Boorjian, Stephen A.

TPS5125 Background: B7-H3 is a member of the B7 superfamily, which includes PD-L1 (B7-H1) and PD-L2 (B7-DC). Enoblituzumab is a humanized Fc-optimized B7-H3–targeting antibody that induces antibody-dependent cellular cytotoxicity (ADCC). A recent investigator-initiated trial demonstrated that enoblituzumab therapy, used in the neoadjuvant prostate cancer setting, is feasible, safe, may enhance short-term clinical outcomes, and appears to stimulate intratumoral immune activation including CD8+ T cell infiltration and peripheral expansion of tumor-infiltrating T-cell clones that correlated with undetectable PSA at 1-year post-prostatectomy. To assess the impact of enoblituzumab on recurrence-free survival following prostatectomy, a phase 2, randomized, neoadjuvant clinical trial in high-risk localized prostate cancer patients has been started. We hypothesize that targeting B7-H3 with enoblituzumab will delay or prevent recurrence following prostatectomy compared to standard of care (SOC) . Methods: The HEAT trial is an investigator-initiated, multi-center, randomized, phase 2 study that is presently enrolling (NCT06014255). Eligible patients will undergo a pre-treatment prostate biopsy and conventional imaging (CT and bone scan) as well as PSMA-PET. Patients who have clinical stage cT1c-T3b, cN0 cM0 disease by conventional imaging (N1 by PSMA allowed with up to 3 LNs each ≤1 cm) will be eligible as long as concurrent hormonal or radiation therapy is not given. Prostate biopsy, within 3 months of enrollment, needs to show at least 3 positive cores containing at least 1 core with at least 50% disease involvement with Gleason ≥4+3=7 disease (with at least 1 additional high-risk feature such as PSA>20 ng/ml or cT3) or a Gleason sum ≥8. Patients will receive enoblituzumab at a dose of 15mg/kg IV biweekly for 6 doses (12 weeks) on the treatment arm, followed by prostatectomy, or will be scheduled for prostatectomy directly within 4-8 weeks on the SOC arm. 219 patients will be randomized (2:1) to treatment versus SOC. Pre-treatment, on-treatment, and post-treatment biomarkers of response and resistance will be collected. Patients will be followed according to standard institutional practices, but will require PSA evaluations every 3 (±1) months during year 1 and every 6 (±2) months during years 2-5. In both arms, salvage or adjuvant therapy will occur after biochemical or radiographic progression. The primary endpoint is recurrence-free survival (RFS) defined as any metastasis events, local pelvic visceral or lymph node recurrence, detectable prostate-specific antigen (PSA), or start of subsequent local or systemic therapy (including salvage or adjuvant therapy), or death for any cause, whichever occurs first. Secondary endpoints include additional clinical and immunologic correlates. Clinical trial information: NCT06014255 .

Objectives To characterise the prevalence of impostor phenomenon (IP; tendency for high‐achieving individuals to perceive themselves as fraudulent in their successes) amongst attending staff in urology, to identify variables that predict more severe impostorism, and to study the association of IP with burnout. Subjects and Methods A survey composed of the Clance Impostor Phenomenon Scale (CIPS), demographic information, practice details, and burnout levels was e‐mailed to urologists via urological subspecialty societies. Survey results were analysed to identify associations between IP severity, survey respondent characteristics, and symptoms of professional burnout. This study was conducted in the United States of America. Results A total of 614 survey responses were received (response rate 11.0%). In all, 40% ( n = 213) of responders reported CIPS scores qualifying as either ‘frequent’ or ‘intense’ impostorism (i.e., scores of 61–100). On multivariable analysis, female gender, fewer years in practice (i.e., 0–2 years), and lower academic rank were all independently associated with higher CIPS scores (adjusted P < 0.05). Regarding burnout, 46% of responders reported burnout symptoms. On multivariable analysis, increase in CIPS score was independently associated with higher odds of burnout (odds ratio 1.06, 95% confidence interval 1.04–1.07; P < 0.001). Conclusion Impostor phenomenon is prevalent in the urological community and is experienced more severely in younger and female urologists. IP is also independently associated with burnout. Increased female representation may improve IP amongst our female colleagues. More work is needed to determine strategies that are effective in mitigating feelings of IP and professional burnout amongst urologists, particularly those earlier in their careers.

93 Background: The treatment paradigm for mCSPC patients has rapidly evolved over the last few years with the emergence of triplet therapy and prognostication by volume of disease. However, the health economic implications of triplet therapy by disease volume remain unclear. Methods: A Markov model where patients transitioned between the progression-free, progression and death states was developed. State utilities were derived from the LATITUDE trial. Point probabilities for overall survival, progression-free survival, grade ≥ 3 and 5 toxicities were obtained from the eligible mCSPC phase III clinical trials. Medicare Advantage and commercial total paid amounts (2022 US$) of treatments were obtained from OptumLabs Data Warehouse. Costs and disutilities of adverse events were derived from published literature. Half-cycle corrected costs and utilities were accrued monthly over a 20-year lifetime horizon and were discounted at 3%. Monte Carlo simulation was used to calculate incremental cost-effectiveness ratios (ICERs). A willingness-to-pay (WTP) threshold of US$100,000 was used. Results: In terms of Medicare Advantage payer’s perspective (Table), docetaxel (D)+ADT was observed to provide additional 0.068 QALYs compared to ADT at an ICER of US$16,544 per QALY in high volume disease. Compared to D+ADT, abiraterone (AAP) triplet provided additional 1.03 QALYs at US$56,641 per QALY. Compared to AAP triplet, apalutamide (APA)+ADT provided additional 0.048 QALYs at US$5,846,248 per QALY in high volume disease. In low volume disease, D+ADT provided 0.45 more QALYs at US$20,690 per QALY compared to ADT alone. Compared to D+ADT, AAP triplet provided an additional 1.51 QALYS at US$44,267 per QALY. In terms of total paid commercial costs, AAP triplet provided an additional 1.19 QALYs compared to ADT at US$91,952 per QALY in high volume disease. In low volume, D+ADT provided additional 0.38 QALYs at US$22,058 per QALY compared to ADT. Compared to D+ADT, AAP triplet provided a 0.97 QALY gain at US$105,958 per QALY. Compared to AAP triplet, darolutamide (DARO) triplet provided a 0.47 QALY at US$689,196 per QALY. Compared to DARO triplet, APA+ADT provided an additional 0.49 QALYs at an ICER of US$971,389 per QALY. All other treatments (not reported here) were dominated. Conclusions: At the selected WTP of US$100,000 per QALY, AAP triplet therapy was most likely the cost-effective strategy in overall mCSPC population particularly in patients with high volume disease. However, these results should be interpreted with careful accounting for timing of metastases. [Table: see text]