Single Agent Research Articles

Niraparib plays synergistic antitumor effects with NRT in a mouse ovarian cancer model with HRP

ObjectivePARPi offers less clinical benefit for HRP patients compared to HRD patients. PARPi has an immunomodulatory function. NRT therapy targets tumor neoantigens without off-target immune toxicity. We explored the synergy between Niraparib and NRT in enhancing antitumor activity in an HRP ovarian cancer mouse model. MethodsIn the C57BL/6 mouse ID8 ovarian cancer model, the effect of Niraparib on reshaping TIME was evaluated by immune cell infiltration analysis of transcriptomic data. The antitumor effects of Niraparib, NRT, and their combined use were systematically evaluated. To corroborate alterations in TILs, TAMs, and chemokine profiles within the TIME, we employed immunofluorescence imaging and transcriptome sequencing analysis. ResultsNiraparib increased the M1-TAMs and activated CD8+ T cells in tumor tissues of C57BL/6 mice with ID8 ovarian cancer. GSEA showed that gene set associated with immature DC and INFα, cytokines and chemokines were significantly enriched in immune feature, KEGG and GO gene sets, meanwhile CCL5, CXCL9 and CXCL10 play dominant roles together. In the animal trials, combined group had a tumor growth delay compared with Niraparib group (P < 0.01) and control group (P < 0.001), and longer survival compared with the single agent group (P<0.01) . ConclusionsNiraparib could exert immune-reshaping effects, then acts synergistic antitumor effects with NRT in HRP ovarian cancer model. Our findings provide new ideas and rationale for combined immunotherapy in HRP ovarian cancer.

Respiratory illness in young and adult cattle caused by bovine viral diarrhea virus subgenotype 2b in singular and mixed bacterial infection in a BVDV-vaccinated dairy herd.

Bovine respiratory disease (BRD) is a common global health problem in dairy cattle. The definitive diagnosis of BRD is complex because its etiology involves several predisposing and determining factors. This report describes the etiology of a BRD outbreak in a dairy herd in the mesoregion of Central Eastern Paraná, which simultaneously affected young (calves and heifers) and adult (cows) Holstein-Friesian cattle. Nine biological samples, consisting of five lung samples from two cows and three suckling calves, and four nasal swab samples from heifers, were used for etiological diagnosis. The nucleic acids extracted from lung fragments and nasal swabs were subjected to PCR and RT-PCR assays for partial amplification of the genes of five viruses [bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoAHV1), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus 3 (BPIV-3), and bovine coronavirus (BCoV)] and four bacteria (Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni) involved in the etiology of BRD. All nine biological samples from the animals with BRD tested negative for BoAHV1, BRSV, BPIV-3, BCoV, and H. somni. Therefore, the involvement of these microorganisms in the etiology of BRD outbreak can be ruled out. It was possible to identify the presence of BVDV and M. bovis in singular and mixed infections of the lower respiratory tract in cattle. BVDV was also identified in two nasal swabs: one as a single etiological agent and the other in association with two bacteria (P. multocida and M. haemolytica). The phylogenetic analysis conducted in the nucleotide sequence of the 5'UTR region and Npro gene of the BVDV amplicons demonstrated that the BVDV field strains of this BRD outbreak belong to subgenotype 2b. To the best of our knowledge, this is the first report of BVDV-2b involvement in the etiology of BRD in Brazil. Finally, it is necessary to highlight that the cattle were obtained from an open dairy herd with biannual vaccinations for BVDV-1a and - 2a.

Entinostat as a combinatorial therapeutic for rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common childhood soft tissue sarcoma. For the alveolar subtype (ARMS), the presence of the PAX3::FOXO1 fusion gene and/or metastases are strong predictors of poor outcome. Metastatic PAX3::FOXO1+ ARMS often responds to chemotherapies initially, only to subsequently relapse and become resistant with most patients failing to survive beyond 8 years post-diagnosis. No curative intent phase II or phase III clinical trial has been available for patients in the past 10 years (ARST0921). Thus, metastatic ARMS represents a significantly unmet clinical need. Chemotherapy resistance in ARMS has previously been attributed to PAX3::FOXO1-mediated cell cycle checkpoint adaptation, which is mediated by an HDAC3-SMARCA4-miR-27a-PAX3::FOXO1 circuit that can be disrupted by HDAC3 inhibition. In this study, we investigated the therapeutic efficacy of combining the epigenetic regulator entinostat, a Class I Histone Deacetylase (HDAC1-3) inhibitor, with RMS-specific chemotherapies in patient derived xenograft (PDX) models of RMS. We identified single agent, additive or synergistic relationships between relapse-specific chemotherapies and clinically relevant drug exposures of entinostat in three PAX3::FOXO1+ ARMS mouse models. This preclinical data provides further rationale for clinical investigation of entinostat, already known to be well tolerated in a pediatric phase I clinical trial (ADVL1513).

LTβR Agonism Promotes Anti-Tumor Immune Responses via Modulation of the Tumor Microenvironment.

The presence of high endothelial venules (HEV) and tertiary lymphoid structures (TLS) in solid tumors is correlated with favorable prognosis and better responses to immune-checkpoint blockade (ICB) in many cancer types. Elucidation of the molecular mechanisms underlying intratumoral HEV and TLS formation and their contribution to anti-tumor responses may facilitate development of improved treatment strategies. Lymphotoxin beta receptor (LTβR) signaling is a critical regulator of lymph node organogenesis and can cooperate with antiangiogenic and ICB treatment to augment tumor-associated HEV formation. Here, we demonstrated that LTβR signaling modulates the tumor microenvironment via multiple mechanisms to promote anti-tumor T cell responses. Systemic activation of the LTβR pathway via agonistic antibody treatment induced tumor-specific HEV formation, upregulated the expression of TLS-related chemokines, and enhanced dendritic cell (DC) and T cell infiltration and activation in syngeneic tumor models. In vitro studies confirmed direct effects of LTβR agonism on DC activation and maturation and associated DC-mediated T cell activation. Single agent LTβR agonist treatment inhibited syngeneic tumor growth in a CD8+ T cell- and HEV-dependent manner, and the LTβR agonist enhanced anti-tumor effects of anti-PD-1 and CAR T cell therapies. An in vivo tumor screen for TLS-inducing cytokines revealed that the combination of LTβR agonism and lymphotoxin alpha (LT⍺) expression promoted robust intratumoral TLS induction and enhanced tumor responses to anti-CTLA-4 treatment. Collectively, this study highlights crucial functions of LTβR signaling in modulating the tumor microenvironment and could inform future HEV/TLS-based strategies for cancer treatments.

MERTK Is a Potential Therapeutic Target in Ewing Sarcoma.

Outcomes are poor in patients with advanced or relapsed Ewing sarcoma (EWS) and current treatments have significant short- and long-term side effects. New, less toxic and more effective treatments are urgently needed. MER proto-oncogene tyrosine kinase (MERTK) promotes tumor cell survival, metastasis, and resistance to cytotoxic and targeted therapies in a variety of cancers. MERTK was ubiquitously expressed in five EWS cell lines and five patient samples. Moreover, data from CRISPR-based library screens indicated that EWS cell lines are particularly dependent on MERTK. Treatment with MRX-2843, a first-in-class, MERTK-selective tyrosine kinase inhibitor currently in clinical trials, decreased the phosphorylation of MERTK and downstream signaling in a dose-dependent manner in A673 and TC106 cells and provided potent anti-tumor activity against all five EWS cell lines, with IC50 values ranging from 178 to 297 nM. Inhibition of MERTK correlated with anti-tumor activity, suggesting MERTK inhibition as a therapeutic mechanism of MRX-2843. Combined treatment with MRX-2843 and BCL-2 inhibitors venetoclax or navitoclax provided enhanced therapeutic activity compared to single agents. These data highlight MERTK as a promising therapeutic target in EWS and provide rationale for the development of MRX-2843 for the treatment of EWS, especially in combination with BCL-2 inhibitors.

Efficacy and safety of low-dose versus standard-dose immune checkpoint inhibitor as monotherapy in patients with solid tumors: A meta-analysis and systematic review.

188 Background: Immunotherapy is a novel anti-cancer therapy with different mechanisms compared with chemotherapy. Several studies have reported that low dose of immune checkpoint inhibitors (ICIs) is effective. However, it is unknown whether the efficacy of low-dose immunotherapy is inferior to that of standard dose immunotherapy. We aimed to compare the existing randomized clinical trials on the efficacy of immunotherapy at low dose and standard dose as a single agent for patients with solid tumors. Methods: We searched PubMed, EMBASE, and the Cochrane Library for randomized clinical trials with the clinical outcomes of low dose and standard dose of programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitor as monotherapy until November 30, 2023. The low dose is defined as lower than the dose approved by FDA. The hazard ratio (HR) and 95% confidence interval (CI) of overall survival (OS) and disease control rate (DCR) were collected. The Stata 15.0 software was used to analyze the data. Results: Twenty-two studies with 3226 patients with five ICIs for 22 solid tumors were included. There is no difference in OS (HR 1.12, 95% CI = 0.97-1.31; p &gt; 0.05), ORR (Odds ratio (OR) 0.92, 95% CI = 0.76-1.11; p &gt; 0.05) and DCR (OR 0.83, 95% CI = 0.65-1.06; p &gt; 0.05) for patients with low dose and standard dose of PD-1/PD-L1 inhibitors. Conclusions: Our results suggested that PD-1/PD-L1 inhibitor as monotherapy with a low dose may be as effective as standard dose for patients with solid tumors. The regular dose-response relationship may not be appropriate for ICIs. Further work is needed to explore the optimal dose of ICIs based on the comprehensive consideration of efficacy, safety, and economic assessment.

OPERA-01: A randomized, open-label, phase 3 study of palazestrant (OP-1250) vs standard-of-care for patients with ER+, HER2- advanced or metastatic breast cancer after endocrine therapy and CDK4/6 inhibitors.

TPS22 Background: In estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) metastatic breast cancer (MBC), endocrine therapy (ET) plus a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) is the standard-of-care (SOC) treatment in the first-line setting. However, patients develop resistance, most commonly due to acquired mutations in ESR1. Efficacy of available ET post CDK4/6i treatment is limited. Therefore, a significant unmet need exists for patients with ET-CDKi-resistant ER+, HER2– MBC to improve outcomes and delay time to chemotherapy. Palazestrant is an oral small molecule complete ER antagonist (CERAN) and selective ER degrader (SERD) that binds ER and completely blocks ER-driven transcriptional activity, irrespective of ESR1 mutation status. In a phase 1/2 monotherapy study in heavily pretreated patients with ER+, HER2– advanced or MBC (NCT04505826), palazestrant showed a tolerable safety profile, favorable pharmacokinetics and encouraging antitumor efficacy in patients with and without ESR1 mutation at the recommended Phase 2 dose of 120 mg once a day (qd) (Lin et al. ESMO 2023 MO382). Methods: OPERA-01 (NCT06016738) is a multicenter, randomized, open-label, phase 3 clinical trial comparing the efficacy and safety of palazestrant as a single agent to SOC ET (fulvestrant, anastrozole, letrozole, or exemestane) in patietns with ER+, HER2– MBC that relapsed or progressed on 1-2 prior lines of ET, including a CDK4/6i. Eligible patients are adults who have a confirmed diagnosis of evaluable ER+, HER2– inoperable locally advanced or MBC and an Eastern Cooperative Oncology Group performance status of 0 or 1. Prior treatments must include 1-2 prior lines of ET, last ET duration for ≥6 months; must have received CDK4/6i with ET and have disease progression during or within 28 days of completion of each line of prior treatment for MBC. No prior chemotherapy in the metastatic setting is permitted. In the dose selection part of the study, 120 patients are randomized to 90 mg qd or 120 mg qd palazestrant or SOC monotherapy. The dose selection will be conducted when 80 patients in both palazestrant arms have had an opportunity to be on treatment for 16 weeks. Overall, 510 patients, including patients from the dose selection part, will be randomized to palazestrant or SOC ET. The primary endpoint of progression-free survival will be assessed by blinded independent central review in patients with and without ESR1 mutations in the intent-to-treat population. Secondary endpoints include overall survival, antitumor activity (objective response rate, clinical benefit rate, and duration of response), safety, patient-reported outcomes, and PK in patients with and without ESR1 mutations. The study started recruitment in November 2023. Clinical trial information: NCT06016738 .

OUTCOMES OF PEDIATRIC FLUID-REFRACTORY SEPTIC SHOCK ACCORDING TO DIFFERENT VASOACTIVE STRATEGIES: A SYSTEMATIC REVIEW AND META-ANALYSIS.

Background: Hemodynamic support using vasoactive agents is a mainstay in the management of patients with pediatric fluid-refractory septic shock (FRSS). However, evidence supporting the appropriate choice of vasoactive agent is limited. This study aimed to perform a systematic review and meta-analysis on the effect of different first-line vasoactive strategies on mortality in pediatric FRSS. Methods: MEDLINE, Embase, Scopus, CINAHL, Web of Science, the Cochrane Library, ClinicalTrials.gov , and the ISRCTN registry were searched up until December 2023. Randomized controlled trials and observational cohort studies reporting vasoactive agent-specific outcomes of children with FRSS were included. Mortality was assessed as primary outcome in studies on patients receiving dopamine, epinephrine, or norepinephrine as first-line. Random-effects meta-analyses were conducted. Prevalence ratio (PR) estimates were calculated between two drugs when was available in the same study. Findings: Of the 26,284 identified articles, 13 were included, for a total of 997 children. Twelve studies included 748 patients receiving a single vasoactive agent. Of these, 361 received dopamine, 271 epinephrine, and 116 norepinephrine. Overall pooled mortality for patients receiving a single vasoactive was 12% (95% CI 6%-21%) of which 11% (95% CI 3%-36%) for patients receiving dopamine, 17% (95% CI 6%-37%) for epinephrine, and 7% (95% CI 1%-48%) for norepinephrine. Four first-line dopamine (176 patients) and first-line epinephrine (142 patients): dopamine showed a tendency toward higher mortality (PR 1.38, 95% CI 0.81-2.38) and a significant higher need for mechanical ventilation (PR 1.12, 95% CI 1.02-1.22). Interpretation: Among children with FRSS receiving a single vasoactive agent, norepinephrine was associated with the lowest mortality rate. Comparing dopamine and epinephrine, patients receiving epinephrine needed less mechanical ventilation and showed a trend for lower mortality rate. Further research is needed to better delineate the first-line vasoactive agent in this population.

Discovery of Preclinical Candidate AD1058 as a Highly Potent, Selective, and Brain-Penetrant ATR Inhibitor for the Treatment of Advanced Malignancies.

The ataxia telangiectasia-mutated and Rad3-related protein (ATR) plays a crucial role in regulating the cellular DNA-damage response (DDR), making it a promising target for antitumor drug development through synthetic lethality. In this study, we present the discovery and detailed characterization of AD1058, a highly potent and selective ATR inhibitor, with good preclinical pharmacokinetic profiles. AD1058 exhibits superior efficacy in inhibiting cell proliferation, disrupting the cell cycle, and inducing apoptosis compared to AZD6738. AD1058 displays potent antitumor effects as a single agent or in combination with clinically approved tumor therapies such as PARP inhibitors, ionizing radiotherapy, or chemotherapy in vivo. Considering its enhanced ability to permeate the blood-brain barrier, AD1058 is a promising clinical candidate for the treatment of brain metastases and leptomeningeal metastases in solid tumors. Additionally, among reported ATR inhibitors, AD1058 features the shortest synthesis route and the highest efficiency to date.

CHD1L Regulates Cell Survival in Breast Cancer and Its Inhibition by OTI-611 Impedes the DNA Damage Response and Induces PARthanatos.

The Chromodomain helicase DNA-binding protein 1-like (CHD1L) is a nucleosome remodeling enzyme, which plays a key role in chromatin relaxation during the DNA damage response. Genome editing has shown that deletion of CHD1L sensitizes cells to PARPi, but the effect of its pharmacological inhibition has not been defined. Triple-negative breast cancer SUM149PT, HCC1937, and MDA-MB-231 cells were used to assess the mechanism of action of the CHD1Li OTI-611. Cytotoxicity as a single agent or in combination with standard-of-care treatments was assessed in tumor organoids. Immunofluorescence was used to assess the translocation of PAR and AIF to the cytoplasm or the nucleus and to study markers of DNA damage or apoptosis. Trapping of PARP1/2 or CHD1L onto chromatin was also assessed by in situ subcellular fractionation and immunofluorescence and validated by Western blot. We show that the inhibition of CHD1L's ATPase activity by OTI-611 is cytotoxic to triple-negative breast cancer tumor organoids and synergizes with PARPi and chemotherapy independently of the BRCA mutation status. The inhibition of the remodeling function blocks the phosphorylation of H2AX, traps CHD1L on chromatin, and leaves PAR chains on PARP1/2 open for hydrolysis. PAR hydrolysis traps PARP1/2 at DNA damage sites and mediates PAR translocation to the cytoplasm, release of AIF from the mitochondria, and induction of PARthanatos. The targeted inhibition of CHD1L's oncogenic function by OTI-611 signifies an innovative therapeutic strategy for breast cancer and other cancers. This approach capitalizes on CHD1L-mediated DNA repair and cell survival vulnerabilities, thereby creating synergy with standard-of-care therapies.

67 Preclinical evaluation of PSMA-based68Ga-/225Ac-labeled radiotheranostic pair in a syngeneic mouse model of renal cell carcinoma

Abstract Background Despite the significant progress achieved with PD-1/PD-L1 inhibitors in the treatment of metastatic renal cell carcinoma (mRCC), most patients ultimately progress. Targeted radiotheranostics offer a new potential approach. Although a radiotheranostic platform targeting the prostate-specific membrane antigen (PSMA) has been tested in mRCC in patients preliminarily, thorough preclinical optimization has not been reported. Prostate-specific membrane antigen (PSMA) is overexpressed in tumor-associated neovascular endothelial cells of many solid tumors, including metastatic RCC. Furthermore, radiopharmaceutical therapy using β- and α-particle emitting agents causes immunomodulation by inducing immunogenic cell death, and release of tumor-associated antigens, potentially enhancing inflammatory phenotype. Here, we investigated whether PSMA-based radiotheranostics can be utilized to improve the efficacy of PD-1 therapy. Methods The PSMA+ RENCA model was developed by lentiviral transduction of RENCA (wt) cells and then characterized for basal and IFN-g induced PD-L1 expression. 68Ga-L1 and 225Ac-L1 were synthesized in high radiochemical yield and purity following our reported methods. Male and female BALB/c mice were used for tumor inoculation. 68Ga-L1 was evaluated in small animal PET/CT imaging in flank and PET/MR imaging in orthotopic implantation. A treatment study was conducted to assess the effect of combination therapy in seven groups in the flank tumors at 2 weeks post-inoculation: Control (saline); PD-1 (10 mg/kg); Anti-PD-1 (10 mg/kg)+axitinib (tyrosine kinase inhibitor, 5 mg/kg, oral gavage, for five days/wk); 225Ac-L1 (37 kBq); 225Ac-L1 (2×37 kBq, 1 wk apart); [225Ac-L1 (37 kBq)+PD-1 (10 mg/kg) and [225Ac-L1 2×37 kBq)+PD-1 (10 mg/kg)]. Therapeutic efficacy was assessed by tumor weight and time to progression of tumor volume doubling (TVD). To determine the mechanism of action of the 225Ac-L1/anti-PD-1 combination treatment, tumor-infiltrating lymphoid populations from tumor samples were collected at day 30, and Fluorescence-Activated Cell Sorting analysis was done with fluorochrome-labeled antibodies against CD45, CD3, CD8, IL10, and IL12. Results 68Ga-L1 and 225Ac-L1 confirmed 10-fold and 2-fold higher uptake, respectively, in the PSMA+ RENCA cells compared to RENCA (wt) cells. PET imaging in the flank model displayed ~7-fold higher accumulation of 68Ga-L1 in PSMA+ RENCA than the RENCA (wt). Two-fold higher accumulation of 68Ga-L1 was observed in orthotopic tumors than the normal kidneys during 1-3 h post-injection. Significant lung metastases were detected with 68Ga-L1 PET at 3 weeks in mice with orthotopic tumors. A combination therapy study was conducted using anti-PD-1 and anti-PD-1+axitinib and compared the efficacy with 225Ac-L1 as a single agent (37 kBq and 2×37 kBq, 1 wk apart) and in combination with PD-1. Median TVD increased from 12 d (control) to 16 d (anti-PD-1), 16 d (anti-PD-1+axitinib), 24 d [225Ac-L1 (37 kBq) P&amp;lt;0.001], 24 d [225Ac-L1 (2 × 37 kBq) P&amp;lt;0.0001}, 30 d [anti-PD-1+225Ac-L1 (1×37 kBq) P&amp;lt;0.0001], and undefined, [anti-PD-1+225Ac-L1 2×37 kBq), P&amp;lt;0.0001], respectively. Furthermore, treatment with 225Ac-L1 (2×37 kBq, 1 wk) resulted in a significant lowering of tumor growth (P&amp;lt; 0.01) compared to control, whereas anti-PD-1 (vs. control) alone moderately reduced tumor growth. The combination of the treatment of [PD-1+225Ac-L1 (2×37 kBq), P=0.0001] was the most effective in enhancing tumor growth inhibition compared with the PD-1+axitinib group. Flow cytometry of tumor-infiltrating immune cells of the treatment groups PD-1+225Ac-L1(37 kBq) and PD-1+225Ac-L1 (2×37 kBq) revealed a higher proportion of effector CD3+CD8+ T cells, accompanied by a significant decline in the proportion of immunosuppressive and pro-tumoral CD8+IL10+ T cells and increase in antitumor CD8+IL12+ T cells compared to untreated and treatment control groups (PD-1 or PD-1+axitinib groups). Conclusions Combining radiotheranostic platform, 68Ga-L1/225Ac-L1 with PD-1 therapy reduces tumor burden and improves TVD in a syngeic model of RCC. This is a promising option for metastatic RCC patients with low and heterogeneous PSMA expression. Translation of this method will be pursued actively. DOD CDMRP Funding: yes

Discovery of a Myeloid Cell Leukemia 1 (Mcl-1) Inhibitor That Demonstrates Potent In Vivo Activities in Mouse Models of Hematological and Solid Tumors.

Myeloid cell leukemia 1 (Mcl-1) is a key regulator of the intrinsic apoptosis pathway. Overexpression of Mcl-1 is correlated with high tumor grade, poor survival, and both intrinsic and acquired resistance to cancer therapies. Herein, we disclose the structure-guided design of a small molecule Mcl-1 inhibitor, compound 26, that binds to Mcl-1 with subnanomolar affinity, inhibits growth in cell culture assays, and possesses low clearance in mouse and dog pharmacokinetic (PK) experiments. Evaluation of 26 as a single agent in Mcl-1 sensitive hematological and solid tumor xenograft models resulted in regressions. Co-treatment of Mcl-1-sensitive and Mcl-1 insensitive lung cancer derived xenografts with 26 and docetaxel or topotecan, respectively, resulted in an enhanced tumor response. These findings support the premise that pro-apoptotic priming of tumor cells by other therapies in combination with Mcl-1 inhibition may significantly expand the subset of cancers in which Mcl-1 inhibitors may prove beneficial.

Advanced, recurrent, and persistent cervical cancer management: in the era of immunotherapy.

Cervical cancer constitutes a significant health burden for women worldwide despite being preventable by vaccination and screening. Advanced stages of the disease are associated with a poor prognosis, and treatment approaches have seen little change over several decades, resulting in an overall survival rate of no more than 17 months. Additionally, there are limited options for second-line treatment. The urgent need for innovative and effective therapies to improve the outlook for this group of patients, along with an enhanced understanding of the interactions between the disease and the host's immune system, has propelled immunotherapy into a rapidly advancing field with notable achievements. Among various immunotherapeutic approaches, immune checkpoint inhibitors emerge as the most advanced treatment option. Clinical trials assessing these inhibitors as single agents or in combination with chemotherapy show promising results. As immunotherapy begins to redefine standards of care for metastatic, recurrent, or persistent cervical cancer, this review addresses recent advances and current recommendations for its management in both first and second-line treatment. The goal is to provide insights into the evolving landscape of cervical cancer treatment, specifically focusing on immunotherapeutic interventions.

22 Association of a germline single nucleotide polymorphism (SNP) in the interleukin-7 (IL7) gene with immune-related adverse events (irAEs)

Abstract Background Adverse events (AEs) can limit treatment immune checkpoint inhibitors (ICI) efficacy and worsen patient outcomes. Our group recently identified a germline IL7 SNP as a potential biomarker for prediction of irAEs (Groha, Nat Med 2022). In the current study, we sought to replicate the association between this IL7 SNP (rs16906115) and AEs in two clinical trials of patients with cancer treated with ICI regimens. Methods In the CheckMate-025 (CM025) trial (NCT01668784), involving patients with metastatic renal cell carcinoma (mRCC) randomized to either nivolumab (NIVO) or everolimus (EVE), whole-exome sequencing (WES) data from tumor and peripheral blood samples were analyzed. The Cancer Genome Analysis pipeline was utilized to identify somatic alterations, and the STITCH pipeline was employed to determine SNP carrier status. In the BinTA-0037 (BTA-0037) trial (NCT03631706), focusing on patients with metastatic non-small cell lung cancer (mNSCLC), the carrier status of a surrogate SNP rs16906062 (R2=0.66) was determined from tumor WES in the pembrolizumab (PEMBRO) arm. Within each treatment arm, time to incident AEs were compared between carriers (SNP+) and non-carriers (SNP-) via multivariable Cox regression, controlling for age, sex, race, ECOG and sample purity. A SNP´treatment interaction term was also included in the entire CM025 cohort. Censoring for AEs occurred at death or last follow-up. A recurrent event analysis for AEs was conducted using the Andersen-Gill model, controlling for the same variables. Additionally, overall survival (OS) and progression-free survival (PFS) were also assessed. Results In total, 534 pts were included (NIVO: n=189, PEMBRO: n=152, EVE: n=193), among which 82 (15.4%) were SNP+. There were no differences in clinical and pathological characteristics between SNP+ and SNP-, except for sex (SNP+ 16.1% vs. SNP- 30.1% in females, P=0.046). Similarly, no differences in somatic alterations, including single nucleotide and copy number variants were seen between SNP+ and SNP- in CM025. SNP carrier status had no effect on OS nor PFS in all treatment arms (all P≥0.22). The rate of grade 2+ AEs was significantly higher in SNP+ vs. SNP- in the NIVO arm (Figure A, HR=2.91[1.48-5.72]), but not in the EVE (Figure B, control, non-ICI) arm (HR=0.63[0.3-1.29], SNP´treatment Pinteraction=0.002). Similarly, the rate of all grade AEs in the PEMBRO arm of BTA-0037 was higher in SNP+ vs. SNP- (Figure C, HR=2.30[1.60-4.60]). The rate of recurrent grade 2+ AEs was also significantly higher in SNP+ vs. SNP- in the NIVO arm (HR=3.43[1.83-6.43]), whereas a trend for fewer recurrent grade 2+ AEs was seen in SNP+ vs. SNP- in the EVE arm (HR=0.46[0.17-1.25], SNP´treatment Pinteraction=0.0005). Figure: Kaplan-Meier curves showing the cumulative rate of adverse events in the NIVO (A) and EVE (B) arms of CM025, as well as the PEMBRO arm of BTA0037 (C), in SNP- and SNP+. Conclusions The IL7 SNP (rs16906115) is associated with significantly higher rates of grade 2+ AEs, including recurrent events, in pts with mRCC or mNSCLC treated with single agent PD-1 inhibitors but not with non-ICI regimens, with no effect on survival and efficacy outcomes. These results confirm the SNP’s predictive potential as a biomarker for irAEs to guide therapeutic decisions in pts treated with ICIs.

17 CDK4/6 inhibition with Abemaciclib in in patients (pts) with previously treated advanced renal carcinoma (RCC)

Abstract Background Preclinical data suggests rationale for CDK4/6 alone and in combination with HIF-2 inhibitors; single agent activity for CDK4/6 inhibitors in RCC has not been reported. Abemaciclib is an oral CDK4/6 inhibitor approved in combination with hormonal therapy for metastatic breast cancer. In our phase 1b clinical trial (NCT04627064), we investigated the safety and clinical efficacy of abemaciclib monotherapy in pts with advanced pretreated RCC with clear cell component. Methods In this single center trial, adult pts with advanced RCC with a clear cell component and ECOG status of ≤1 progressing after at least one prior regimen including immunotherapy and a VEGF TKI received abemaciclib 200 mg twice daily in 4-week cycles until progression or unacceptable toxicity. Primary objective was to evaluate the objective response rate (ORR) of abemaciclib with secondary endpoint of safety. First imaging was performed after 2 cycles. Response assessed per RECIST 1.1 and toxicity per CTCAE v5.0. Results 11 pts (10 clear cell RCC and 1 translocation RCC) were enrolled between 12/31/2020 and 10/03/2023. Median age was 62 years (range 54-68) with 18% (n=2) showing sarcomatoid features. 73% (n=8) had IMDC intermediate risk disease and one patient had translocation RCC (tRCC) with a clear cell component. Median number of prior therapies was 4 (range 1-9). Seven patients received 2 cycles and 4 patients received &amp;lt; 2 cycles. ORR was 0% (0/11; 8 progressive disease, 1 stable disease in tRCC stopping for clinical progression, 2 pts not evaluable with clinical progression). 27% (n=3) experienced grade ≥3 treatment-related adverse events (diarrhea n=1, nausea n=1, neutropenia n=1). Conclusions In pts with heavily pretreated RCC, abemaciclib had manageable toxicity profile but no clinically meaningful activity as monotherapy. This data will offer important insight into interpretation of results for ongoing trials exploring CDK4/6 inhibition in combination with HIF-2 inhibitors.

58 Tumor immune microenvironment determinants of response to Lenvatinib and aPD-1 blockade in clear cell renal cell carcinoma

Abstract Background Combinations of immune checkpoint blockade (ICB) and anti-angiogenesis tyrosine kinase inhibitors (TKI) are the mainstay of metastatic ccRCC front-line treatment, but heterogenous responses and lack of biomarkers strongly emphasizes the need to understand RCC-specific mechanisms of effective treatment-related anti-tumor immunity. Although prior work consistently highlights tumor associated macrophages (TAMs) in RCC prognosis and treatment response, TAM targeting has yet to experimentally assessed as a viable treatment sensitizer. Methods We therefore assessed the impact of TAM depletion using a clinical-grade colony stimulating factor receptor-1 inhibitor (CSF1Ri) on ICB or TKI sensitivity in a spontaneous mouse model of ccRCC with inducible kidney-specific Vhl, p53 and Rb1 deletions (KVpR). Mice were randomized to receive either no treatment, single agent Lenvatinib (TKI), aPD-1, or combinations with CSF1Ri. We longitudinally monitored a total of 307 tumors from 96 mice using magnetic resonance imaging (MRI) and collected responding and non-responding tumors for single cell RNA sequencing (scRNAseq) to elucidate the underlying mechanisms of response. Results Surprisingly we found that TAM depletion abolished aPD-1 response, with no effect on Lenvatinib response. ScRNAseq analyses suggest that CSF1R selectively depletes antigen presenting TAMs, leading to a striking loss of T cell infiltration. This suggests that TAMs, rather than dendritic cells as shown in other cancer types, may play a dominant role in eliciting T cells during aPD-1 therapy in RCC. On the other hand, Lenvatinib, which elicited a stronger T cell response than aPD-1, was associated with significant increases in cDC1 and plasma cells in responders, together suggesting that these two treatment modalities may operate through distinct antigen-presenting cells. Also unexpectedly, we found that both Lenvatinib and CSF1Ri induced severe intratumor hypoxia, which is typically associated with poor outcomes in most cancers. We identify a hypoxic niche-specific TAM subset that when abundant at baseline is predictive for poor response to ICB/TKI combos across multiple RCC trials, but post-treatment seems to capture hypoxia-mediated tumor cell death in responders in mouse and humans. We therefore wondered whether high levels of existing tumor hypoxia would exacerbate TKI-induced hypoxia leading to worst outcomes and found that in two novel RCC syngeneic models with high-baseline hypoxia, TKI indeed augments metastatic disease. Conclusions Our results offer mechanistic insight into the failure of CSF1R-based TAM depletion approaches in clinical trials and presents cautionary evidence against the use of hypoxia-inducing agents in tumors with high-baseline hypoxia. We show that TKI and ICB-induce distinct TME and hypoxia-related changes which require further study. More generally our study strongly emphasizes the importance of developing mechanism-guided clinical biomarkers. DOD CDMRP Funding: yes

Complexity in low-carbon transitions: Uncertainty and policy implications

We explore the uncertain dimension induced by the complexity of energy systems, analyzing whether and under which conditions low-carbon transitions can effectively take place. By accounting for social and environmental considerations, heterogeneous single utility-maximizing agents optimally decide whether to adopt a green technology which reduces carbon emissions, allowing eventually for a green energy transition. We characterize the determinants of the success of such a transition, emphasizing that even if the favorable conditions are met the low-carbon transition may not result in long run environmental improvements due to the path-dependency and metastability phenomena which characterize the complexity arising from agents’ interactions. Public policy may solve these issues by increasing the incentive for single individuals to adopt, ensuring thus the achievement of a permanent low-carbon state. By extending the analysis to a spatial network characterized by multiplexity due to the social and environmental interconnections, we show that spatial interactions negatively affect agents’ adoption incentive and reduce the effectiveness of public policy by interacting in a complex way with path-dependency and metastability. In particular, spatial interactions may require a larger subsidy to support a permanent low-carbon transition, thus neglecting their effects on agents’ behavior and environmental outcomes may compromise our chances to achieve a greener future.

Assessments of prostate cancer cell functions highlight differences between a pan-PI3K/mTOR inhibitor, gedatolisib, and single-node inhibitors of the PI3K/AKT/mTOR pathway.

Metastatic castration-resistant prostate cancer (mCRPC) is characterized by loss of androgen receptor (AR) sensitivity and oncogenic activation of the PI3K/AKT/mTOR (PAM) pathway. Loss of the PI3K regulator PTEN is frequent during prostate cancer (PC) initiation, progression, and therapeutic resistance. Co-targeting the PAM/AR pathways is a promising mCRPC treatment strategy but is hampered by reciprocal negative feedback inhibition or feedback relief. Most PAM inhibitors selectively spare (or weakly inhibit) one or more key nodes of the PAM pathway, potentiating drug resistance depending on the PAM pathway mutation status of patients. We posited that gedatolisib, a uniformly potent inhibitor of all class I PI3K isoforms, as well as mTORC1 and mTORC2, would be more effective than inhibitors targeting single PAM pathway nodes in PC cells. Using a combination of functional and metabolic assays, we evaluated a panel of PC cell lines with different PTEN/PIK3CA status for their sensitivity to multi-node PAM inhibitors (PI3K/mTOR: gedatolisib, samotolisib) and single-node PAM inhibitors (PI3Kα: alpelisib; AKT: capivasertib; mTOR: everolimus). Gedatolisib induced anti-proliferative and cytotoxic effects with greater potency and efficacy relative to the other PAM inhibitors, independent of PTEN/PIK3CA status. The superior effects of gedatolisib were likely associated with more effective inhibition of critical PAM-controlled cell functions, including cell cycle, survival, protein synthesis, oxygen consumption rate, and glycolysis. Our results indicate that potent and simultaneous blockade of all class I PI3K isoforms, mTORC1, and mTORC2 could circumvent PTEN-dependent resistance. Gedatolisib, as a single agent and in combination with other therapies, reported promising preliminary efficacy and safety in various solid tumor types. Gedatolisib is currently being evaluated in a Phase 1/2 clinical trial in combination with darolutamide in patients with mCRPC previously treated with an AR inhibitor, and in a Phase 3 clinical trial in combination with palbociclib and fulvestrant in patients with HR+/HER2- advanced breast cancer.

An update on the status of HSP90 inhibitors in cancer clinical trials.

The evolutionary conserved molecular chaperone heat shock protein 90 (HSP90) plays an indispensable role in tumorigenesis by stabilizing client oncoproteins. Although the functionality of HSP90 is tightly regulated, cancer cells exhibit a unique dependence on this chaperone, leading to its overexpression, which has been associated with poor prognosis in certain malignancies. While various strategies targeting heat shock proteins (HSPs) involved in carcinogenesis have been explored, only inhibition of HSP90 has consistently and effectively resulted in proteasomal degradation of its client proteins. To date, a total of 22 HSP90 inhibitors (HSP90i) have been tested in 186 cancer clinical trials, as reported by clinicaltrials.gov. Among these trials, 60% have been completed, 10% are currently active, and 30% have been suspended, terminated, or withdrawn. HSP90 inhibitors (HSP90i) have been used as single agents or in combination with other drugs for the treatment of various cancer types in clinical trials. Notably, improved clinical outcomes have been observed when HSP90i are used in combination therapies, as they exhibit a synergistic antitumor effect. However, as single agents, HSP90i have shown limited clinical activity due to drug-related toxicity or therapy resistance. Recently, active trials conducted in Japan evaluating TAS-116 (pimitespib) have demonstrated promising results with low toxicity as monotherapy and in combination with the immune checkpoint inhibitor nivolumab. Exploratory biomarker analyses performed in various trials have demonstrated target engagement that suggests the potential for identifying patient populations that may respond favorably to the therapy. In this review, we discuss the advances made in the past 5 years regarding HSP90i and their implications in anticancer therapeutics. Our focus lies in evaluating drug efficacy, prognosis forecast, pharmacodynamic biomarkers, and clinical outcomes reported in published trials. Through this comprehensive review, we aim to shed light on the progress and potential of HSP90i as promising therapeutic agents in cancer treatment.

Outcomes Analysis of Patients Receiving Local Ablative Therapy for Oligoprogressive Metastatic NSCLC Under First-Line Immunotherapy

ContextNonsmall Cell Lung Cancer (NSCLC) treatment relies on first-line immunotherapy as single agent or combined with chemotherapy. Oligoprogression may be observed in this setting. Material and MethodWe performed a European multicentric retrospective study on patients treated with first-line immunotherapy, who presented with oligoprogressive disease, treated with a local ablative treatment. ResultsA total of 61 patients were retrospectively included between 2018 and 2022. Twenty-four patients (39%) received immunotherapy as single agent, and 37 (61%) chemo-immunotherapy. First oligoprogression occurred more frequently in pre-existing metastatic sites (47% of patients). Median PFS1 (defined as time to first oligoprogression) was 11.5 months [IC95%: 10.0-12.3]. We observed that 37 patients (61%) progressed after first oligoprogression, and 20 (54%) from them presented second oligoprogression. Median OS for the whole cohort was 72.0 months [IC95%: 19.3-124.8], with positive correlation between OS and PFS1 (R=0.65, P < .0001). After loco-ablative treatment with radiotherapy, disease control rate was 89% with ablative radiotherapy: 88% with conventional radiotherapy, and 89% with stereotactic radiotherapy. ConclusionPatients with oligoprogression under/after immunotherapy have better prognosis with a high risk of subsequent oligoprogression.