line was used. ResultsdMMR/MSI-H (n = 50) BRAFm mCRC patients were more often > 70-year-old, with right-sided primary tumors, without liver but more lymphnode metastases than pMMR/MSS (n = 170). They were treated more frequently beyond 2nd line and 45 % were primary progressors to ICIs. Lower ORR (18 % versus 32 %, p = 0.09) and DCR (60 % versus 73 %, p = 0.11) was seen without reaching significance in dMMR/MSI-H as compared to pMMR/MSS patients. After a median follow-up of 14.04 months, no differences in PFS (median 5.13 versus 4.50 months, HR 0.83, 95 %CI: 0.57–1.20, p = 0.31) and OS (median 10.75 versus 9.11 months, HR 0.89, 95 %CI: 0.59–1.32, p = 0.55) were observed. ConclusionsOur results show that BRAFm dMMR/MSI-H mCRC patients benefit from BRAFi+EGFRi+/-MEKi after progression under ICIs. Despite lower ORR and DCR, the outcome is not different from that observed in pMMR/MSS BRAFm CRC and is in line with the results of the BEACON registration trial.

Novel ERBB2 Variant Potentially Associated with Resistance against Anti-HER2 Monoclonal Antibody-Based Therapy in ERBB2-Amplified Metastatic Colorectal Cancer.

HER2-targeted therapies in ERBB2-amplified metastatic colorectal cancer (mCRC) are effective; however, a notable portion of patients do not respond to treatment, and secondary resistance occurs in most patients receiving these treatments. The purpose of this study was to investigate determinants of treatment efficacy and resistance in patients with ERBB2-amplified mCRC who received HER2-targeted therapy by analyzing multiomics data. We investigated genomic data from a nationwide large cancer genomic screening project, the SCRUM-Japan project. We analyzed paired genome and transcriptome data of tissue and genomic data of ctDNA collected pre- and postprogression in patients enrolled in the related trial, TRIUMPH, in ERBB2-amplified mCRC. In 155 patients with ERBB2-amplified solid tumors who received HER2-targeted therapy based on the SCRUM-Japan project, the objective response rate was 50%, 51%, and 35% in ERBB2 wild-type, variant of unknown significance, and pathogenic variant groups, respectively. In the paired genome and transcriptome data analyses in TRIUMPH, we identified the novel splicing-associated variant c.644-66_-2del in one of the 11 patients with paired whole-exome sequencing and whole-transcriptome sequencing data sets, which lacks the binding domain of pertuzumab, in progressed metastatic tumor as a variant with potential pathogenicity. The time-course ctDNA analysis detected c.644-66_-2del as an acquired variant. This study highlighted the importance of ERBB2 genomic status when evaluating the efficacy of HER2-targeted therapies in ERBB2-amplified mCRC. The identification of a novel splicing-associated variant may provide insights into potential mechanisms of treatment resistance. Furthermore, we demonstrated the utility of ctDNA to follow the acquired genomic status of mCRC tumors.

Benefits of osimertinib treat a lung adenocarcinoma patient with germline EGFR T790M, somatic EGFR 19-Del, TP53 and PIK3CA mutations

BackgroundSomatic mutations in the EGFR gene occur in about 50% of non-small cell lung cancers, with the T790M mutation significantly contributing to secondary resistance against EGFR-TKI drugs. However, EGFR T790M germline mutations rarely occur.Case presentationIn this study, we report a case of a lung adenocarcinoma family lineage linked to a germline EGFR T790M mutation. The main subject was diagnosed with stage IV lung adenocarcinoma and experienced a 19-month period without disease progression while treated with Osimertinib. We collected both clinicopathological and familial data from a patient with lung adenocarcinoma. Next-generation sequencing of 40 key genes was performed on the proband’s tumor tissue. To detect EGFR germline mutations, Sanger sequencing was conducted on peripheral blood mononuclear cells from the proband and his two daughters. Mutations such as EGFR T790M, EGFR 19-Del, TP53, and PIK3CA were identified in the proband’s lung cancer tissue. Additionally, germline EGFR T790M mutations were confirmed in the proband and his daughters through sequencing of their peripheral blood samples. CT scans revealed multiple pulmonary nodules in both daughters.ConclusionsThese observations suggest that germline mutations in EGFR T790M could be strongly linked to a familial predisposition to lung cancer.

Experimental and theoretical evaluation of the effect of fluid resistance on the performance of a tubular indirect evaporative cooler

To evaluate the impact of fluid resistance on the performance of tubular indirect evaporative coolers (TIECs), a mathematical model of secondary air channel resistance was developed. An experimental setup was created to study the effects of factors such as secondary air flow rate and water spray flow rate on R2 under actual conditions. The model used the same conditions to analyze how factors like air flow, water flow, and droplet size influenced R2. The relationship between R2 and wet-bulb effectiveness (εwb) was also examined experimentally. The data from the experiments were compared to the model's predictions, showing a maximum relative error of 10 %, confirming the model's accuracy. It was found that R2 and secondary air flow rate (V2) are positively correlated, and εwb increases with R2. The experiments yielded secondary air resistances ranging from a minimum of 548.2 Pa to a maximum of 554.26 Pa. These results are valuable for selecting appropriate fans for the secondary air channel. Additionally, simulations were conducted to predict and calculate energy losses in the secondary air channel under real working conditions, providing a useful basis for future fan selection.

Gut resistome of NSCLC patients treated with immunotherapy.

The newest method of treatment for patients with NSCLC (non-small cell lung cancer) is immunotherapy directed at the immune checkpoints PD-1 (Programmed Cell Death 1) and PD-L1 (Programmed Cell Death Ligand 1). PD-L1 is the only validated predictor factor for immunotherapy efficacy, but it is imperfect. Some patients do not benefit from immunotherapy and may develop primary or secondary resistance. This study aimed to assess the intestinal resistome composition of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors in the context of clinical features and potentially new prediction factors for assessing immunotherapy efficacy. The study included 30 advanced NSCLC patients, 19 (57%) men and 11 (33%) women treated with first- or second-line immunotherapy (nivolumab, pembrolizumab or atezolizumab). We evaluated the patient's gut resistome composition using the high sensitivity of targeted metagenomics. Studies have shown that resistome richness is associated with clinical and demographic factors of NSCLC patients treated with immunotherapy. Smoking seems to be associated with an increased abundance of macrolides, lincosamides, streptogramins and vancomycin core resistome. The resistome of patients with progression disease appears to be more abundant and diverse, with significantly higher levels of genomic markers of resistance to lincosamides (lnuC). The resistance genes lnuC, msrD, ermG, aph(6), fosA were correlated with progression-free survival or/and overall survival, thus may be considered as factors potentially impacting the disease. The results indicate that the intestinal resistome of NSCLC patients with immune checkpoint inhibitors treatment differs depending on the response to immunotherapy, with several distinguished markers. Since it might impact treatment efficacy, it must be examined more deeply.

75 WIRE: Window of Opportunity Clinical Trials Platform for Evaluation of Novel Treatments Strategies in Renal Cell Cancer

Abstract Background Despite the success of immunotherapy and VEGFR directed tyrosine kinase inhibitors (TKIs) for the treatment of renal cell carcinoma (RCC), a significant proportion of patients display primary or secondary resistance to systemic therapy. New treatment approaches are needed for these patients. Pre-surgical clinical trials allow us to study the effects of cancer treatment on the tumour microenvironment, comparing baseline biopsy with post-treatment nephrectomy in a ‘window of opportunity’ study. The results may give us insight into the mechanisms of new cancer therapies, that may be advanced into further clinical trials. Methods The WIRE trial (NCT03741426) is a phase II, multi-centre, multi-arm, non-randomised, neoadjuvant clinical trial platform. The overall aim of the trial is proof of mechanism for new RCC therapies. There are five investigational arms: 1. Cediranib (a VEGFR directed TKI), 2. Cediranib + Olaparib (a PARP inhibitor), 3. Olaparib, 4. Volrustomig (anti PD-1/CTLA-4 bispecific) and 5. Rilvegostomig (anti PD-1/TIGIT bispecific). The study uses a Bayesian adaptive design to optimise recruitment, with pre-specified criteria assessed at interim analyses to stop for futility, continue recruitment to that arm, or move to the next investigational arm. Eligible patients have cT1b+, cN0/1, cM0/1 clear cell RCC, planning to undergo surgery, without medical contraindication to trial therapy. Patients undergo baseline biopsy to confirm clear cell RCC and multiparametric dynamic contrast enhanced (DCE) MRI scan of the primary tumour. For tablet arms 1-3, patients receive at least 14 days of investigational medicinal product (IMP). For immunotherapy arms 4 &amp; 5, patients receive one infusion of IMP. The tumour is re-evaluated by DCE-MRI immediately before surgery. At nephrectomy, multi-region tissue sampling from the tumour is performed both pre-arterial ligation and post resection. Serial translational blood and urine samples are collected before, during and after treatment. The primary endpoint for arms 1-3 is a ≥30% reduction in DCE-MRI assessed capillary permeability (Ktrans) compared to baseline. The primary endpoint for arms 4 &amp; 5 is a ≥30% increase in IHC assessed CD8+ T cell density comparing the resected tumour to baseline biopsy. Secondary endpoints include RECIST v1.1 primary tumour response and adverse events. A comprehensive translational science programme accompanies the trial, which will assess the tumour microenvironment and peripheral blood response to therapy, using techniques including imaging mass cytometry and single cell RNA sequencing. This will allow us to gain a deep understanding of mechanisms of response in each investigational arm. To date, arms 1 &amp; 2 have completed recruitment, and arm 3 is actively recruiting. Conclusions WIRE offers a unique opportunity to investigate the mechanisms of new therapies for RCC. Successful completion of these peri-surgical studies depends on co-ordination between many specialties, including surgery, oncology, radiology, and pathology. The adaptive design allows for efficient allocation of patients to treatment arms to generate optimal data for each IMP. WIRE may identify novel biomarkers of response and toxicity, to inform treatment selection for patients. The data generated will be a foundation for further trials of these IMPs in advanced disease.