Winer, Ira Seth

e13730 Background: Financial toxicity, the burden of treatment cost, affects up to half of people with cancer and can affect survival. Financial toxicity is a health equity issue, disproportionately affecting Black patients. This cross-sectional study used baseline data from the Discussions of Cost (DISCO) Trial, an RCT to improve patient-provider treatment cost discussions and, in turn, mitigate financial toxicity, to examine whether Black and White patients differed in patient-provider communication perceptions and financial toxicity correlates. Methods: Data were collected from 2021-2025 at an NCI-designated comprehensive cancer center. Participants were Black or White patients diagnosed with solid tumor cancers. At baseline, patients completed demographic measures; communication measures of self-efficacy in patient-provider interactions (e.g., “I am confident I know what questions to ask a provider”); self-efficacy in managing cancer treatment costs (e.g., “I am confident I can understand treatment costs”); and whether they have a provider- or patient-centered approach (e.g., “the provider should decide what gets talked about”); and financial measures including economic burden (e.g., “it’s difficult to live on my income”); treatment cost distress (e.g., “worries about paying for my cancer treatment keep me up at night”); and anticipated material hardship (e.g., “I worry about the financial problems I will have in the future as a result of my treatment”). Comparisons were conducted by patient race. Results: A total of 202 patients participated (116 Black patients, 86 White patients). White patients were more likely to have advanced degrees, a higher annual income, and less likely to have Medicaid compared to Black patients. Black patients reported higher self-efficacy for managing treatment costs ( p = .002) and a higher provider-focused orientation to the patient-provider relationship ( p = .001), than White patients. Black patients reported greater levels of financial burden ( p < .001), cost distress ( p = .005), and anticipated material hardship ( p = .003). There was no difference in self-efficacy for interacting with providers. Conclusions: These results suggest that a communication intervention for patients may help mitigate the experience of financial toxicity, especially for Black patients. Clinical trial information: NCT04766190 . Patient characteristics. Black Patients White Patients p -value Race 116 86 Education < High School High School/GED Some College 2 or 4-year College Degree Graduate/Professional College Trade/Technical/Vocational School 10352626712 0141631187 < .001 Annual Household Income 0 - $19,999 $20,000 - 39,999 $40,000 - 59,999 $60,000 - 79,999 $80,000 - 99,999 $100,000 - 149,999 $150,000 + 53201611431 51215991716 <.001 Insurance Type* Medicaid Medicare Medicare supplement Private None 604911330 113726393 <.001>.99<.001.20.15 *Patients could select more than one

e13729 Background: Financial toxicity, the burden of treatment cost, affects up to half of people with cancer and can affect survival. Financial toxicity is a health equity issue, disproportionately affecting Black patients. Patient education about cost and patient-provider cost discussions are recommended to mitigate financial toxicity but occur infrequently. The Discussions of Cost (DISCO) App, designed to mitigate financial toxicity through a tailorable education and communication intervention, was assessed for efficacy in an RCT with Black and White patients. Here we describe the DISCO App's feasibility and acceptability. Methods: Data were collected from 2021 to 2025 at an NCI-designated comprehensive cancer center. Participants were Black or White patients diagnosed with solid tumor cancers. While waiting to see their provider, patients randomized to the intervention arm used the DISCO App on a tablet. The DISCO App includes a video about treatment costs, ways to manage costs, and the importance of discussing costs with providers. Once patients enter their socio-demographic information (e.g., employment) and financial concerns, they receive a tailored list of cost questions to ask their provider. Patients responded to measures immediately after using the DISCO App. Feasibility was assessed by patient reports of how much time they needed to use the DISCO App and if they were able to use the DISCO App before the provider entered the exam room. Acceptability was measured by items assessing patient perceptions of the DISCO App (1 = strongly disagree; 5 = strongly agree). Descriptive statistics summarized results and mean comparisons were used to assess perceptions by patient self-identified race. Results: Of the 202 patients recruited, 124 were randomized to the intervention arm (67 Black patients; 57 White patients). All patients completed using the DISCO App prior to their provider entering the exam room and 80% of patients needed 15 minutes or less to use the DISCO App, with no difference by patient race. Black patients ( M = 4.4) reported finding the DISCO App more helpful than White patients ( M = 3.9; p = .02) and it brought up cost issues they had not considered (Black patients = 3.5; White patients = 3.0; p = .05). Patients reported the questions were easy to understand ( M = 4.4), helped them feel it was okay to talk with their provider about cost ( M = 4.0), that it prompted cost questions ( M = 3.3), that they learned what costs to consider (55%), and learned ways to manage cost (62%) with no differences by patient race. Conclusions: The DISCO App was feasible and acceptable to Black and White patients with cancer, with Black patients reporting more favorable perceptions than White patients. Next steps include assessing effectiveness in improving outcomes including prompting patient-provider treatment cost discussions and related financial toxicity outcomes (e.g., treatment adherence). Clinical trial information: NCT04766190 .

Abstract Background: Pyrimidine synthesis is a therapeutic vulnerability in cancer but inhibition results in toxicity to normal cells. Differential targeting of CTP synthase 1 (CTPS1), sparing the CTPS2 isoenzyme, is a therapeutic strategy in lymphoid cancers, supported by human genetic studies, that can potentially avoid toxicity; however, CTPS2 activity may compensate in epithelial tumours. Loss of CTPS2 protein expression characterises 25% of solid tumours and is predicted to expose a synthetic lethal vulnerability to CTPS1 inhibition. Dencatistat (STP938) is a first in class oral CTPS1 inhibitor showing &gt;1,300-fold selectivity over CTPS2. In preclinical studies, CTPS2 expression was confirmed as a key modulator of response to CTPS1 inhibition, and dencatistat induced tumour regression in an in vivo model of CTPS2 negative ovarian cancer. Study design: The study comprises a standard 3+3 phase 1a dose escalation design, in which intra-patient dose escalation is encouraged, followed by a phase 1b safety expansion. The dose escalation study is recruiting participants with high grade advanced tumours who have exhausted standard of care therapy (excluding haematological cancers, salivary gland tumours and low grade tumours of any tissue). In addition, participants with high grade serous ovarian cancer whose tumours lack expression of CTPS2 (per central laboratory testing by immunohistochemistry) are eligible for backfill into cleared cohorts during dose escalation. The recommended phase 2 dose (RP2D) will be nominated based on safety, tolerability, target engagement and early signs of clinical efficacy. The phase 1b safety expansion study will recruit participants with CTPS2 negative ovarian, lung or endometrial cancer who will receive treatment at the RP2D. Standard inclusion criteria apply; patients with ECOG performance score &gt;2 (&gt;1 for phase 1a in France) or active/symptomatic CNS metastases are not eligible. The primary objectives of the study are to evaluate the safety and tolerability of single agent dencatistat and to determine the RP2D for further development. Secondary objectives comprise evaluation of pharmacokinetic properties and preliminary clinical activity. Exploratory endpoints include evaluation of target engagement, molecular features associated with response, and determination of drug metabolites. The study opened to enrolment in the UK, France and USA in September 2024 and is currently in dose escalation (NCT06297525). The phase 1b study is expected to commence mid-2026 and will include additional centres in Spain. Citation Format: Donna M. Graham, David Sommerhalder, Douglas Orr, Rowan Miller, Neeharika Makani, David O'Malley, Ira Winer, Philip A. Beer, Karen Smith, Maureen Higgins, John R. Hawse, Xiyin Wang, Saravut J. Weroha, Christophe Massard, Patricia Roxburgh. Lack of CTPS2 expression exposes synthetic lethal vulnerability to selective CTPS1 inhibition: A phase 1 dose escalation study of dencatistat (STP938) with safety expansion in biomarker selected cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT075.

This joint Clinical Consensus Statement on the safety and feasibility of concomitant urogynecologic and gynecologic oncology surgical procedures reflects statements drafted by content experts from the American Urogynecologic Society and the Society of Gynecologic Oncology. The writing group used a Delphi process to evaluate statements developed from a structured literature search and assessed consensus. A total of 35 statements were assessed in the following categories: (1) background, (2) treatment options, (3) timing of concurrent surgery, (4) risk factors, and (5) value-based care. Of the 35 statements, 28 reached consensus on initial review. Three statements were omitted, and 4 statements were revised and reached consensus following second review utilizing the Delphi process.

Background Novel treatment options are required in patients with platinum-resistant ovarian cancer (PROC). Myeloid-derived suppressor cells promote a hostile tumor microenvironment and are associated with worse clinical outcomes in PROC. We evaluated the safety and preliminary efficacy of PY159, an agonist antibody to Triggering receptor expressed on myeloid cells-1 (TREM1) that reprograms immunosuppressive intratumoral myeloid cells, and PY314, an antagonist antibody to Triggering receptor expressed on myeloid cells-2 (TREM2) that depletes tumor-associated macrophages, as single agents and in combination with pembrolizumab in subjects with PROC. Methods PY159 and PY314 were individually evaluated in patients with PROC. Patients were treated with monotherapy (PY159 3 mg/kg or PY314 10 mg/kg), based on the recommended dose for expansion derived from the phase 1a studies. At the time of first progression, patients could continue study drug and crossover to combination therapy with pembrolizumab (200 mg) every 3 weeks at the discretion of the investigator. Disease assessment by Response Evaluation Criteria in Solid Tumor version 1.1 was performed every 6 weeks. Results 17 patients were enrolled in the PY159 study (median age 67, range 22–77; median prior therapies 6, range 2–18) and 16 patients in PY314 (median age 65.5, range 49–81; median prior therapies 4, range 2–10). 7 patients in PY159 and 8 patients in PY314 crossed over to combination therapy. Safety events included the following: treatment-related adverse events occurred in 15 patients (88.2%) in PY159 and 9 patients (56.3%) in PY314. Infusion-related reactions occurred in 6 patients (35.3%) in PY159 and 3 patients (18.8%) in PY314. Immune-related adverse events occurred in 13 patients (76.5%) in PY159 (arthralgias) and 1 patient (6.3%) in PY314 (diarrhea). Serious adverse events occurred in 6 patients (36.3%) in PY159 (1 related) and 12 patients (75%) in PY314 (all unrelated). The best radiographic response in PY159 was stable disease in 8/16 patients (50%; median 16 weeks, range 9–33), and in PY314, it was stable disease in 8/16 patients (50%; median 12 weeks, range 6–36). Median PFS was 2.76 months and 2.69 months in PY159 and PY314, respectively. There were no responses in the crossover arm. Conclusions Both PY159 and PY314 were well tolerated, with an acceptable safety profile, as both single agents and in combination with pembrolizumab. Both agents warrant further investigation in heavily pretreated PROC.

PURPOSE The adjunctive use of intraoperative molecular imaging (IMI) is gaining acceptance as a potential means to improve outcomes for surgical resection of targetable tumors. This confirmatory study examined the use of pafolacianine for real-time detection of folate receptor–positive ovarian cancer. METHODS This phase III, open-label, 11-center study included subjects with known or suspected ovarian cancer, scheduled to undergo cytoreductive surgery. The objectives were to confirm safety and efficacy of pafolacianine (0.025 mg/kg IV), given ≥ 1 hour before intraoperative near-infrared imaging to detect macroscopic lesions not detected by palpation and normal white light. RESULTS From March 2018 through April 2020, 150 patients received a single infusion of pafolacianine (safety analysis set); 109 patients with folate receptor–positive ovarian cancer comprised the full analysis set for efficacy. In 33.0% of patients (95% CI, 24.3 to 42.7; P < .001), pafolacianine with near-infrared imaging identified additional cancer on tissue not planned for resection and not detected by white light assessment and palpation, exceeding the prespecified threshold of 10%. Among patients who underwent interval debulking surgery, the rate was 39.7% (95% CI, 27.0 to 53.4; P < .001). The sensitivity to detect ovarian cancer was 83%, and the patient false-positive rate was 24.8%. Investigators reported achieving complete R0 resection in 62.4% (68 of 109) of patients. Drug-related adverse events were reported by 30% of patients (45 of 150) and most commonly included nausea, vomiting, and abdominal pain. No drug-related serious adverse events or deaths were reported. CONCLUSION This phase III study of pafolacianine met its primary efficacy end point, identifying additional cancers not otherwise identified or planned for resection. Pafolacianine may offer an important real-time adjunct to current surgical approaches for ovarian cancer.

2648 Background: To characterize the safety and tolerability of PY314, an immunosuppressive macrophage depleting antibody, as a single agent and in combination with pembrolizumab in subjects with advanced refractory solid tumors including subject’s refractory to checkpoint inhibitors if approved for that indication. Methods: Two were evaluated in subjects with advanced solid tumors, single agent PY314 and PY314 in combination with 200 mg of pembrolizumab using a 3+3 dose escalation study design. Dosing was intravenous and administered once every 3-weeks, a defined cycle. Disease assessment by RECIST 1.1 was performed every 6 weeks. Each stratum included 4 dose levels of PY314 (1, 3, 10, and 20 mg/kg). Pharmacokinetics were evaluated at specified time points. Archival tumor tissue was analyzed for TREM2 expression by immunohistochemistry. Based on preclinical evaluation of TREM2 expression, HR+ HER2- and triple negative breast cancer, colorectal cancer, renal cell cancer, non-small cell lung cancer and gynecologic cancers were studied. Results: 28 subjects (median age 60 years [range 26-76], 22 females and 6 ) with an ECOG PS <2 were enrolled and all, but one was (1 subject withdrew consent after dosing). 15 subjects were treated with single agent PY314 and 13 were treated with the combination. No infusion-related reactions, dose limiting toxicities, suspected unexpected serious adverse reactions or high-grade treatment related adverse events (TRAEs) that resulted in treatment discontinuance was seen. 12 subjects experienced at least one TRAE, and in all but one subject, these were low grade. One subject experienced a treatment-related immune system disorder. serious adverse events, all unrelated to treatment. TREM2 expression in archival tumor ranged from 0.0-20%. PY314 pharmacokinetics were linear, dose proportional, unaffected by concomitant pembrolizumab and with a half-life of 8-9 days. Best radiographic response was stable disease seen in 11 subjects (39.3%) ranging in duration from 9-42 weeks. 6 subjects with stable disease have progressed and 5 remain on treatment. Conclusions: PY314 was well tolerated and has an excellent safety profile both as a single agent and in combination with pembrolizumab. A recommended dose for expansion was derived and enrollment in five prespecified cancers is ongoing. Clinical trial information: 04691375.

5503 Background: Pafolacianine sodium is under investigation as an adjunct to visual inspection and palpation by providing intra-operative imaging of folate receptor positive (FR+) ovarian cancer. Since complete resection (R0) is the strongest predictor of overall survival, methods to enhance detection of lesions are expected to benefit patient outcomes. Methods: For this phase 3, randomized, multicenter, single dose, open-label pivotal trial (NCT03180307), patients with ovarian cancer who were scheduled to undergo cytoreductive surgery were recruited from 11 sites in the US and Netherlands from March 2018 through April 2020. The study objectives were to confirm efficacy and safety of pafolacianine sodium (0.025 mg/kg i.v., ≥1 h prior to imaging) in combination with intraoperative near-infrared fluorescence (NIRF) imaging to detect additional lesions not detected by palpation and normal white light alone. Results: Pafolacianine sodium was administered to 150 total patients (safety analysis set); 109 patients comprised the full analysis set for efficacy analyses. Patients had primarily serous adenocarcinoma (n = 72; 68.6%) and advanced stage disease (n = 83; 76.1%). In 33% of patients (36 of 109), NIRF imaging with pafolacianine sodium identified additional lesions that were not planned for resection and were not detected by normal white light and palpation ( P < 0.001, 95% CI [0.243, 0.427]). Among patients who underwent interval debulking surgery, the rate was higher, at 39.7% of patients (23 of 58; 95% CI [0.270, 0.534]). At the individual lesion level, the accuracy of pafolacianine sodium with NIRF to detect ovarian cancer is reflected by sensitivity of 83% (95% CI [73.9, 89.4]) and a false positive rate of 32.7% (95% CI [25.6, 40.7]). Investigators reported achieving complete resection (R0) in 62.4% (68 of 109) of patients. Drug-related adverse events (AEs) were reported by 30% of patients (45 out of 150). The most frequently reported drug-related AEs were nausea (18.0%), vomiting (5.3%), and abdominal pain (4.7%). Infusion reactions at the time of the procedure were mostly (96%) mild or moderate in severity; 89% resolved within 24 hours of onset. No drug-related serious AEs or deaths were reported. Conclusions: This phase 3 trial of pafolacianine sodium with NIRF imaging met its primary endpoint, intraoperatively identifying additional cancer not planned for resection in a statistically significant number of patients. Therefore, pafolacianine sodium may offer a novel real-time adjunct to current surgical imaging practice in ovarian cancer surgery. Clinical trial information: NCT03180307.