Kolinsky, Michael Paul

Abstract Introduction: Most people who die from prostate cancer are older than 75 years. However, prostate cancer diagnosed at younger ages is often more aggressive. While epidemiologic studies have examined the association between age and survival in patients with prostate cancer overall, the clinical drivers of this relationship in patients with advanced disease remain unclear. We leveraged the International Registry of Men with Advanced Prostate Cancer (IRONMAN, NCT03151629) to (1) quantify the association between age and overall survival and (2) explore whether this association is explained by treatments. Methods: We included 3, 734 patients enrolled from 15 countries with new diagnoses of metastatic hormone sensitive (mHSPC, N=2, 642) or castration resistant prostate cancer (CRPC, N=1, 092). Age at enrollment was categorized as <55, 55-59, 60-64 (reference), 65-69, 70-74, 75-79, 80-84, 85+ years. We computed age-specific death rates (95% confidence intervals [CIs]) by disease state (mHSPC, CRPC) at enrollment. To explore whether this relationship was explained by treatment, we fitted disease state-stratified Cox models and sequentially adjusted for (1) de novo metastatic status and country, and (2) baseline treatment (androgen deprivation therapy [ADT] alone, ADT + androgen receptor pathway inhibitors [ARPI], ADT + chemotherapy, ADT + ARPI + chemotherapy, other). Results: Over 5.5 years of follow-up (median: 3.2 years, IQR: 1.7, 4.8), 995 patients died from any cause. Younger patients were more likely to have de novo metastatic disease. Among those with mHSPC at enrollment, the age-specific death rates per 1, 000 person-years followed a J-shaped pattern: 80 (95% CI: 54, 117) in patients under 55 years, 58 (46, 74) in patients aged 60-64, 102 (78, 133) in patients aged 80-84, and 172 (125, 236) in patients aged 85 and older. The death rates among those with CRPC followed a similar pattern, albeit rates were higher in magnitude: 212 (95% CI: 140, 323) in patients under 55 years, 153 (115, 202) in patients aged 60-64, 200 (155, 258) in patients aged 80-84, and 204 (142, 291) in patients aged 85 and older. After adjusting for disease state, country, and the timing of diagnosis of metastases, death rates were substantially higher for ages 75-79 (HR 1.4; 95% CI 1.1, 1.7), 80-84 years (HR 1.6; 95% CI 1.2, 2.1), and 85 years and older (HR 2.0; 95% CI: 1.5, 2.7) compared to ages 60-64 years. Patients aged under 55 years had 1.4-fold higher death rates (95% CI: 1.0, 1.9) compared to those 60-64 years. After additionally adjusting for baseline treatment, overall survival remained worse for the older patients and the youngest age group with hazard ratios remaining meaningfully unchanged. Conclusion: Age at enrollment is associated with overall survival in people with advanced prostate cancer enrolled in IRONMAN in a J-shaped pattern. This relationship is not explained by differences in baseline treatment. Citation Format: Hannah E. Guard, Michelle O. Sodipo, Colleen B. McGrath, Anna Siefkas, Lauren E. Howard, Konrad H. Stopsack, Christopher M. Sauer, Robert Dreicer, Emilio Esteban, Hassan M. Dogo, Ademola Popoola, Charles Waihenya, Anders Bjartell, Kim N. Chi, Sebastien Hotte, Richard Cathomas, Deborah Enting, Scott Tagawa, Michael Ong, Michael Kolinsky, Vincent Khoo, Joaquin Mateo, Chidiebere N. Ogo, Rana R. McKay, Stefanie Fischer, Heather H. Cheng, Russell Szmulewitz, Young E. Whang, Anand Sharma, Frédéric Pouliot, Simon Crabb, Monica S. Chatwal, Miguel A. Climent, Raymond McDermott, Ian D. Davis, Camille Ragin, Folakemi T. Odedina, Simon Anderson, Simone Badal, Natalie Greaves, Karen A. Autio, Laurel Cannon, Alyssa Chan-Cuzydlo, Marie Grant, Travis Gerke, Hannah D. McManus, Philip W. Kantoff, Daniel J. George, Lorelei A. Mucci, IRONMAN investigator team. Disentangling the association between age and overall survival in an international cohort of patients with advanced prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4935.

5029 Background: Pembro had activity as monotherapy in pretreated advanced mCRPC. Data are presented here from cohort B (pembro + docetaxel/prednisone) of KEYNOTE-365 (NCT02861573), a phase 1b/2 umbrella study to test combinations in mCRPC. Methods: Pts who progressed on or became intolerant to ≥4 wk of abi or enza in the prechemotherapy mCRPC state and progressed within 6 mo before screening were eligible. Pts received pembro 200 mg IV with docetaxel 75 mg/m2 IV Q3W plus prednisone 5 mg orally twice daily. The primary end points were safety and PSA response rate (confirmed PSA decrease ≥50%). Key secondary end points were investigator-determined ORR (RECIST v1.1), disease control rate (DCR: CR+PR+SD ≥6 mo), time to PSA progression, rPFS, and OS. Results: 72 pts (median age, 68 y; visceral disease, 36%; measurable disease, 50%) began pembro + docetaxel. Median (95% CI) follow-up was 10 (8-12) mo. Efficacy is outlined in the table. Treatment-related AEs occurred in 69 (96%) pts; most frequent (≥30%) were alopecia (43%), fatigue (40%), and diarrhea (39%). Grade 3-5 treatment-related AEs occurred in 27 (38%) pts, including 2 deaths from treatment-related AEs (pneumonitis). Most commonly reported immune-mediated AEs were infusion-related reactions (11%) and colitis (10%). Conclusions: Pembro + docetaxel/prednisone has activity in pts with mCRPC who previously progressed on second-generation hormone therapy. AEs were considered mild for the treatment combination. Clinical trial information: NCT02861573. [Table: see text]

170 Background: Pembro had antitumor activity as monotherapy in pretreated advanced mCRPC (KEYNOTE-028; KEYNOTE-199). KEYNOTE-365 (NCT02861573) is a phase 1b/2 umbrella study testing combinations in mCRPC; we report early results from cohort B combining pembro + docetaxel in mCRPC. Methods: Pts who failed or became intolerant to ≥4 weeks of abi or enza in the pre-chemotherapy mCRPC state received pembro 200 mg IV with docetaxel 75 mg/m2 IV Q3W plus prednisone 5 mg orally twice daily. Pts also progressed within 6 months prior to screening as determined by either PSA progression or radiologic progression in bone or soft tissue. Response was evaluated by PSA levels Q3W and imaging Q9W for first year and Q12W thereafter. Primary end points: safety and PSA response rate (confirmed PSA decline ≥50%). Key secondary end points: investigator-determined ORR (RECIST v1.1), disease control rate (DCR: CR+PR+SD ≥6 mo), time to PSA progression, rPFS, and OS. Results: 72 pts (median age 68 years; PD-L1+ 29%; visceral disease 36%; measurable disease 50%) initiated pembro + docetaxel. Median (95% CI) follow-up was 10 (8-12) mo. Efficacy is outlined in table below. Treatment-related AEs occurred in 69 (96%) pts; most frequent (≥30%) were alopecia (43%), fatigue (40%), and diarrhea (39%). Grade 3-5 treatment-related AEs occurred in 27 (38%) pts, including 2 deaths due to treatment-related AEs (pneumonitis). Conclusions: Combination of pembro + docetaxel/prednisone has activity in pts with mCRPC previously failing anti-hormonal therapy. Observed safety profile for the combination was consistent with known safety profile of each component. Clinical trial information: NCT02861573. [Table: see text]