Colón‐Otero, Gerardo

Importance Decentralized clinical trials (DCTs) aim to increase trial access for underrepresented populations (URP) and ensure study outcomes, conclusions, and policy-related decisions are applicable to diverse populations. Objective To assess trends in the percentage of accrued participants from more than 120 miles from the research site upon DCT program implementation. Design, Setting, and Participants This descriptive quality improvement study was conducted from January 2024 to March 2025 at Mayo Clinic, a US multiregional, academic medical center (AMC) comprising 3 sites and an affiliated, community-based health care system. All individuals who consented and/or accrued to an institutional review board–approved clinical trial were included. Exposure DCTs are defined as trials with at least 1 decentralized capability beyond remote consent. DCT program development began July 2022. By January 2024, remote consent, video telehealth visits, remote phlebotomy, and device services were implemented across all sites and departments. Remote monitoring and oral medication delivery were available on a limited basis. Prospective automated program and DCT participant data collection and quarterly reporting began in January 2024. Main Outcomes and Measures Percentage of all DCT accrued participants with a residential zip code more than 120 miles from 1 of 3 AMC sites. Results There were 7469 participants (median [IQR] age, 62 [51-70] years; 3594 [48.1%] female; 241 [3.2%] Asian, 391 [5.2%] Black or African American, and 6347 [85.0%] White individuals) accrued to 765 DCTs. During the study period, the percentage of DCT participants residing more than 120 miles from an AMC site ranged from 18.9% in the first quarter (Q1) of 2024 (383 of 2032 participants) to 29.6% in Q1 of 2025 (346 of 1170 participants). Of those accrued, 1147 (15.4%) were of a racial or ethnic URP, ranging from 12.5% in Q1 of 2024 (253 participants) to 17.4% in Q1 of 2025 (204 participants). There were 1554 (20.8%) participants from a rural location, ranging from 16.6% in Q1 of 2024 (338 participants) to 24.9% in Q1 of 2025 (291 participants). Additionally, by geospatial distance from an AMC site, the male-to-female ratio was nearly 50:50, and the age distribution appeared similar. Conclusions and Relevance In this quality improvement study of a DCT program implementation, DCT accruals trended favorably among those residing more than 120 miles from an AMC site and those of rural or URP populations. While these findings cannot be directly attributed to program implementation, they are reassuring that this strategy may address some barriers to clinical trial access. Future studies should assess the sustained effectiveness and scalability of DCT models in improving equitable trial access.

PURPOSE We sought to characterize outcome associations of poly ADP-ribose polymerase inhibitors (PARPi) in patients with ovarian cancer (OVCA) whose cancers contain homozygous loss (deletions) of homologous recombination repair (HRR) pathway genes, an alteration class not uniformly reported on clinical testing and not susceptible to acquired resistance via secondary reversion mutations. METHODS This study used US-based deidentified Flatiron Health-Foundation Medicine OVCA Clinico-Genomic Database. Patients with advanced OVCA and genomic profiling by Foundation Medicine were assembled into cohorts evaluating PARPi monotherapy use, and separately, PARPi maintenance therapy use, with outcomes associated with HRR gene alterations: BRCA1 / 2 , PALB2 , RAD51B/C/D , BARD1 , and BRIP1 . RESULTS 1.5% (82/5,404) had HRR gene homozygous loss, with BRCA1 and BRCA2 loss being most common. Among all OVCAs with BRCA1/2 alterations, 7.5% (63/836) were homozygous losses. Most BRCA1 (34/38, 89%) and BRCA2 (18/25, 72%) homozygous losses were intragenic, with breakpoints not spanning entire gene. Maintenance cohort: 22 patients had HRR gene homozygous loss, with strongly improved progression-free survival (PFS) for PARPi versus no PARPi use (HR, 0.06, 95% CI, 0.01 to 0.37). Monotherapy cohort: patients without HRR alterations (n = 198), HRR mutations or rearrangements (n = 93), and HRR homozygous loss (n = 8) had median PFS of 4.9, 10.6, and 25.4 months, and median overall survival of 18.5, 22.5, and 51.8 months, respectively. CONCLUSION We observe durable PARPi effectiveness for patients with OVCA and HRR gene homozygous loss in routine practice. We demonstrate the importance of detecting and reporting homozygous loss in HRR genes, an aspect not standard to all sequencing assays.

Abstract Background: DS-8201a is a HER2-targeting antibody drug conjugate with a topoisomerase 1 (topo1) inhibitor payload. Preclinical evidence suggests that inhibiting PARP can potentiate topo1 inhibitor-induced DNA damage and cytotoxicity. However, the clinical activity of combined topo1-inhibiting chemotherapy and PARP inhibition has been limited by toxicity. We hypothesized that targeted delivery of a topo1 inhibitor via DS-8201a may reduce systemic toxicity, while maintaining synergistic cytotoxic activity in combination with olaparib (PARPi). DS-8201a + olaparib was evaluated in the ongoing CTEP #10355 trial (NCT04585958). Results from Dose Escalation are presented. Methods: Accrual was limited to pts ≥18 years old with advanced or recurrent solid tumors expressing HER2, defined as HER2 IHC ≥1+ or ERBB2 amplification by NGS or ISH (local testing allowed). DS-8201a was given Q3W across all dose escalation regimens. Olaparib dosing in continuous (Module 1 D1-21) and intermittent schedules (Module 2 D8-14; Module 3 D3-9) were explored. A 3+3 dose escalation design was followed in Mod 1 & 2 and up to 6 pts in a safety cohort were planned for Mod 3. Primary endpoints included safety as graded by CTCAE v5 and determination of an RP2D. Results: As of Oct 26, 2025, 30 pts were enrolled and 28 pts were treated. 12 pts had uterine and 16 pts had ovarian cancer; mean age was 61.6 years, median number of prior therapies was 4 (range 1-10). HER2 expression by local testing was: 4 pts IHC 1+, 17 pts IHC 2+, 6 pts IHC 3+, 1 pt ERBB2 amplification (IHC not reported). 9/10 pts enrolled in Mod 1 (continuous olaparib) were DLT-evaluable: 1/7 pts at DL1 (DS-8201a 4.4mg/kg IV Q3W + olaparib 100mg BID D1-21) and 3/3 pts at DL2 (DS-8201a 5.4mg/kg IV Q3W + olaparib 100mg BID D1-21) experienced DLTs (G4 neutropenia, febrile neutropenia, WBC decrease, colitis), halting further Mod 1 enrollment. 12/16 pts enrolled to Mod 2 (intermittent olaparib) were DLT-evaluable and only 1 pt at the highest dose level (DL3, DS-8201a 5.4mg/kg IV Q3W + olaparib 300mg BID D8-14) experienced a DLT (G3 colitis). Hematologic TRAEs were markedly attenuated in Mod 2 compared to Mod 1: 12% vs 30% G3 and 19% vs 50% G4 neutropenia; 25% vs 70% G3 anemia; 6% vs 20% G3 and 0% vs 20% G4 thrombocytopenia. 2/2 DLT-evaluable pts in Mod 3 (intermittent olaparib; DS-8201a 5.4mg/kg IV Q3W + olaparib 300mg BID D3-9) experienced DLTs (G3 diarrhea, G3 nausea & vomiting, G4 neutropenia), halting further Mod 3 enrollment. The Mod 2 DL3 regimen of DS-8201a 5.4mg/kg IV Q3W + olaparib 300mg BID D8-14 was declared the RP2D and is under further investigation in an ongoing Dose Expansion cohort enrolling HER2 IHC 1+ platinum resistant ovarian cancer. Objective responses were observed across all modules and dose levels. Conclusions: In pts with HER2-expressing advanced solid tumors, DS-8201a in combination with intermittently-dosed olaparib was tolerable. DS-8201a 5.4mg/kg IV Q3W + olaparib 300mg BID D8-14 was selected as the RP2D for further evaluation in Dose Expansion. Additional endpoints of clinical activity will be presented. Citation Format: Elizabeth K. Lee, Andrea Wahner Hendrickson, Gerardo Colon-Otero, Cheryl A. Pickett, Yinglu Zhou, Su-Chun Cheng, Madeline Polak, Hannah Sawyer, Martin Hayes, Ursula A. Matulonis, Geoffrey I. Shapiro, Panagiotis A. Konstantinopoulos. CTEP #10355 A phase 1 trial of DS-8201a and olaparib in HER2-expressing malignancies: Results from dose escalation [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 CT035.

Abstract Background: Zedoresertib (zedo) and lunresertib (lunre) are oral, highly selective WEE1 and PKMYT1 inhibitors, respectively. Inhibition of these targets leads to premature mitotic entry, and in the presence of high replication stress causes mitotic catastrophe. In preclinical models, the combination of the zedo and lunre is synthetically lethal, supporting this first-in-class trial combination (NCT04855656). Methods: In this Phase 1 trial, patients (pts) with advanced solid tumors with CCNE1 amplification (amp), or FBXW7 or PPP2R1A deleterious mutations (mut) were treated with zedo (daily dosing) plus lunre (3 days on/4 days off), guided by preclinical modelling of the pharmacological contributions of WEE1 and PKMYT1 inhibition in achieving tumor regression. Objectives included safety, tolerability, recommended doses (RD), pharmacokinetics (PK), pharmacodynamics (PDy), antitumor activity and molecular response rate (MRR; ≥50% decline in circulating tumor DNA). Results: As of 18 Nov 2025, 54 pts (55.6% female ; prior lines of therapy 1 - 9, main cancer types: ovarian (OC) (35.2%), colorectal (31.5%), pancreatic (7.4%) and breast (5.6%)) were treated at 5 dose levels (DL) from 150 mg to 260 mg of zedo plus 60 mg or 80 mg of lunre. The most common ≥G3 treatment related adverse events (TRAEs) were anemia (9.3%), neutropenia (7.4%) and Palmar Plantar Erythrodysesthesia (PPE) (7.4%). There were no G5 TRAEs. 4 (9.3%) of 54 pts had a dose-limiting toxicity (G3 pain in extremity and G1 rash in same pt (zedo 150 mg / lunre 60 mg), G3 rash (200 mg / 80 mg), G3 PPE (260 mg / 60 mg), G3 vomiting (260 mg / 60 mg)). PK/PDy analyses showed dose-dependent exposures for both zedo and lunre and target engagement in most pts, with reductions in pCDK1 Thr14 and Tyr15 and yH2AX induction. 24 (55.5%) of 44 RECIST v1.1 evaluable pts showed tumor shrinkage (3 cCR, 5 uPR, 15 SD and 1 PD). Of 16 evaluable pts with advanced OC (12 platinum resistant , 2 unknown and 2 platinum sensitive) with CCNE1 amp (13 pts) or FBXW7 mut (3 pts), 13 (81.3%) showed tumor shrinkage (3 cCR, 3 uPR and 7 SD); clinical benefit rate (pts with CR, PR or SD) was 93.8%; 7 (43.8%) OC pts were on treatment for at least 16 weeks; 4 (25%) OC pts achieved GCIG CA-125 responses. Of 23 pts with a post baseline ctDNA analysis, a MRR of 39% was seen across all DLs. Conclusion: We report the first disclosure of clinical data of the first-in-field synthetic lethal combination of WEE1 and PKMYT1 inhibitors in a molecularly defined pt population. The safety profile of zedo and lunre was expected and manageable. Promising antitumor activity was observed in pts with CCNE1 amp or FBXW7 mut solid tumors, especially pts with OC. Further dose optimization of this combination is ongoing. Citation Format: Timothy A. Yap, Rahul Aggarwal, Elisa Fontana, Martin Hojgaard, Benedito A. Carneiro, Linda Duska, Patricia LoRusso, Siddhartha Yadav, Stephanie Lheureux, Cara Mathews, Ryan H. Moy, Nehal Lakhani, Mia Weiss, Joan Tymon-Rosario, Gerardo Colon-Otero, Ignacio Garrido-Laguna, Elisabeth K. Lee, Esteban Rodrigo Imedio, Jonathan Wessen, Luke Piggott, Vito Dozio, Noemie Luong, Christophe Mas, Alison M. Schram. First data disclosure of the Phase I trial of the first in class combination of WEE1 inhibitor zedoresertib with PKMYT1 inhibitor lunresertib in patients with advanced solid tumors harboring CCNE1, FBXW7, or PPP2R1A genomic alterations [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 CT022.

Abstract Introduction: This ongoing study investigates the impact of vitamin D deficiency on the immune response to prostate cancer (CaP) in Black patients and its potential contribution to CaP disparities. The study also evaluates differences in immune function, including p53 and CaP associated antibody levels, in Black men with localized versus metastatic CaP. Methodology: Eligible patients with a history of localized or metastatic CaP are enrolled following informed consent (in person or remote). At baseline, blood is collected for calcium and vitamin D3 levels, and for immune testing. Patients who participate in the screening portion of the trial and are found to have vitamin D3 levels <30 ng/mL are prescribed oral vitamin D3 (2000 IU daily) and asked to record adherence in a medication diary. Follow-up includes a 4-week check-in and end-of-treatment labs at 8 weeks for calcium, vitamin D3 levels, and immune re-testing. Virtual consults occur after baseline and at 8 weeks. Quality of life is measured at baseline and EOT follow-up using the CDC HRQOL–4. The study began accruing patients in December 2021. In an attempt to accelerate patient accrual, the protocol was amended to become one of Mayo Clinic’s first fully decentralized clinical trials. Newly integrated components included at-home and community-based blood collection (outside of Mayo Clinic southern sites) and continued virtual engagement. These changes were designed to reduce barriers linked to social determinants of health (SDOH) and expand participation among medically underserved populations. This is a report on the impact of clinical trial DCT. Results: From December 2021 to September 2023 (pre-DCT), 24 patients were enrolled from 66 patients who participated in the screening portion for the trial (mean accrual: 1.09/month; SD: 1.15). Following the DCT amendment, enrollment rose to 102 patients from 213 screened (mean: 4.86/month; SD: 3.12) through June 2025. Of 126 enrolled patients, 119 (94.4%) returned medication diaries, with only 6 non-returns occurring post-DCT. QOL measures were completed by approximately 75% of participants. Importantly, 90 of 126 participants (71%) were enrolled from outside Jacksonville, FL or Scottsdale/Phoenix, AZ, indicating successful national expansion. A total of 111 patients failed the screening due to baseline vitamin D levels >30 ng/ml. The total number of protocol deviations increased post-DCT (60 from 10/23–6/25 vs. 14 from 12/21–9/23), there was no change in the number of protocol deviations per enrolled patients. Minor documentation and study timeline deviations were the most common in both periods. Conclusions: The successful implementation of a fully decentralized model was associated with a marked increase in the accrual of underserved patients and allows the completion of critical clinical trials that address important cancer care disparities without impacting protocol integrity. Clinical trial DCT can potentially reduce SDOH-related barriers and improve representation of underserved populations in research. Citation Format: Sandra Casanova Leyva, Kim M. Barbel Johnson, Tufia Haddad, Lydia Mercado, Trevanne Matthews Hew, Cassandra Moore, Gerardo Colon-Otero, Devina Joshi, Roselyn Heduvor. Feasibility of an interventional clinical trial addressing prostate cancer disparities in Black men by decentralization (DCT): A potential solution to disparities in clinical trial participation [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C064.

e13808 Background: Cancer is a leading cause of death for Latinos. They experience higher rates than their white peers of preventable, infectious-agent-causing-cancers, such as stomach & liver cancer. Latina women have experienced a 1% rise in cancer cases since 2011 & Latino children & adolescents experience higher rates of leukemia than any other racial/ethnic group. Latinos face disparities in access to healthcare, cancer screening & treatment, medical representation & experience lower rates of survival due to late-stage cancer diagnosis. Methods: To combat these inequities & identify equitable interventions for Latino health, the Institute of Health Promotion Research & the Mays Cancer Center established the Advancing the Science of Cancer in Latinos (ASCL) Conference. The fourth ASCL Conference convened in San Antonio, TX from February 21-23, 2024. The conference objectives were 1) Examine the intersection of health equity & biological underpinnings in cancer control, prevention, and treatment 2) Foster collaborative initiatives among attendees aimed at addressing cancer-related health disparities within the Latino community. The conference hosted 286 participants (speakers, researchers, physicians, healthcare professionals, patient advocates & students). It comprised of 23 sessions (3 keynotes, 6 plenaries, 6 breakouts, 3 general sessions, 1 special session, 1 lunch panel session) featuring insights from 51 speakers, a poster session highlighting 80 research abstracts & a rapid-fire session tailored for early-career investigators. Sessions focused on multiple topics relevant to Latino cancer research, clinical trials, survivorship, patient advocacy, climate change impacts on cancer, precision medicine, health policy & social determinants of health. Results: A post-conference survey from a cohort of 48 respondents underscored high levels of satisfaction, with 90% expressing contentment regarding the conference experience. Nearly all respondents (98%) rated the relevance of conference content to Latino cancer science as excellent, with 93% regarding the conference as an exceptional platform for information exchange. Impressions regarding session quality were positive, with 90% of respondents indicating a high level of satisfaction, & all survey respondents acknowledging the objectivity, balance & absence of commercial bias in the session content. Conclusions: Results showed that the resounding positivity in attendee feedback reflects the conference's success in fostering meaningful engagement among attendees. The ASCL conference facilitated an understanding of cultural nuances and barriers specific to the Latino community, stimulating collaborative efforts aimed at enhancing Latino health outcomes. Overall, this analysis affirms the conference's success in achieving its stipulated objectives and underscores the need of having consistently coordinated research endeavors to reduce Latino health disparities.

Abstract Cancer is the leading cause of mortality within the Latino population. Projections suggest a 142% increase in cancer incidence among Latinos over the next two decades. This trend is concerning given that Latinos, the largest minority group in the United States, are expected to constitute at least 28% of the nation's populace by 2060. To address the need for enhanced comprehension of these trends and to identify equitable interventions targeting Latino health disparities, the Institute of Health Promotion Research and the Mays Cancer Center jointly established the biennial Advancing the Science of Cancer in Latinos (ASCL) Conference. The fourth ASCL Conference convened in San Antonio, TX from February 21-23, 2024. The conference objectives were twofold: 1) Examine the intersection of health equity and biological underpinnings in cancer control, prevention, and treatment; and 2) Foster collaborative initiatives among attendees aimed at addressing cancer-related health disparities within the Latino community. The 2024 conference attracted 286 participants compared to 251 attendees in 2022, encompassing guest speakers, researchers, physicians, healthcare professionals, patient advocates, researchers, and students. It comprised 23 sessions (3 keynotes, 6 plenaries, 6 breakouts, 3 general sessions, 1 special session, 1 lunch panel session) featuring insights from 51 speakers, alongside a poster session highlighting 80 research abstracts and a rapid-fire session tailored for early-career investigators. Sessions encompassed multiple topics relevant to Latino cancer research, spanning health disparities, clinical trials, survivorship, patient advocacy, climate change impacts on cancer, precision medicine, health policy and social determinants of health. A post-conference survey from a cohort of 48 respondents underscored high levels of satisfaction, with 90% expressing pronounced contentment regarding the conference experience, compared to 85% in 2022. Moreover, nearly all respondents (98%) rated the relevance of conference content to Latino cancer science as excellent, with 93% regarding the conference as an exceptional platform for information exchange, compared to 79% in 2022. Impressions regarding session quality were overwhelmingly positive, with 90% of respondents indicating a high level of satisfaction, and all survey respondents acknowledging the objectivity, balance, and absence of commercial bias in the session content. Our results showed that the resounding positivity in attendee feedback reflects the conference's success in fostering meaningful engagement among researchers committed to alleviating Latino cancer health disparities. The ASCL conference facilitated an understanding of cultural nuances and barriers specific to the Latino community, stimulating collaborative efforts aimed at enhancing Latino health outcomes. Overall, this retrospective analysis affirms the conference's success in achieving its stipulated objectives and underscores the need of having consistently coordinated research endeavors to reduce Latino health disparities. Citation Format: Amelie G. Ramirez, Rebecca T. Jones, Matthew P. Banegas, Maria C Camargo, Gerardo Colon-Otero, Cliff Despres, Laura Fejerman, Filipa Lynce, Martin Mendoza, Patricia I. Moreno, Alejandro Recio-Boiles, Barbara Segarra-Vazquez, Sandi Stanford, Mariana Stern, Katherine Y. Tossas, Edward J. Trapido, Nicolette M Orozco. Advancing the science of cancer in Latinos conference [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B032.

Background: The Clinical Treatment Score post-5 years (CTS5) is a risk stratification tool used to determine the risk of late recurrence in hormone receptor–positive (HR+), HER2-negative breast cancer (BC). Limited data exist on its use in HR+, HER2-positive (HER2+) BC. Patients and Methods: CTS5 was evaluated in HR+, HER2+ BC in the North Central Cancer Treatment Group (NCCTG) N9831 (Alliance) and NSABP B-31 (NRG) trials. Results: A total of 1,862 patients with HR+, HER2+ BC without recurrence 5 years after enrollment were included. Overall, the CTS5 score was significantly associated with recurrence-free survival (RFS), with a hazard ratio (HR) of 1.35 (95% CI, 1.12–1.63; P=.002), but did not reach statistical significance in patients who received trastuzumab (n=829; HR, 1.29; 95% CI, 0.98–1.71; P=.07). CTS5 risk category was not significantly associated with RFS. In patients who received trastuzumab, other variables used in CTS5, including patient age and tumor size, were not significantly associated with RFS. N3 was significantly associated with worse outcomes (HR, 1.86; 95% CI, 1.09–3.17; P=.02) compared with N0–N1. Paradoxically, higher tumor grade was associated with better outcomes after 5 years in the multivariate analysis (HR, 0.71; 95% CI, 0.50–1.00; P=.05). The incidence of recurrences or deaths between years 5 to 10 was 10.6% in the CTS5 low-risk category, 5.6% in the intermediate-risk category, and 9.8% in the high-risk category. Conclusions: The CTS5 model does not accurately predict the risk of late recurrence in HR+, HER2+ BC treated with adjuvant trastuzumab in the N9831 and B-31 trials. This study underlines the need to develop a new prognostic model to better delineate the risk of late recurrence in patients with HR+, HER2+ BC receiving adjuvant trastuzumab. ClinicalTrials.gov identifiers: NCT00005970 (NCCTG N9831) and NCT00004067 (NRG/NSABP B-31).

TPS3173 Background: ELU001, pasifolate exatecan, is an ultra-small nanoparticle drug conjugate, known as a CDC (~6 nm), designed to target and penetrate into solid tumors. Due to its size, ELU001 exhibits rapid renal elimination which is expected to reduce or eliminate the toxicities associated with many antibody drug conjugates. ELU001 has ~13 folic acid targeting moieties and ~21 cathepsin-B cleavable exatecan topoisomerase-1 inhibitor payloads covalently bound to short polyethylene glycol chains surrounding a silica core, the C’Dot. ELU001 binds to cancer cells expressing FRα and is internalized into the lysosome where it releases the exatecan payload. ELU001’s dose escalation study reported at ESMO Congress 2023 (1), examined weekly, bi-weekly (Q2W), and tri-weekly schedules over a range of doses in 42 patients. The study revealed that ELU001 could be administered safely and identified a dose level and schedule for the Expansion Studies described below. 22 of the patients with ovarian or endometrial cancers had >1 post-baseline scan(s), of these 2 had a PR and 19 had SD by RECIST v1.1 criteria. ELU001 demonstrated activity against tumors across a range of FRα expression levels, from low to high, retrospectively assessed using the VENTANA FOLR1 RxDx assay and the PS2+ scoring system. Methods: The current multicenter, Tumor Group Expansion open-label phase 1/2 clinical trial investigates ELU001 in patients with ovarian and endometrial cancers and is enrolling three cohorts; 1) ovarian cancer with high FRα expression, 2) ovarian cancer with moderate and low expression and 3) endometrial cancer with low to high expression with assessments based upon the PS2+ scoring system (high = ≥ 75%, moderate = ≥ 50% to < 75%, low = 25% to < 50%, negative = <25% of tumor cells with 2+ or 3+ staining intensity). An initial exploratory dose of 2.0 mg/m2 Q2W was employed in all three cohorts and a second dose of 1.7 mg/m2 Q2W will be studied in the ovarian cancer cohorts. Patients will ultimately be randomized to one of two or more doses to optimize dosing for registration. Primary endpoint: Objective Response Rate (ORR); secondary endpoints include DOR, PFS, TFST, PFS2, OS, adverse events, PK, and ADA assessments. Approximately 20 patients per tumor group will be recruited in the U.S. 1. Ann. Oncol. (2023) 34 (suppl_2): S458-S497. Clinical trial information: NCT05001282 .