Advanced Solid Tumor Malignancies Research Articles

Efficacy and safety of penpulimab-containing regimens for advanced malignant solid tumors that have failed immunotherapy: A real-world study.

e14700 Background: Immuno-checkpoint inhibitors (ICI) have shown good anti-tumor efficacy and survival benefits in a variety of solid tumors, such lung cancer, gastric cancer, esophageal cancer, head and neck squamous cell carcinoma (HNSCC). ICI have rewritten the guidelines for multiple tumor types. However, there are still a large number of patients who are ineffective or initially effective after use ICI, and subsequently develop ICI resistance. For these patients, how we choose further treatment is currently uncertain clinically. Some studies suggest that even if the treatment of PD - (L) 1 is ineffective or progresses, it can still bring a certain degree of benefit to re-challenge with other target ICI. This study was to evaluate the efficacy and safety of the patients with advanced malignant solid tumors with the regimen of penpulimab. Methods: This is a non-interventive registration study. Eligible participants must be ≥ 18 years old and have proven malignant tumors that are ineffective, fail for immunotherapy and have no other standard treatment. Patients were treated with penpulimab alone or in combination with chemotherapy or anti-angiogenic agents until progression or unacceptable toxicity. The primary endpoint is objective response rate (ORR). Secondary endpoints were disease control rate (DCR), progression free survival (PFS), overall survival (OS) and safety. Results: Form Sep 2021 to Feb 2023, 28 patients (median age 59.5 years, male 71.4%）were recruited, including 9 pts with NSCLC, 5 pts with HNSCC, 4 pts with Nasopharyngeal carcinoma (NPC), 3 pts with esophageal cancer and 7 with other tumor types. Among all, 1 achieved confirmed PR, 21 achieved SD, the ORR was 3.6% (1/28) and the DCR was 78.6% (22/28). The median treatment duration was 9 months. Among the 9 pts with NSCLC, the median treatment duration was 5.6 months and the DCR was 77.8%. Treatment-related adverse events (TRAEs) of grade 3 were observed in 5 (17.9%) of the 28 patients. The most common TRAEs were decreased lymphocyte count (50%, 14/28), anemia (50%, 14/28), hypoalbuminemia (39.3%, 11/28), hyponatremia (25%, 7/28) and hypercholesterolemia (25%, 7/28). Conclusions: Penpulimab-containing regimens for advanced malignant solid tumors that have failed ICI have shown significant efficacy and a favorable safety profile.

A novel anti-HER2 monoclonal antibody IAH0968 in HER2-positive, heavily pretreated solid tumors: Results from a phase Ⅰa/Ⅰb, first-in-human, open-label, single-center study.

e15098 Background: IAH0968 is an afucosylated anti-epidermal growth factor receptor 2 (HER2) monoclonal antibody which possessing the same binding properties to HER2 as trastuzumab and improving antibody-dependent cellular cytotoxicity (ADCC) activity and superior anti-tumor efficacy. We present results from patients with advanced HER2 positive malignant solid tumors including trastuzumab resistant and ineffective patients to establish the recommended dose of IAH0968 for phase II trials, as well as to investigate the safety, tolerability, pharmacokinetics (PK) and preliminary clinical activity of the drug. Methods: This was a single institution investigator-initiated phaseⅠa/Ⅰb study, using 3+3 design. The primary endpoint was safety, tolerability and preliminary clinical activity. Secondary endpoints included PK, recommended phase II dose, and anti-drug antibody (ADA). PK detection used ELISA to quantitatively determine blood drug concentration of IAH0968. Results: Eighteen pts were evaluable for safety and fifteen pts were suitable for efficacy analysis. The primary cancer sites included breast (8/18), colon (3/18), stomach (2/18), rectum (2/18), biliary tract (2/18), and pancreas (1/18). Median age was 54.2±9.7, ECOG 1/2 = 17/1, and 72.2% received anti-HER2 therapy in prior lines. Doses escalation were 6mg/kg (N = 3), 10mg/kg (N = 6), 15mg/kg (N = 5), and tolerable up to 20mg/kg (N = 4). Only one DLT was found at dosage 10mg/kg, and no MTD was reached. No ADA against IAH0968 was detected. The main PK parameters included mean T1/2 for doses 6~20 mg/kg ranging from 105 to 118 hours. The volume of distribution (Vz-obs) ranged from 4110.16 mL to 5395.64 mL. EC50 of ADCC activity of IAH0968 was 17.75~63.25 ×10-3 µg/mL. All grade treatment-related adverse events (TRAEs) occurred in 100% of pts, including grade 3 in 16.7%, and grade 4 in 5.6% of pts. The most common grade 3 TRAEs were hypokalemia (5.6%), arrhythmia (5.6%), QTC interval extension (5.6%), and infusion reaction (5.6%). The grade 4 TRAE was arrhythmia (5.6%). No serious TRAE or G5 were reported. 22.2% of pts had a TRAE leading to dose adjustment and 16.7% leading to discontinuation of IAH0968. After a median follow-up of 56.5 days (range, 0-479), objective response rate (ORR) was 13.3% (2/15), disease control rate (DCR) was 53.3% (8/15), and median progression-free survival (PFS) was 57.5 days (range, 42-236), with 4/15 responses ongoing. Conclusions: In heavily pretreated metastatic pts with HER2 positive, IAH0968 demonstrated promising clinical activity and tolerable safety profiles. IAH0968 will be further assessed in Phase Ⅱ study in combination treatment. Clinical trial information: NCT04934514 .

Phase 1 study of LB1410, a bivalent TIM-3/PD-1 bispecific antibody, in patients with advanced solid tumors or lymphoma.

TPS2663 Background: Cancer immunotherapies targeting PD-1 or PD-L1 have been proven effective in causing durable antitumor immune responses with less toxicity in many types of tumors. However, the response rate of anti-PD-1/PD-L1 treatments is far from satisfactory and most patients show primary or acquired resistance to the treatments. Tim-3, one of the next generation of immune checkpoint targets, co-expressed on exhausted T cells with PD-1. It is also expressed by innate immune populations, including NK and DC. Dual blocking PD-1 and Tim-3 not only on T cells but also on DC, NK cells may achieve better clinical benefit. LB1410 is a recombinant humanized anti-PD-1/TIM-3 bispecific antibody (BsAb) developed by L&L Biopharma Co., Ltd. for the patients who are resistant to or refractory from PD-1/PD-L1 treatments. It blocked the immune checkpoint PD-1 and TIM-3-mediated immunosuppressive signal pathways simultaneously, showed better T/DC cell activity and in vivo anti-tumor efficacy compared to Tim-3 and PD-1 antibody combination in preclinical studies. Methods: This is a FIH, multicenter, non-randomized, open label, phase 1 study of LB1410 in Participants With Advanced Solid Tumor or Lymphoma（Keyplus-001）. The planned sample size is approximately 100 patients in two parts: part 1 dose escalation will evaluate safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and determine the maximum tolerated dose (MTD) and/or the recommended phase 2 dose (RP2D), and Part 2 dose expansion will further characterize the safety profile and preliminary tumor response in several cohorts including NSCLC, CRC, EC etc. Enrollment criteria include adults with life expectancy of > 3 months, ECOG performance status 0-1，histologically or cytologically confirmed advanced and/or metastatic solid tumor malignancies or lymphoma for which standard treatment fails, or no standard treatment is available, or standard treatment is not applicable at this stage. Exclusion criteria include pregnancy, lactation, or breastfeeding, ongoing or recent evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments. The primary endpoints are incidence of dose limiting toxicities and adverse events, MTD, and recommended phase 2 dose. Secondary objectives will evaluate PK parameters, preliminary antitumor activity, and immunogenicity of LB1410. Besides, the pharmacodynamics (PD) biomarkers related to LB1410 treatment, clinical activity will be explored. This clinical trial is in progress; cohorts 1 to 5 in dose escalation part have been completed. Clinical trial information: NCT05357651 .

First-in-human, phase 1a dose finding of LVGN6051 CD137/4-1BB agonistic antibody with or without pembrolizumab in patients with advanced solid tumors.

2525 Background: LVGN6051 is a conditional 4-1BB agonistic monoclonal antibody with Fc γ-receptor IIB selective binding in the tumor microenvironment for optimal activity. Preclinical studies showed potent antitumor activity by LVGN6051 alone and in combination with anti-PD-1 antibody. Methods: We conducted this first in human (FIH) multicenter phase 1 dose escalation study in the US. Eligible pts with advanced solid tumor malignancies received escalating doses of LVGN6051 alone or in combination with pembrolizumab 200 mg IV Q3W until unacceptable toxicity, progressive disease, or withdrawal of consent. Results: As of Jan 23, 2023, 55 pts were enrolled and received LVGN6051 alone with the dose range of 0.003–7 mg/kg (n=18), or combination therapy of LVGN6051 2 mg/kg + pembrolizumab (n=22) or LVGN6051 4 mg/kg + pembrolizumab (n=15). The median age was 58 years (range 20-83) and number of prior therapies was 5; 46 pts (84%) had ECOG PS 1 and 21 pts (38%) had received prior immune checkpoint inhibitors (ICI). In pts who received LVGN6051 alone, the MTD was not reached up to 7 mg/kg and the RP2D was selected as 4 mg/kg IV Q3W for tolerance. The RP2D for combination therapy was established as LVGN6051 4 mg/kg and pembrolizumab 200 mg IV Q3W. Pts received a median of 2.8 months and a mean of 4.0 months (range 0.5 – 19.2) of study treatment. 33 pts (60%) experienced any grade treatment-related adverse events (TRAEs) with noteworthy (> 5%) AST increased (27%), ALT increased (26%), thrombocytopenia (16%), infusion related reaction (IRR) (9%), fatigue (7%), lipase increased (6%), nausea (6%) and chills (6%). 14 pts (25%), 1 mono- and 13 combination therapy, showed ≥ grade 3 TRAEs: AST increased (11%), ALT increased (9%), thrombocytopenia (7%), fatigue (4%), IRR (2%), lipase increased (2%) and nausea (2%). 6 drug-related serious adverse events and 1 DLT (grade 4 thrombocytopenia), all in combination therapy, were reported. In 42 evaluable pts, the disease control rate (DCR) was 50%. Combination therapy showed that target lesions were reduced by 57%, 42% and 48% in melanoma (n=2) and pancreatic cancer (n=1), respectively. Among 11 melanoma pts (10 had progressed on anti-CTLA4 and anti-PD-1 therapy), 2 PR and 5 SD were observed per RECIST 1.1, including one being treated for 19+ months (26+ cycles). Pts with HNSqCC (n=1) and CRPC (n=1) also showed remarkable tumor shrinkage. Paired tumor biopsies for single cell RNAseq biomarker exploration confirmed activation of effector T cells following LVGN6051 treatment. Conclusions: We established the RP2Ds of LVGN6051 alone and in combination with pembrolizumab in this FIH phase 1a study. These regimens were well tolerated. Preliminary efficacy data showed encouraging anti-tumor activity in heavily pretreated pts who had progressed on ICI. Phase 1b dose expansion for the combination therapy is ongoing in pts with melanoma, GI malignancies and NSCLC. Clinical trial information: NCT04130542 .

A phase 2 study of the WEE1 inhibitor AZD1775 in SETD2-deficient advanced solid tumor malignancies.

3104 Background: AZD1775 is an inhibitor of the WEE1 kinase, leading to loss of genome integrity. Pathogenic SETD2 mutations lead to genome-wide loss of histone H3K36 trimethylation (H3K36me3) and hypersensitivity to WEE1 inhibition with a synthetic lethal effect. AZD1775 was studied in 2 cohorts of patients: A) Patients (pts) with locally advanced/metastatic solid tumor malignancy other than clear cell renal cell carcinoma (ccRCC) and B) pts with locally advanced/metastatic ccRCC. Methods: Eligible pts had a locally advanced/metastatic cancer with progression on ≥ 1 prior systemic therapy (including prior tyrosine kinase inhibitor or checkpoint inhibitor for cohort B), and a pathogenic SETD2 mutation by CLIA-certified next generation sequencing panel. Pts received AZD1775 at a starting dose of 300 mg PO daily on days 1-5, 8-12 of each 21-day cycle. The primary objective was to determine the objective response rate (ORR) by RECIST 1.1 criteria in each cohort. Planned sample size was 9 pts in each cohort in stage 1 of a Simon two-stage design. Secondary objectives were to determine the clinical benefit rate (CBR) (defined as partial response or stable disease [SD] > 4 months), duration of response (DOR), and safety. Correlative assays include the evaluation of H3K36me3 mark by immunohistochemistry (IHC) in archival tumor tissue. Results: Between 05/2019 and 10/2021, 18 pts whose tumor harbored a pathogenic mutation in SETD2 were enrolled (9/cohort). The median age was 60 years (range 45 – 74), ECOG PS 0 in 8 (44.4%). One patient remains on treatment; 17 have discontinued (disease progression, n = 9; adverse event, n = 4; patient withdrawal, n = 2; patient death, n = 1). The median duration of treatment was 1.89 months (range 0.75 – 13.5). There were no confirmed objective responses and therefore enrollment was halted following accrual to stage 1. Tumor regression of any magnitude was observed in 5/17 (29%) evaluable pts. Stable disease was the best overall response in 10/17 (59%) evaluable pts, including 3 pts with SD for > 4 months. One patient with RCC remains on treatment with SD for 14+ months duration. The most common adverse events of any grade were nausea (59%), anemia (41%), diarrhea (41%), and neutropenia (41%). Twelve pts (67%) experienced a Grade ≥ 3 adverse event. Evaluation of H3K36me3 using IHC as an exploratory biomarker is underway. Conclusions: AZD1775 given as monotherapy failed to achieve an objective response in SETD2-altered RCC and other solid tumor malignancies. However, a subset of pts derived clinical benefit as manifested by tumor regressions and/or durable stable disease. Evaluation of AZD1775 in combination with other DNA damage-inducing agents that cause replication stress may be warranted, potentially with the integration of the H3K36me3 mark as a biomarker for patient selection. Clinical trial information: NCT03284385 .

Abstract ND11: EO-3021: An antibody drug conjugate targeting CLDN18.2 expressing cancers

Abstract Claudin 18.2 is tight junction protein with a highly selective cell surface expression profile that is limited to the normal gastric mucosa. Importantly, it is often overexpressed in several types of cancers including gastric, pancreatic, esophageal, ovarian, and lung. There are currently no approved targeted therapies for claudin 18.2-expressing cancers. As such, we designed an antibody drug conjugate, EO-3021/SYSA1801 with the potential to selectively target and kill claudin 18.2-expressing cancer cells. EO-3021 is comprised of a novel tumor-targeting monoclonal antibody that selectively binds claudin 18.2 (Kd = 0.6 nM) that is conjugated to monomethyl auristatin E (MMAE). EO-3021 is internalized in claudin 18.2-expressing cells as well as demonstrates cell killing across a range of cancer cell lines with low (IC50 = 228 ng/ml), medium (IC50 = 7 ng/ml), and high levels of claudin 18.2 (IC50 = 28 ng/ml) expression. More specifically, claudin 18.2-expressing cells undergo G2/M cell cycle arrest and apoptosis upon EO-3021 treatment. EO-3021 demonstrates tumor regressions with a single dose across low, medium, and high claudin 18.2-expressing in vivo models derived from pancreatic (9 mg/kg), gastric (2 mg/kg), and lung cancers (8 mg/kg), respectively. In addition, a single dose of EO-3021 outperforms standard of care chemotherapies, such as cisplatin and gemcitabine, across in vivo models. Nonclinical toxicology studies suggested that EO-3021-mediated toxicities were reversible and manageable as well as afford a therapeutic index suitable for testing in humans. EO-3021/SYSA1801 is currently being evaluated in a Phase I dose escalation study (NCT05009966) in patients with claudin 18.2 positive advanced malignant solid tumors. A case study will be presented where a confirmed and durable partial response (66.7% tumor reduction) was observed following EO-3021 treatment. Citation Format: David Dornan. EO-3021: An antibody drug conjugate targeting CLDN18.2 expressing cancers [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 ND11.

Abstract CT248: First in human trial of DB1305 in patients with advanced malignant solid tumors

Abstract Background: Trophoblast cell-surface antigen 2 (Trop-2) is known as tumor-associated calcium signal transducer 2 (TACSTD2) and plays a role in tumor progression, given its active interplay with several key molecular pathways associated with cancer development and progression. DB-1305 is a Trop-2 antibody-drug conjugate (ADC) composed of a humanized anti-Trop-2 immunoglobulin G1 (IgG1) monoclonal antibody, covalently linked to a proprietary DNA topoisomerase I inhibitor P1021 via a cleavable linker containing maleimide tetrapeptide, with a drug-to-antibody ratio (DAR) of approximately 4. Preclinical in vivo models show that DB-1305 demonstrates robust anti-tumor activity in Trop-2-high triple-negative breast cancer (TNBC), Trop-2-low small cell lung cancer (SCLC) and Trop-2-medium colon cancer but not Trop-2-negative SCLC, demonstrating the dependence of Trop-2 expression for the tumor-suppression activity of DB-1305 and appropriate safety profile supports the intended clinical use. This study aims to evaluate DB-1305 in terms of tolerability and preliminary anti-tumor activity in patients with advanced solid tumors. Methods: This is an open-label, multicenter, multiple-dose, Phase 1/2a study (NCT05438329), including dose escalation Phase 1 and dose-expansion Phase 2a in patients with pretreated advanced solid tumors. Patients should have histologically documented progressed/refractory disease on or after standard systemic anticancer treatments with proven benefits for their disease or without available standard treatments; adequate performance score (ECOG 0-1); adequate organ function and measurable disease as per RECIST v1.1 while without uncontrolled metastatic central nervous system (CNS) involvement and history of interstitial lung diseases. The dose escalation part will evaluate approximately five ascending dose levels of DB-1305 with accelerated titration for the first dose level followed by a “3+3” design for subsequent dose levels to identify the optimal dose, which will enroll up to 70 patients from the United States and China. Upon determining the optimal dose, seven tumor cohorts of 10-40 patients will be included in the dose expansion part, including non-small cell lung cancer, SCLC, hormone receptor-positive breast cancer, and TNBC. DB-1305 will be dosed in both parts until disease progression, clinical deterioration, withdrawal of consent, or unacceptable toxicity. The primary objectives are evaluating safety tolerability and identifying the optimal dose from Phase 1; assessing safety, tolerability, and objective response rate per RECIST v1.1 from Phase 2a. Secondary objectives include the assessment of the pharmacokinetics and immunogenicity of DB-1305. Exploratory objectives include the assessment of pharmacodynamic biomarkers and Exposure-Response correlation. As of 19 Dec 2022, 20 patients have been enrolled in the dose escalation part. Citation Format: Naoto T. Ueno, Jie Gao, Liming Liu, Rong Shi, Shengxue Liu, Lili Tang, Peizhen Miao, Yang Qiu, Wei Gu, Cheng Ying. First in human trial of DB1305 in patients with advanced malignant solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT248.

Abstract OT3-13-01: First in Human Study of AG01 a chimerized monoclonal antibody to Progranulin/Glycoprotein 88 (GP88)

Abstract Progranulin (PGRN/GP88) is an 88 kDa glycoprotein characterized by seven and a half double cysteine rich repeats in the granulin-epithelin family. PGRN/GP88 is an autocrine biological driver of tumorigenesis, survival & drug resistance in several cancers including breast, ovarian, multiple myeloma, prostate cancers, non-small cell lung carcinoma (NSCLCA) & digestive cancers. PGRN/GP88 tissue expression is an independent prognostic factor of recurrence while elevated serum PGRN/GP88 level in metastatic breast, lung & prostate cancer patients is associated with poor outcomes such as progression & shortened survival. An anti-human PGRN/GP88 monoclonal antibody inhibiting PGRN/GP88 action has been developed & expressed as recombinant antibody in CHO cells. Activities including pharmacology, manufacturing, formulation & GLP toxicology studies have been carried out. The IND application has been cleared by the Food and Drug Administration to proceed with the first-in-human AG01 clinical study in adult patients ((pts) with advanced solid tumors. We present an ongoing First in Human Phase 1A (dose escalation,1+(3+3) & IB (expansion cohorts) study of AG01 in pts advanced solid tumor malignancies (1A) with 4 expansion cohorts (1B) in pts with advanced Triple Negative Breast Cancer (TNBC), Hormone Resistant ER+/Her2- BC, advanced NSCLC & mesothelioma. Study Design: This is an open-label, dose escalation study of AG01 antibody administered intravenously (IV) over 90 minutes every 14 days +/- 1 day (1A), followed by 4 predefined expansion cohorts, which will be treated at the RP2D determined in the phase 1A of this study. In the 1A part, initially accelerated titration design will be utilized to guide dose progression & estimation of the maximum tolerated dose (MTD and/or maximum administered dose (MAD). In the 1A portion of the study pts with advanced relapsed/refractory solid tumor malignancies who failed 1 or more standard of care (SOC) therapies (tx) or for whom no SOC tx exists will be accrued. The primary objective of the 1A part is to determine the MTD and/or MAD of AG01. Secondary objectives are to determine the RP2D, assess the safety/tolerability, the pharmacokinetics (PKs) & immunogenicity of AG01 & the preliminary anti-tumor activity of AG01 via RECIST 1.1. The exploratory objectives are to determine PGRN/GP88 expression in tumor tissue and PGRN/GP88 blood levels using A&G’s ELISA test. In the 1B Cohort Expansion phase, 4 separate cohorts of pts with PGRN/GP88 tissue expression of 1+, 2+, 3+ by IHC will be enrolled. Cohort 1- TNBC: ER and/or PR < 1% by IHC, HER2 < 3+ by IHC and/or FISH negative, pts must have failed 1 or more SOC tx for metastatic BC. Cohort 2- Hormone-resistant BC: ER and/or PR >1%, HER2 < 3+ by IHC and/or FISH negative, failed 1 or more prior hormonal tx (HT) or HT/CD4/6 kinase inhibitor tx or other targeted tx. Cohort 3- NSCLCA: metastatic/recurrent NSCLCA failed 2 or more SOC tx. Cohort 4 -Mesothelioma- failed 1 or more SOC tx for metastatic/recurrent mesothelioma or not a candidate for SOC tx. The primary objective of 1B part is to evaluate the antitumor efficacy of AG01 by overall response rate (ORR) defined as completed response (CR), partial response (PR), stable disease >=24 weeks (SD) (CR+PR+ SD) based on RECIST v1.1 in the 4 cohorts with each cohort assessed separately for response. Secondary objectives are to evaluate progression free survival (PFS), duration of response (DOR) & overall survival (OS) of pts in cohorts 1-4, & to evaluate the ORR, DOR & PFS based on GP88 tissue expression, to further characterize the PKs & the safety/tolerability of AG01. Exploratory objectives in 1B part will assess AG01 effect on circulating PGRN/GP88 levels in plasma or other potential biomarkers in the 4 cohorts. The estimated study sample is approximately 77 pts; 17 pts for the 1A part & 60 pts for 1B part. The study is open to accrual at the UMGCCC. Supported by NCI grants R44CA224718 and R44CA162629 Citation Format: KATHERINE TKACZUK, Paula Rosenblatt, Ranee Mehra, Katherine Scilla, Nancy Tait, Binbin Yue, Ginette Serrero. First in Human Study of AG01 a chimerized monoclonal antibody to Progranulin/Glycoprotein 88 (GP88) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-13-01.

Outcomes of Immune Checkpoint Inhibitor Administration in Hospitalized Patients With Solid Tumor Malignancies.

More oncologists desire to treat their patients with immune checkpoint inhibitors (ICIs) in the inpatient setting as their use has become more widespread for numerous oncologic indications. This is cost-prohibitive to patients and institutions because of high drug cost and lack of reimbursement in the inpatient setting. We sought to examine current practice of inpatient ICI administration to determine if and in which clinical scenarios it may provide significant clinical benefit and therefore be warranted regardless of cost. We conducted a retrospective chart review of adult patients who received at least one dose of an ICI for treatment of an active solid tumor malignancy during hospitalization at a single academic medical center between January 2017 and June 2018. Patient, disease, and admission characteristics including mortality data were examined, and cost analysis was performed. Sixty-five doses of ICIs were administered to 58 patients during the study period. Nearly 40% and 80% of patients died within 30 days and 180 days of ICI administration, respectively. There was a trend toward longer overall survival in patients with good prognostic factors including positive programmed death-ligand 1 (PD-L1) expression or microsatellite instability-high (MSI-H) status. Slightly over 70% of patients were discharged within 7 days of ICI administration. The total cost of inpatient ICI administration over the 18-month study period was $615,016 US dollars. Inpatient ICI administration is associated with high costs and poor outcomes in acutely ill hospitalized patients with advanced solid tumor malignancies and therefore should largely be avoided. Careful discharge planning to expedite outpatient treatment after discharge will be paramount in ensuring patients with good prognostic features who will benefit most from ICI therapy can be promptly treated in the outpatient setting as treating very close to discharge in the inpatient setting appears to be unnecessary, regardless of tumor features.

A Phase1/1b Dose Escalation/Dose Expansion Study of Prgn-3007 Ultracar-T Cells in Patients with Advanced Hematologic and Solid Tumor Malignancies

Background: Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a promising target for cancer treatment as its expression enhances tumor cell growth and survival, promotes epithelial-mesenchymal transition and metastasis and participates in pro-survival pathways such as PI3-Kinase/AKT, EGFR signaling, and the p38-MAPkinase pathway. ROR1 is undetectable in normal adult tissues, however aberrant expression of ROR1 in malignancies has been detected in B-cell malignancies such as B-cell acute lymphoblastic leukemia (B-ALL), diffuse large cell B-cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), and mantle cell lymphoma (MCL). Furthermore, upregulated expression has been detected in various solid tumors, including ovarian cancer, breast adenocarcinomas encompassing triple negative breast cancer (TNBC), pancreatic cancer, Ewing's sarcoma and lung adenocarcinoma. The increased expression of ROR1 in hematological and solid tumor malignancies has been associated with tumor proliferation, metastasis and poor clinical outcomes. The autologous UltraCAR-T® platform is designed to overcome the limitations of traditional CAR T which leads to an exhausted T cell phenotype, high manufacturing costs, and treatment delays, using advanced non-viral gene delivery system and a decentralized, overnight manufacturing process. Scientific Rationale: PRGN-3007 is built on Precigen's UltraCAR-T platform and is engineered to simultaneously express a ROR1-specific chimeric antigen receptor (ROR1 CAR); membrane bound interleukin-15 (mbIL15) for enhanced in vivo expansion and persistence; a kill switch for improved safety profile; and a novel mechanism for the intrinsic blockade of programmed cell death protein 1 (PD-1) gene expression. Preclinical studies with PRGN-3007 UltraCAR-T cells showed significant reduction in PD-1 expression with increased ROR1 specific cytotoxicity and inflammatory cytokine production upon co-culture with ROR1+ PD-L1+ hematological and solid tumor cells. Furthermore, PRGN-3007 was selectively and effectively eliminated by the kill switch activator antibody treatment. In vivo, a single administration of PRGN-3007, effectively reduced tumor burden and significantly improved overall survival (p<0.05) of tumor bearing mice compared to Control ROR1 CAR-T in an aggressive xenograft model of mantle cell lymphoma. Blood analyses demonstrated sustained downregulation of PD-1 expression, rapid expansion, long-term persistence, and a predominant central memory phenotype of PRGN-3007 in tumor bearing mice. (Blood (2021) 138 (Supplement 1): 1694.) Study Design: This is a first-in-human, Phase 1/1b dose escalation/dose expansion study to evaluate the safety and effectiveness of PRGN-3007 UltraCAR-T cells in patients with advanced ROR1-postive (ROR1+) hematologic (CLL, MCL, ALL, and DLBCL; Arm 1) and solid tumors (TNBC; Arm 2). Key inclusion criteria include absolute lymphocyte count ≥ 0.2k/µL, KPS > 70, adequate organ function, confirmed expression of ROR1 and: relapsed or refractory CLL; pathologically confirmed ALL B-cell precursor and measurable disease, pathologically confirmed MCL with overexpression of cyclin D1 or presence of t (11;14); pathologically confirmed DLBCL or high grade B-cell lymphoma including transformation from low grade lymphoma; or locally advanced unresectable or metastatic histologically confirmed TNBC with measurable disease as per RECIST 1.1. Study subjects undergo leukapheresis followed by lymphodepletion with either fludarabine 30mg/m2 and cyclophosphamide 500mg/m2 for 3 days (Arm 1) or 60 mg/kg cyclophosphamide for 2 days (Arm 2). The study will enroll in 2 phases: an initial dose escalation phase followed by a dose expansion phase. Up to 4 dose levels are planned in dose escalation phase (Table 1), and the MTD will be determined separately in subjects in the hematologic arm and the solid tumor arm. The MTD for each arm will be expanded independently in the dose expansion phase of the study. All subjects will be followed for adverse events, CAR-T-related toxicities, disease response and PRGN-3007 cell expansion and persistence. In addition, the mechanisms of safety and effectiveness of PRGN-3007 cells will be evaluated with correlative assays of specific immune response pathways. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A first-in-human phase 1 trial of nx-1607, a first-in-class oral CBL-B inhibitor, in patients with advanced solid tumor malignancies.

TPS2691 Background: Casitas B-lineage lymphoma proto-oncogene B (CBL-B) is an E3 ubiquitin ligase expressed in multiple immune cell lineages, which in contrast to cell surface immune checkpoints, acts as a regulator of both T and NK cell activation. Inhibition of CBL-B enhances T-cell response, increases response to suboptimal priming, and restores response in exhausted T cells. Thus CBL-B is a promising immune-oncology target and may overcome challenges seen with other T-cell directed therapies. NX-1607 is an oral small molecule inhibitor of CBL-B that has demonstrated anti-tumor activity and long-term survival in murine models as both a single agent and in combination with programmed cell death protein-1 (PD-1) antibodies. Further, NX-1607 elicits dose-dependent increases in cytokine secretion and proliferation in T-cell receptor-stimulated primary human T cells with enhanced tumor antigen-specific T-cell and NK cell anti-tumor responses. Thus, NX-1607 may be effective as a single agent or it may significantly enhance efficacy of other anti-tumor agents. Methods: NX-1607-101 is a first-in-human, multicenter, open-label, Phase 1 dose escalation and expansion trial evaluating NX-1607 in a variety of indications including platinum-resistant epithelial ovarian cancer (EOC), gastric cancer, squamous cell carcinoma of the head and neck (HNSCC), metastatic melanoma, non-small cell lung cancer (NSCLC), metastatic castration-resistant prostate cancer (mCRPC), malignant pleural mesothelioma (MPM), triple-negative breast cancer (TNBC), locally advanced or metastatic urothelial cancer, cervical cancer, microsatellite stable colorectal cancer (MSS CRC), and diffuse large B-cell lymphoma with Richter transformation (DLBCL-RT). The main objective is to establish the safety and tolerability of NX-1607, characterize PK/PD, and determine the recommended Phase 1b dose. NX-1607 will be given orally once daily at doses ranging from 5 to 100 mg in up to 6 dose levels. Dose escalation will proceed using an accelerated modified Fibonacci dose escalation design that transitions to a standard 3 + 3 design based on protocol-specific criteria. Up to 8 expansion cohorts in Phase 1b will be composed of patients with subsets of advanced cancers. Key eligibility criteria include patients with metastatic or unresectable disease that have progressed after prior therapy and for whom standard therapy with proven clinical benefit does not exist, is no longer effective, or is not appropriate. Prior treatment with immune checkpoint inhibitors or CAR-T cells with washout is allowed, but a history of active autoimmune disease is not. Up to 336 patients (60 in Phase 1a, 276 in Phase 1b using a Simon 2-stage design) will be enrolled at approximately 20 sites in the UK and US and treated until disease progression or unacceptable toxicity. Dose escalation is ongoing. Clinical trial information: NCT05107674.

Pathogenic fusion detection in solid malignancies utilizing RNA-DNA based comprehensive genomic profiling (CGP) testing.

3078 Background: Gene fusions caused by chromosomal rearrangements comprise a key category of oncogenic driver mutations. However, given the diverse array of potentially novel loci where each proto-oncogene can translocate, many assays including DNA-based CGP have technical limitations that disallow the detection of all relevant fusion partners potentially leading to false negatives. Hybrid Capture RNA sequencing renders a more comprehensive evaluation of genes and allows detection of novel and known fusion partners. Here we assessed the impact of utilizing in-house CGP testing with a paired RNA-DNA hybrid assay in the identification of pathogenic fusions and their potential clinical actionability for patients with solid tumors across a large US health system. Methods: Patients in the Providence health system diagnosed with advanced solid tumor malignancies over a two-year period (2019-2021) received reflex CGP testing at the time of diagnosis utilizing an internally validated workflow. DNA/RNA sequencing results as well as histology and staging information were curated from deidentified electronic medical records and in-house databases, and tumor types were mapped to OncoTree tissue categories. Potential clinical actionability was assessed based on OncoKB therapeutic levels 1-3 and clinical trial eligibility matched to the biomarker inclusion criteria for ASCO TAPUR, NCI-MATCH and MyPathway studies (both without time limits and at time of testing). Results: The median patient age at diagnosis was 67 years, 52% of patients were female, and the majority (80%) were white. Across all tested advanced solid tumors, 6.7% (217/3218) were found to harbor a pathogenic fusion. The tumor types most enriched in this set of pathogenic fusions were prostate (30%), lung (27%), CUP (10%) and breast (9%). 29% (n = 64) of the identified pathogenic fusions were identified as actionable based on OncoKB criteria (levels 1-3), and 31% (n = 69) matched to one or more arms in the ASCO TAPUR, NCI-MATCH or MyPathway basket clinical trials. The most frequent actionable fusion driver genes identified were ALK (12%), FGFR 1-3 (12%), RET (7%) NTRK 1-3 (3%), and ROS1 (2%) and a subset of these key drivers were fused with novel gene pairs. A subset of fusions co-occurred with other targetable biomarkers, with the most common comprising tumor mutational burden high (TMB-H) (13%), PIK3CA (7%) and high microsatellite instability (MSI-H) (2%). Conclusions: In-house CGP testing utilizing an RNA-DNA based assay identified actionable fusion targets across tumor types, with many novel fusion partners that may be undetectable by prior generation sequencing assays. While many of these actionable targets are rare individually, the expanding totality of actionable gene alterations supports the growing utility of CGP for identifying patients who are candidates for approved targeted therapies and clinical trials.

A phase 1 study of TPST-1120 as a single agent and in combination with nivolumab in subjects with advanced solid tumors.

3005 Background: TPST-1120 is a first-in-class oral therapy that inhibits PPARα, a transcription factor that regulates fatty acid oxidation (FAO). TPST-1120 has diverse mechanisms of anti-tumor activity in preclinical studies, including inhibiting tumor proliferation, increasing the anti-angiogenic factor thrombospondin 1, and reducing T cell exhaustion. Methods: Subjects with advanced solid tumor malignancies received escalating doses of TPST-1120 as a single agent or in combination with nivolumab 480 mg IV every 4 weeks (combination cohort limited to RCC, cholangiocarcinoma [CCA] and HCC). Study objectives included evaluation of safety, pharmacokinetics, MTD, RP2D and anti-tumor activity as monotherapy and in combination with nivolumab. AEs were assessed per CTCAE v5 and efficacy per RECIST v1.1 Results: As of 14-Jan-2022, 35 subjects have been dosed (20 with TPST-1120 monotherapy at doses from 100 mg to 600 mg PO BID and 15 in combination with nivolumab at doses from 200 mg to 600 mg PO BID). Median prior lines of systemic therapy were 3 (2-11) in monotherapy and 2 (2-6) in combination cohorts. An MTD was not reached in monotherapy or combination, and the TPST-1120 RP2D was 600 mg PO BID for both cohorts. For TPST-1120 monotherapy, the most common treatment related AEs (TRAEs) were nausea (20%), fatigue (15%), and diarrhea (10%), all Grade 1-2. One monotherapy subject (5%) experienced a Grade 3 TRAE (hypertension). In the combination cohort the most common TRAEs related to either drug were fatigue (40%), diarrhea (27%) and nausea (20%), all Grade 1-2. Three combination subjects (19%) experienced Grade 3 TRAEs (one each arthralgia, hepatic enzyme increased, muscle spasms). A best response of stable disease was observed in 53% (10/19) of subjects treated with monotherapy. In combination, the ORR was 23% (3/13, all PRs) across all dose levels and 38% (3/8) at TPST-1120 dose levels ≥400 mg BID. These responses included 2 subjects with late-line RCC (2/2 RCC subjects enrolled, both with progression on prior anti-PD1 therapy) and one subject with heavily pre-treated CCA. At data cut off, 2 of 3 responding patients (CCA and one RCC) remained in PR and on study at 8.4 and 14 mo, respectively. Conclusions: TPST-1120 is a novel therapy designed to inhibit tumor proliferation and angiogenesis and stimulate anti-cancer immunity through inhibition of PPARα, a key regulator of FAO. The drug is well tolerated as a single agent and in combination with nivolumab. Promising objective responses have been observed in combination with nivolumab in subjects previously refractory to anti-PD-1 therapy, including 2/2 responders in late-line RCC, and a subject with heavily pretreated CCA, a tumor type generally not responsive to anti-PD-1 alone. Notably, all responders were treated at the two highest doses of TPST-1120 (ORR 38%). Updated study results including exploratory biomarkers will be presented. Clinical trial information: NCT03829436.

Inpatient chemotherapy for patients with advanced solid tumors: A single-center observational study.

158 Background: We sought to identify a population of patients with advanced-stage solid tumor diagnoses for whom inpatient chemotherapy is appropriate. In so doing, we endeavor to define standards of practice in addressing prognostic awareness and goals of therapy prior to treatment. Methods: We identified 124 patients with Stage IV solid tumors who were given at least one dose of inpatient chemotherapy in 2019. We performed manual chart review to collect information on patient demographics, details of cancer diagnosis and chemotherapy regimen, and dates of admission, chemotherapy administration, discharge, readmission, and death. Results: Ninety-four percent of patients studied were admitted for cancer-related reasons. The 30-day mortality for patients with Stage IV cancer given inpatient chemotherapy was 20.2%, including 12 patients (9.7%) who died during the same admission. The 30-day readmission rate was 40.2%. Median overall survival and readmission-free survival were both 15 days (range, 3-510 and 3-642, respectively). Among patients who died within 30 days, 18.2% (4/22) had a serious illness conversation documented prior to chemotherapy administration. Conclusions: This study demonstrates that there is a high mortality and readmission rate among patients with advanced solid tumor malignancies who receive inpatient chemotherapy. Standardizing the expectation of informed consent and/or goals of care discussion prior to treatment is necessary. This may prevent administration of futile chemotherapy to patients requiring hospitalization for advanced cancer.

512O Interim results from a phase II study of the ATR inhibitor ceralasertib in ARID1A-deficient and ARID1A-intact advanced solid tumor malignancies

Loss of ARID1A leads to increased reliance on ATR (Ataxia Telangiectasia and Rad3 Related) kinase. ATR inhibition induces synthetic lethality in ARID1A-deficient preclinical models. We evaluated ceralasertib, an ATR inhibitor, alone and in combination with Olaparib, in patients harboring ARID1A-deficient and -intact solid tumors, respectively.

Mechanistic Modeling of a Novel Oncolytic Virus, V937, to Describe Viral Kinetic and Dynamic Processes Following Intratumoral and Intravenous Administration.

V937 is an investigational novel oncolytic non-genetically modified Kuykendall strain of Coxsackievirus A21 which is in clinical development for the treatment of advanced solid tumor malignancies. V937 infects and lyses tumor cells expressing the intercellular adhesion molecule I (ICAM-I) receptor. We integrated in vitro and in vivo data from six different preclinical studies to build a mechanistic model that allowed a quantitative analysis of the biological processes of V937 viral kinetics and dynamics, viral distribution to tumor, and anti-tumor response elicited by V937 in human xenograft models in immunodeficient mice following intratumoral and intravenous administration. Estimates of viral infection and replication which were calculated from in vitro experiments were successfully used to describe the tumor response in vivo under various experimental conditions. Despite the predicted high clearance rate of V937 in systemic circulation (t1/2 = 4.3 min), high viral replication was observed in immunodeficient mice which resulted in tumor shrinkage with both intratumoral and intravenous administration. The described framework represents a step towards the quantitative characterization of viral distribution, replication, and oncolytic effect of a novel oncolytic virus following intratumoral and intravenous administrations in the absence of an immune response. This model may further be expanded to integrate the role of the immune system on viral and tumor dynamics to support the clinical development of oncolytic viruses.

Abstract 1031: Translatome and protein synthesis machinery remodeling by rocaglates drives antitumor activity

Abstract Rocaglates are under active development for cancer therapy, with the first-in-class member zotatifin recently entering Phase I/II clinical trial for advanced solid tumor malignancies (NCT04092673). Initiation of this trial was based purely on rocaglates' inhibitory activity against translation initiation factor and RNA helicase eIF4A. Rapid development of these compounds towards clinical use urgently requires a complete understanding of their mechanisms. Critically, however, the full effects of rocaglates on protein synthesis are unknown, especially with regards to up-regulated proteins and rocaglate-activated translation factors that mediate their potent anticancer activity. Past rocaglate studies focused exclusively on mechanisms and targets of translational inhibition, relying exclusively on indirect RNA-based approaches that do not reliably capture proteome-level changes, a caveat proven in cancer cells responding to drugs. Formal proteomic investigations of rocaglate effects are non-existent in the literature. We addressed these vital knowledge gaps in this study. An original proteome-level analysis using metabolic pulse-labeling and TMT-mass spectrometry revealed extensive rocaglate-induced changes in protein output (translatome), including myriad rocaglate-up-regulated proteins that drive cytotoxicity through currently uncharacterized mechanisms. Specifically, we find in vitro and in vivo that rocaglates, including zotatifin, induce GEF-H1, activating anti-survival RHOA/JNK signaling. Intriguingly, these responses occur regardless of eIF4A expression. Beyond translatome remodeling, mass spectrometry-based MATRIX interrogation of the protein synthesis machinery revealed widespread rocaglate-dependent changes. As a prime example, rocaglate-augmented eEF1ϵ1 activity mediates initiator methionine-tRNAiMet delivery to drive synthesis of rocaglate-inducible proteins and phenotypes. Overall, this study transforms the current definition of rocaglates from one-dimensional eIF4A inhibitors to translation remodelers that globally reprogram protein output and the translation machinery. As human patients begin treatment with these compounds, our discovery of rocaglate-inducible proteins and rocaglate-activated translation factors that drive drug-specific responses highlights an entirely uncharacterized yet critical aspect of rocaglate potency. These timely findings emphasize systemic translational modeling as a newer concept for cancer therapy, and advocate for a systematic overhaul in our understanding of drugs traditionally defined as translation inhibitors. Citation Format: Jyun David Ho, Jr, Tyler A. Cunningham, Caroline A. Coughlin, Artavazd Arumov, Evan R. Roberts, Daniel Bilbao, Jonathan R. Krieger, Stephen Lee, Jonathan H. Schatz. Translatome and protein synthesis machinery remodeling by rocaglates drives antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1031.

Phase 1 trial of a novel, first-in-class G protein-coupled estrogen receptor (GPER) agonist, LNS8801, in patients with advanced or recurrent treatment-refractory solid malignancies.

3084 Background: The G protein-coupled estrogen receptor (GPER) is a broadly expressed G protein-coupled receptor that is tumor suppressive. LNS8801 is an oral, highly selective small molecule agonist of GPER. GPER activation results in c-Myc depletion, inhibition of tumor proliferation, and enhancement of tumor immune recognition. Preclinically, LNS8801 demonstrates potent single-agent and combinatorial anti-cancer activity and can overcome established resistance to standard-of-care anti-cancer therapies including immune checkpoint inhibitors. Methods: The primary objective of this phase 1/1B first-in-human, open-label, multicenter study (NCT04130516) was to determine the safety and tolerability and recommended phase 2 dose (RP2D) of LNS8801 in patients (pts) with locally advanced or metastatic solid tumor malignancies, both as monotherapy and in combination with the anti-PD-1 antibody, pembrolizumab. Dose levels were escalated in a 3+3 fashion and included 10, 40 and 125 mg dosed 3/7, 125 mg daily, and 125 and 250 mg twice daily. Dose limiting toxicity (DLT) was defined via NCI CTCAE v5.0 during the first 21 days of treatment. An increase in prolactin over the initial 12 hrs of dosing was measured to assess systemic GPER signaling. Tumor c-Myc expression was measured as a surrogate of treatment-related biologic response. Radiographic response (RECIST v1.1) was evaluated every 8 weeks until progression. Results: 33 pts (19 M/14 F) with median age 58.8 y and 4 (1-9) prior therapies enrolled. Median duration of treatment was 66 d (1–367+). With monotherapy (n = 28), no DLTs, treatment-related SAEs, or treatment-related study discontinuations were observed up through the maximum administered dose (250 mg bid). Possibly related AEs were grade 1 or 2 and did not correlate with dose level. Exposure was above that predicted for efficacy and t1/2 was ̃10 hr at all doses. Of 26 evaluable monotherapy pts, 8 (27%) experienced stable disease (SD) for up to a year. All SD pts had a prolactin response. Among tumors expressing GPER, c-Myc depletion was observed in 100% (5/5) of paired pre and on-treatment biopsies. In the combination cohort (n = 5), 2/2 evaluable pts demonstrated net tumor reductions on initial f/up scans, including one RECIST partial response. Based on PK/PD data, 125 mg daily has provisionally been identified as the monotherapy and combination RP2D. Conclusions: LNS8801 is well tolerated and demonstrates signals of anti-tumor activity when administered both as monotherapy and in combination with pembrolizumab. Confirmation of RP2Ds and updated efficacy data will be presented in June. A phase 2A expansion study to evaluate these RP2Ds in clinical settings of high unmet need is now in development. Clinical trial information: NCT04130516.

A phase 1 open label trial of intravenous administration of MVA-BN-Brachyury vaccine in patients with advanced cancer.

2617 Background: Brachyury is a member of the T-box family of transcription factors which is overexpressed in several tumor types and has been associated with treatment resistance, epithelial to mesenchymal transition and metastatic potential. MVA-BN-Brachyury vaccine is a vector-based therapeutic cancer vaccine which demonstrated immunogenicity and safety in previous clinical trials. Preclinical studies suggested that IV administration of vaccines can induce superior CD8 + T-cell responses as compared with SC or IM routes. This is the first-in-human study to evaluate safety and tolerability of IV administration of this vaccine. Methods: Patients with metastatic or unresectable locally advanced malignant solid tumors were treated with MVA-BN-Brachyury vaccine in a phase 1, open-label, 3+3 dose-escalation study. Eligible patients received a total of three vaccine doses intravenously Q3W at 1x107 (DL1), 1x108 (DL2), or 1x109 infections units (Inf.U) (DL3). Patients were admitted for 48 hours for observation after each dose and had imaging at baseline and 1 and 3 months after the last vaccine dose. Primary objective was to determine the safety and tolerability and establish the recommended phase 2 dose (RP2D). Immune assays were performed in the first 10 enrolled patients. Results: In 13 patients (10 chordoma, 1 small cell breast, 1 prostate, 1 colorectal cancer), no dose-limiting toxicities were observed. Right upper quadrant abdominal pain was the only grade 3 TRAE. All other TRAEs were grade 1 or 2; most common was cytokine release syndrome (four grade 2 and one grade 1. As of Feb 2021, 9 patients completed treatment and two planned restaging scans: 5 patients had PD (3 in DL1 and 2 in DL2), 3 had SD (2 in DL2 and 1 in DL3) and 1 had PR (DL3) as their best treatment response per RECIST 1.1. One patient with advanced sacral chordoma had significant reduction of ulcerated skin metastases after 2 doses, followed by 33% shrinkage at the end of trial. Two chordoma patients with SD reported significant pain improvement. Multifunctional Brachyury, CEA, and MUC1 specific T cells were increased after vaccination in in 60%, 67%, and 50% of patients, respectively. Conclusions: MVA-BN-Brachyury IV vaccine is safe across all tested dose levels and suggesting activity in chordoma at DL3 for which this vaccine was granted FDA orphan drug designation. Mild cytokine release syndrome (rigors, chills, fever and hypotension) has been observed in 5 patients and managed with IV fluids and steroids in 2 patients. A dose 1 x 109 Inf.U (DL3) was selected for RP2D based upon available safety data. Further research is pending to evaluate clinical benefit and immunogenicity. Clinical trial information: NCT04134312.

Symptomatic methemoglobinemia in a patient with metastatic clear cell renal cell carcinoma treated with pembrolizumab and axitinib combination therapy: a case report

BackgroundCombination regimens that include immune checkpoint (ICI) and vascular endothelial growth factor (VEGF) inhibition have opened the door to new treatment opportunities for patients with metastatic renal cell carcinoma (mRCC). While these treatment options have provided improved tolerability and better outcomes compared to older regimens, many patients still experience a myriad of treatment-related adverse events. Given that these regimens were recently approved for mRCC, the complete side effect profile may not be fully elucidated yet.Case presentationWe report a case of a 73-year old White male with mRCC who was managed with an ICI-VEGF inhibitor combination regimen. He experienced a partial response (Fig. 1) but had side effects including symptomatic cyanosis diagnosed as methemoglobinemia which led to treatment discontinuation. Upon holding his therapy, his methemoglobinemia and cyanosis resolved.ConclusionsCombination VEGF-ICI therapy provide novel regimens for advanced solid tumor malignancies including mRCC. While shown to have improved efficacy in clinical trials, it is crucial that oncologists uncover the full side effect profile of these novel agents especially as their use becomes more standard in the management of advanced malignancies. To our knowledge, this is the first reported case of a patient experiencing symptomatic methemoglobinemia as an adverse event associated with a VEGF-ICI combination regimen. While the cause of this side effect is unclear, in this paper we attempt to elucidate a process that is in line with the mechanism of action of these therapies to explain how these agents, specifically the axitinib, could have caused the methemoglobin to rise to a symptomatic level.