Formal Hypothesis Research Articles

Safety, pharmacokinetics, and early bactericidal activity of quabodepistat in combination with delamanid, bedaquiline, or both in adults with pulmonary tuberculosis: a randomised, active-controlled, open-label trial

Quabodepistat (formerly OPC-167832) showed potent activity in preclinical studies and in the first stage of an early bactericidal activity study in adults with smear-positive, drug-susceptible pulmonary tuberculosis. Stage 2 of this study was designed to evaluate the safety, tolerability, pharmacokinetics, and early bactericidal activity of quabodepistat in combination with delamanid, bedaquiline, or both versus rifampicin, isoniazid, ethambutol, and pyrazinamide combination therapy for 14 days. Stage 2 of this open-label, active-controlled, randomised, parallel-group study was conducted at two research sites in South Africa in adults (aged 18-64 years) with drug-susceptible pulmonary tuberculosis. Eligible participants had a BMI of 16-32 kg/m2 and the ability to produce an adequate volume of sputum (≥10 mL overnight) and were excluded if they had drug-resistant tuberculosis or previous treatment for Mycobacterium tuberculosis within the past 3 years. Participants were centrally randomly assigned via interactive web response technology system, with no stratification, into four treatment groups in a ratio of 14:14:14:4 (quabodepistat 30 mg plus delamanid 300 mg, quabodepistat 30 mg plus bedaquiline 400 mg, or quabodepistat 30 mg plus delamanid 300 mg plus bedaquiline 400 mg orally once daily for 14 days, or rifampicin, isoniazid, ethambutol, and pyrazinamide combination therapy [control] according to local standard of care for 20 days). The primary outcomes were safety and tolerability during and after 14 days of treatment in all participants who received any study medication and pharmacokinetics at day 1 and day 14 in participants in the quabodepistat groups with adequate data for deriving pharmacokinetics parameters. The main secondary outcome was bactericidal activity from baseline to day 14 in all eligible participants who were quantitatively culture-positive at baseline. The study was not powered for formal statistical hypothesis testing; therefore, data were summarised by treatment group with descriptive statistics. This study is registered with ClinicalTrials.gov (NCT03678688) and is closed to new participants. 98 participants were screened for entry into stage 2 of the trial between Feb 1, 2021, and Jan 27, 2022, of whom 46 were randomly assigned (14 to each quabodepistat group, 4 to the control group) and 44 received at least one dose of study medication (one patient excluded from the quabodepistat plus delamanid and quabodepistat plus bedaquiline groups). 32 (73%) of 44 participants had at least one treatment-emergent adverse event. Most events (30/32 [94%]) were mild or moderate; the most common treatment-emergent adverse events (≥2 participants; not related to study drugs) were headache (4/44 [9%]), dizziness (3/44 [7%]), abdominal pain (2/44 [5%]), pruritus (2/44 [5%]), and nausea (2/44 [5%]). Two serious adverse events were reported in two participants in the quabodepistat and bedaquiline cohort (anal abscess [n=1], pneumothorax [n=1]); both were deemed not related to study drug. Quabodepistat exposure was minimally affected by coadministration of delamanid or bedaquiline, with lower exposure in the quabodepistat and bedaquiline cohorts (maximum plasma concentration for quabodepistat plus delamanid 208 ng/mL [SD 61; n=11]; quabodepistat plus bedaquiline 175 ng/mL [31; n=10]; quabodepistat plus delamanid plus bedaquiline 183 ng/mL [52; n=11]). Maximum quabodepistat concentrations were achieved approximately 3 h after administration in all combinations. Mean elimination half-life was shorter in combinations with bedaquiline than without bedaquiline (12·3-14·5 h vs 15·2 h). Mean changes from baseline to day 14 of sputum log10 colony-forming units per mL were -2·73 (SD 1·51) for quabodepistat plus delamanid plus bedaquiline (n=12) and -2·71 (SD 0·92) for control (n=19); mean change was -2·17 (SD 1·83) in the quabodepistat plus delamanid cohort (n=11) and -1·97 (SD 1·29) in the quabodepistat plus bedaquiline cohort (n=11). In this 14-day trial, quabodepistat plus delamanid plus bedaquiline, a novel three-drug combination, appeared to be safe, well tolerated, and provided robust early bactericidal activity in adults with drug-susceptible pulmonary tuberculosis. Further evaluation is warranted. Otsuka Pharmaceutical Development & Commercialization and the Bill & Melinda Gates Foundation.

Atezolizumab Plus Chemotherapy With or Without Bevacizumab in Advanced Biliary Tract Cancer: Clinical and Biomarker Data From the Randomized Phase II IMbrave151 Trial.

Biliary tract cancers (BTCs) harbor an immunosuppressed tumor microenvironment and respond poorly to PD-1/PD-L1 inhibitors. Bevacizumab (anti-vascular endothelial growth factor) plus chemotherapy can promote anticancer immunity, augmenting response to PD-L1 inhibition. This randomized, double-blind, proof-of-concept phase II study enrolled patients (n = 162) with previously untreated advanced BTC (IMbrave151; ClinicalTrials.gov identifier: NCT04677504). Patients were randomly assigned 1:1 to receive cycles of atezolizumab (1,200 mg) plus bevacizumab (15 mg/kg) or atezolizumab plus placebo once every 3 weeks until disease progression or unacceptable toxicity. All patients received cisplatin (25 mg/m2) plus gemcitabine (1,000 mg/m2; cisplatin plus gemcitabine [CisGem]) on days 1 and 8 once every 3 weeks for up to eight cycles. Stratification of patients was by disease status, geographic region, and primary tumor location. The primary end point was progression-free survival (PFS). No formal hypothesis testing was performed. Exploratory correlative biomarker analysis was undertaken using transcriptome analysis (n = 95) and mutation profiling (n = 102) on baseline tumor samples. Between February and September 2021, 162 patients were enrolled. Median PFS was 8.3 months in the bevacizumab arm and 7.9 months in the placebo arm (stratified hazard ratio [HR], 0.67 [95% CI, 0.46 to 0.95]). Median overall survival (OS) was 14.9 and 14.6 months in the bevacizumab and placebo arms, respectively (stratified HR, 0.97 [95% CI, 0.64 to 1.47]). The incidence of grade 3 or 4 adverse events was 74% in both arms. High VEGFA gene expression was associated with improved PFS (HR, 0.44 [95% CI, 0.23 to 0.83]) in the bevacizumab arm versus placebo. In unselected patients with advanced BTC, adding bevacizumab to atezolizumab plus CisGem modestly improves PFS but not OS. High VEGFA gene expression may represent a predictive biomarker of benefit from atezolizumab/bevacizumab, warranting further investigation.

Pembrolizumab or Placebo Plus Adjuvant Chemotherapy With or Without Radiotherapy for Newly Diagnosed, High-Risk Endometrial Cancer: Results in Mismatch Repair-Deficient Tumors.

Mismatch repair-deficient (dMMR) endometrial cancer (EC) is an inflamed phenotype with poor outcomes when meeting high-risk criteria and limited treatment options in the adjuvant setting. We report protocol-prespecified subgroup analysis of patients with dMMR tumors from the phase III ENGOT-en11/GOG-3053/KEYNOTE-B21 study (ClinicalTrials.gov identifier: NCT04634877) in newly diagnosed, high-risk EC after surgery with curative intent. Patients were randomly assigned to pembrolizumab 200 mg or placebo (six cycles) plus carboplatin-paclitaxel (four to six cycles) once every 3 weeks, then pembrolizumab 400 mg or placebo once every 6 weeks (six cycles), respectively. MMR status was a stratification factor. Patients received radiotherapy at investigator discretion. Investigator-assessed disease-free survival (DFS) was a primary end point. No formal hypothesis testing was performed for subgroup analysis. In the intention-to-treat population, 141 patients in the pembrolizumab arm and 140 in the placebo arm had dMMR tumors. At this interim analysis, hazard ratio for DFS favored pembrolizumab (0.31 [95% CI, 0.14 to 0.69]); median DFS was not reached in either group. Two-year DFS rates were 92.4% (95% CI, 84.4 to 96.4) and 80.2% (95% CI, 70.8 to 86.9), respectively. No new safety signals occurred. Longer-term follow-up of outcomes will be evaluated at final analysis. Preplanned subgroup analysis on the basis of the study's stratification factors suggests that pembrolizumab plus chemotherapy improves DFS and is clinically relevant for patients with dMMR tumors in the curative-intent setting.

12275 Effect Of Osilodrostat On Cardiovascular And Metabolic Manifestations Of Hypercortisolism In Patients With Non-Pituitary Cushing’s Syndrome: Findings From A Retrospective Observational Study (LINC 7)

Abstract Disclosure: N. Scheyer: Other; Self; Recordati Rare Diseases. J. Bertherat: Consulting Fee; Self; Novartis, HRA Pharma, Recordati Rare Diseases. B. Decoudier: Consulting Fee; Self; Recordati Rare Diseases. H. Lasolle: Speaker; Self; Recordati Rare Diseases. H. Lefebvre: Speaker; Self; Recordati Rare Diseases. D. Drui: None. C. Vaillant: None. J. Morera: None. F. Castinetti: Consulting Fee; Self; HRA Pharma Rare Diseases, Recordati Rare Diseases. Grant Recipient; Self; HRA Pharma Rare Diseases, Recordati Rare Diseases. J. Cristante: Grant Recipient; Self; HRA Pharma, Pfizer, Inc.. N. Chevalier: None. S. Fodil-Cherif: None. A. Antonellini: Employee; Self; Recordati Rare Diseases. W. Agbotounou: Employee; Self; Recordati Rare Diseases. A. Mueller: Employee; Self; Recordati Rare Diseases. A. Tabarin: Consulting Fee; Self; H Lundbeck A/S, Crinetics Pharmaceuticals, HRA Pharma, Recordati Rare Diseases. Introduction: Endogenous Cushing’s syndrome (CS) is associated with increased cardiovascular morbidity and mortality because of hypercortisolism. Osilodrostat, a potent oral 11β-hydroxylase inhibitor, is approved for patients (pts) with endogenous CS (EMA) and Cushing’s disease (CD; for whom pituitary surgery is not an option or has not been curative; FDA). The long-term safety and efficacy of osilodrostat has been demonstrated in Phase II (LINC 2, NCT01331239) and Phase III (LINC 3, NCT02180217; LINC 4, NCT02697734) studies of CD pts. Here, we investigated the effect of osilodrostat on clinical manifestations of hypercortisolism in a real-world, retrospective, observational study conducted in a heterogeneous patient population with non-pituitary CS (LINC 7; NCT05633953). Methods: Adult pts with non-pituitary CS who initiated osilodrostat prior to EU approval under the French Autorisation Temporaire d’Utilisation scheme and/or, once approved, in routine clinical practice were followed up retrospectively for up to 36 months. The primary endpoint was proportion of pts with mean urinary free cortisol (mUFC) ≤upper limit of normal (ULN) at week (W) 12, based on the modified intention-to-treat (mITT) population (pts with any cortisol measurement at W12 or not collected because of safety reasons). Secondary endpoints included cardiovascular and metabolic parameters, recorded every 4 or 12W, depending on clinical practice. No formal statistical hypothesis testing was performed; all analyses are descriptive. Results: 103 pts were enrolled (mean [SD] age: 59.3 years [15.5]; female 61.2% [n=63]; adrenal adenoma [16.5%, n=17/103; mITT: 9.6%, n=5/52], adrenocortical carcinoma [18.4%, n=19/103; mITT: 11.5%, n=6/52], macronodular adrenal hyperplasia [13.6%, n=14/103; mITT: 17.3%, n=9/52], ectopic adrenocorticotropic hormone secretion [51.5%, n=53/103; mITT: 61.5%, n=32/52]). Median (min-max) osilodrostat exposure and dose at baseline was 164.0 days (1-1178) and 5.0 mg/day (1-60), respectively. Median (min-max) osilodrostat dose at W12 and W36 was 6.0 mg/day (0-60) and 10.0 mg/day (0-120), respectively. 23/52 pts (44.2%; 95% CI 30.5-58.7) had mUFC ≤ULN at W12. Mean (95% CI) changes in cardiovascular and metabolic-related parameters from baseline to W12 and W36, respectively, were: systolic blood pressure (−5.7 [−17.9, −6.6] mmHg, n=29 and −6.3 [−19.0, −6.5] mmHg, n=11); diastolic blood pressure (−4.7 [−10.6, −1.1] mmHg, n=29 and −8.2 [−20.7, −4.3] mmHg, n=11); weight (−2.3 [−4.2, −0.4] kg, n=27 and −3.6 [−9.6, −2.5] kg, n=12); body mass index (−0.8 [−1.5, −0.2] kg/m2, n=27 and −1.2 [−3.2, −0.8] kg/m2, n=12). No new safety signals were identified. Conclusions: Findings from this real-world setting show that osilodrostat provides cortisol control alongside improvements in clinical manifestations of hypercortisolism in non-pituitary CS pts, alleviating the disease burden. Presentation: 6/1/2024

6907 Continued Improvements in Hypertension and Diabetes During Long-Term Osilodrostat Therapy in Patients with Cushing’s Disease: A Pooled Analysis from the Phase III LINC 3 and LINC 4 Studies

Abstract Disclosure: M. Fleseriu: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). Grant Recipient; Self; Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). R. Pivonello: Consulting Fee; Self; Corcept Therapeutics, Recordati AG, Crinetics Pharmaceuticals, H Lundbeck A/S. Grant Recipient; Self; Recordati AG, Corcept Therapeutics, Xeris Pharmaceuticals (Strongbridge), Neurocrine Biosciences. J. Newell-Price: Consulting Fee; Self; Crinetics, Diurnal, HRA Pharmaceuticals, Recordati Rare Diseases. Grant Recipient; Self; Crinetics, Diurnal, HRA Pharmaceuticals, Recordati Rare Diseases. M. Gadelha: Advisory Board Member; Self; Novo Nordisk, Recordati, Crinetics Pharmaceuticals. Speaker; Self; Recordati, Ipsen, Pfizer, Inc., Crinetics Pharmaceuticals, Novo Nordisk. R.J. Auchus: Consulting Fee; Self; Xeris Pharmaceuticals (Strongbridge), Spruce Biosciences, Neurocrine Biosciences, Corcept Therapeutics, Diurnal, Sparrow Pharmaceuticals, Crinetics Pharmaceuticals, Recordati Rare Diseases, Adrenas Therapeutics, Janssen Pharmaceuticals, Quest Diagnostics, H Lundbeck A/S, Novo Nordisk, Besins Pharmaceuticals. Grant Recipient; Self; Xeris Pharmaceuticals (Strongbridge), Spruce Biosciences, Neurocrine Biosciences, Corcept Therapeutics, Diurnal, Sparrow Pharmaceuticals, Crinetics Pharmaceuticals, Recordati Rare Diseases. R. Feelders: Consulting Fee; Self; Recordati. A. Lacroix: Consulting Fee; Self; Novartis Pharmaceuticals, Recordati, Pfizer, Inc.. Grant Recipient; Self; Novartis Pharmaceuticals, Recordati, Pfizer, Inc. A. Shimatsu: Advisory Board Member; Self; Recordati. Consulting Fee; Self; Recordati. Speaker; Self; Recordati. P. Witek: Speaker; Self; Novartis Pharmaceuticals, Ipsen, Recordati, Novo Nordisk, Xeris Pharmaceuticals (Strongbridge), Lilly USA, LLC. Other; Self; Novartis Pharmaceuticals, Ipsen, Recordati, Novo Nordisk, Xeris Pharmaceuticals (Strongbridge), Lilly USA, LLC. M. Bex: Consulting Fee; Self; Recordati. A. Piacentini: Employee; Self; Recordati. A.M. Pedroncelli: Employee; Self; Recordati, Camurus. B.M. Biller: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; H Lundbeck A/S, Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). Introduction: Alleviating the burden of comorbidities such as hypertension (HTN) and diabetes mellitus (DM), through control of hypercortisolism, is an important treatment goal in the management of Cushing’s syndrome. Osilodrostat, a potent oral 11β-hydroxylase inhibitor, provided rapid, sustained cortisol normalization in Cushing’s disease (CD) patients (pts) in two Phase III studies (LINC 3, NCT02180217; LINC 4, NCT02697734), with improvements in clinical manifestations of hypercortisolism. Here, we report on the long-term changes in blood pressure (BP) and markers of glucose homeostasis in a large, pooled pt population from both trials at weeks (W) 48 and 72. Methods: LINC 3 comprised a 48W core phase, including an 8W randomized withdrawal phase for eligible pts. LINC 4 included an upfront 12W, double-blind, randomized, placebo-controlled period and 36W of open-label osilodrostat. Both studies had an optional extension. Baseline (BL) HTN was defined as prior diagnosis, taking antihypertensive medication, and/or systolic/diastolic BP (SBP/DBP) >130/>90 mmHg. BL DM was defined as prior diagnosis, taking antidiabetic medication, HbA1c ≥6.5%, and/or fasting plasma glucose (FPG) ≥126 mg/dL. Data from LINC 3 and LINC 4 were pooled in a secondary exploratory analysis for all pts with data at BL and the given visit, excluding periods where pts were randomized to placebo. No formal statistical hypothesis testing was performed; all analyses are descriptive. Results: In pts with BL HTN (n=174/210; 82.9%), mean (95% CI) change in SBP/DBP was -13.9 (-18.5, -9.4)/-9.1 (-12.4, -5.8) mmHg at W48 and -14.7 (-20.1, -9.4)/-9.4 (-13.0, -5.7) mmHg at W72 for those not receiving antihypertensive medication during the study, and -8.4 (-11.9, -4.9)/-5.3 (-7.5, -3.1) mmHg at W48 and -10.1 (-14.3, -5.8)/-5.7 (-8.1, -3.2) mmHg at W72 for those who received antihypertensives. Of pts with BL SBP >130 mmHg (n=110), 50.0% had SBP ≤130 mmHg at W48 and 49.1% at W72. Of pts with BL DBP >90 mmHg (n=65), 64.6% had DBP ≤90 mmHg at W48 and 58.5% at W72. The proportion of pts taking antihypertensive medication declined from 54.3% at BL to 47.3% at W72. Mean (95% CI) change in potassium levels was -0.1 (-0.1, 0.0) mmol/L at W48 and 0.0 (-0.1, 0.1) mmol/L at W72 in pts with BL HTN, and -0.1 (-0.3, 0.1) mmol/L at both W48 and W72 in pts without BL HTN. 40.0% (n=84/210) of pts had BL DM. Of pts with BL FPG ≥100 mg/dL (n=60), 43.3% and 33.3% had FPG <100 mg/dL at W48 and W72, respectively. The proportion of pts taking antidiabetic medication declined from 21.9% at BL to 17.1% at W72. Conclusions: Many pts with CD and HTN or DM showed improvements during osilodrostat therapy, which were maintained or further improved with long-term therapy. Cortisol normalization is associated with improvements in hypercortisolism-associated comorbidities in pts with CD. Presentation: 6/2/2024

Aztreonam-avibactam versus meropenem for the treatment of serious infections caused by Gram-negative bacteria (REVISIT): a descriptive, multinational, open-label, phase 3, randomised trial.

There is a need for additional therapeutic options for serious infections caused by Gram-negative pathogens. In the phase 3, descriptive REVISIT study, we investigated the safety and efficacy of aztreonam-avibactam in the treatment of complicated intra-abdominal infections or hospital-acquired pneumonia or ventilator-associated pneumonia (HAP-VAP) caused, or suspected to be caused, by Gram-negative bacteria. This prospective, multinational, open-label, central assessor-masked study enrolled adults who were hospitalised with a complicated intra-abdominal infection or HAP-VAP. Patients were randomly allocated via block randomisation using interactive response technology stratified by infection type in a 2:1 ratio to aztreonam-avibactam (with metronidazole for complicated intra-abdominal infection) or meropenem with or without colistin for 5-14 days for complicated intra-abdominal infection or 7-14 days for HAP-VAP. The primary endpoint was clinical cure at the test-of-cure visit (within 3 days before or after day 28) in the intention-to-treat (ITT) population. Secondary endpoints included 28-day mortality in the ITT population and safety in patients in the ITT population who received study drug (safety analysis set). No formal hypothesis testing was planned. The study was registered with ClinicalTrials.gov (NCT03329092) and EudraCT (2017-002742-68) and is complete. Between April 5, 2018, and Feb 23, 2023, we screened 461 patients. 422 patients were enrolled and randomly allocated (282 in the aztreonam-avibactam group and 140 in the meropenem group, forming the ITT analysis set), of whom ten patients (seven in the aztreonam-avibactam group and three in the meropenem group) were randomly allocated but did not receive study treatment. 271 (64%) of 422 patients had at least one Gram-negative pathogen from an adequate specimen identified at baseline. The most frequent baseline pathogens were Enterobacterales (252 [93%] of 271). Overall, 19 (24%) of 80 isolates tested for carbapenemases were carbapenemase-positive (serine, metallo-β-lactamase, or both). 193 (68·4%) of 282 patients in the aztreonam-avibactam group and 92 (65·7%) of 140 in the meropenem group had clinical cure at the test-of-cure visit (treatment difference 2·7% [95% CI -6·6 to 12·4]). For patients with complicated intra-abdominal infection, the adjudicated clinical cure rate was 76·4% (159 of 208) for the aztreonam-avibactam group and 74·0% (77 of 104) for the meropenem group. Cure rates in patients with HAP-VAP were 45·9% (34 of 74) for aztreonam-avibactam and 41·7% (15 of 36) for meropenem. 28-day all-cause mortality rates were 4% (12 of 282) for aztreonam-avibactam and 7% (ten of 140) for meropenem; in patients with complicated intra-abdominal infection, mortality was 2% (four of 208) and 3% (three of 104) for aztreonam-avibactam and meropenem, respectively, and in patients with HAP-VAP, mortality was 11% (eight of 74) and 19% (seven of 36), respectively. Aztreonam-avibactam was generally well tolerated, and safety findings were consistent with the known safety profile of aztreonam monotherapy. There were no treatment-related serious adverse events in the aztreonam-avibactam group. These phase 3 efficacy and safety data provide support for aztreonam-avibactam as a potential therapeutic option for complicated intra-abdominal infection or HAP-VAP caused by Gram-negative bacteria. Pfizer.

Trastuzumab deruxtecan in HER2-positive advanced breast cancer with or without brain metastases: a phase 3b/4 trial.

Trastuzumab deruxtecan (T-DXd) intracranial activity has been observed in small or retrospective patient cohorts with human epidermal growth factor receptor 2-positive (HER2+) advanced/metastatic breast cancer (mBC) and stable or active (untreated/previously treated and progressing) brain metastases (BMs). The phase 3b/4 DESTINY-Breast12 study investigated T-DXd in patients with HER2+ mBC and is, to our knowledge, the largest prospective study of T-DXd in patients with BMs in this setting. Patients (stable/active BMs (n = 263) and no BMs (n = 241)) treated with one or more prior anti-HER2-based regimens received T-DXd (5.4 mg per kg). Primary endpoints were progression-free survival (PFS; BMs cohort) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (non-BMs cohort). Additional endpoints included central nervous system (CNS) PFS, ORR, time to second progression, CNS ORR (BMs cohort), incidence of new symptomatic CNS metastases (non-BMs cohort), time to progression, duration of response, overall survival and safety (both cohorts). No formal hypothesis testing was conducted for this single-arm, open-label study. In the BMs cohort, 12-month PFS was 61.6% (95% confidence interval (CI): 54.9-67.6), and 12-month CNS PFS was 58.9% (95% CI: 51.9-65.3). In the non-BMs cohort, ORR was 62.7% (95% CI: 56.5-68.8). Grade 3 or higher adverse events occurred in 51% (BMs cohort) and 49% (non-BMs cohort) of patients. Investigator-reported interstitial lung disease/pneumonitis occurred in 16% (grade ≥3: 3%) of patients with BMs and 13% (grade ≥3: 1%) of patients without BMs. These data show substantial and durable overall and intracranial activity for T-DXd, supporting its use in previously treated patients with HER2+ mBC irrespective of stable/active baseline BMs. ClinicalTrials.gov identifier: NCT04739761 .

A Bayesian approach for estimating the uncertainty on the contribution of nitrogen fixation and calculation of nutrient balances in grain legumes

BackgroundThe proportion of nitrogen (N) derived from the atmosphere (Ndfa) is a fundamental component of the plant N demand in legume species. To estimate the N benefit of grain legumes for the subsequent crop in the rotation, a simplified N balance is frequently used. This balance is calculated as the difference between fixed N and removed N by grains. The Ndfa needed to achieve a neutral N balance (hereafter θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta$$\\end{document}) is usually estimated through a simple linear regression model between Ndfa and N balance. This quantity is routinely estimated without accounting for the uncertainty in the estimate, which is needed to perform formal statistical inference about θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta$$\\end{document}. In this article, we utilized a global database to describe the development of a novel Bayesian framework to quantify the uncertainty of θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta$$\\end{document}. This study aimed to (i) develop a Bayesian framework to quantify the uncertainty of θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta$$\\end{document}, and (ii) contrast the use of this Bayesian framework with the widely used delta and bootstrapping methods under different data availability scenarios.ResultsThe delta method, bootstrapping, and Bayesian inference provided nearly equivalent numerical values when the range of values for Ndfa was thoroughly explored during data collection (e.g., 6–91%), and the number of observations was relatively high (e.g., ≥100\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\ge 100$$\\end{document}). When the Ndfa tested was narrow and/or sample size was small, the delta method and bootstrapping provided confidence intervals containing biologically non-meaningful values (i.e. < 0% or > 100%). However, under a narrow Ndfa range and small sample size, the developed Bayesian inference framework obtained biologically meaningful values in the uncertainty estimation.ConclusionIn this study, we showed that the developed Bayesian framework was preferable under limited data conditions ─by using informative priors─ and when uncertainty estimation had to be constrained (regularized) to obtain meaningful inference. The presented Bayesian framework lays the foundation not only to conduct formal comparisons or hypothesis testing involving θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta$$\\end{document}, but also to learn about its expected value, variance, and higher moments such as skewness and kurtosis under different agroecological and crop management conditions. This framework can also be transferred to estimate balances for other nutrients and/or field crops to gain knowledge on global crop nutrient balances.

Modeling the output from a commercial chemical process using regression models from survival analysis

This article is concerned with the modeling of the gas output of a commercial chemical plant using the coal sources as predictor variables. We consider the use of two models to incorporate these predictors; the Cox proportional hazards and accelerated failure time regression models. These models are chosen for their simplicity and for the ease with which the effects of explanatory variables can be interpreted. The contribution of this article lies therein that these models are used in the current context for the first time. We show, using both graphical and formal hypothesis testing procedures that these models (with a Weibull baseline distribution) fit observed gas production data well. We provide a discussion of the interpretation of the estimated model parameters and we comment on how these estimates can be of substantial practical value. The large scale of production from the chemical plant in question ensures that potential cost savings and increases in production associated with more accurate models are of great practical importance.

Outcomes of Deep Hypothermic Circulatory Arrest for Descending and Thoracoabdominal Aneurysm Repair

ObjectiveDeep hypothermic circulatory arrest (DHCA) in patients undergoing descending (DTAA) or thoracoabdominal aortic aneurysm (TAAA) repair is associated with increased morbidity and mortality. We present our outcomes after open DTAA and TAAA repair with and without DHCA. MethodsFrom 1999 to 2022, 81 (38.8%) patients undergoing DTAA or TAAA repair required DHCA because proximal cross-clamping was not feasible or aneurysmal pathology extended into the arch and 128 (61.2%) patients required only distal bypass. Because of intrinsic pathological differences in patients requiring DHCA, confidence intervals were used to compare groups in lieu of formal hypothesis tests. ResultsDHCA patients had more chronic dissections (64.2% vs 43.8%, 95% CI for difference: 6% - 35%) and higher BMIs (29.5 ± 6.8 vs 27.2 ± 6.6, CI: 26% - 421%). More non-DHCA patients had medial degeneration (9.9% vs 31.3%, CI: -33% - -7%). There were 10 (12.4%) in-hospital deaths for the DHCA and 10 (7.8%) for the non-DHCA group (CI: -5% - 14%). Survival at 10 years was 52.6% (CI: 42.1%-65.7%) for the non-DHCA group and 48.3% (CI: 40.3%-57.9%) for the DHCA group. The only meaningful differences in postoperative outcomes were ICU (5.5 days vs 6 days, CI: 12%-410%) and hospital stay (19 days vs 12 days, CI: 74%-470%), which were longer in the DHCA group. ConclusionsDespite longer ICU and hospital length of stays, selective use of DHCA is safe and effective with comparable morbidity and mortality to non-DHCA in open DTAA and TAAA repair.

Sotorasib (960 mg or 240 mg) once daily in patients with previously treated KRAS G12C-mutated advanced NSCLC

BackgroundSotorasib 960 mg once daily is approved to treat KRAS G12C-mutated locally advanced or metastatic non-small cell lung cancer (NSCLC). Sotorasib exhibits non-dose proportional pharmacokinetics and clinical responses at lower doses; therefore, we evaluated the efficacy and safety of sotorasib 960 mg and 240 mg. MethodsIn this phase 2, randomized, open-label study, adults with KRAS G12C-mutated advanced NSCLC received sotorasib 960 mg or 240 mg once daily. Primary endpoints were objective response rate (ORR) and safety. Secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and pharmacokinetics. The study was not powered for formal statistical hypothesis testing. ResultsIn the 960 mg group (n = 104), ORR was 32.7 % and DCR was 86.5 %. In the 240 mg group (n = 105), ORR was 24.8 % and DCR was 81.9 %. Median PFS was 5.4 months (960 mg) and 5.6 months (240 mg). At a median follow-up of 17.5 months, median OS was 13.0 months (960 mg) and 11.7 months (240 mg). AUC0–24 h and Cmax were 1.3-fold numerically higher with the 960 mg dose. Treatment-emergent adverse events (TEAEs, ≥10 %) for 960 mg and 240 mg doses, respectively, were diarrhea (39.4 %; 31.7 %), nausea (23.1 %; 19.2 %), increased alanine aminotransaminase (14.4 %; 17.3 %), and increased aspartate aminotransferase (13.5 %; 13.5 %). ConclusionsPatients treated with sotorasib 960 mg once daily had numerically higher ORR and DCR, and longer DOR and OS, than patients treated with 240 mg in this descriptive analysis. TEAEs were manageable with label-directed dose modifications. Clinical trial registrationNCT03600883

GEMINI-Hepatobiliary: A phase 2 study of novel first-line immuno-oncology-based treatments in patients with advanced hepatobiliary cancers.

TPS4187 Background: Although targeted therapies and immuno-oncology (IO)-based regimens have improved overall survival (OS) in advanced hepatobiliary carcinomas, long-term survival rates remain unsatisfactory. Early-phase studies have demonstrated the efficacy of volrustomig (volru; anti-PD-1/CTLA-4 bispecific humanized IgG1 monoclonal antibody [mAb]) in patients (pts) with non-small-cell lung cancer (NSCLC) and renal cell carcinoma, and of rilvegostomig (rilve; anti-PD-1/TIGIT bispecific humanized IgG1 mAb) in pts with NSCLC, along with manageable safety profiles. GEMINI-Hepatobiliary (NCT05775159) is a phase 2, open-label, multidrug, multicenter, master protocol study designed to evaluate the preliminary efficacy and safety of novel IO bispecific mAbs as monotherapy or in combination with standard of care anticancer agents in pts with advanced hepatocellular carcinoma (HCC) and biliary tract cancer (BTC). Methods: The GEMINI-Hepatobiliary platform design permits separate independent substudies (Table). Substudy 1 includes treatment-naïve adults (≥18 years) with histologically confirmed advanced HCC not eligible for locoregional therapy, Barcelona Clinic Liver Cancer Stage B/C, Child-Pugh class A 5–6, and an ECOG performance status (PS) of 0–1. Pts will be treated with volru as monotherapy or in combination with bevacizumab or lenvatinib. Primary endpoints for Substudy 1 are safety and objective response rate (ORR) per RECIST v1.1 by investigator’s assessment. Substudy 2 includes treatment-naïve adults with locally advanced or metastatic, histologically confirmed BTC and an ECOG PS of 0–1. Pts will be treated with gemcitabine + cisplatin with either rilve or volru. Primary endpoints for Substudy 2 are safety and progression-free survival (PFS) per RECIST v1.1 by investigator’s assessment. Secondary endpoints for both substudies include duration of response, disease control rate, ORR, PFS, OS, pharmacokinetics, and immunogenicity. While there are no formal statistical comparisons or hypothesis testing, sample sizes were selected to provide adequate precision for the primary endpoints. The study is currently recruiting at sites in the US, Asia, and Europe. GEMINI-Hepatobiliary master protocol design. Clinical trial information: NCT05775159 . [Table: see text]

Results of a phase 2 study of evorpacept (E, ALX148), cetuximab (C), and pembrolizumab (P) in patients with refractory microsatellite stable metastatic colorectal cancer (MSS CRC).

3530 Background: Single-agent anti-PD-1/PD-L1 drugs are ineffective in MSS CRC. E is an engineered protein (high-affinity CD47-blocker fused to an inactive IgG Fc region), which blocks the CD47/SIRPα innate immune inhibitory phagocytosis checkpoint expressed on CRC and phagocytes, respectively. Preclinical evidence suggests ECP may be effective in MSS CRC. Methods: This phase 2, single-arm, two-stage, multicenter, investigator-initiated trial of E (15 or 10 mg/kg weekly at dose level [DL] 1 and -1, respectively), C (400 mg/m2 then 250 mg/m2 weekly), and P (200 mg every 3 weeks) in 21-day cycles enrolled patients with MSS CRC, regardless of tumor sidedness and RAS/BRAF status, refractory to ≥ 2 prior lines of therapy, including EGFR inhibitor if indicated (NCT05167409). All patients in both Stage 1 (safety run-in) and Stage 2 (expansion) received ECP until progression or unacceptable toxicity. The co-primary objectives were to determine the recommended dose (RD) of E with CP and objective response rate (ORR) by RECIST v1.1 (by one-sided exact test with α=0.05, H0 p ≤ 3% [historical controls], HA p ≥ 15%; power is 87% with N=48). Results: The safety-evaluable population included 16 patients, of whom 69% were male and median age 53 years. The primary tumor was in the right, left, and transverse colorectum in 31%, 31%, and 6% of patients, and was unknown in 31%. Mutations in KRAS, NRAS, and BRAF genes were present in 38%, 6%, and 0% of patients. The median number of prior lines of therapy was 3, including prior EGFR inhibitor in 44%. In Stage 1, 9 and 3 patients were enrolled at E DL1 and DL-1, respectively. E DL1 was established as the RD for Stage 2, in which 4 patients were enrolled. The most common any-grade treatment-emergent adverse events were headache (32%), fatigue (26%), anemia (21%), diarrhea (21%), dyspnea (16%), abdominal pain (16%), nausea/vomiting (16% each), and acneiform rash (16%). There were two on-study deaths assessed as related to all three study drugs (hemophagocytic lymphohistiocytosis and cytokine release syndrome; 1 each). While both are known associations with checkpoint inhibitors, other significant factors contributing to these event outcomes included cancer progression with high tumor burden in the former and patient decision to transition to comfort care in the latter. In the safety-evaluable population, ORR was 6.3% (1 ongoing partial response, 95% confidence interval [CI] 0.2-30.2%), disease control rate was 12.5% (95% CI 1.6-38.4%), median progression-free survival was 2.6 months (mo; 95% CI 2.1-2.9 mo), and median overall survival was 10.9 mo (95% CI 3.3 mo-infinity). Formal hypothesis testing was not performed. Conclusions: Further dose optimization of ECP is needed to establish a RD in the refractory MSS CRC population. While initial activity was seen, at the DLs evaluated, criteria for study termination were met. Clinical trial information: NCT05167409 .

Randomised Controlled Pilot Trial on GHOST Ileostomy versus Conventional Loop Ileostomy in Patients Undergoing low Anterior Resection for Rectal Cancer

Abstract Background Anastomotic leakage is the most important complication after colorectal surgery. In patients undergoing low anterior resection with total mesorectal excision (LAR/TME) a loop ileostomy is fashioned to protect the low anastomosis. Ghost ileostomy is a pre-stage ileostomy, which can be converted to a diverting ileostomy, if anastomotic leakage is suspected. If there are no signs of anastomotic leakage an actual ileostomy can be avoided. Aims The objective was to evaluate whether ghost ileostomy is a safe alternative to a conventional loop ileostomy. Methods GHOST was a randomised controlled pilot trial without formal hypothesis. Patients undergoing LAR/TME for rectal cancer were intraoperatively randomised to receive a ghost ileostomy or loop ileostomy. Patients were followed prospectively for 6 months. Comprehensive complication index, transformation of ghost ileostomy into loop ileostomy, presence of an ostomy at 6 months, Wexner score and quality of life were assessed. Results Thirty patients were equally randomised. The CCI was 30.7 (± 17.7) in the ghost ileostomy group compared to 29.7 (± 18.6) in the loop ileostomy group at 6 months (p=0.889). The ghost ileostomy was converted into a loop ileostomy in 6 of 15 (40.0%) patients. At 6 months after low anterior resection, 6 (40.0%) patients in the ghost ileostomy group and 7 (46.7%) patients in the ileostomy group still had an ileostomy. There was no mortality and no need for creation of a terminal ostomy within the trial. Neither postoperative function assessed by the Wexner score, nor the overall quality of life showed significant differences. Conclusion Ghost ileostomy seems to be a viable and safe option to a more selective approach regarding creation of an ileostomy in patients undergoing LAR/TME. However, the difficult patient selection with exclusion of patients at high risk of anastomotic leakage limits its widespread application and should be optimised in future trials.

Using lineups to evaluate goodness of fit of animal movement models

Abstract Movement models are frequently fit to animal location data to understand how individuals respond to and interact with local environmental features. Several open‐source software packages are available for analysing animal movements and can facilitate parameter estimation, yet there are relatively few methods available for evaluating model goodness of fit. We describe how a simple graphical technique, the lineup protocol, can be used to evaluate goodness of fit of integrated step‐selection analyses and hidden Markov models, but the method can be applied much more broadly. We leverage the ability to simulate data from fitted models and demonstrate the approach using both an integrated step‐selection analysis and a hidden Markov model applied to fisher (Pekania pennanti) data. A variety of responses and movement metrics can be used to evaluate models, and the lineup protocol can be tailored to focus on specific model assumptions or movement features that are of primary interest. Although it is possible to evaluate statistical significance using a formal hypothesis test, the method can also be used in a more exploratory fashion (e.g. to explore variability in model behaviour across stochastic simulations or to identify areas where the model could be improved). We provide coded examples and vignettes to demonstrate the flexibility of the approach. We encourage movement ecologists to consider how their models will be applied when choosing appropriate graphical responses for evaluating goodness of fit.

Abstract PO1-05-06: Health-related QOL and physical activity collected via wearable device in patients with HR+/HER2− advanced breast cancer in Japan treated with palbociclib+endocrine therapy (ET) or ET alone: 6-month longitudinal study (JBCRG-26)

Abstract Background: Palbociclib (PAL) is a first-in-class cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) for the treatment of HR+/HER2− advanced breast cancer (ABC). In phase 3 clinical trials, PAL+ET prolonged progression-free survival and maintained health-related quality of life (HRQOL) compared with placebo+ET. However, few studies have evaluated the day-to-day effects of PAL+ET treatment on patients’ HRQOL and daily activities in a real-world setting. Here, we report the daily life of the patients treated with PAL+ET or ET alone evaluated with a mobile application and wearable device. Methods: This is a prospective, observational, multicenter study conducted in Japanese women with HR+/HER2- ABC initiating PAL+ET (Group 1) or ET alone (Group 2) in first- or second-line setting. HRQOL was assessed with the EORTC-QLQ-C30 at baseline and Day 15 of each cycle via a smartphone-based application for 6 treatment cycles (24 weeks). Physical activity (PA) data were collected via wearable device (CentrePoint Insight Watch®, ActiGraph LLC, the USA). Patients were instructed to wear the device at all-times, except of while bathing and sleeping, during the baseline period (at least 4 days prior to treatment initiation was recommended) and 6 cycles. PA metrics were averaged on a weekly basis. Patient data, including baseline characteristics, treatment, and adverse events, were collected via electronic case report forms. As primary endpoints, change in Global health status (GHS) of EORTC-QLQ-C30 and “sedentary time” from baseline were evaluated at each time point. No formal hypothesis testing or comparisons between groups was planned. Results: Ninety-nine patients were enrolled (Group 1: 78 patients, Group 2: 21 patients). Patients had a median age of 56/52 years (Group 1/Group 2); 51%/33% had visceral metastases; 86%/86% had ECOG performance status of 0; 76%/91% initiated first-line treatment; 36%/33% were fully employed. Seventy-four of 78 patients (95%) in Group 1 and 20 of 21 patients (95%) in Group 2 completed the 6-cycle observation period. Baseline mean GHS score was 60.9 and 64.3 in Group 1 and 2, respectively. The change from baseline to Cycle 6 in GHS score was 4.6 and 1.2 in Group 1 and 2, respectively, not reaching the deterioration-threshold of 8 points in either treatment group. Results for each functional subscale are summarized in Table 1. Baseline mean “sedentary time” was 580.7 and 565.1 min/day in Group 1 and 2, respectively. The change from baseline to Cycle 6 in “sedentary time” was —67.2 and —139.4 min/day in Group 1 and 2, respectively. Results of other PA metrics are summarized in Table. No new safety signals were identified. Conclusion: In this study, PAL+ET or ET alone did not have any significant adverse impact on HRQOL and PA measured by wearable devices in patients with HR+/HER2- ABC. (NCT04736576) Citation Format: Hiroko Bando, Mari Oba, Aya Ueda, Kaori Terata, Mihoko Doi, Shigenori Nagai, Masaya Hattori, Ken-Ichi Watanabe, Nobuko Tamura, Manabu Futamura, Kei Koizumi, Naoki Niikura, Tempei Miyaji, Yasuaki Muramatsu, Linghua Xu, Norikazu Masuda, Shigehira Saji. Health-related QOL and physical activity collected via wearable device in patients with HR+/HER2− advanced breast cancer in Japan treated with palbociclib+endocrine therapy (ET) or ET alone: 6-month longitudinal study (JBCRG-26) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-05-06.

Abstract PO2-14-09: Baseline genomic alterations and the activity of lasofoxifene (LAS) plus abemaciclib (Abema) in patients with ER+/HER2- metastatic breast cancer (mBC): the ELAINE 2 study

Abstract Introduction: Estrogen receptor-positive (ER+)/HER2-negative (HER2-) breast cancers commonly acquire constitutively active mutations in the ERα-encoding gene (ESR1), resulting in endocrine therapy (ET) resistance. In the phase 2, ELAINE 2 study (NCT04432454), LAS (a breast ER antagonist) combined with Abema provided a median progression-free survival (PFS) of ~13 months (mos) and clinical benefit rate (CBR) of 66% in patients with endocrine-resistant, ER+/HER2- mBC and ESR1 mutations (mESR1; Damodaran. J Clin Oncol 2023;41:suppl16;1057). Our objective was to describe baseline genomic alterations co-occuring with mESR1 and treatment responses to LAS plus Abema in patients with these concurrent genomic alterations. Methods: Women (age ≥18 yrs) with ER+/HER2- mBC that progressed after prior ET and CDK4/6 inhibitor (CDK4/6i) with an mESR1 detected in blood using the Sysmex-Inostics SafeSeq circulating tumor DNA (ctDNA) test were enrolled in ELAINE 2. Oral LAS 5 mg/day and Abema (provided by Eli Lilly and Co) 150 mg BID were taken until disease progression, death, unacceptable toxicity, or withdrawal. The Guardant360 CDx test was used to identify and describe baseline genomic alterations in ctDNA (including mESR1). Median PFS and CBR were assessed in patients with mESR1 and co-existing baseline genomic alterations. For patients who withdrew before disease progression, their last observation time was used as the progression time for PFS estimation. Data were summarized descriptively with no formal hypothesis testing. Results: Of the 29 patients (median age 60 yrs) enrolled, mutations in ESR1 were identified in 26 by Guardant360; all these 26 patients had received prior CDK4/6i, 21 (81%) prior fulvestrant, and 12 (46%) prior chemotherapy for mBC. Alterations in 39 genes were concurrently identified with mESR1, including TP53 mutations (n=11), PIK3CA mutations (n=8), CCND1 amplifications (n=6), and FGFR1 amplifications (n=5); co-amplification of CCND1 and FGFR1 was identified in 3 patients. LAS plus Abema treatment was associated with a CBR of 73% and a median PFS of 12.9 mos in the 26 patients with mESR1 (Table). CBRs were 63% in the co-occurring PIK3CA mutation subgroup and 64% in the TP53 mutation subgroup; median PFS times were 7.8 and 8.3 mos, respectively. All patients in the CCND1 and FGFR1 amplification subgroups achieved clinical benefit (CBR 100%) and the median PFS was 16.6 mos for both subgroups. In patients with mESR1 and co-alterations in ≥2 other genes of interest (PIK3CA, FGFR1, CCND1, TP53, ERBB2, CCNE1, or RB1), CBR was 83% and median PFS was 16.6 mos. Conclusion: Using Guardant360 ctDNA profiling from patients in ELAINE 2, we demonstrate that other baseline genomic alterations are frequently detected concurrently with mESR1 in the endocrine resistant setting, but without apparent compromise on the efficacy of LAS plus Abema. These results should be interpreted with caution considering the small numbers of patients and the exploratory nature of the analysis. The ELAINE 2 study suggests the potential of LAS plus Abema for treating ESR1-mutated, ER+/HER2- mBC in the post-CDK4/6i setting. This will be further evaluated in the larger, registrational, phase 3, ELAINE 3 study (NCT05696626) that compares LAS plus Abema with fulvestrant plus Abema. Table. Treatment response by genomic alterations concurrent with ESR1 mutations (n=26). aFor patients who withdrew before disease progression, the last observation time was used as the progression time for PFS estimation. bOther genes of interest include PIK3CA, FGFR1, CCND1, TP53, ERBB2, CCNE1, or RB1. CBR, clinical benefit rate; mPFS, median progression-free survival. Citation Format: Senthil Damodaran, Massimo Cristofanilli, Matthew Goetz, Ciara O'Sullivan, Gary Riordan, Hope Rugo, Daniel Stover, Seth Wander, Dominic Carroll, Paul V. Plourde, David J Portman, Einav Nili-Gal Yam. Baseline genomic alterations and the activity of lasofoxifene (LAS) plus abemaciclib (Abema) in patients with ER+/HER2- metastatic breast cancer (mBC): the ELAINE 2 study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-14-09.

Combining low-dose regorafenib with pembrolizumab for patients with MSI-H colorectal cancer: REGPEM-CRC-01.

TPS238 Background: Treatment for microsatellite instability-high (MSI-H)/mismatch repair deficient (MMR-D) colorectal cancer (CRC) has rapidly evolved in the last decade. The KEYNOTE 177 trial recently established pembrolizumab as a frontline therapy for patients with MSI-H CRC. However, in this study, approximately 40% of patients were noted to have disease progression within 6 months of treatment. Furthermore, an additional 10% of patients experienced acquired resistance to therapy. Therefore, there is an unmet need to improve outcomes for patients with MSI-H CRC. Preclinical studies have shown vascular endothelial growth factor (VEGF) signaling to be overactive in MSI-H compared to MSS CRC (Hansen et al. Colorectal Dis. 2011). Moreover, exploratory analysis of CALBG-80405 and PARADIGM trials showed that patients with MSI-H CRC were more likely to benefit from anti-VEGF therapy than those with MSS disease. Regorafenib, an FDA-approved agent for patients with mCRC, is a potent VEGF inhibitor with immune modulatory effects on the tumor microenvironment. We hypothesize that adding low-dose regorafenib to pembrolizumab as frontline therapy may create synergistic activity in addition to the known clinical activity of each agent in MSI-H CRC. Methods: In the lead-in arm of this prospective study, 22 patients will be enrolled. Patients will receive regorafenib 60 mg daily on days 1–14 (2 weeks on) followed by 7 days off (1 week off) in combination with pembrolizumab 200 mg in the cycle 1. In the following cycles, patients will receive regorafenib 90 mg daily for 2 weeks on 1 week off in combination with pembrolizumab 200 mg every 3 weeks. The primary outcome for the lead-in arm is overall response rate (ORR) within 12 months of treatment by RECIST 1.1. criteria. A formal one-sided hypothesis test will be conducted for futility, assuming that we will reject the null hypothesis of a target ORR only if we have strong evidence. In this study, we assume a null hypothesis that ORR is 0.60, which would reflect significant clinical improvement over the current standard of ORR = 0.43 from KEYNOTE 177. The alternative hypothesis is that ORR is less than 0.60. For the lead-in phase of the study, the emphasis is on controlling Type I error to be small, approximately 0.05. In the randomized phase of the study, patients will receive pembrolizumab monotherapy or pembrolizumab in combination with regorafenib 90 mg. The sample size for the randomized phase of trial was determined based on an assumed median of PFS of 28 months with pembrolizumab and regorafenib combination (investigational arm). The standard of care pembrolizumab monotherapy results in a median PFS of 16 months when given as a first-line therapy. We hypothesize the proposed treatment will increase median PFS to 28 months from 16 months (N=132; H0: 16 months vs., H1: 28 months; Type I error: 0.05, power 80%). Clinical trial information: NCT06006923 .

Atezolizumab plus chemotherapy with or without bevacizumab in advanced biliary tract cancer: Results from a randomized proof-of-concept phase II trial (IMbrave151).

435 Background: VEGF blockade coupled with cytotoxic chemotherapy can promote an immune-permissive tumor microenvironment that augments response to PD-L1 inhibition. IMbrave151 (NCT04677504) is a randomized, double-blinded, global proof-of-concept Phase II study evaluating atezolizumab (atezo), bevacizumab (bev) and cisplatin and gemcitabine (CisGem) as first-line treatment for advanced biliary tract cancer (aBTC). Here we report updated clinical data and molecular correlates of response and resistance. Methods: Patients (pts) with previously untreated aBTC were randomized 1:1 to receive atezo (1200 mg every 3 weeks [q3w]) + bev (15 mg/kg q3w) or placebo (plb) + CisGem (Cis 25 mg/m2 and Gem 1000 mg/m2 on Days 1 and 8 q3w) for up to 8 cycles, followed by atezo (1200 mg q3w) + bev (15 mg/kg q3w) or plb until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response (DOR), and safety. The final OS analysis was done when ≈90 deaths occurred or when all pts had ≥2 years of follow-up. Transcriptome analysis (n=98) and mutation profiling (n=103) were done on baseline tumor samples. This was a signal-seeking trial to estimate the treatment effect in each arm with no formal hypothesis testing. Results: In total, 162 pts were randomized to either atezo + bev + CisGem (atezo/bev; n=79) or atezo + plb + CisGem (atezo/plb; n=83). The updated PFS HR was 0.67 (95% CI: 0.46, 0.95) in favor of atezo/bev. Updated median PFS was 8.35 mo for atezo/bev and 7.9 mo for atezo/plb, with 6-mo rates of 78% and 63%, respectively. The updated OS HR was 0.97 (95% CI: 0.64, 1.47), with a median of 14.9 mo for atezo/bev and 14.6 mo for atezo/plb. Confirmed ORR was 26.6% for atezo/bev and 26.5% for atezo/plb, with median DORs of 10.28 (95% CI: 6.7, 16.7) and 6.18 mo (95% CI: 4.3, 6.7), respectively. The incidence of Grade 3/4 adverse events was 73% with atezo/bev and 74% with atezo/plb. High VEGFA gene expression was associated with an improved PFS (HR, 0.43; 95% CI: 0.22, 0.83) and OS (HR, 0.66; 95% CI: 0.31, 1.4) in favor of atezo/bev. Hepatocytes high gene signature also was associated with an improved PFS (HR, 0.47; 95% CI: 0.24, 0.92) and OS (HR, 0.66; 95% CI: 0.31, 1.4) in favor of atezo/bev. Pts with PI3k/AKT pathway mutations appeared to have worse OS than pts without mutations (HR, 3.7; 95% CI: 1.5, 9.1) with atezo/bev. Conclusions: Final analysis of the IMbrave151 study indicates a modest PFS benefit in intent-to-treat pts combining atezo with bev and chemotherapy. The trial is limited by small numbers and a non-comparative design. Exploratory analysis of correlative biomarkers suggests that high VEGF-A gene expression and hepatocytes high gene signature may be predictive markers of benefit with atezo/bev, warranting further investigation. Clinical trial information: NCT04677504 .

Trial in Progress: A Phase 2 Study of Linvoseltamab for the Treatment of High-Risk Smoldering Multiple Myeloma (LINKER-SMM1)

Background and Significance Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder that precedes the development of multiple myeloma (MM). Traditionally, patients with SMM have undergone observation until progression to MM, but this paradigm can result in poor outcomes for some patients. Phase 3 clinical trials have demonstrated that early treatment with lenalidomide with or without dexamethasone can delay the development of end-organ damage and improve overall survival among SMM patients with high-risk features. Linvoseltamab (REGN5458) is a fully human B-cell maturation antigen (BCMA)×CD3 bispecific antibody that targets BCMA on plasma cells and CD3 on T cells, resulting in targeted T-cell-mediated cytotoxicity. In the Phase 1/2 LINKER-MM1 study, linvoseltamab alone induced deep and durable responses with a generally manageable safety profile in patients with relapsed/refractory MM (Lee et al. EHA. 2023). These data highlight the potential of novel immunotherapies with promising single-agent activity to be attractive therapeutics for early intervention to prevent progression to MM. Study Design and Methods LINKER-SMM1 is an open-label, Phase 2 study (NCT05955508) designed to evaluate the safety and efficacy of linvoseltamab monotherapy in adult participants with SMM who are at a high risk of progression to MM. High-risk criteria include having both ≥95% clonal plasma cells in the bone marrow (BM) and immunoparesis and/or ≥2 of the following: serum M-protein &amp;gt;2 g/dL, free light chain ratio &amp;gt;20, and BM plasma cells &amp;gt;20%. Participants must have a confirmed diagnosis of SMM within 5 years of enrollment, Eastern Cooperative Oncology Group performance status ≤1, and adequate organ function to be eligible. Participants will be excluded from enrollment if they have myeloma-defining events, uncontrolled infection, history of allogeneic stem cell transplantation, or received prior treatment for SMM. The study will take place at approximately 15 sites in Spain and will include two parts: Part 1 (safety run-in) to evaluate the preliminary safety and tolerability of linvoseltamab and Part 2 (expansion) to evaluate the clinical activity of the selected dosing regimen. In Part 1, at least 6 participants will receive linvoseltamab starting with a step-up schedule before reaching the full dose. All subsequent treatment with full-dose linvoseltamab will be given over 28-day cycles until completion of 24 cycles or occurrence of a protocol-defined reason for discontinuation. Assuming that initial safety is shown to be acceptable, an additional 34 participants will be enrolled in Part 2 according to the dosing regimen established in Part 1. Post-treatment safety monitoring will continue for up to 90 days after the last dose of linvoseltamab, and participants with an ongoing response will continue routine efficacy assessments until confirmed biochemical progression, start of non-protocol cancer therapy, or death. Long-term follow-up will continue for up to 5 years after the last dose of linvoseltamab. The primary endpoints in Part 1 are frequency of adverse events (AEs) of special interest, including grade ≥2 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and frequency and severity of treatment-emergent AEs. In Part 2, the primary endpoints are complete response (assessed by International Myeloma Working Group criteria) and minimal residual disease (MRD) negativity (10 -5 sensitivity) after 12 and 24 months of treatment. Secondary endpoints include cumulative safety, overall response rate, duration of response, sustained MRD negativity, biochemical and clinical progression-free survival (PFS), time to myeloma-defining event, time to initiation of first-line treatment for MM, and overall survival as well as immunogenicity and serum concentration of linvoseltamab over time. Exploratory endpoints include PFS after the start of first-line treatment for MM, adequacy of stem cell collection, patient-reported outcomes, and various biomarker changes. As this is a proof-of-concept study, results will be analyzed using descriptive statistics and no formal hypothesis testing is planned. Study accrual is planned to begin in Q4 2023.