Citations

5074 Background: PC commonly expresses PSMA and has dose-responsive radiosensitivity. 177Lu-based radioligands usually use an empiric dosing regimen. This 1st dose-escalation study of 177Lu-PSMA-617 employed a dose-dense fractionation schedule intended to allow delivery of higher total doses to overcome radioresistance due to repopulation. Here, we report mature results of the study. Methods: Progressive mCRPC following > 1 potent ARPI (e.g., abi/enza) and chemo (or unfit/refuse taxane) without limit of # prior therapies provided adequate organ function and ECOG PS 0-2. Treatment: single cycle of fractionated dose 177Lu-PSMA-617 on D1 and D15. In Ph I dose-escalation, patients (pts) received one cycle of 7.4 - 22 GBq followed by Simon 2-stage Ph II at 22.2 GBq. PSMA expression was not required for treatment, but pre- and post-treatment 68Ga-PSMA11 PET/CT and/or 177Lu-PSMA-617 SPECT done. Primary efficacy by PSA changes with 2ndary outcomes with CT/bone scans, PSMA PET, circulating tumor cell (CTC; CellSearch) counts, plasma DNA (PCF_SELECT), and survival. Results: Between 1/2017 – 2/2021, 50 pts treated with median PSA 164.3, 35 (70%) CALGB (Halabi) poor risk. 47 (94%) bone, 38 (76%) nodal, 12 (24%) lung, 5 (10%) liver mets (4 additional pts with PSMA PET+ liver mets not apparent on CT). 29 (58%) with prior >2 ARPI, 29 (58%) with >1 chemo, 14 (28%) with Ra-223, 2 (4%) with 177Lu-J591. 27 (54%) treated at 22 GBq. No dose-limiting toxicity during Ph I. 38 (76%) with any PSA decline, 27 (54%) with >50% PSA. Median rPFS 8.3 mo [5.6-16.7], and OS 15.7 mo [10.9-20.6]. Of 17 RECIST measurable, 6 (35.3%) responded, 7 (41.2%) stable, 4 (23.5%) progressed. Of 31 with paired CTC counts, 16 (52%) decreased, 5 (16%) were stable; 10 (32.3%) converted to favorable/undetectable. Plasma DNA with high allele-specific ploidy and ARcopy number gain associated with OS (univariate). Treatment emergent adverse events (TEAE): 32 (64%) dry mouth, 22 (44%) pain flare, 22 (44%) fatigue, 19 (38%) nausea, 15 (30%) anemia, 15 (28%) thrombocytopenia (plts), 9 (18%) neutropenia (ANC). All TEAEs restricted to grade (Gr) 1-2 except 6 (12%) with Gr 3 anemia, 2 (4%) Gr 3/4 plts, 1 (2%) Gr 3 ANC. TEAE incidence and Gr were not related to dose. On multivariable analysis, 177Lu dose administered (p=0.09), CALGB risk (p=0.04), prior chemo (p=0.009), associated with OS; dose (p=0.1), CALGB risk (p=0.2), and AR copy number (p=0.2) associated with PSA50 decline. Baseline PSMA imaging (by imaging score or SUVmax) was not associated with OS or response. Conclusions: A single-cycle of fractionated-dose 177Lu-PSMA-617 is safe. Despite no pre-selection for PSMA expression, most had PSA decline with favorable PFS and OS compared to historical controls and similar to PSMA-selected targeted radionuclide studies administering multiple cycles in a less dose-intense approach. Clinical trial information: NCT03042468 .

Background: Despite growing interest in delivering high-value orthopaedic care, the costs associated with hip arthroscopy remain poorly understood. By employing time-driven activity-based costing (TDABC), we aimed to characterize the cost composition of hip arthroscopy for labral pathological conditions and to identify factors that drive variation in cost. Methods: Using TDABC, we measured the costs of 890 outpatient hip arthroscopy procedures for labral pathological conditions across 5 surgeons at 4 surgery centers from 2015 to 2022. All patients were ≥18 years old and were treated by surgeons who each performed ≥20 surgeries during the study period. Costs were normalized to protect the confidentiality of internal hospital cost data. Descriptive analyses and multivariable linear regression were performed to identify factors underlying cost variation. Results: The study sample consisted of 515 women (57.9%) and 375 men (42.1%), with a mean age (and standard deviation) of 37.1 ± 12.7 years. Most of the procedures were performed in patients who were White (90.6%) or not Hispanic (93.4%). The normalized total cost of hip arthroscopy per procedure ranged from 43.4 to 203.7 (mean, 100 ± 24.2). Of the 3 phases of the care cycle, the intraoperative phase was identified as the largest generator of cost (>90%). On average, supply costs accounted for 48.8% of total costs, whereas labor costs accounted for 51.2%. A 2.5-fold variation between the 10th and 90th percentiles for total cost was attributed to supplies, which was greater than the 1.8-fold variation attributed to labor. Variation in total costs was most effectively explained by the labral management method (partial R 2 = 0.332), operating surgeon (partial R 2 = 0.326), osteoplasty type (partial R 2 = 0.087), and surgery center (partial R 2 = 0.086). Male gender (p < 0.001) and younger age (p = 0.032) were also associated with significantly increased costs. Finally, data trends revealed a shift toward labral preservation techniques over debridement during the study period (with the rate of such techniques increasing from 77.8% to 93.2%; P trend = 0.0039) and a strong correlation between later operative year and increased supply costs, labor costs, and operative time (p < 0.001 for each). Conclusions: By applying TDABC to outpatient hip arthroscopy, we identified wide patient-to-patient cost variation that was most effectively explained by the method of labral management, the operating surgeon, the osteoplasty type, and the surgery center. Given current procedural coding trends, declining reimbursements, and rising health-care costs, these insights may enable stakeholders to design bundled payment structures that better align reimbursements with costs. Level of Evidence: Economic and Decision Analysis Level IV . See Instructions for Authors for a complete description of levels of evidence.

AbstractMyhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016–2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence‐based guidelines in anticipation of disease‐specific therapies.

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute‐on‐chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first‐line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so‐called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug‐induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up‐to‐date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug‐induced, autoimmune‐like hepatitis (DI‐AIH).

Diabetic kidney disease (DKD) is the worldwide leader in end-stage kidney failure and has limited treatment options. Cellular senescence abundance and inflammation contribute to DKD pathogenesis. We previously demonstrated that activin A, an inflammatory mediator of pro-fibrotic kidney injury and cellular senescence, is increased in DKD and correlates with DKD injury and kidney function. We hypothesized that activin A contributes to DKD injury causing pro-fibrotic, pro-inflammatory, and cellular senescence effects in vitro, and that antagonism of activin A is achieved with follistatin. An in vitro model of DKD injury was applied with high-glucose (HG) and transforming growth factor-β (TGFβ) exposure for 24 hours in U-937-derived macrophages and renal epithelial (HK2) cells. Prior to exposure, U-937 cells were converted to M0 macrophages with phorbol myristate acetate (PMA). To examine the potential of reducing activin A release by DKD injured cells, follistatin, an activin A antagonist, was added to the media of cells at the time of injury for 24 hours. Additionally, an activin A neutralizing antibody was added to the collected supernatant of DKD injured cells. Activin A, senescence (p16), pro-fibrotic (collagen I), and pro-inflammatory (monocyte chemoattractant protein [MCP]-1, tumor necrosis factor [TNF]-alpha, interleukin [IL]-6) markers were measured through qPCR, ELISA (activin A), and immunofluorescence staining (activin A). DKD injury in renal epithelial cells increased protein expression of activin A, increased gene expression of activin A, p16, and collagen I, but did not significantly increase MCP-1 expression at 24 hour exposure (Figure 1). Furthermore, DKD injury led to increased activin A release in conditioned medium vs. control renal epithelial cells. Administration of follistatin reduced activin A release by renal epithelial cells. Application of neutralizing antibody reduced activin A levels in collected medium after cell injury. After DKD injury in U-937 derived macrophages, activin A gene expression was increased. Injured macrophages had increased gene expression of TNF-alpha and IL-6, demonstrating a pro-inflammatory phenotype. In conclusion, diabetic kidney injury increases activin A release, inflammation markers, and senescence markers in kidney cells and macrophages, therein contributing to downstream effects that further propagate disease. As shown, follistatin antagonism reduces activin A release by injured cells. Additional studies are needed to explore activin A as a promising therapeutic target and follistatin as a possible treatment in DKD. NIH 5TL1TR002380-07, AG076537, DK123492, DK109134. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Hepatorenal syndrome-acute kidney injury (HRS-AKI) is associated with significant morbidity and mortality. While liver transplantation is the definitive treatment, continuous terlipressin infusion for HRS-AKI may provide benefit and, as such, was assessed in a population composed of candidates for liver transplant (LT). Fifty hospitalized LT-eligible patients with HRS-AKI received a single bolus followed by continuous terlipressin infusion. Acute-on-chronic liver failure grade 3, serum creatinine (SCr)>5.0 mg/dL, or Model for End-Stage Liver Disease (MELD) ≥35 were exclusions. Fifty hospitalized patients who received midodrine and octreotide or norepinephrine for HRS-AKI served as a historical comparator cohort. Complete response (CR) was defined as a ≥30% decrease in SCr with end-of-treatment (EOT) SCr≤1.5, partial response as a ≥30% decrease in SCr with EOT SCr>1.5, and nonresponse as a <30% decrease in SCr. CR rate was significantly higher in the terlipressin cohort compared to the historical cohort (64% vs. 16%, p<0.001). Survival, while numerically higher in those who received terlipressin, was statistically similar (D30: 94% vs. 82%, p=0.12; D90: 78% vs. 68%, p=0.37). Renal replacement therapy (RRT) was more common among terlipressin NR than CR and PR (70% vs. 3% vs. 13%, p < 0.001). EOT MELD and SCr were significantly lower within terlipressin cohort (MELD: 19 vs. 25, SCr: 1.4 vs. 2.1 mg/dL, p<0.001). Sixteen of 40 terlipressin-treated patients received LT-alone (terlipressin CR in 10/16). One patient on terlipressin had a hypoxic respiratory failure that responded to diuretics; one possibly had drug-related rash. With continuous terlipressin infusion, a CR rate of 64% was observed with a favorable safety profile. Terlipressin use was associated with lower EOT MELD and SCr than the historical midodrine and octreotide/norepinephrine cohort; LT-alone was accomplished in a high proportion of complete terlipressin responders.