Common Treatment-emergent Adverse Events Research Articles

Efficacy of Lemborexant in Adults ≥ 65 Years of Age with Insomnia Disorder.

Pharmacologic treatments are available to treat insomnia, a common and burdensome sleep disorder, but may be contraindicated in older adults who are prone to side effects from sleep-promoting drugs. These analyses of sleep diary data from Study E2006-G000-303 (Study 303) investigated the benefits of lemborexant 5mg (LEM5) and 10mg (LEM10) in the subgroup age ≥ 65years with insomnia. Study 303, a 12-month, double-blind study of LEM5 and LEM10 in adults (age ≥ 18years) with insomnia disorder (sleep onset and/or maintenance difficulties) assessed subject-reported (subjective) sleep-onset latency (sSOL), sleep efficiency (sSE), wake after sleep onset (sWASO), and total sleep time (sTST). Morning sleepiness/alertness, insomnia severity (Insomnia Severity Index [ISI]), fatigue (Fatigue Severity Scale [FSS]), perceptions of sleep-related medication effects (Patient Global Impression-Insomnia [PGI-I] questionnaire), and safety were also evaluated. In this subgroup of older adults (≥ 65years; n = 262), there were significantly larger changes from baseline for sSOL, sSE, sTST, and sWASO with LEM5 and LEM10 versus placebo through month 6 (except sWASO month 1), indicating improvement; these improvements were sustained through month 12. Subject-reported increases in morning alertness were significantly greater with one or both LEM doses versus placebo through month 6 and sustained through month 12. There were significantly larger ISI total and daytime functioning score decreases (improvement) from baseline with LEM versus placebo at months 1, 3, and 6 (total score: both doses; daytime functioning: LEM5 month 1 and both doses months 3 and 6) and decreases from baseline FSS at months 1 and 3 (LEM5) and month 6 (both doses), sustained to month 12. Compared with placebo, more subjects reported that LEM (both doses) positively impacted ability to sleep, time to fall asleep, and TST through month 6, sustained to month 12, with no rebound after drug withdrawal. LEM was well tolerated to month 12; mild somnolence was the most common treatment-emergent adverse event. Improvements in subject-reported efficacy in LEM-treated adults age ≥ 65years with insomnia were observed as early as the first week of treatment and sustained through end of month 12. LEM was well tolerated. ClinicalTrials.gov identifier NCT02952820: E2006-G000-303; Study 303; SUNRISE-2 (First posted: October 2016); EudraCT 2015-001463-39 (First posted: November 2016).

Safety And Efficacy Of Combination Lurbinectedin Plus Doxorubicin From A Phase 1b Trial In Patients With Advanced/Metastatic Soft Tissue Sarcoma

Abstract Purpose: While cytotoxic chemotherapy is standard first-line treatment for patients with metastatic soft tissue sarcoma (STS), clinical outcomes remain suboptimal. Our prior study showed lurbinectedin plus doxorubicin is well-tolerated with promising clinical activity in STS. We designed this phase 1b trial to optimize dosing as the basis for a randomized trial in leiomyosarcoma (LMS) and to further explore the safety profile and efficacy signal. Patients and Methods: Patients had advanced/metastatic STS and no prior anthracycline/lurbinectedin/trabectedin. Escalation followed a 3+3 design with 3-week cycles: lurbinectedin (3.2 mg/m2 day 1) and two doxorubicin levels (DL1: 25 mg/m2 day 1; DL2 25 mg/m2 days 1 and 8). The primary objectives were to identify the maximum tolerated dose (MTD) and recommended dose for subsequent randomized trials. Results: Ten patients were enrolled in a 6-month period. The most common treatment-emergent adverse events (TEAE) were grade (G) 2 fatigue and nausea, and G2 cytopenias with no febrile neutropenia events. There were 2 dose-limiting toxicities (DLTs) at DL2 (day 8 [G2 ALT/AST increase, G3 neutropenia]), and 1 DLT in DL1 (G3 ALT increase). These were reversible and all patients continued the study. DL1 was chosen for further study. At the time of data cutoff, the estimated median PFS is 16.5 months (95%CI 6.0-ND). The ORR was 60% (6/10 confirmed partial responses [PR]). Conclusions: In this phase 1b study, the recommended dose is lurbinectedin 3.2 mg/m2 in combination with doxorubicin 25 mg/m2 every 3 weeks. The study combination was well-tolerated and demonstrated intriguing clinical activity.

Pemigatinib in previously treated solid tumors with activating FGFR1-FGFR3 alterations: phase 2 FIGHT-207 basket trial.

Fibroblast growth factor receptor (FGFR) alterations drive oncogenesis in multiple tumor types. Here we studied pemigatinib, a selective, potent, oral FGFR1-FGFR3 inhibitor, in the phase 2 FIGHT-207 basket study of FGFR-altered advanced solid tumors. Primary end points were objective response rate (ORR) in cohorts A (fusions/rearrangements) and B (activating non-kinase domain mutations). Secondary end points were progression-free survival, duration of response and overall survival in cohorts A and B, and safety. Exploratory end points included ORR of cohort C (kinase domain mutations, potentially pathogenic variants of unknown significance) and analysis of co-alterations associated with resistance and response. ORRs for cohorts A, B and C were 26.5%, 9.4% and 3.8%, respectively. Tumors with no approved FGFR inhibitors or those with alterations not previously confirmed to be sensitive to FGFR inhibition had objective responses. In cohorts A and B, the median progression-free survival was 4.5 and 3.7 months, median duration of response was 7.8 and 6.9 months and median overall survival was 17.5 and 11.4 months, respectively. Safety was consistent with previous reports. The most common any-grade treatment-emergent adverse events were hyperphosphatemia (84%) and stomatitis (53%). TP53 co-mutations were associated with lack of response and BAP1 alterations with higher response rates. FGFR1-FGFR3 gatekeeper and molecular brake mutations led to acquired resistance. New therapeutic areas for FGFR inhibition and drug failure mechanisms were identified across tumor types. ClinicalTrials.gov identifier: NCT03822117 .

The safety of trastuzumab deruxtecan (DS-8201) with a focus on interstitial lung disease and/or pneumonitis: A systematic review and single-arm meta-analysis.

Previous studies involving risk-benefit analysis of trastuzumab deruxtecan (DS-8201) have indicated the benefit of this treatment, although it may increase the risk of interstitial lung disease (ILD) and/or pneumonitis in certain patients. This study aimed to assess the safety of DS-8201. A search was done for relevant articles in four electronic databases: PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov. All reports published up until November 2, 2022, were included, and study types were restricted to clinical trials; the last search was then updated to January 10, 2023. We also assessed the quality of the literature with the Cochrane Handbook for Systematic Reviews of Interventions and the Methodological Index for Non-Randomized Studies tool, and then performed a meta-analysis with R version 4.2.1. A total of 1428 patients reported in 13 articles were included in this study. The analysis revealed that the most common all-grade treatment-emergent adverse events (TEAEs) were nausea and fatigue. The most common TEAE of grade 3 or above (grade ≥3) was neutropenia. The incidences of ILD and/or pneumonitis for all-grade and grade ≥3 TEAEs were 12.5% and 2.2%, respectively. This comprehensive summary of the incidence of TEAEs associated with DS-8201 in clinical trials provides an important guide for clinicians. The most common TEAEs were gastrointestinal reactions and fatigue; meanwhile, the most common grade ≥3 TEAE was hematological toxicity. ILD and/or pneumonitis were specific adverse drug reactions associated with DS-8201, of which physicians should be particularly aware for their higher morbidity and rates of grade ≥3 TEAEs.

Efficacy and Safety of the Melphalan/Hepatic Delivery System in Patients with Unresectable Metastatic Uveal Melanoma: Results from an Open-Label, Single-Arm, Multicenter Phase 3 Study.

Uveal melanoma (UM) has a poor prognosis once liver metastases occur. The melphalan/Hepatic Delivery System (melphalan/HDS) is a drug/device combination used for liver-directed treatment of metastatic UM (mUM) patients. The purpose of the FOCUS study was to assess the efficacy and safety of melphalan/HDS in patients with unresectable mUM. Eligible patients with mUM received treatment with melphalan (3.0 mg/kg ideal body weight) once every 6 to 8 weeks for a maximum of six cycles. The primary end point was the objective response rate (ORR). The secondary end points included duration of response (DOR), overall survival (OS), and progression-free survival (PFS). The study enrolled 102 patients with mUM. Treatment was attempted in 95 patients, and 91 patients received treatment. In the treated population (n = 91), the ORR was 36.3 % (95 % confidence interval [CI], 26.44-47.01), including 7.7 % of patients with a complete response. Thus, the study met its primary end point because the lower bound of the 95 % CI for ORR exceeded the upper bound (8.3 %) from the benchmark meta-analysis. The median DOR was 14 months, and the median OS was 20.5 months, with an OS of 80 % at 1 year. The median PFS was 9 months, with a PFS of 65 % at 6 months. The most common serious treatment-emergent adverse events were thrombocytopenia (15.8 %) and neutropenia (10.5 %), treatedmostly on an outpatient basis with observation. No treatment-related deaths were observed. Treatment with melphalan/HDS provides a clinically meaningful response rate and demonstrates a favorable benefit-risk profile in patients with unresectable mUM (study funded by Delcath; ClinicalTrials.gov identifier: NCT02678572; EudraCT no. 2015-000417-44).

Abstract PO2-04-13: TWT-203: PHASE 1b/2 STUDY OF CFI-402257 AS MONOTHERAPY IN ADVANCED SOLID TUMORS AND IN COMBINATION WITH FULVESTRANT IN PATIENTS WITH ER+/HER2- ADVANCED BREAST CANCER AFTER PROGRESSION ON PRIOR CDK4/6 INHIBITORS AND ENDOCRINE THERAPY

Abstract Background: TTK (Threonine Tyrosine Kinase also known as Monopolar spindle 1), is a dual-specificity serine-threonine kinase critical for anaphase promoting complex inhibition at the spindle assembly checkpoint and is required for chromosome alignment and error correction. TTK inhibition results in premature mitosis exiting with unattached chromosomes potentially leading to aneuploidy and cell death. High TTK tumor levels correlate with worse prognosis and contribute to the survival and proliferation of aneuploid cells. CFI-402257, a potent and selective inhibitor of TTK, inhibits the growth of a variety of human cancer-derived cell lines. A first-in-human phase 1 study of CFI-402257 (NCT02792465) demonstrated a tolerable safety profile when enrolled as a monotherapy in solid tumors, and in combination with fulvestrant in hormone receptor positive, HER2 negative (HR+/HER2-) breast cancer1. The dose for expansion was 168 mg, dose limiting toxicity was dose-dependent neutropenia which was manageable and reversible. Investigator-confirmed partial responses (cPR) were observed in 5 pts (8%) with 32 (50.8%) exhibiting disease control. In the HR+/HER2- breast cancer population previously treated with cyclin dependent kinase 4/6 inhibitors (CDK4/6i) and aromatase inhibitors (N=25), there were 4 cPR’s with a median duration of response of 223 days, with responses emerging after 2 cycles of therapy. Responses were observed with CFI-402257 as a single agent and in combination with fulvestrant. Based on these data, study TWT-203 will focus on advanced solid tumors for dose confirmation then focus on advanced HR+/HER2- breast cancers in combination with an approved endocrine therapy. Methods: In TWT-203 study, safety and clinical activity of CFI-402257 monotherapy will be evaluated in patients (pts) with advanced solid tumors (Part A) or in combination with fulvestrant in pts with HR+/HER2- advanced breast cancer (Part B). Part A will confirm the RP2D using a 3+3 design with a starting dose of 126 mg daily. Part B evaluates CFI-402257 in combination with fulvestrant in pts with HR+/HER2- advanced breast cancer following progression on prior CDK4/6i and endocrine therapy. Efficacy endpoints include overall response rate and disease control rate. Safety endpoints include incidence of treatment emergent adverse events. Exploratory objectives include characterization of protein and molecular alterations relevant to the cell cycle and CFI-402257 response. Results: At data cutoff of 11 May 2023, 14 pts were enrolled. All received monotherapy treatment. Median treatment duration was 2.1 months (range, 0.2-7.3+). Median age was 67 years (57-76). Median number of prior regimens was 3.5 (2-12). Tumor types enrolled were colorectal (n=6, 43%), breast (3, 21%), and endometrial, hepatocellular, leiomyosarcoma, pancreatic, and sarcoma (1 each, 7%). 4 dose levels, from 126 to 252 mg, were studied. Most pts (12, 86%) experienced ≥1 treatment emergent adverse event (TEAE). More than half of pts (8, 57%) experienced ≥1 treatment related TEAE. Most common TEAEs were fatigue (5, 36%) and nausea (4, 29%). 5 pts (36%) experienced TEAEs grade ≥3, most common were fatigue, neutrophil count decrease, white blood cell count decrease (2 pts each, 14.3%). 1 pt (7%) experienced a serious adverse event (hematuria), not related to study therapy. No patients discontinued treatment due to TEAE. All pts who ended treatment were due to disease progression (8, 57%). No grade 5 TEAEs occurred. No dose limiting toxicities were reported. Disease control rate (CR, PR, or SD ≥ 6 weeks from baseline) was 54.5% (6 pts/11): all achieved SD. 3 of the 6 pts remain on study. Conclusion: CFI-402257 is a potent inhibitor of TTK. It is well tolerated with manageable TEAEs, no dose limiting or treatment limiting toxicities, and no treatment related deaths. Dose expansion in the patient population of interest will commence. 1. John Hilton et al. Cancer Res 2023;83(5 Suppl): P6-10-13. Citation Format: Justin Call, Muralidhar Beeram, Alexander I. Spira, Mark Bray, Dih-Yih Chen, Long Kwei, Emily Roberts-Thomson, Trisha Denny, Roger Sidhu, Robert Wesolowski. TWT-203: PHASE 1b/2 STUDY OF CFI-402257 AS MONOTHERAPY IN ADVANCED SOLID TUMORS AND IN COMBINATION WITH FULVESTRANT IN PATIENTS WITH ER+/HER2- ADVANCED BREAST CANCER AFTER PROGRESSION ON PRIOR CDK4/6 INHIBITORS AND ENDOCRINE THERAPY [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-04-13.

Abstract PS17-08: A Phase Ib Study to Evaluate the Efficacy and Safety of Afuresertib Plus Fulvestrant in Patients with Locally Advanced or Metastatic HR+/HER2- Breast Cancer Who Failed Standard of Care Therapies

Abstract Background The combination of an aromatase inhibitor with a CDK4/6 inhibitor is the mainstay of first-line endocrine therapy (ET) for locally advanced or metastatic HR+/HER2− breast cancer (LA/mBC). Management of recurrent disease in the post-CDK4/6 inhibitor setting includes additional lines of ET single agent or in combination with a targeted agent. For patients with HR+/HER2− LA/mBC tumors, fulvestrant monotherapy as the second- or third-line therapy has limited activity with a median PFS of 1.9-3.6 months. Effective targeted treatments for these patients are needed to maintain quality of life, improve survival, and delay the initiation of cytotoxic chemotherapy. Methods This ongoing single arm, open-label global study (NCT04851613) is to evaluate the efficacy and safety of the combination therapy of afuresertib (a pan-AKT inhibitor) plus fulvestrant in patients with HR+/HER2− LA/mBC. Eligible patients must have received 1-2 prior lines of ET. Patients may have prior treatment of CDK4/6 inhibitors (up to 1 therapy), and/or up to 1 line of chemotherapy. Patients received afuresertib (125 mg PO, QD) in combination with fulvestrant (500 mg IM; Day 1 and 15 in Cycle 1, and Day 1 in subsequent 28-day cycles). The safety of the initial treatment doses of the combination therapy was evaluated in the first 6 patients during the Cycle 1 safety run-in period. Radiographic assessment per RECIST 1.1 was performed every 8 weeks for the first 6 cycles and every 12 weeks thereafter. The primary endpoint was the investigator-assessed objective response rate (ORR). The secondary endpoints included safety and tolerability of the combination therapy and pharmacokinetic characterization. Results Twenty patients (1 male and 19 females, 3 in the US and 17 in China) were enrolled between May 2022 and April 2023. As of the data cut-off date of May 26th, 2023, 10 patients had discontinued the study treatment (9 due to disease progression, 1 due to patient’s withdrawal of consent) and 10 patients were still in treatment. Of the 19 patients who had at least one post-baseline tumor assessment, 4 patients observed confirmed Partial Response (cPR), 12 had best overall response of Stable Disease, and 3 had Progressive Disease (PD). The Disease Control Rate is 84%. Of the 15 patients who had at least 2 tumor assessments or who discontinued treatment early due to PD, the confirmed ORR is 26.7% (4 cPR). No dose modification was required during the safety run-in. The most common treatment-emergent adverse events (TEAEs, > 20% of patients) of all grades were hyperglycemia (50%), diarrhea (45%), ALT/AST increase (40%), nausea (35%), rash (35%), hypercholesterolemia (35%), and anemia (30%), the majority of which were Grade 1. Grade 3 AEs were reported in 4 patients, including diarrhea (1 patient), WBC increase (1 patient), creatine phosphokinase increase (1 patient), and ALT/AST increase and rash (1 patient). No SAE or TEAE >= Grade 4 were reported. No patient discontinued treatment due to TEAE. Conclusions The preliminary data from the combination therapy of afuresertib plus fulvestrant has shown promising efficacy with a well-tolerated safety profile in patients with HR+/HER2− LA/mBC who progressed on 1-2 prior lines of standard of care therapies. These results support further evaluation of this combination therapy in this patient population in an upcoming phase III study. Citation Format: Binghe Xu, Pin Zhang, Tao Sun, Ying Wang, Zhongsheng Tong, Sneha Phadke, Trevor Feinstein, Pengfei Guo, Jing Qu, Xiaoyu Wang. A Phase Ib Study to Evaluate the Efficacy and Safety of Afuresertib Plus Fulvestrant in Patients with Locally Advanced or Metastatic HR+/HER2- Breast Cancer Who Failed Standard of Care Therapies [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS17-08.

Abstract PS16-02: Efficacy and safety of first-line atezolizumab + bevacizumab + paclitaxel in patients with advanced triple-negative breast cancer: the ATRACTIB phase 2 trial

Abstract BACKGROUND Triple-negative breast cancer (TNBC) is an aggressive tumor characterized by poor outcomes and new treatment strategies are urgently required. The programmed cell death-ligand 1 (PD-L1) antibody (Ab) atezolizumab (ATZ) combined with first-line (1L) nab-paclitaxel (nab-PTX) is approved in multiple countries for the treatment of PD-L1-positive patients (pts) with advanced TNBC (aTNBC) based on a significant improvement in progression-free survival (PFS) and a numerically higher and clinically meaningful median overall survival (OS). A synergism between antiangiogenic therapy and immunotherapy (IO)-based strategies has been observed preclinically and in different tumor types, but data in aTNBC is lacking. METHODS ATRACTIB (NCT04408118) is an international, open-label, single-arm, phase 2 trial evaluating the efficacy and safety of 1L ATZ + BVZ + PTX for pts with aTNBC, regardless of their tumors’ PD-L1 status. Adult pts with untreated, unresectable locally advanced/metastatic TNBC were included. Pts who had received (neo)adjuvant taxane-based chemotherapy (CT) and/or IO and/or an antiangiogenic agent had to have had a relapse with a disease-free interval beyond 12 months (mo). Pts received intravenous ATZ 840 mg + BVZ 10 mg/kg on days (D)1 and D15 + PTX 90 mg/m2 on D1, 8, and 15 of every 28-day cycle until disease progression, intolerable toxicity, death, or patient withdrawal. Tumor assessments were performed every 8 weeks for the first 12 mo and every 12 weeks thereafter. Baseline PD-L1 expression was centrally assessed using 22C3 (combined positive score [CPS]) and SP142 (expression on tumor-infiltrating immune cells [ICs]) Abs. The primary endpoint was investigator-assessed PFS by RECIST v.1.1. Key secondary endpoints included OS, objective response rate (ORR), clinical benefit rate (CBR), duration of response (DoR), and safety. Median PFS was analyzed with exponential maximum likelihood estimation (H0: ≤7.0 mo; HA: ≥9.5 mo). We estimated that enrolling 100 pts would provide 80% power at one-sided α nominal level of 5%, assuming a 10% drop-out rate. RESULTS Between October 2020 and May 2022, 100 female pts from 28 centers across 5 European countries were included. Median age was 55.0 years (32.0 - 84.0), 57.0% of pts had visceral disease, 46.0% had ≥3 metastatic sites, and 70.0% had received prior treatment for early BC (taxane-based CT in 87.1% of them). A total of 82 and 85 tumor samples out of 100 pts were available for PD-L1 assessment using 22C3 and SP142 assays, respectively. Most pts had PD-L1-negative tumors (87.8% with 22C3 [CPS < 10] and 97.6% with SP142 [expression on < 1% positive of ICs]). At data cutoff (15th September 2023), 23 pts were still on therapy. With a median follow-up of 16.7 mo (1.1 - 34.1), median PFS was 11.0 mo (95% CI, 9.0 - 13.2). OS data were immature at data cutoff, with 30 events. Estimated 18-month OS was 69.4% (95% CI, 58.4% - 78.1%). ORR was 63.0% (95% CI, 52.8% - 72.4%), CBR was 79.0% (95% CI, 69.7% - 86.5%), and median DoR was 10.0 mo (95% CI, 7.2 - 13.8). Regarding safety, the most common treatment-emergent adverse events (TEAEs) were peripheral neuropathy (68.0%) and fatigue (62.0%). Grade (G) 3/4 treatment-related TEAEs occurred in 47.0% of pts, mainly peripheral neuropathy (13.0%) and neutropenia (12.0%). Any-grade immune-related TEAEs, thrombosis or embolism, and bleeding occurred in 13.0% (5.0%; G≥3), 4.0% (1.0%; G≥3), and 10.0% (0.0%; G≥3) of pts, respectively. There were no drug-related deaths. CONCLUSIONS 1L ATZ + BVZ + PTX demonstrated encouraging anti-tumor activity in aTNBC pts, most of them presenting with PD-L1-negative tumors. Median PFS seems to be much higher compared with that previously reported with other IO-based regimens in a similar patient population. The safety profile was consistent with the known safety data of ATZ and BVZ combined with CT, without significant added toxicity. These results merit further research of this combination for PD-L1-negative aTNBC. Citation Format: Maria Gion, Patricia Cortez-Castedo, Isabel Blancas, Alfonso Cortés, Frederik Marmé, Salvador Blanch, Serafin Morales Murillo, Nieves Díaz, Isabel Calvo-Plaza, Sabela Recalde, Alejandro Martínez-Bueno, Manuel Ruiz-Borrego, Elisenda Llabres, María Teresa Taberner, Michelino de Laurentiis, José Ángel García-Sáenz, Jana Repkova, Antonio Antón, Joseph Gligorov, Susana de la Cruz, Oliver Hoffmann, Jacques Medioni, Melissa Phillips, Miguel Sampayo-Cordero, Daniel Alcalá-López, José Manuel Pérez-García, Antonio Llombart-Cussac, Javier Cortés. Efficacy and safety of first-line atezolizumab + bevacizumab + paclitaxel in patients with advanced triple-negative breast cancer: the ATRACTIB phase 2 trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS16-02.

Abstract GS01-10: HER2CLIMB-02: Randomized, Double-Blind Phase 3 Trial of Tucatinib and Trastuzumab Emtansine for Previously Treated HER2-Positive Metastatic Breast Cancer

Abstract Background Tucatinib is a highly selective HER2-directed tyrosine kinase inhibitor approved in combination with trastuzumab and capecitabine for previously treated HER2+ locally advanced or metastatic breast cancer (LA/MBC). Trastuzumab emtansine (T-DM1) is a HER2-directed antibody-drug conjugate approved to treat HER2+ LA/MBC previously treated with trastuzumab and a taxane. This is the first report of HER2CLIMB-02 (NCT03975647), a randomized, double-blind, placebo-controlled phase 3 study assessing the efficacy and safety of tucatinib combined with T-DM1 in patients with previously treated HER2+ LA/MBC. Methods Eligible patients had HER2+ LA/MBC previously treated with trastuzumab and a taxane in any setting with ECOG performance status ≤1 and adequate hepatic, renal, hematologic, and cardiac function. Patients with previously treated stable, progressing, or untreated brain metastases (BMs) not requiring immediate local therapy were also eligible. Patients were randomly assigned 1:1 to receive 21-day cycles of either tucatinib (300 mg orally twice a day [PO BID]) or placebo (PO BID), combined with T-DM1 (3.6 mg/kg intravenously every 3 weeks). The primary endpoint was progression-free survival (PFS) by investigator assessment per RECIST v1.1. Alpha-controlled secondary endpoints included overall survival (OS) and objective response rate (ORR) per RECIST v1.1 for the overall population, and PFS and OS for the subset of patients with BMs at baseline. Safety was analyzed as a secondary endpoint. Results From October 8, 2019, to June 16, 2022, 463 patients were randomly assigned, comprising 228 to the tucatinib arm (tucatinib + T-DM1) and 235 to the control arm (placebo + T-DM1). The median duration of follow-up (OS) was 24.4 months for the overall population. Patient demographics and baseline characteristics were balanced between the 2 arms. Almost half (44.1%) of the overall population had either active or stable BMs at baseline. As of the data cutoff (June 29, 2023), the study met its primary endpoint with a statistically significant improvement in PFS in the tucatinib arm vs control arm. The risk of progression or death decreased by 24.1% in the tucatinib arm (hazard ratio [HR]=0.759 [95% CI, 0.607-0.950]; P=0.0163). Median PFS was 9.5 months (95% CI, 7.4-10.9) vs 7.4 months (95% CI, 5.6-8.1) for the tucatinib and control arms, respectively. HRs for PFS across all prespecified subgroups were consistent with the HR of the overall population, including patients with BMs at baseline (HR=0.639 [95% CI, 0.459-0.891]). The interim OS results were immature with 134 of 253 total required events (53%) and did not meet the prespecified crossing boundary. The confirmed ORR was numerically higher in the tucatinib arm (42.0%) vs the control arm (36.1%). The most common treatment-emergent adverse events (TEAEs) included nausea (65.4% vs 49.4% for tucatinib and control arms, respectively), diarrhea (56.7% vs 26.6%), and fatigue (48.9% vs 37.3%). The most common grade ≥3 TEAEs in the tucatinib arm were alanine and aspartate aminotransferase elevations, each reported in 38 patients (16.5%) in the tucatinib arm and 6 patients (2.6%) in the control arm. TEAEs associated with any treatment discontinuation occurred in 51 patients (22.1%) in the tucatinib arm and 27 (11.6%) in the control arm. TEAEs leading to deaths occurred in 3 patients (1.3%) in the tucatinib arm and 2 patients (0.9%) in the control arm. Conclusion HER2CLIMB-02 demonstrated that the addition of tucatinib to T-DM1 significantly improved median PFS in patients with previously treated HER2+ LA/MBC, including those with BMs. Although discontinuations due to TEAEs were more common in the tucatinib arm, no new safety signals emerged for the combination therapy. Citation Format: Sara Hurvitz, Sherene Loi, Joyce O'Shaughnessy, Alicia Okines, Sara Tolaney, Joo Hyuk Sohn, Cristina Saura, Xiaofu Zhu, David Cameron, Thomas Bachelot, Erika Hamilton, Giuseppe Curigliano, Antonio Wolff, Nadia Harbeck, Norikazu Masuda, Linda Vahdat, Khalil Zaman, Frances Valdes-Albini, Margaret Block, Timothy Pluard, Tira Tan, Chelsea Gawryletz, Arlene Chan, Philippe Bedard, Rinat Yerushalmi, Binghe Xu, Konstantinos Tryfonidis, Michael Schmitt, Joan Xie, Virginia Borges. HER2CLIMB-02: Randomized, Double-Blind Phase 3 Trial of Tucatinib and Trastuzumab Emtansine for Previously Treated HER2-Positive Metastatic Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-10.

Abstract PO3-04-06: A comparison of the efficacy of trastuzumab deruxtecan in advanced HER2-positive breast cancer: active brain metastasis versus progressive extracranial disease alone

Abstract Background Trastuzumab deruxtecan (T-DXd) has demonstrated efficacy in patients with brain metastasis (BM), a group historically with poor outcomes. The prevalence of BMs in patients commencing T-DXd is currently unknown. To date, no direct comparisons have been made of the activity of T-DXd in patients with active BM versus those with extracranial progression alone. This real-world study explored the prevalence of BMs at commencement of T-DXd, the efficacy of T-DXd in active BM versus extracranial progression alone and the safety of T-DXd. Methods Patients with HER2-positive advanced breast cancer treated with T-DXd between June 2021 and February 2023 at our specialist cancer hospital were identified and notes reviewed. Clinico-pathological information, prior treatment, the presence or absence of CNS disease, outcomes and treatment-emergent adverse events (TEAE) were recorded. Data cut-off was 28th February 2023. Results 29 female patients: 16 extracranial disease alone, 12 BM and 1 LMD were identified. Prevalence of BM at commencement of T-DXd was 41% (12 of 29). Median age was 52 (IQR 44-62), with a median 2 (range 2-6) prior lines of HER2 directed and chemotherapy:86% (25 of 29) had received prior trastuzumab and pertuzumab, 100% (29 of 29) T-DM1 and 3% (1 of 29) patient trastuzumab duocarmazine. At a median follow-up of 13.8 months, median progression free survival (PFS) for overall population was 13.9 months (95% CI: 12.4-NE), 16.1 months (95% CI: 15.1-NE) for active BMs, and 12.4 months (95% CI: 8.3-NE) for progressive extracranial disease alone (P=0.106). 12-month OS rate was 74% (95% CI: 59-95) in the overall population, 83% (95% CI: 58-100) and 66% (95% CI: 45-96) for active BMs, and extracranial only disease respectively (P=0.678). Objective response rates: overall population was 69% (95% CI: 52-86), active BMs was 60% (95% CI: 30-90), and progressive extracranial disease alone was 69% (95% CI: 46-91). 6% (1 of 16) with extracranial disease alone developed BM during treatment with T-DXd. Reasons for treatment discontinuation: 67% (10 of 15) disease progression or death; 33% (5 of 15) toxicity. 48% (14 of 29) remain on treatment. Most common TEAEs were fatigue (97%; 28 of 29), alopecia (76%; 22 of 29), and constipation (72%; 21 of 29). Pneumonitis occurred in 9 patients (31%, included 2 deaths). 1 pathologically confirmed case of radionecrosis was documented. An updated analysis with an additional 9 patients who commenced T-DXd since February 2023 will be presented. Conclusion In this real-world study a significant number of patients had BM at the commencement of T-DXd. We demonstrate that in advanced HER2 positive breast cancer that T-DXd is as effective, in terms of PFS and OS, in active BMs as it is in progressive extracranial disease alone. These data provide the first evidence that in contrast to the historical data that active BM may no longer be a detriment to survival as compared to progressive extracranial disease alone when treated with T-Dxd. These observations warrant further investigations in larger series. The high rate of pneumonitis warrants further consideration. Citation Format: James Pearson, Adeel Khan, Talvinder Bhogal, Helen Wong, Andrea Law, Samantha Mills, Nuria Santamaria, Joanne Cliff, Douglas Errington, Allison Hall, Clare Hart, Zafar Malik, Raj Sripadam, Helen Innes, Helen Flint, Gabriella Langton, Eliyaz Ahmed, Jill Bishop, Richard Jackson, Carlo Palmieri. A comparison of the efficacy of trastuzumab deruxtecan in advanced HER2-positive breast cancer: active brain metastasis versus progressive extracranial disease alone [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-04-06.

Abstract PS05-09: A single-arm Phase II clinical study of fulvestrant combined with chemotherapy in the neoadjuvant treatment of HR+/HER2- locally advanced breast cancer

Abstract Background: HR+/HER2- breast cancer has been found to be less sensitive to neoadjuvant chemotherapy (NCT), leading to an objective response rate (ORR) of approximately 65%. Endocrine therapy combined with chemotherapy may help improve the ORR in these patients. The objective of this Phase II study was to evaluate the efficacy and safety of adding fulvestrant to NCT in patients with HR+/HER2- locally advanced breast cancer(LABC). Additionally, the study aimed to investigate the association of 18F-FES PET/CT and metabolites with efficacy. Methods: In this single-arm Phase II study, eligible patients were females with histologically confirmed HR+/HER2- LABC (Stage IIB-IIIC). Patients received fulvestrant (500 mg, on days 0, 14, 28, then every 28 days thereafter, every 4 weeks for six cycles) plus AC-T regimen, followed by surgery. Premenopausal women were administered a concomitant GnRH analogue. Patients underwent 18F-FES PET/CT before the initiation of fulvestrant, and plasma samples were collected for LC-MS analysis at baseline. The primary endpoint was ORR. Secondary endpoints included pathological complete response (tpCR) and safety. Results: From December 2020 to September 2022, 36 patients were enrolled. The median age was 53 years (range35-67). 78% were ECOG PS of 1, 69% were postmenopausal, 92% were nodal involved, and 83% were in stage III. After neoadjuvant therapy, the ORR was 86.1%. All patients completed the surgery, with a tpCR rate of 8.3% (3/36). 80.6% (29/36) patients were classified as Miller-Payne (MP) grade ≥3. Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 22% (8/36) of the participants. The most common TEAEs were neutropenia (13.9%) and leukopenia (8.3%). The expression of ER, PR, and Ki-67 in postoperative pathology significantly decreased compared to baseline (p < 0.05). Additionally, the change in ER expression was significantly correlated with the regression volume of primary breast tumors (R = 0.56, p = 0.0044). The decrease in ER value in patients with MP ≥ 4 was significantly larger than in patients with MP ≤ 3 (p = 0.0054). Among the 36 patients, 24 completed the 18F-FES PET/CT scan before initiating fulvestrant.The average SUVmax in primary breast lesions was 4.17 (range 1.00-12.80). The SUVmax of breast lesions was significantly correlated with clinical efficacy (p = 0.0018) and with changes in ER expression before and after treatment (R = 0.68, p = 0.00023). Meanwhile, the SUVmax of patients with MP ≥ 4 grade was significantly higher than that of patients with MP ≤ 3 grade (p=0.018). A total of 25 plasma samples were available for metabolic analysis. Among these samples, 13 differential metabolites were identified between patients with MP ≥ 4 grade and MP ≤ 3 grade, which were markedly enriched in 19 metabolic pathways. Conclusions: The addition of fulvestrant to NCT showed manageable toxicity and promising antitumor activity for patients with HR+/HER2- LABC. 18F-FES PET/CT might serve as a tool to predict the effectiveness of neoadjuvant combination therapy. Altered metabolites or metabolic pathways might be associated with the response to this combined treatment approach. Keywords: breast cancer, HR+/HER2-, fulvestrant, neoadjuvant treatment, 18F-FES PET/CT Citation Format: Qing Shao, Jing Wu, Ningning Zhang, Xiaohua Zeng. A single-arm Phase II clinical study of fulvestrant combined with chemotherapy in the neoadjuvant treatment of HR+/HER2- locally advanced breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS05-09.

Abstract PS11-05: Trastuzumab Deruxtecan in patients with HER2[+] or HER2-Low Advanced Breast Cancer and Pathologically Confirmed Leptomeningeal Carcinomatosis: Results from Cohort 5 of the DEBBRAH Study

Abstract Background: Leptomeningeal carcinomatosis (LMC) occurs in approximately 5-15% of patients (pts) with advanced breast cancer (ABC) and is associated with poor survival and a significant reduction in quality of life. The antibody-drug conjugate trastuzumab deruxtecan (T-DXd) has shown remarkable intracranial and extracranial activity, leading to its widespread clinical use. DEBBRAH is evaluating the efficacy and safety of T-DXd in pts with HER2[+] and HER2-low ABC with a history of brain metastases (BM) and/or LMC. Here, we report results from cohort 5 that included pts with pathologically confirmed LMC. Methods: DEBBRAH (NCT04420598) is a single-arm, open-label, five-cohort, phase 2 study conducted across 18 sites in Spain and Portugal. A total of 39 pts aged ≥18 years with pretreated HER2[+] or HER2-low ABC with stable, progressing, or untreated BM and/or LMC were enrolled in 5 cohorts: (1) HER2[+] ABC with non-progressing BM after radiotherapy and/or surgery; (2) HER2[+] or HER2-low ABC with asymptomatic untreated BM; (3) HER2[+] ABC with progressing BM after local treatment; (4) HER2-low ABC with progressing BM after local treatment; (5) HER2[+] or HER2-low ABC and LMC with positive cerebrospinal fluid cytology. Pts received 5.4 mg/kg T-DXd intravenously once every 21 days until disease progression, unacceptable toxicity, or consent withdrawal. Primary endpoint for cohort 5 was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall response, clinical benefit rate (CBR) according to RANO-BM (intracranial lesions) and RECIST v.1.1 (extracranial and overall lesions); and safety and tolerability as per NCI-CTCAE v.5.0. OS was tested with the maximum likelihood exponential method (H0: median OS ≤2 months; H1: median OS≥6 months). We estimate that 7 pts are needed to attain an 80% power at the nominal level of one-sided α of 0.05. Results: Between Apr 14, 2021, and Apr 5, 2022, 7 pts were allocated into cohort 5. Median age was 57 (range, 42–69) years, 3 (42.9%) pts were HER2[+], 6 (85.7%) pts had synchronous extracranial metastases, 2 of whom (28.6%) also presented BM, and 3 (42.9%) pts had measurable disease. Median number of previous lines of therapy for advanced disease was 4 (range, 1-8) and no patient received prior local treatment for central nervous system involvement. At data cut-off (Apr 4, 2023), median follow-up was 12 months (range, 2.5-18.6). Median duration of treatment was 9.0 months (range, 2.1-18.6). Two (28.6%) pts remained on treatment: 1 HER2[+] and 1 HER2-low, after 18.6 and 12.0 months, respectively. Median OS rate was 13.3 months (95% CI, 5.7-NA, p< 0.001) meeting the primary endpoint. Among 5 pts with disease progression, none had intracranial progression. A total of 4 (57.1%) pts presented extracranial progression and 1 (14.3%) patient had clinical worsening. No objective responses were observed, but 5 out of 7 pts had prolonged stabilization (≥24 weeks) for an overall CBR of 71.4% (95% CI, 29.0-96.3) and a median PFS of 8.9 months (95% CI, 4.9-NA) according to RECIST v.1.1. The most common non-hematological treatment emergent adverse events (TEAEs) of any grade (G) were nausea (57.1%; 14.3% G3), fatigue (42.9%; 0% G3), vomiting (42.9%; 0% G3), headache (42.9%; 0% G3), and urinary tract infection (42.9%; 0% G3). Anemia (42.9%; 0% G3) and thrombocytopenia (28.6%; 14.3% G3) were the most frequent hematological TEAEs. No cases of interstitial lung disease/pneumonitis were reported. Serious unrelated TEAEs occurred in 4 (57.1%) of 7 pts, and 1 patient experienced a related serious TEAE (nausea G3). No treatment-related deaths were reported. Conclusions: T-DXd showed promising activity with no new safety concerns in HER2[+] and HER2-low pts with previously untreated, pathologically confirmed LMC. These encouraging data warrant further investigation to address the unmet need in this difficult-to-treat condition. Citation Format: Marta Vaz Batista, José Manuel Pérez-García, Laia Garrigós, José Ángel García-Sáenz, Patricia Cortez-Castedo, Fabriccio Racca, Salvador Blanch, Manuel Ruíz - Borrego, Adela Fernández, María Fernández-Abad, Vega Iranzo, Maria Gion, Griselda Martrat, Daniel Alcalá-López, Jhudit Pérez-Escuredo, Miguel Sampayo-Cordero, Antonio Llombart-Cussac, Sofía Braga, Javier Cortés. Trastuzumab Deruxtecan in patients with HER2[+] or HER2-Low Advanced Breast Cancer and Pathologically Confirmed Leptomeningeal Carcinomatosis: Results from Cohort 5 of the DEBBRAH Study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS11-05.

Abstract PS15-04: A Phase 1b/2 study of palazestrant (OP-1250), an oral complete estrogen receptor antagonist (CERAN) and selective ER degrader (SERD), with palbociclib in ER-positive, HER2-negative, advanced or metastatic breast cancer patients

Abstract Background: Palazestrant (OP-1250) is a small molecule oral complete estrogen receptor (ER) antagonist (CERAN) and selective ER degrader (SERD) that binds the ligand binding domain of ER and completely blocks ER-driven transcriptional activity in both wild-type (ESR1-wt) and mutant (ESR1-mut) forms of ER. In preclinical studies, palazestrant demonstrated improved tumor growth inhibition and shrinkage when combined with a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. In a Phase 1/2 monotherapy clinical study in patients with ER-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer, palazestrant was well tolerated with demonstrated antitumor efficacy and favorable pharmacokinetics (PK) supporting once a day (qd) dosing at the recommended Phase 2 dose of 120 mg. In this study, pts received palazestrant at escalating doses of 30, 60, 90, and 120 mg qd in combination with palbociclib (125 mg qd) and no dose-limiting toxicities were observed. Palazestrant did not affect palbociclib PK and no drug–drug interactions (DDIs) occurred. Here we report updates on safety, efficacy, and PK from the ongoing study of palazestrant in combination with palbociclib. Methods: Patients with advanced or metastatic breast cancer with progression on or after ≤1 line of endocrine therapy (prior CDK4/6 inhibitor therapy and ≤1 chemotherapy allowed) were enrolled to receive oral palazestrant 120 mg qd with oral palbociclib 125 mg qd for 21 of 28 days (NCT0526610). Results: As of May 12, 2023, 33 patients have been treated with palazestrant in combination with palbociclib; 12 pts were dosed in the dose-escalation phase and 21 patients were dosed in the dose-expansion phase of the study. Twenty-two patients (67%) received prior CDK4/6 inhibitor therapy; 15 patients received prior palbociclib. Thirteen of 25 patients (52%) with available baseline ctDNA had an ESR1 mutation. The most common (≥20%) treatment-emergent adverse events (TEAEs) were neutropenia, nausea, vomiting, constipation, and diarrhea. Most of these events were grade 1 or 2. The most common grade 3 or 4 related AE was neutropenia (18/33 [55%] were grade 3; 3/33 [9%] were grade 4). The steady-state exposure of palazestrant when dosed with 125 mg palbociclib was consistent with the monotherapy study. Palbociclib exposure at steady-state was comparable to published monotherapy data when combined with palazestrant at all dose levels tested. As of the data cut-off, there were 4 partial responses (2 confirmed) out of 19 response-evaluable patients, with a clinical benefit rate (CBR) of 42% (8/19) across all patients and 67% (6/9) in patients with ESR1 mutations. Conclusions: Palazestrant and palbociclib dosed in combination were well tolerated with a safety profile consistent with the individual profiles of each drug as monotherapy, and there were no DDIs. Tumor responses and clinical benefit were observed in this population of patients, including those who received prior CDK4/6 inhibitors. Expanding on our previous report, these data provide the rationale to continue advancing the clinical development of palazestrant with the approved dose of palbociclib. Updated data will be presented. Citation Format: Arlene Chan, Daphne Day, Phuong Dinh, Michael Slancar, Janine Lombard, Vinod Ganju, Nicole McCarthy, Rosalind Wilson, Demiana Faltaos, Gurpreet Mathauda-Sahota, Caitlin Murphy. A Phase 1b/2 study of palazestrant (OP-1250), an oral complete estrogen receptor antagonist (CERAN) and selective ER degrader (SERD), with palbociclib in ER-positive, HER2-negative, advanced or metastatic breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS15-04.

Abstract PO1-06-10: Overall survival results from EVER-132-001, a phase 2b single-arm study of sacituzumab govitecan in Chinese patients with metastatic triple-negative breast cancer

Abstract Background Breast cancer is the most frequently diagnosed cancer and the 5th most common cause of cancer-related death in Chinese women with over 416,000 new cases and over 117,000 deaths estimated in 2020. Triple-negative breast cancer (TNBC) represents 10%-20% of cases in women with breast cancer. Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate and is approved for second-line or later (2L+) treatment of metastatic (m)TNBC in multiple countries, including the US and China. In the pivotal phase 3 study ASCENT, which enrolled predominantly non-Asian patients (pts), SG demonstrated improved efficacy outcomes vs treatment of physician’s choice (TPC) in pts with mTNBC treated in 2L+, with a manageable safety profile. For pts treated with SG, median progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) were improved vs TPC (Bardia A et al, 2021). The single-arm phase 2b EVER-132-001 study was conducted to assess the efficacy and safety of 2L+ SG in Chinese pts with mTNBC. In preliminary findings from EVER-132-001, SG demonstrated substantial clinical activity and a manageable safety profile (Xu B et al, 2023). Here, we present additional efficacy and safety results from EVER-132-001, including the first report of median OS. Methods Pts with mTNBC who had received at least 2 prior lines of chemotherapy for mTNBC received SG (10 mg/kg IV on days 1 and 8, Q3W). The primary end point was ORR per independent review committee (IRC). Secondary end points included duration of response (DoR) per IRC, clinical benefit rate (CBR) per IRC, PFS per IRC, OS, and safety. Results Eighty pts were enrolled, with a median age of 48 years (range 24-70). Pts had received a median of 4 prior treatment regimens (range 2-8), and 59% of pts had ECOG performance status of 1. At the data cutoff, September 19, 2022, with a median follow-up of 14.7 mo (range 1.2-25.3), median OS was 14.7 mo (95% CI 10.3-18.3) and the OS rate at 12 months was 54% (95% CI 42-64) (Table). ORR was 40% (95% CI 29-52) with median DoR of 11.6 mo (95% CI 7.0-13.8), and CBR was 46% (95% CI 35-58) (Table). Median PFS was 5.6 mo (95% CI 4.1-8.3) (Table). Grade ≥ 3 treatment-emergent adverse events (TEAEs) occurred in 79% of pts, and TEAEs leading to dose reduction, treatment interruption, and treatment discontinuation occurred in 20%, 48%, and 8% of patients, respectively (Table). The most common TEAEs of any grade were decreased neutrophil count (85%), anemia (84%), and decreased white blood cell count (83%). The most common grade ≥ 3 TEAEs were decreased neutrophil count (64%), decreased white blood cell count (50%), and anemia (23%). Conclusions SG continued to demonstrate substantial clinical activity, with OS, ORR, DoR, CBR, and PFS results in the EVER-132-001 trial, consistent with the phase 3 ASCENT trial of SG in mTNBC. TEAEs were manageable and no new safety signals were identified. These results support the use of SG as a new standard of care for Chinese pts with pretreated mTNBC. Table Citation Format: Fei Ma, Shusen Wang, Zhongsheng Tong, Wei Li, Xinhong Wu, Xiaojia Wang, Tao Sun, Yueyin Pan, Herui Yao, Xian Wang, Ting Luo, Jin Yang, Xiaohua Zeng, Weihong Zhao, Kimberly Komatsubara, Rachel Nakamura, Catherine Lai, Bo Zhang, Xiuyu Cong, Binghe Xu. Overall survival results from EVER-132-001, a phase 2b single-arm study of sacituzumab govitecan in Chinese patients with metastatic triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-06-10.

Seralutinib in adults with pulmonary arterial hypertension (TORREY): a randomised, double-blind, placebo-controlled phase 2 trial

Morbidity and mortality in pulmonary arterial hypertension (PAH) remain high. Activation of platelet-derived growth factor receptor, colony stimulating factor 1 receptor, and mast or stem cell growth factor receptor kinases stimulates inflammatory, proliferative, and fibrotic pathways driving pulmonary vascular remodelling in PAH. Seralutinib, an inhaled kinase inhibitor, targets these pathways. We aimed to evaluate the efficacy and safety of seralutinib in patients with PAH receiving standard background therapy. The TORREY trial was a phase 2, randomised, multicentre, multinational, double-blind, placebo-controlled study. Patients with PAH from 40 hospital and community sites were randomly assigned 1:1 via interactive response technologies to receive seralutinib (60 mg twice daily for 2 weeks, then increased to 90 mg twice daily as tolerated) or placebo by dry powder inhaler twice daily for 24 weeks. Randomisation was stratified by baseline pulmonary vascular resistance (PVR; <800 dyne·s/cm5 and ≥800 dyne·s/cm5). Patients were eligible if classified as WHO Group 1 PH (PAH), WHO Functional Class II or III, with a PVR of 400 dyne·s/cm5 or more, and a 6 min walk distance of between 150 m and 550 m. The primary endpoint was change in PVR from baseline to 24 weeks. Analyses for efficacy endpoints were conducted in randomly assigned patients (intention-to-treat population). Safety analyses included all patients who received the study drug. TORREY was registered with ClinicalTrials.gov (NCT04456998) and EudraCT (2019-002669-37) and is completed. From Nov 12, 2020, to April 20, 2022, 151 patients were screened for eligibility, and following exclusions, 86 adults receiving PAH background therapy were randomly assigned to seralutinib (n=44; four male, 40 female) or placebo (n=42; four male, 38 female), and comprised the intention-to-treat population. At baseline, treatment groups were balanced except for a higher representation of WHO Functional Class II patients in the seralutinib group. The least squares mean change from baseline to week 24 in PVR was 21·2 dyne·s/cm5 (95% CI -37·4 to 79·8) for the placebo group and -74·9 dyne·s/cm5 (-139·7 to -10·2) for the seralutinib group. The least squares mean difference between the seralutinib and placebo groups for change in PVR was -96·1 dyne·s/cm5 (95% CI -183·5 to -8·8; p=0·03). The most common treatment-emergent adverse event in both treatment groups was cough: 16 (38%) of 42 patients in the placebo group; 19 (43%) of 44 patients in the seralutinib group. Treatment with inhaled seralutinib significantly decreased PVR, meeting the primary endpoint of the study among patients receiving background therapy for PAH. Gossamer Bio.

Safety, tolerability, and pharmacokinetics of single- and multiple-ascending doses of olamkicept: Results from randomized, placebo-controlled, first-in-human phase I trials.

Olamkicept selectively inhibits the cytokine interleukin-6 (IL-6) trans-signaling pathway without blocking the classic pathway and is a promising immunoregulatory therapy for inflammatory bowel disease (IBD). These first-in-human, randomized, placebo-controlled, single- (SAD) and multiple-ascending dose (MAD) trials evaluated olamkicept safety, tolerability, pharmacokinetic, and pharmacodynamic characteristics. Doses tested in the SAD trial included seven single intravenous doses (0.75, 7.5, 75, 150, 300, 600, and 750 mg) and one subcutaneous (SC) dose (60 mg) given to healthy subjects (N = 64), and three intravenous doses (75 mg, 300 mg, and 750 mg) given to patients with Crohn's disease (CD; N = 24). Doses tested in the MAD trial included multiple intravenous doses (75, 300, and 600 mg once weekly for 4 weeks) given to healthy subjects (N = 24). No severe or serious treatment-emergent adverse events (TEAEs) were recorded. The most common TEAEs were headache, nasopharyngitis, and myalgia in the SAD trial, and diarrhea, headache, and cough in the MAD trial. Infusion-related reactions occurred in one and two subjects in the SAD and MAD trial, respectively, leading to treatment discontinuation in the MAD trial. Olamkicept showed dose-independent pharmacokinetics after single and multiple administrations, and there was no major difference in systemic exposure between healthy subjects and patients with CD. Complete target engagement (inhibition of phosphorylation of signal transducer and activator of transcription-3) was achieved in blood around or above olamkicept serum concentrations of 1-5 μg/mL. Overall, these results suggest that olamkicept is safe and well-tolerated in healthy subjects and patients with CD after single intravenous/SC and multiple intravenous administrations.

Efficacy and Safety of Erenumab in Participants With Episodic Migraine in Whom 2-4 Prior Preventive Treatments Had Failed: LIBERTY 3-Year Study.

The LIBERTY study assessed the efficacy and safety of erenumab in participants with episodic migraine (EM) and 2-4 prior preventive treatment failures. The results have been presented after 3 years of erenumab exposure in its open-label extension phase (OLEP). Participants completing the 12-week double-blind treatment phase (DBTP) of the LIBERTY study could enter the OLEP and receive 140 mg of erenumab once monthly for 3 years. The main outcomes included the proportion of participants achieving ≥50% reduction in monthly migraine days (MMDs), the mean MMD change from baseline, and tolerability and safety. Overall, 240/246 (97.6%) participants entered the OLEP and 168/240 (70.0%) completed the study (85/118 continuing erenumab [n = 1 lost during follow-up]; 83/122 switching from placebo [n = 2 lost during follow-up]). In the overall population, 79/151 participants (52.3%) with valid data points achieved ≥50% reduction in MMDs at week 168 (i.e., responders). In the continuous erenumab group, 35/117 participants (29.9%) were ≥50% responders at week 12 of the DBTP and 26/35 (74.3%) remained ≥50% responders in at least half of OLEP visits. Of the 82/117 participants (70.1%) not achieving responder status at week 12 in the continuous erenumab group, 17/82 (20.7%) converted to ≥50% responders in at least half of OLEP visits. Of 103/120 participants (85.8%) not achieving responder status at week 12 in the placebo-erenumab group, 42/103 (40.8%) converted to ≥50% responders in at least half of OLEP visits after switching to erenumab. Overall, the mean (SD) MMD change from baseline showed sustained improvement over 3 years (-4.4 [3.9] days at week 168). The most common treatment-emergent AEs (per 100 person-years) were nasopharyngitis (28.8), influenza (7.5), and back pain (5.8). Overall, 9.6% (3.9 per 100 person-years) and 6.7% (2.7 per 100 person-years) of participants reported events of treatment-emergent hypertension and constipation, respectively. The safety and tolerability profile remained consistent with earlier studies. Erenumab (140 mg) showed sustained efficacy over 3 years in participants with EM and 2-4 prior preventive treatment failures. No new safety signals were observed. ClinicalTrials.gov Identifier: NCT03096834.

Toripalimab Plus Bevacizumab as First-line Treatment for Advanced Hepatocellular Carcinoma: A Prospective, Multicenter, Single-Arm, Phase II Trial.

This phase II, multicenter, prospective, single-arm study aimed to evaluate the efficacy and safety of toripalimab plus bevacizumab in treating advanced hepatocellular carcinoma (HCC). Treatment-naïve patients with advanced HCC received toripalimab 240 mg plus bevacizumab 15 mg/kg every 3 weeks. Primary endpoints included safety and tolerability, and objective response rate (ORR) assessed by the investigator per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Fifty-four patients were enrolled between Apr 17, 2020 and Dec 11, 2020. As assessed by the investigator according to RECIST v1.1, the ORR was 31.5% [95% confidence interval (CI), 19.5-45.6] and the lower bound of the 95% CI was above the pre-specified boundary of 10%. The independent review committee (IRC) assessed ORR according to modified RECIST (mRECIST) was 46.3% (95% CI, 32.6-60.4). The median progression-free survival were 8.5 months (95% CI, 5.5-11.0) and 9.8 months (95% CI, 5.6-not evaluable) assessed by the investigator according to RECIST v1.1 and IRC according to mRECIST criteria, respectively. The median overall survival (OS) was not reached, and the 12- and 24-month OS rates were 77.3% and 63.5%, respectively. Grade 3 or higher treatment-emergent adverse events (TEAEs) occurred in 27 patients (50.0%). The most common TEAEs were proteinuria (59.3%), hypertension (38.9%), aspartate aminotransferase increased (33.3%), amylase increased (29.6%), platelet count decreased (27.8%), and bilirubin increased (27.8%). Toripalimab plus bevacizumab showed a favorable efficacy and safety profile, supporting further studies of this combination regimen as a first-line treatment of advanced HCC.

Multicenter, phase 1 study of etavopivat (FT-4202) treatment for up to 12 weeks in patients with sickle cell disease

AbstractEtavopivat is an investigational, once daily, oral, selective erythrocyte pyruvate kinase (PKR) activator. A multicenter, randomized, placebo-controlled, double-blind, 3-part, phase 1 study was conducted to characterize the safety and clinical activity of etavopivat. Thirty-six patients with sickle cell disease (SCD) were enrolled into 4 cohorts: 1 single-dose, 2 multiple ascending doses, and 1 open-label (OL). In the OL cohort, 15 patients (median age 33.0 years [range, 17-55]) received 400 mg etavopivat once daily for 12 weeks; 14 patients completed treatment. Consistent with the mechanism of PKR activation, increases in adenosine triphosphate and decreases in 2,3-diphosphoglycerate were observed and sustained over 12 weeks’ treatment. This translated clinically to an increase in hemoglobin (Hb; mean maximal increase 1.6 g/dL [range, 0.8-2.8]), with >1 g/dL increase in 11 (73%) patients during treatment. In addition, the oxygen tension at which Hb is 50% saturated was reduced (P = .0007) with a concomitant shift in point of sickling (P = .0034) to lower oxygen tension in oxygen-gradient ektacytometry. Hemolysis markers (absolute reticulocyte count, indirect bilirubin, and lactate dehydrogenase) decreased from baseline, along with matrix metalloproteinase-9 and erythropoietin. In the OL cohort, adverse events (AEs) were mostly grade 1/2, consistent with underlying SCD; 5 patients had serious AEs. Vaso-occlusive pain episode was the most common treatment-emergent AE (n = 7) in the OL cohort. In this, to our knowledge, the first study of etavopivat in SCD, 400 mg once daily for 12 weeks was well tolerated, resulting in rapid and sustained increases in Hb, improved red blood cell physiology, and decreased hemolysis. This trial was registered at www.ClinicalTrials.gov as #NCT03815695.

Subgroup analyses from the phase 3 ASCENT study of sacituzumab govitecan in metastatic triple-negative breast cancer

In this post hoc analysis of the ASCENT study, we compared outcomes with sacituzumab govitecan (SG) vs single-agent chemotherapy in clinically important subgroups of patients with metastatic triple-negative breast cancer (mTNBC). Patients with mTNBC refractory to/relapsing after ≥2 prior chemotherapies (≥1 in the metastatic setting) were randomized 1:1 to receive SG or treatment of physician’s choice (TPC) until unacceptable toxicity/progression. The primary endpoint was progression-free survival (PFS) per RECIST 1.1 by central review in patients without brain metastases. Patients with brain metastases were allowed if metastases were stable ≥4 weeks. In the intention-to-treat (ITT) population, 19% of patients were age ≥65 years; 12% were Black, and 12% had brain metastases. SG improved PFS and overall survival (OS), respectively, vs TPC in patients age ≥65 years (7.1 vs 2.4 months and 14.7 vs 8.9 months), or of Black race (5.4 vs 2.2 months and 13.8 vs 8.5 months), consistent with outcomes in the ITT population. Patients with brain metastases had numerically higher median PFS with SG vs TPC, but median OS was similar between treatment groups. SG was well tolerated and had a manageable safety profile consistent with the full safety population across all subgroups; neutropenia and diarrhea were the most common treatment-emergent adverse events. These findings confirm the meaningful clinical benefit of SG vs standard chemotherapy in patient subgroups with high unmet needs. SG should be considered an effective and safe treatment option for patients with mTNBC eligible for second-line or later therapy. ClinicalTrials.gov Number: NCT02574455.