LoRusso, Patricia

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.

ImportanceSystematic data on the association between anticancer therapies and thromboembolic events (TEEs) in patients with COVID-19 are lacking.ObjectiveTo assess the association between anticancer therapy exposure within 3 months prior to COVID-19 and TEEs following COVID-19 diagnosis in patients with cancer.Design, Setting, and ParticipantsThis registry-based retrospective cohort study included patients who were hospitalized and had active cancer and laboratory-confirmed SARS-CoV-2 infection. Data were accrued from March 2020 to December 2021 and analyzed from December 2021 to October 2022.ExposureTreatments of interest (TOIs) (endocrine therapy, vascular endothelial growth factor inhibitors/tyrosine kinase inhibitors [VEGFis/TKIs], immunomodulators [IMiDs], immune checkpoint inhibitors [ICIs], chemotherapy) vs reference (no systemic therapy) in 3 months prior to COVID-19.Main Outcomes and MeasuresMain outcomes were (1) venous thromboembolism (VTE) and (2) arterial thromboembolism (ATE). Secondary outcome was severity of COVID-19 (rates of intensive care unit admission, mechanical ventilation, 30-day all-cause mortality following TEEs in TOI vs reference group) at 30-day follow-up.ResultsOf 4988 hospitalized patients with cancer (median [IQR] age, 69 [59-78] years; 2608 [52%] male), 1869 had received 1 or more TOIs. Incidence of VTE was higher in all TOI groups: endocrine therapy, 7%; VEGFis/TKIs, 10%; IMiDs, 8%; ICIs, 12%; and chemotherapy, 10%, compared with patients not receiving systemic therapies (6%). In multivariable log-binomial regression analyses, relative risk of VTE (adjusted risk ratio [aRR], 1.33; 95% CI, 1.04-1.69) but not ATE (aRR, 0.81; 95% CI, 0.56-1.16) was significantly higher in those exposed to all TOIs pooled together vs those with no exposure. Among individual drugs, ICIs were significantly associated with VTE (aRR, 1.45; 95% CI, 1.01-2.07). Also noted were significant associations between VTE and active and progressing cancer (aRR, 1.43; 95% CI, 1.01-2.03), history of VTE (aRR, 3.10; 95% CI, 2.38-4.04), and high-risk site of cancer (aRR, 1.42; 95% CI, 1.14-1.75). Black patients had a higher risk of TEEs (aRR, 1.24; 95% CI, 1.03-1.50) than White patients. Patients with TEEs had high intensive care unit admission (46%) and mechanical ventilation (31%) rates. Relative risk of death in patients with TEEs was higher in those exposed to TOIs vs not (aRR, 1.12; 95% CI, 0.91-1.38) and was significantly associated with poor performance status (aRR, 1.77; 95% CI, 1.30-2.40) and active/progressing cancer (aRR, 1.55; 95% CI, 1.13-2.13).Conclusions and RelevanceIn this cohort study, relative risk of developing VTE was high among patients receiving TOIs and varied by the type of therapy, underlying risk factors, and demographics, such as race and ethnicity. These findings highlight the need for close monitoring and perhaps personalized thromboprophylaxis to prevent morbidity and mortality associated with COVID-19–related thromboembolism in patients with cancer.

ImportanceCytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.ObjectiveTo determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.Design, Setting, and ParticipantsThis registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.ExposuresImmunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).Main Outcomes and MeasuresThe primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.ResultsThe median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).Conclusions and RelevanceThis cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.Trial RegistrationClinicalTrials.gov Identifier: NCT04354701

2579 Background: HA, a glycosaminoglycan, accumulates in ~25% of solid tumors and is associated with poor prognosis. Tumors that accumulate HA develop high interstitial fluid pressure (IFP) and become resistant to chemotherapy. In animal models, PEGPH20 reduced tumor-associated HA and increased efficacy of chemotherapy. Methods: This ongoing phase 1 study was designed to assess safety, tolerability, PK, PD, and the maximum tolerated dose (MTD) of PEGPH20 as a single agent in patients with treatment-refractory solid tumors. IV PEGPH20 was administered in a twice weekly or a once weekly dosing schedule with oral dexamethasone (dex) pre-and post dose. Biomarkers included tumor histochemistry to detect HA depletion, plasma HA catabolites, and DCE-MRI or FDG-PET. Results: Fifteen patients have been enrolled into the study. Dose administration ranged from 0.5 µg/kg to 5 µg/kg. Musculoskeletal events (MSEs) were the most common and dose limiting toxicities. To date, up to 3 µg/kg twice weekly IV infusions of PEGPH20 were well tolerated with manageable Grade 1 MSEs in most patients. MTD has not been reached. Plasma concentrations of PEGPH20 showed dose proportional exposure with a terminal half life of ~2 days. Enzymatic activity of PEGPH20 was reflected by dose-dependent HA catabolites in plasma. Pre- and post-dose tumor biopsies from 2 colon patients demonstrated 23-60% reduction in tumor HA after 4 weeks of dosing. Serial DCE-MRI and FDG-PET demonstrated increased tumor perfusion (Ktrans) and decreased metabolic activity 8 and 24hrs post-PEGPH20 in one patient each. Doses of ≤3 µg/kg were tolerated with intermittent Grade 1-2 MSE. Enrollment at dose levels > 3 µg/kg is ongoing. Conclusions: Repeated IV PEGPH20 infusion resulted in dose-dependent systemic exposure and is tolerated with concomitant dex treatment. HA catabolites in plasma demonstrated the in vivo enzymatic activity of PEGPH20. Reduced HA in tumor biopsies and serial DCE-MRI and FDG-PET images confirmed PD activity. Increased tumor perfusion by PEGPH20 may enhance drug delivery to tumor. Combination studies of PEGPH20 with cytotoxic chemotherapy are planned.

166 Background: T-DM1 is an antibody-drug conjugate composed of trastuzumab, a stable linker, and the cytotoxic agent DM1. Few T-DM1 data are available in settings approximating clinical practice. We present safety and efficacy data from T-PAS, an expanded access study of T-DM1 in patients (pts) with previously treated HER2-positive MBC. Methods: T-PAS is a US multicenter study of T-DM1 (3.6 mg/kg q3w) in HER2-positive (IHC 3+ or FISH/CISH+) locally advanced or MBC. Key eligibility criteria: prior anthracycline and taxane; prior capecitabine or 5-FU and ≥2 HER2-directed agents (including trastuzumab and lapatinib) for MBC; LVEF ≥50%. Primary endpoint: safety; secondary endpoint: investigator-assessed objective response rate (ORR) in pts with measurable disease. Safety was assessed on day 1 of each cycle; ECHO/MUGA scans were every 12 weeks. Results: This analysis includes 215 pts enrolled in May 2010–Sep 2011 (data cutoff 7/31/2012). Pts received a median of 7 prior systemic MBC therapies (range 1–23) with a median cumulative anthracycline dose of 240 mg/m2(range 6–2645). At baseline, median LVEF was 60% and 50% of pts had investigator-reported cardiovascular disease. Median follow-up was 5.9 months (range 0.1–25.3); median T-DM1 duration was 5.0 months (range 0–23) with 15.8% receiving >18 cycles. ORR was 25.6% (42/164). Rate of grade ≥3 AEs was 43.7% and of SAEs of any grade was 18.1%. Most common all-grade AEs were fatigue (50.7%), nausea (36.3%), and headache (24.2%). Most common grade ≥3 AEs were thrombocytopenia (7.9%), fatigue (4.7%), and increased aspartate aminotransferase and anemia (each 3.7%). There were no grade ≥3 bleeding events. Cardiac dysfunction (primarily asymptomatic decreases in LVEF) was reported in 8 pts (3.7%); 4 were grade ≥3, 3 resulting in T-DM1 discontinuation. Conclusions: In this study that more closely reflects the real-world setting, the safety profile of T-DM1 was similar to that previously reported in conventional clinical trials, with no new safety signals. In this pretreated population (median of 7 prior therapies for HER2-positive MBC), significant activity was observed. Clinical trial information: NCT01120561.