Winters, Jeffrey L.

TPS898 Background: Enfortumab vedotin with pembrolizumab (EV/Pembro) is now first-line therapy for locally advanced or metastatic urothelial carcinoma (la/mUC) following the EV-302/KEYNOTE-A39 trial, which demonstrated a 67.7% response rate and prolonged survival. However, ~35% of cancers exhibited primary resistance and most responders relapse within one year, with post-EV/Pembro therapies achieving < 15% response and median survival < 3 years. We previously showed that therapeutic plasma exchange (TPE) removed soluble PD-L1 and other immune checkpoint inhibitor (ICI) blocking soluble factors from the blood and that this overcame ICI resistance. Combining TPE with EV/Pembro rechallenge may overcome acquired resistance and restore antitumor immunity. Methods: RECIPE-B1 [NCT07087860] is an open-label, randomized phase II trial enrolling 50 patients (1:1) with EV/Pembro-refractory la/mUC and ECOG 0–2. Arm A receives TPE on days 1–3 followed by EV 1.25 mg/kg IV plus pembrolizumab 200 mg IV on day 3 of each 21-day cycle for the first three cycles, then continues EV/Pembro alone from cycle 4. Arm B receives investigator’s-choice next-line standard of care (SOC) per NCCN guidelines. Tumor assessments occur at the end of cycle 4 (±28 days) and every 12 weeks thereafter; safety is monitored each cycle (CTCAE v5.0). The primary endpoint is objective response rate (ORR) by RECIST 1.1, comparing TPE + EV/pembro versus SOC. Secondary endpoints include progression-free survival, overall survival, duration of response, quality of life (EORTC QLQ-CIPN20), and safety. Correlative studies evaluate circulating and urinary tumor DNA and exosomal biomarkers (including exosomal Nectin-4) as predictors of response and resistance. The trial is open at Mayo Clinic; as of September 2025, 2 of 50 patients have been enrolled, with planned accrual of ~2 patients/month and central coordination at Mayo Clinic and affiliates. Clinical trial information: NCT07087860 .

AbstractBackgroundSince FDA approval in 2017, CAR‐T therapy has seen rapid clinical adoption. Shifting clinical trends have emerged with increasing utilization of CAR‐T therapies and a downward trend in HSCTs. Given the overlapping resources required for the manufacture and storage of these products, we sought to examine trends over a 6‐year period.MethodsThe apheresis patient database and Lab database were reviewed to compile a list of patients that underwent either CAR‐T or HSCT (autologous) collections, and/or received CAR‐T or autologous HSCT infusions between January 1, 2018 and December 12, 2023. This was further examined by year and disease group.ResultsThe total number of patients collecting for CAR‐T increased from 52 in 2018 to 150 in 2023 (slope = 21.97; p = .0013), accompanied by a decrease in the number of patients collecting for HSCT, from 425 in 2018 to 341 in 2023 (slope = −21.2; p = .0177). Neither total number (calculated as number of HSCT + CAR‐T) of patients collected (mean 476 + 20.4 per year), nor collection procedures (mean 972 ± 75.8 per year) changed significantly over the 6‐year period. The total number of CAR‐T infusions increased from 24 in 2018 to 111 in 2023 (slope = 17.7; p = .004), with a decrease in auto‐HSCT from 400 to 289 (slope = −28.7; p = .008). The overall number of infusions (calculated as number of HSCT + CAR‐T) did not change significantly (slope = −10.9; p = .13) over the 6‐year period.DiscussionOur findings confirm the increasing adoption of CAR‐T therapy occurring alongside a decreasing stem‐cell transplants, with stable overall resource utilization.

Background/Case Studies: A 79-year-old male was admitted to our institution with anemia, with a hemoglobin nadir of 5.5g/dL, and no recent transfusion history. Given a remote history of occult colonic bleeding, the working diagnosis was GI bleeding. The referring blood bank had reported “possible antibody to high prevalence antigens of the Kell system, suspected McLeod.” The American Rare Donor Program had been contacted and confirmed no Ku or KX negative blood was available in the United States. Study Design/Methods: Initial testing by our immunohematology reference lab showed that the patient's plasma reacted with all cells tested, including the patient's own red blood cells (RBCs). The patient had a positive DAT (W+ poly, W+ IgG and negative C3d). Further testing showed the plasma and eluate prepared from the patient's RBCs did not react with cells treated with dithiothreitol (DTT) and did not react with an RBC designated as K0. Red cell morphology and creatinine kinase measurements were not consistent with the McLeod phenotype. The antibody was interpreted as having anti-Ku specificity. A serologic phenotype was performed on the patient's RBCs following treatment with chloroquine diphosphate and showed the following results: K-k-, Kp(b-), Js(b-) and Ku-. A molecular phenotype using Immucor Precise type gave the following results: K-k+, Kp(a-b+), Js(a-b+). Results/Findings: A sample was sent to the American Red Cross National Molecular Laboratory for KEL-cDNA analysis and genotype for KX blood group system. The probable genotype was KEL*02/KEL*02 with a predicted phenotype of K-k+, Kp(a-b+), Js(a-b+). The probable genotype was XK*01 (homozygous or hemizygous) with a predicted phenotype of Kx+. Given the positive DAT and the absence of an identifiable source of GI bleeding, a diagnosis of autoimmune hemolytic anemia with suppression of Kell system antigens was made. The patient was initially treated with 100mg oral prednisone daily for two weeks with subsequent weekly taper, four doses of 1g/kg IVIg daily, four doses of rituximab weekly, and three doses of daratumumab on weeks 1, 2 and 4. During the initial work-up and treatment, the patient did not receive a transfusion. Testing was repeated 3 months later: the DAT remained W+ and the antibody reactivity now demonstrated apparent anti-Jsb specificity. However, serologic antigen typing using chloroquine diphosphate now showed the following results: k+, Kp(b+), Js(b+) and Ku+. At this time, the patient's hemoglobin increased to a maximum of 11.6g/dL. Unfortunately, the patient relapsed about 4.5 months after his initial presentation. He was restarted on 100mg oral prednisone daily for two weeks followed by weekly taper. This led to only a modest improvement in his hemoglobin concentration. The DAT and phenotyping results remained unchanged but the antibody identification now demonstrated apparent anti-k (Cellano) specificity during this period. As the patient continued to have symptomatic anemia, in the setting of massive splenomegaly, the was decision made to proceed to splenectomy. During the operation, the patient received two K- units that were otherwise not typed for additional Kell system antigens. In the four weeks post-transfusion, there was no evidence of an acute worsening of his hemolytic anemia. Conclusions: This is a case of an autoantibody with apparent specificity to a high prevalence KEL antigen(s). The antibody was originally thought to be an alloantibody, requiring Ku- or Kx- RBCs. The KEL system antigens were depressed due to the patient's disease state and were re-expressed following treatment with multimodal immunomodulatory treatment. Specificity of the antibody appeared to change during therapy reacting more strongly with different high incidence Kell system antigens. When the patient was transfused with K- RBCs later in his disease course, there was no acute worsening of hemolysis. This finding is consistent with an autoantibody rather than an alloantibody to KEL antigen(s). This case shows the importance of incorporating molecular testing along with serology.

Abstract Introduction: Immune checkpoint inhibitors (ICI) are an essential systemic therapy for advanced melanoma. However, most melanomas develop resistance to ICI. Tumor-derived soluble PD-L1 (sPD-L1) and other soluble immunosuppressive factors drive checkpoint inhibitor resistance and correlate with inferior survival. We previously showed that therapeutic plasma exchange (TPE) removes sPD-L1 from circulation. Thus, we hypothesized that TPE-mediated removal of sPD-L1 and other immunosuppressive factors could overcome immunotherapy resistance in refractory melanoma. Methods: In this clinical trial (NCT04581382), we prospectively enrolled eighteen (18) patients with widely metastatic melanoma with progression despite anti-PD-1 ICI and elevated sPD-L1 by ELISA (≥1.7ng/mL). Each patient received radiotherapy to between one and three metastatic lesions (at least two unirradiated lesions) followed by three TPE sessions on consecutive days and re-challenge with checkpoint inhibitor. The primary safety and efficacy endpoints of the study were adverse events (AEs) and sPD-L1 reduction by TPE, respectively. Secondary endpoints included RECIST-based response in unirradiated lesions and overall survival. Correlative studies included kinetics of sPD-L1 and soluble immonsuppressive factors and dynamics of peripheral immune cell phenotypes. Results: Mean age was 62 (SD 13) and seven of eighteen (39%) were female. Mean baseline sPD-L1 was 26.31 ng/mL (40.01). The treatment was well-tolerated with one (6%) patient with grade 3 and 4 adverse events from a central line infection after TPE. Levels of sPD-L1 were significantly reduced by TPE (mean 80.2% reduction, p<0.0001). Two patients (11.1%) experienced complete response (CR), one (5.6%) partial response, three (16.7%) stable disease, and 12 (66.7%) progressive disease. In one case, immunotherapy was discontinued after two years due to no detectable lesions. Changes in tumor-reactive (TTR) GZMB+/CX3CR1+/CD11ahigh and other peripheral immune cell populations predicted overall survival in this cohort. In addition to sPD-L1, other soluble mediators of ICI resistance were also reduced by TPE and predicted overall survival in this cohort. Summary/Conclusion: sPD-L1 and other soluble immunoregulatory signaling molecules are important mediators of ICI resistance. SBRT and TPE can resensitize ICI-refractory melanoma by removing these factors. Patients with persistently elevated or rapid rebound of sPD-L1 following TPE experienced poor response and overall survival. Serial monitoring of sPD-L1 may predict response to ICI and multiple courses of TPE may be necessary. Our findings may apply in other ICI-resistant cancers with elevated sPD-L1. ClinicalTrials.gov registration: NCT04581382, ReCIPE-M1 (Rescuing Cancer Immunotherapy with Plasma Exchange in Melanoma 1).

AbstractBackgroundSome patients express concerns regarding receipt of allogeneic blood transfusions from donors potentially vaccinated against SARS‐CoV‐2 (COVID‐19). However, limited information exists about patients' expression of these concerns or how to address them during the blood transfusion consent process. In this study, we describe our experience of working collaboratively with patients with vaccine‐related transfusion concerns prior to elective surgery, summarizing treatment decisions and clinical outcomes.Study Design and MethodsThis observational descriptive study includes patients seen in our Bloodless Medicine and Surgery clinic between June 2022 and June 2024 for vaccine‐related transfusion concerns prior to elective surgery. A shared decision‐making framework was employed to foster conversation, share information, provide reassurance, reconcile conflict, and match preferences with available care options. Patient characteristics, treatment decisions, and surgical outcomes were reviewed and summarized.ResultsThirty‐five patients were included, with median (1st, 3rd quartile) age of 61 (53, 69) years. Cardiac surgery was the most common type of surgery (29%). Twelve patients (34%) were anemic preoperatively, and all received preoperative treatment. After discussion with a Bloodless Medicine specialist, 24 (68.6%) decided to consent to the use of all blood products, 5 (14.3%) accepted only red blood cells, and 6 (17.1%) declined all blood products. Among 28 patients undergoing surgery, only 4 (14%) received allogeneic transfusion perioperatively.ConclusionMany patients concerned about the vaccination status of blood donors may ultimately consent to allogeneic blood products after shared decision‐making with a Bloodless Medicine specialist, highlighting the importance of patient empowerment and collaborative care.

ABSTRACTApheresis is performed worldwide for an increasing number of indications. The development of common data elements (CDE) for apheresis related areas may facilitate conduct of new research, enhance quality initiatives including benchmarking, and improve patient care. This report describes the systematic development of the Uniform Apheresis Case Report Form (UACRF) as part of the Apheresis in the United States (ApheresUS) program. A consensus panel of 17 diverse experts in apheresis, related specialties, and electronic case report form (eCRF), and database development was assembled. The panel met via online conferencing from November 17, 2020 to December 1, 2021. A draft document was posted online for public comment from October 11, 2021 to November 10, 2021. Feedback was collected using an online survey tool. The consensus panel revised the UACRF. This version was converted to an eCRF with additional changes made to improve usability in this format. The final version of the UACRF was created on August 24, 2023. The UACRF contains 16 modules: procedure and subject eligibility, patient demographics, general procedure information, laboratory parameters, vascular access, common procedure elements, eight procedure specific modules (mononuclear cell collection and seven therapeutic modalities), outcomes, and site information. A total of 137 data elements were created, including 57 with one or more subelements. The UACRF is the first systematic attempt to develop CDE for therapeutic apheresis and white blood cell collections. Further validation of the UACRF is necessary to confirm the tool's ability to collect the relevant data elements and determine the usability of the form.

Abstract Background Professional medical societies recommend that carrier screening for 113 different genetic disorders be offered during pregnancy or preconception to all individuals, regardless of ancestry, in order to provide more equitable opportunities for patients to ascertain their reproductive risks. In our clinical laboratory experience, however, the vast majority of healthcare providers continue to order carrier screening for only cystic fibrosis (CF), which is disproportionately common in white individuals of Northern European descent. Our highest volume CF screening test is performed on &gt;10,500 diverse patients per year and utilizes a targeted genotyping array that detects &gt;500 variants in CFTR and &gt;1200 variants in &gt;150 other pertinent genes. Here we report the inequities in diagnostic yield among our first 8,000 patients for whom only limited testing was ordered and examine the barriers to widespread adoption of more inclusive carrier screening. Methods Three carrier screening options (CF, CF+spinal muscular atrophy [SMA], CF+SMA+fragile X syndrome [FXS]+hemoglobinopathies) were ordered clinically and performed on DNA extracted from 8,000 whole blood samples from unique individuals utilizing a custom SNP array (Thermo Fisher GeneTitanTM platform) designed to detect &gt;1700 pathogenic variants in 218 different genes. Data was retrospectively reviewed to determine overall detection rates for carriers of all recommended conditions vs. only the condition(s) included in the originally ordered service. Finally, reproductive health providers at nine different ordering sites across the U.S. were interviewed regarding their current carrier screening practices. Results Patients were referred for testing by 119 different clinical facilities. 98.1% (7847/8000) had CF-only testing ordered, 1.2% (99/8000) had CF+SMA testing ordered, and 0.68% (54/8000) had testing for CF+SMA+FXS+hemoglobinopathies ordered. 7.1% (568/8000) of patients had reportable variants in CFTR. Had CF+SMA testing been ordered on all 8,000 patients, however, the diagnostic yield would have been 8.9%. Of the patients who had CF-only or CF+SMA testing ordered, 11.9% (943/7946) were found to be carriers of hemoglobinopathies. Finally, had all 8000 patients had testing for all currently recommended targets on the panel, the diagnostic yield would have increased to 55% (4396/8000). Ordering providers at 9/50 different contacted sites agreed to interview requests. 100% (9/9) of respondents indicated that their patients experience significant disparities in access to carrier screening, and that the primary cause of these inequities was insufficient insurance reimbursement. 67% (6/9) of respondents indicated that &gt;50% of their patient population identified as non-white and would have “very strongly” benefitted from “testing for other disorders beyond CF.” Conclusions Despite clinical practice guidelines urging for more population-neutral carrier screening, major gaps exist between what is recommended versus ultimately ordered. This significantly limits the clinical utility of testing, especially in patients from underrepresented backgrounds. Improved insurance coverage for more inclusive carrier screening is needed to help reduce such disparities.