Improvement In PFS Research Articles

Patient-reported outcomes (PROs) in patients (pts) with primary advanced or recurrent endometrial cancer (pA/rEC) treated with dostarlimab (D) plus carboplatin/paclitaxel (CP) compared with CP in the ENGOT-EN6/GOG3031/RUBY trial.

332 Background: In RUBY (NCT03981796), a phase 3, global, randomized, double-blind trial, D+CP demonstrated significant and clinically meaningful improvement in PFS vs placebo + CP (P+CP) in pA/rEC. Methods: 494 pts with pA/rEC were randomized 1:1 to D+CP or P+CP Q3W for 6 cycles (C), followed by D or placebo monotherapy Q6W for ≤2 y. EORTC QLQ-C30 and EN24 (prespecified secondary endpoints) were administered on day 1 of each C, at end of treatment (EOT), and at safety and survival follow-ups. Change (chg) from baseline (BL) to C7 (end of chemotherapy) and C13 (1 y) was calculated in the overall and mismatch repair–deficient (dMMR)/microsatellite instability–high (MSI-H) populations. Least-squares means (LSM) were generated using mixed models for repeated measures, adjusting for correlations across multiple assessments within a pt and controlling for BL global, pain, fatigue, and physical function (PF) scores. Results: In the overall population, PROs were similar with D+CP and P+CP through C7, and no differences between arms across the 3-y period were reported; mean chg from BL to EOT showed numerical improvement with D+CP in back/pelvic pain and deterioration with P+CP in global QOL/GHS, social function (SF), body image, and chg in taste. In the dMMR/MSI-H population, at C7, nominally significant improvements in QOL, PF, role function (RF), pain, and back/pelvic pain were seen with D+CP vs P+CP (Table). Conclusions: Dostarlimab+CP significantly improved PFS and maintained HRQOL in dMMR/MSI-H and overall populations, further supporting its use as a standard of care in pA/rEC. Clinical trial information: NCT03981796 .[Table: see text]

Revisiting Concurrent Radiation Therapy, Temozolomide, and the Histone Deacetylase Inhibitor Valproic Acid for Patients with Glioblastoma-Proteomic Alteration and Comparison Analysis with the Standard-of-Care Chemoirradiation.

Glioblastoma (GBM) is the most common brain tumor with an overall survival (OS) of less than 30% at two years. Valproic acid (VPA) demonstrated survival benefits documented in retrospective and prospective trials, when used in combination with chemo-radiotherapy (CRT). The primary goal of this study was to examine if the differential alteration in proteomic expression pre vs. post-completion of concurrent chemoirradiation (CRT) is present with the addition of VPA as compared to standard-of-care CRT. The second goal was to explore the associations between the proteomic alterations in response to VPA/RT/TMZ correlated to patient outcomes. The third goal was to use the proteomic profile to determine the mechanism of action of VPA in this setting. Serum obtained pre- and post-CRT was analyzed using an aptamer-based SOMAScan® proteomic assay. Twenty-nine patients received CRT plus VPA, and 53 patients received CRT alone. Clinical data were obtained via a database and chart review. Tests for differences in protein expression changes between radiation therapy (RT) with or without VPA were conducted for individual proteins using two-sided t-tests, considering p-values of <0.05 as significant. Adjustment for age, sex, and other clinical covariates and hierarchical clustering of significant differentially expressed proteins was carried out, and Gene Set Enrichment analyses were performed using the Hallmark gene sets. Univariate Cox proportional hazards models were used to test the individual protein expression changes for an association with survival. The lasso Cox regression method and 10-fold cross-validation were employed to test the combinations of expression changes of proteins that could predict survival. Predictiveness curves were plotted for significant proteins for VPA response (p-value < 0.005) to show the survival probability vs. the protein expression percentiles. A total of 124 proteins were identified pre- vs. post-CRT that were differentially expressed between the cohorts who received CRT plus VPA and those who received CRT alone. Clinical factors did not confound the results, and distinct proteomic clustering in the VPA-treated population was identified. Time-dependent ROC curves for OS and PFS for landmark times of 20 months and 6 months, respectively, revealed AUC of 0.531, 0.756, 0.774 for OS and 0.535, 0.723, 0.806 for PFS for protein expression, clinical factors, and the combination of protein expression and clinical factors, respectively, indicating that the proteome can provide additional survival risk discrimination to that already provided by the standard clinical factors with a greater impact on PFS. Several proteins of interest were identified. Alterations in GALNT14 (increased) and CCL17 (decreased) (p = 0.003 and 0.003, respectively, FDR 0.198 for both) were associated with an improvement in both OS and PFS. The pre-CRT protein expression revealed 480 proteins predictive for OS and 212 for PFS (p < 0.05), of which 112 overlapped between OS and PFS. However, FDR-adjusted p values were high, with OS (the smallest p value of 0.586) and PFS (the smallest p value of 0.998). The protein PLCD3 had the lowest p-value (p = 0.002 and 0.0004 for OS and PFS, respectively), and its elevation prior to CRT predicted superior OS and PFS with VPA administration. Cancer hallmark genesets associated with proteomic alteration observed with the administration of VPA aligned with known signal transduction pathways of this agent in malignancy and non-malignancy settings, and GBM signaling, and included epithelial-mesenchymal transition, hedgehog signaling, Il6/JAK/STAT3, coagulation, NOTCH, apical junction, xenobiotic metabolism, and complement signaling. Differential alteration in proteomic expression pre- vs. post-completion of concurrent chemoirradiation (CRT) is present with the addition of VPA. Using pre- vs. post-data, prognostic proteins emerged in the analysis. Using pre-CRT data, potentially predictive proteins were identified. The protein signals and hallmark gene sets associated with the alteration in the proteome identified between patients who received VPA and those who did not, align with known biological mechanisms of action of VPA and may allow for the identification of novel biomarkers associated with outcomes that can help advance the study of VPA in future prospective trials.

Optimum Radiation Dose for Palliation in Head and Neck SCC: A Phase III Randomized Controlled Trial (OPRAH)

Palliative radiotherapy has been used to alleviate symptoms in locally advanced (T4b) head and neck Squamous cell carcinoma, but optimum dose is still debated. The trial has been designed to determine if high palliative radiation dose (30 Gy/ 5#/ 5 days) improves progression free survival compared to low palliative dose (20 Gy/ 5# 5 days). The secondary objective was to compare toxicity rates profile between the two radiation doses (CTCAE version 5) and compare Quality of life between the two arms with QOL - HN35 questionnaire. This is a prospective randomized phase III randomized controlled trial. We hypothesized that by increasing the dose per fraction and total dose there would be an improvement in PFS without difference in late toxicity and QOL. The present study will also perform an exploratory analysis of effect of palliative radiotherapy on immune function and its effect on survival. Considering median PFS 2.5 months in 20 Gy arm we assumed that PFS will improve by 1.25 months (total PFS 3.75 months) in 30 Gy arm. To reach the hypothesis with 90% power and alpha error of 0.05, attrition rate of 10% sample size calculated was 286. Patients with cT4b disease of larynx/ Hypopharynx/ Oropharynx/ Oral cavity not amenable to surgery, Carotid encasement > 180 degree, histologically proven squamous cell carcinoma, Age > 18 years and < 75 years ECOG PS 0-2 were eligible. Until December 2022, we completed accrual of 239 patients. Median age: 53 years (Range: 29-70 years); Gender: Male: Female = 9: 1 (214: 25). 145 patients had history of smoking, 87 had additional history of tobacco chewing. 67 patients had history of alcohol consumption, 13 patients had history of smoking, tobacco and alcoholism. All patients had stage IVA or Stage IVB disease. Primary site was oral cavity in 58%, Oropharynx in 19%, larynx in 10% and hypopharynx in 8% cases. 72.3% patients had a PS of 1, 21.7% had PS 2 at presentation. Prior to RT requirement of analgesic was: No pain medicine: 5; WHO step I:173, WHO step II: 52, WHO step III:14. All patients received conformal radiation with 6 MV linear accelerator. Target volume was GTV plus 1 cm margin to form CTV and 5 mm expansion to generate PTV. Out of 239 patients 67 patients had a disease progression. Mucositis is the commonest side effect affecting most of the patients and improve with best supportive care. High dose palliation appears to be equally well tolerated. However, the impact of such dose escalation will be established if final analysis reaches the pre-defined endpoint.

A multicenter retrospective analysis of patients with salivary gland carcinoma treated with postoperative radiotherapy alone or chemoradiotherapy

BackgroundThe aim of this study was to interrogate if the use of postoperative chemoradiotherapy (POCRT) correlated with superior oncological outcomes for certain subgroups of patients with high-risk salivary gland carcinoma (SGC), compared with postoperative radiotherapy (PORT) alone. MethodsThis multicenter retrospective study included 411 patients with surgically resected SGC who underwent PORT (n = 263) or POCRT (n = 148) between 2000 and 2015. Possible correlations of clinical parameters with outcomes were examined using the Kaplan-Meier analysis and Cox proportional-hazards regression model. ResultsThe median follow-up of survivors is 10.9 years. For the entire cohort, adding concurrent chemotherapy to PORT was not associated with OS, PFS, or LRC improvement. However, patients with nodal metastasis who underwent POCRT had significantly higher 10-year OS (46.2% vs. 18.2%, P = 0.009) and PFS (38.7% vs. 10.0%, P = 0.009) rates than those treated with PORT alone. The presence of postoperative macroscopic residual tumor (R2 resection) was identified as an independent prognosticator for inferior OS (P = 0.032), PFS (P = 0.001), and LRC (P = 0.007). Importantly, POCRT significantly correlated with higher 10-year LRC rates in patients with R2 resection (74.2% vs. 40.7%, P = 0.034) or adenoid cystic carcinoma (AdCC, 97.6% vs. 83.6%, P = 0.039). On multivariate analyses, the use of POCRT significantly predicted superior OS (P = 0.037) and PFS (P = 0.013) for node-positive patients and LRC for patients with R2 resection (P = 0.041) or AdCC (P = 0.005). ConclusionsFor surgically resected SGC, POCRT was associated with improved long-term OS and PFS for patients with nodal metastasis and superior LRC for patients with R2 resection or AdCC.

Durvalumab with paclitaxel/carboplatin (PC) and bevacizumab (bev), followed by maintenance durvalumab, bev, and olaparib in patients (pts) with newly diagnosed advanced ovarian cancer (AOC) without a tumor BRCA1/2 mutation (non-tBRCAm): Results from the randomized, placebo (pbo)-controlled phase III DUO-O trial.

LBA5506 Background: Olaparib (ola) maintenance (mtx) improved outcomes in pts with newly diagnosed AOC and a BRCAm (DiSilvestro J Clin Oncol 2023;41:609–17) or with bev in pts with homologous recombination deficiency (HRD+) tumors (Ray-Coquard Ann Oncol 2022: LBA29) in response to 1L treatment, but an unmet need remains. Combining an immune checkpoint inhibitor with an antiangiogenic agent and a PARP inhibitor may enhance antitumor effect (Banerjee Ann Oncol 2022: 529MO). The Phase III DUO-O trial (NCT03737643) evaluates PC + bev + durva, followed by mtx bev + durva + ola, in pts with non-tBRCAm AOC in the 1L setting. Methods: Pts had newly diagnosed FIGO stage III or IV, high-grade epithelial, non-tBRCAm AOC and had completed upfront, or were planned to receive interval, debulking surgery and 1 cycle of PC ± bev. At Cycle 2, pts were randomized 1:1:1 to Arm 1: PC + bev (15 mg/kg IV q3w) + durva pbo (up to 6 cycles) followed by mtx bev (15 mg/kg IV q3w; total 15 months [mo]) + durva pbo (total 24 mo) + ola pbo (total 24 mo); Arm 2: PC + bev + durva (1120 mg IV q3w) followed by mtx bev + durva (1120 mg IV q3w) + ola pbo; or Arm 3: PC + bev + durva followed by mtx bev + durva + ola (300 mg bid tablets). The primary endpoint, progression-free survival (PFS; modified RECIST 1.1 per investigator) in Arm 3 vs Arm 1, was tested first in the non-tBRCAm HRD+ population (GIS ≥42, Myriad MyChoice CDx) and then the intent-to-treat (ITT) population. Results: 1130 pts were randomized: 378 Arm 1, 374 Arm 2, and 378 Arm 3. At a prespecified interim analysis (DCO Dec 5, 2022), a statistically significant improvement in PFS was observed for Arm 3 vs Arm 1: HR 0.49 (95% CI 0.34–0.69; P&lt;0.0001) and HR 0.63 (95% CI 0.52–0.76; P&lt;0.0001) in the HRD+ and ITT populations, respectively; a consistent PFS effect was observed in the HRD- subgroup (HR 0.68, 95% CI 0.54–0.86). A numerical improvement in PFS was shown for Arm 2 vs Arm 1 (ITT population), but statistical significance was not reached (Table). During the study, any serious adverse events were reported in 34%, 43% and 39% of pts in Arms 1, 2 and 3, respectively. Conclusions: PC + bev + durva followed by mtx bev + durva + ola in pts with newly diagnosed non-tBRCAm AOC resulted in a statistically significant and clinically meaningful improvement in PFS vs PC + bev followed by mtx bev. Safety was generally consistent with the known profiles of each agent. Clinical trial information: NCT03737643 . [Table: see text]

Prognostic impact of HLA‐I neoantigen‐specific CD8+ T cells in limited‐stage follicular lymphoma

Introduction: Follicular lymphoma (FL) is the most common indolent NHL. Recently, we demonstrated in limited and advanced stage FL (LSFL, ASFL), that patients with longer remissions had raised clonally expanded intratumoral CD8+ T cells (Tobin, JCO 2019). Durable remissions occur in ∼50% of LSFL patients whereas ASFL is incurable. However, little is known regarding the immunological features associated with this difference. We hypothesized HLA-I neoantigen (neoAg)-specific CD8+ T cells may play a role. Methods: The discovery cohort comprised 101 patients with diagnostic paraffin embedded tissue from the TROG99.03 LSFL clinical trial (MacManus, JCO 2018), in which stage I/II patients were randomized to involved field radiation (IFRT) only or combined modality therapy between 2000 and 2012 (PET from 2006). Contemporaneous validation cohorts were (a) AusLSFL: 60 PET staged, stage I FL patients from Australia (treatment miscellaneous), and (b) CanLSFL: 60 PET staged, stage I FL patients drawn principally from Canada (IFRT only). Digital gene expression (NanoString), targeted sequencing (330 genes), and germline HLA-typing was performed. Mutations observed by sequencing were used to predict neoAgs in TROG99.03 tissues using 8 algorithms (PVACseq) and filtered according to strong binding affinity to HLA-I over wild-type (TESLA consortium guidelines; Wells, Cell 2020). Results: CD8A gene expression was tested for prognostic significance. In TROG99.03, elevated intratumoral CD8A (by MaxStat) was associated with ∼2-fold improvement in PFS for all patients: HR 0.45 (CI: 0.77–0.26, p = 0.0053) and stage I only patients: HR 2.4 (CI: 1.2–4.6, p = 0.036). In keeping with a relationship between CD8+ T cell infiltration and tumor antigen presentation, raised expression of NLRC5 (a transcriptional HLA-I activator) was also associated with superior PFS: HR 0.48 (CI: 0.99–0.24, p = 0.024). CD8A significance was confirmed in both validation cohorts (whereas NLRC5 was validated in AusLSFL only). In keeping with recent IHC CD8 protein data (Los-de Vries, Bld Adv 2022), CD8A gene expression was raised in stage I LSFL vs. 68 ASFL patients treated with immunochemotherapy (p = 0.02). Mutational profiling was concordant with published LSFL data, with CREBBP and KMT2DA most frequent. NeoAg calling methods including functional assays for neoAg peptide binding were confirmed in a separate cohort of fresh FL tissues. 59% of TROG99.03 tissues had ≥1 neoantigens detected. Importantly, unsupervised hierarchical clustering showed 2-fold enrichment of samples with neoantigens among those with high vs. low HLA-I. Conclusions: Raised CD8A is associated with favorable prognosis in LSFL. Our data suggests disease control involves populations of expanded HLA-I neoAg-specific T cells. These findings have implications for novel immunotherapeutic strategies designed to increase the rate of durable remissions. The research was funded by: National Health and Medical Research Council, Australia; Leukaemia Foundation; Mater Foundation Keywords: Diagnostic and Prognostic Biomarkers, Indolent non-Hodgkin lymphoma, Microenvironment Conflicts of interests pertinent to the abstract. C. Keane Honoraria: Takeda, Roche, AZ, MSD, Beigene C. Cheah Consultant or advisory role: Roche, Janssen, Gilead, AstraZenecca, Lilly, TG therapeutics, Beigene, Novartis, Menarini, Daizai, Abbvie, Genmab. BMS Honoraria: BMS, Roche, Abbvie; MSD, Lilly R. Kridel Research funding: Abbvie Educational grants: Eisai M. K. Gandhi Research funding: Beigene, Janssen

Patient-reported outcomes (PROs) in primary advanced or recurrent endometrial cancer (pA/rEC) for patients (pts) treated with dostarlimab plus carboplatin/paclitaxel (CP) as compared to CP in the ENGOT-EN6/GOG3031/RUBY trial.

5504 Background: In RUBY, a phase 3, global, randomized, double-blind, placebo (PBO)-controlled trial, dostarlimab+carboplatin/paclitaxel demonstrated significant and clinically meaningful improvement in PFS compared with PBO+CP in pts with pA/rEC. PROs are reported here. Methods: 494 pts with pA/rEC were randomized 1:1 to dostarlimab (D)+CP or PBO+CP Q3W for 6 cycles followed by D or PBO monotherapy Q6W ≤3 yrs or to disease progression. EORTC QLQ-C30 and EN24 were prespecified secondary endpoints. PROs were administered on Day 1 of each treatment (tx) cycle (C), end of tx (EOT), and at safety and survival follow-ups and reported here for C7, the end of chemotherapy (chemo) and C13, and the end of 1 yr of study. Change (chg) from baseline (BL) to C7/C13 was calculated for all scales assessed. Mixed model for repeated measures analysis was conducted to generate least-squares means (LSM), adjusting for correlations across multiple time point assessments within a pt and controlling for the BL value for the global, pain, fatigue, and physical function (PF) scores. Results: PRO outcomes were similar for D+CP and PBO+CP through the chemo period (C7). The table shows selected scores at C7 and C13 for mean (SD) and chg from BL. Further, no differences across the 3 yr period between the 2 arms were reported; LSM (standard error) for global QoL was 0.5 (1.42; P=0.72), PF was −0.7 (1.39; P=0.63), fatigue was 0.2 (1.75; P=0.91) and pain was −1.0 (1.99; P=0.62). Mean chg from BL to EOT showed improvement in back/pelvic pain for D+CP and deterioration in global QoL/GHS, social functioning, body image, and chg in taste for pts on PBO+CP. Conclusions: Dostarlimab + CP significantly improved PFS while maintaining HRQoL, further supporting its use as a standard of care in pA/rEC. Clinical trial information: NCT03981796 . [Table: see text]

Treatment patterns post atezolizumab plus bevacizumab for advanced hepatocellular carcinoma: Real-world analysis at Veterans Health Administration comparing lenvatinib vs. sorafenib.

e16195 Background: Atezolizumab plus Bevacizumab (A+B) has been the standard first-line therapy for advanced hepatocellular carcinoma (HCC) patients. There needs to be more data on the efficacy and selection of optimal sequences following resistance to A+B. Our study aims to review treatment patterns for disease progression following A+B, focusing on the most common 2nd line treatment utilized by the Veterans Health Administration (VHA). Methods: Patients with advanced HCC receiving line A+B at the VHA between Dec 1, 2019, to Mar 1, 2022, were selected electronically using ICD-9 and ICD-10 codes. Abstractors reviewed EMR following each patient from their index date of A+B initiation, sequential therapies, until death, or their last VHA visit, with the study period ending on Jan 31, 2023. Results: Three hundred thirty-two patients received A+B during our study period, and 1/3rd (n = 107) of these patients went on second-line treatments. 87 % started Tyrosine Kinase Inhibitors with 52, 29,12, and 1 on Lenvatinib, Sorafenib, Cabozantinib, and Regorafenib, respectively. Two second-line cohorts were selected, A (52 on Lenvatinib) and B (29 on sorafenib). The median age was 66 yrs vs. 65 yrs in cohorts A and B, respectively. In both cohorts, 60% non-Hispanic White and 90% with ECOG ≤1, there were no statistically significant differences between both cohorts in overall and progression-free survival. The outcomes are shown. Conclusions: Despite minimal improvement in PFS and a lower discontinuation rate due to toxicity favoring Lenvatinib over Sorafenib, Sorafenib had slightly better overall survival. This study is one of the most significant projects that describes 2nd line treatment patterns post-A+B failure. Further studies are warranted to evaluate larger cohorts to study treatment sequencing in the second and third lines.[Table: see text]

Alliance A092104: A randomized phase 2/3 study of olaparib plus temozolomide versus investigator’s choice for the treatment of patients with advanced uterine leiomyosarcoma after progression on prior chemotherapy.

TPS11584 Background: Uterine leiomyosarcoma (uLMS) is an aggressive sarcoma subtype with frequent metastatic relapse. Advanced uLMS is treated with gemcitabine/docetaxel or anthracycline-based regimens. After failure of initial chemotherapy, remaining options provide limited benefit (trabectedin: objective response rate (ORR) 11%, median progression-free survival (mPFS) 4.0 months (mo); pazopanib: ORR 11%, mPFS 3.0 mo; dacarbazine: ORR 9%, mPFS 1.5 mo). 18-23% of uLMS harbor deleterious alterations in homologous recombination (HR) DNA repair genes. HR-deficient cancers are unable to effectively repair double-stranded DNA breaks and may be sensitive to poly ADP-ribose polymerase (PARP) inhibitor-based strategies. In preclinical studies, the combination of temozolomide (T), an alkylating agent, and olaparib (O), a PARP inhibitor, markedly suppressed proliferation of uLMS models. Among 22 uLMS patients with median 3 prior lines, O+T demonstrated mPFS 6.9 mo and ORR 27% (Ingham M. et al. ASCO 2021: #11506). In correlative analysis, alterations in HR genes including PALB2 and RAD51B or absence of RAD51 foci formation by a functional assay were observed in patients with prolonged PFS (Bose S. et al. ASCO 2022: #11509). Based on these results, we designed a randomized phase 2/3 study to further evaluate O+T in advanced, pretreated uLMS. Methods: Alliance for Clinical Trials in Oncology A092104 is a randomized, open-label phase 2/3 clinical trial of O+T versus investigator’s choice in advanced uLMS. Eligible patients have ECOG performance status ≤2, progression on ≥ 2 prior treatment lines and measurable disease. Patients are randomized 1:1 to receive T 75 mg/m2 orally daily + O 200 mg orally twice daily on days 1-7 in 21-day cycles (Arm 1) or investigator’s choice of trabectedin 1.5 mg/m2 over 24 hours every 21 days or pazopanib 400-600 mg orally daily (Arm 2). For phase 2, the primary endpoint is PFS. The design evaluates for an improvement in PFS from 4 mo to 8 mo, requires 70 patients, and yields 90% power and 1-sided alpha 0.10. If phase 2 is positive, phase 3 will enroll. For phase 3, the primary endpoint is overall survival (OS). The design evaluates for an improvement in OS from 13 mo to 23 mo, requires 165 patients (including 70 from phase 2) and yields 90% power with 1-sided alpha 0.025. Secondary endpoints include ORR, duration of response, safety and patient-reported outcomes. Archival tissue will be collected and evaluated with a RAD51 foci formation assay. Genomic sequencing results will be obtained where available. The study opened to accrual in 1/2023. Support: U10CA180821, U10CA180882, U24 CA196171; https://acknowledgments.alliancefound.org . Clinical trial information: NCT05633381 .

Analysis of survival outcomes in patients with non–small-cell lung cancer with mutations in STK11/LKB1 receiving chemoimmunotherapy.

e15043 Background: Many patients with non-small-cell lung cancer (NSCLC) do not benefit from first-line treatment with immune checkpoint inhibitors (ICI) alone or in combination with chemotherapy due to resistance or toxicity. In NSCLC, significant research has been undertaken to provide prognostic markers for single agent immune checkpoint inhibitor therapy. Co-alterations in TP53, STK11/LKB1 and KRAS have a low reported prevalence in NSCLC, however, potentially may represent a distinct molecular subtype of NSCLC that conveys primary resistance to single-agent ICI. Data continues to accumulate regarding resistance mechanisms to ICI, but limited data exists exploring these alterations and the corresponding survival outcomes in patients that receive chemoimmunotherapy. The primary objective of this study was to assess the association between alterations and co-alterations in STK11/LKB1 and survival outcomes in patients with NSCLC receiving chemo-immunotherapy. Methods: This was a retrospective study of patients ≥18 years old who had completed NGS testing and had a diagnosis of non-small-cell lung cancer that received chemoimmunotherapy from January 2016 to November 2022. NGS reports were reviewed to assess the status of STK11/LKB1, KRAS, KEAP1, and TP53 alterations. Additional markers assessed were PD-L1 status, TPS, CPS, TMB, and MSI if available. Results: Sixty-five patients were identified who had received chemoimmunotherapy for NSCLC, had NGS testing results, and were considered to be evaluable for retrospective review. Four patients were identified with co-altered KRAS, STK11, and TP53, and this alone was not significant for PFS (p= 0.48) or OS (p = 0.52) compared to patients without the alterations, however patients with the co-alterations and a positive PD-L1 showed an improvement in PFS (p =0.053). Patients with altered STK11, including those classified as VUS, had a poorer OS (p = 0.088). Our analysis also showed that PD-L1 negative patients had poorer OS (p = 0.088). Conclusions: The addition of chemotherapy to ICI may overcome resistance previously described in NSCLC patients with co-alterations in KRAS, STK11, and TP53, who received single-agent ICI and these genomic findings should not deter from the use of chemoimmunotherapy based on our limited experience. Patients with alterations in STK11 did have poorer outcomes overall, which is in line with previously published data describing STK11 as a poor prognostic marker in NSCLC. STK11 alterations have previously been described to be associated with PD-L1 negativity which may explain, at least in part, the poorer responses in the STK11 mutated subgroup.

Global prevalence of CLDN18.2 in patients with locally advanced (LA) unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma: Biomarker analysis of two zolbetuximab phase 3 studies (SPOTLIGHT and GLOW).

4035 Background: There is an unmet need for additional therapies to treat patients (pts) with locally advanced (LA) unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma. Claudin-18.2 (CLDN18.2), a new validated target in these pts, is expressed in normal gastric mucosa cells and often retained in G/GEJ tumor cells. There are limited data on the global prevalence of CLDN18.2 in tumors of pts with LA unresectable or mG/GEJ adenocarcinoma. The SPOTLIGHT (NCT03504397) and GLOW (NCT03653507) phase 3 studies demonstrated clinically meaningful and statistically significant improvement in PFS and OS with the CLDN18.2-targeted antibody zolbetuximab + chemotherapy (mFOLFOX6 or CAPOX, respectively) vs placebo + chemotherapy as 1L therapy in pts with CLDN18.2+/HER2− disease. We report the biomarker analysis of these studies. Methods: Pts with LA unresectable or mG/GEJ adenocarcinoma were screened for CLDN18.2 status by IHC before enrollment. Tumors were defined as CLDN18.2+ if they had ≥75% of tumor cells with moderate-to-strong membranous CLDN18 staining per the investigational VENTANA CLDN18 (43-14A) RxDx Assay. HER2 status was evaluated per central or local assessment. Ad hoc PD-L1 IHC was performed via the Dako PD-L1 IHC 28-8 pharmDx assay for a subgroup of enrolled pts. Results exclude pts from mainland China and pts missing data for disease type, Lauren classification, or tumor collection site. Results: Across SPOTLIGHT and GLOW, 3576 pts had valid CLDN18 IHC results; 1399 (39.1%) had CLDN18.2+ tumors. CLDN18.2 prevalence was 43.7% (513/1175) in female pts and 36.9% (886/2401) in male pts. CLDN18.2 prevalence was 44.0% (671/1524) in pts in Europe/Middle East, 37.7% (183/485) in pts in N. America, and 36.5% (479/1314) in pts in Asia Pacific. CLDN18.2 prevalence was 41.0% (1056/2576) in pts with gastric adenocarcinoma and 37.3% (302/809) in pts with GEJ adenocarcinoma. CLDN18.2 prevalence trended higher in pts with diffuse (48.9%, 479/980) vs intestinal (38.9%, 265/682) disease. CLDN18.2 prevalence was 41.1% (175/426) in tumors collected from metastatic sites and 38.6% (1195/3094) in tumors collected from primary sites. CLDN18.2 prevalence was similar across other clinical and histopathological characteristics. Of 2908 HER2− pts with valid CLDN18 IHC results, 1264 (43.5%) had CLDN18.2+ tumors. Of 599 enrolled pts tested for PD-L1 expression, 104 (17.4%) had a PD-L1 CPS ≥5. Conclusions: The SPOTLIGHT and GLOW phase 3 studies are the largest data sources to date for determining global CLDN18.2 prevalence. CLDN18.2 is a high prevalence biomarker, with high tumor expression in ~35–40% of pts with LA unresectable or mG/GEJ adenocarcinoma, for whom zolbetuximab + chemotherapy represents a potential 1L therapy. Clinical trial information: NCT03504397 , NCT03653507 .

Olaparib (O) + ceralasertib (C) in patients (pts) with metastatic triple-negative breast cancer (mTNBC): Translational analysis of the VIOLETTE trial.

1087 Background: O is a PARP inhibitor approved in a number of tumor types and for use in pts with germline (g) mutations in BRCA ( BRCAm) HER2-negative metastatic breast cancer. C is an inhibitor of DDR kinase ATR. Analysis of VIOLETTE (NCT03330847) in pts with mTNBC showed no improvement in PFS with a combination of C and O vs. O, whether in the context of pathogenic BRCAm, non-BRCA HRR pathway mutations (HRRm), or homologous recombination repair (HRR) wildtype (HRRwt) tumors. We report an exploratory translational analysis of predictive genomic biomarkers of response to O ± C beyond g BRCAm. Methods: Pts received O (300 mg twice daily) ± C (160 mg daily; days 1–7; 28-day cycles) as a second- or third-line treatment option. Pts were prospectively stratified into molecular strata based on pathogenic/likely pathogenic alterations in BRCA1/2 ( BRCAm; n=83) or in ≥1 of 13 selected non- BRCA HRR genes (HRRm; n=40) or HRRwt (n=103) using FoundationOneCDx (F1CDx) sequencing assay of archival tumor sample. Advanced genomic analysis included genome-wide loss of heterozygosity (a marker of HRR deficiency [HRD] with a 16% cut-off to define HRD+ [≥16%] vs HRD− [&lt;16%]), zygosity, and predicted g/somatic (s) status of BRCA and HRR alterations based on a validated computational FMI algorithm. Efficacy was evaluated by blinded independent central review of PFS, RECIST response, and best percentage change from baseline in target lesion size. Results: Out of evaluable pts for origin of BRCAm (n=42), 81% (n=34) were of germline, and 19% (n=8) were of somatic origin. Of pts evaluable for zygosity (n=48), most BRCA alterations were biallelic (90%; n=43), and of pts evaluable for HRD status (n=47), most were HRD+ (94%; n=44). Of HRRwt pts evaluable for HRD status (n=79), 57% were HRD+ (n=45). Responses by biomarker are shown. Responses in BRCAm pts were seen in all subgroups (zygosity, HRD, or g/s origin of mutation), including s BRCAm (ORR: n=3/4 on O; n=2/4 on O+C). Responses were also seen in patients with heterozygous BRCA alteration (n=3/5) by genomic result and in BRCAm/HRD− pts (n=3/3) across both arms. Pts with select HRR genes ( BARD1, RAD51C/D, ATM, CDK12) also achieved responses on O or O+C. Conclusions: Responses to O were seen in pts with both g BRCAm and s BRCAm. Beyond BRCAm, the efficacy of O was observed in pts with alterations in select HRR genes, such as BARD1 or RAD51C/D; further clinical investigation is required. Small sample size and HRD analysis performed on archival tumor samples should be considered limitations. Clinical trial information: NCT03330847 . [Table: see text]

KEYNOTE-826: Final overall survival results from a randomized, double-blind, phase 3 study of pembrolizumab + chemotherapy vs placebo + chemotherapy for first-line treatment of persistent, recurrent, or metastatic cervical cancer.

5500 Background: The first interim analysis of KEYNOTE-826 (NCT03635567) showed that first-line pembrolizumab (pembro) + chemotherapy (chemo) provided statistically significant and clinically meaningful improvements in OS and PFS vs placebo (pbo) + chemo in patients (pts) with recurrent, persistent, or metastatic cervical cancer across all prespecified populations (PD-L1 combined positive score [CPS] ≥1, all-comer, and CPS ≥10). Here, we present the protocol-specified final OS analysis results of KEYNOTE-826. Methods: Eligible adults with persistent, recurrent, or metastatic cervical cancer not previously treated with systemic chemo (prior radiosensitizing chemo allowed) and not amenable to curative treatment (surgery or radiation) were randomized 1:1 to pembro 200 mg or placebo Q3W for up to 35 cycles + chemo (paclitaxel 175 mg/m2 + cisplatin 50 mg/m2 or carboplatin AUC 5), ± bev 15 mg/kg. Pts were stratified by metastatic status at diagnosis (yes/no), planned bev use (yes/no), and PD-L1 CPS (&lt;1, 1 to &lt;10, or ≥10). Dual primary end points were OS and PFS per RECIST v1.1 assessed by investigator review, each tested sequentially in the PD-L1 CPS ≥1, all-comer, and CPS ≥10 populations. Results: From Nov 2018 to Jan 2020, 617 patients were randomized (pembro + chemo, n = 308 [63.6% with bev]; pbo + chemo, n = 309 [62.5% with bev]); 548 (88.8%) pts had PD-L1 CPS ≥1 and 317 (51.4%) had CPS ≥10. At the Oct 3, 2022 data cutoff, median follow-up was 39.1 mo. Pembro + chemo significantly improved OS and PFS in the CPS ≥1, all-comer, and CPS ≥10 populations (Table). The pembro + chemo benefit was seen regardless of bev use. Grade ≥3 AE incidence was 82.4% in the pembro + chemo arm and 75.4% in the placebo + chemo arm. The most common grade ≥3 AEs were anemia (30.3% vs 27.8%), neutropenia (12.4% vs 9.7%), and hypertension (10.4% vs 11.7%). Conclusions: The addition of pembro to chemo ± bev significantly reduced the risk of death by 40% in the PD-L1 CPS ≥1 population, by 37% in the all-comer population, and by 42% in the CPS ≥10 population, and had a manageable safety profile. These data are consistent with the earlier results and provide further support for pembro + chemo ± bev as a new standard of care for first-line treatment of persistent, recurrent, or metastatic cervical cancer. Clinical trial information: NCT03635567 . [Table: see text]

A randomized, open-label, phase II study of high-dose interleukin 2 vs high-dose interleukin 2 plus entinostat in renal cell carcinoma.

e16540 Background: Immunosuppressive factors such as regulatory T cells (Tregs) limit the efficacy of immunotherapies such as high dose interleukin 2 (HD-IL2). We previously reported that the histone deacetylase (HDAC) inhibitor entinostat has antitumor effects in combination with HD-IL2 by decreasing Tregs function in a preclinical model of kidney cancer. Based on these preliminary data, we hypothesized that HDAC inhibition may enhance or resensitize patients (pts) with clear cell renal cell carcinoma (ccRCC) to HD-IL2. Our group has previously conducted a Phase II, single arm, clinical trial of entinostat in combination with HD-IL2 in ccRCC, which showed an objective response rate (ORR) of 37% and a median progression-free survival (mPFS) of 13.6 months as compared to historical data with single agent HD-IL2 of 20-25% and 4.2 months, respectively. Thus, we designed a multi-center, randomized, open label Phase II study with entinostat in combination with HD-IL2 in ccRCC patients. Methods: The primary objective was to estimate and compare PFS in pts randomized to receive either HD-IL2 plus entinostat (Arm 1) or HD-IL2 (Arm 2) and stratified by no prior therapies vs prior therapies. Due to unforeseen circumstances, enrollment halted after the first 10 patients. The treatment schedule was HD-IL2 600,000 units/kg administered IV every 8 hrs on Days 1-5 and Days 15-19 (maximum 28 doses) +/- entinostat 5 mg orally given every 2 weeks starting on Day-14, continuously. The study was originally designed to detect a 100% improvement of median PFS to 8.4 months in ARM 1. A one-sided stratified log-rank test with an overall sample size of 46 subjects (23 per group) achieves 80% power at a 0.10 significance level to detect a hazard ratio of 0.5 (median PFS of 4.2 months vs 8.4 months). Results: 10 pts (6 pts in Arm 1 and 4 pts in Arm 2) were enrolled. Among the 10 pts, only one had prior therapy (Arm 1). The most common treatment-related toxicities ( &gt; 50%, any grade) were diarrhea, hypotension, nausea, hypomagnesemia, hypophosphatemia, pruritus, hypocalcemia and thrombocytopenia, hypophosphatemia, proteinuria, diarrhea, fatigue, and neutropenia. The most common ≥ grade 3 toxicities were hypotension (80%), hypophosphatemia (70%), and thrombocytopenia (60%). Two pts (33%: CI 4.3%-77.7%) achieved a partial response in Arm 1 and no pts in Arm 2. The median PFS was 12.4 months (CI 2.3-NE) in Arm 1 (13.3 months in pts with no prior therapies) and 2.8 months (CI 1.2-3.3) in Arm 2 (Logrank p-value 0.0167). We have collected blood samples to conduct several correlative studies including flow cytometry and gene expression analysis on peripheral blood mononuclear cells. Conclusions: The preliminary results from this study confirm that the combination of entinostat and HD-IL2 may be more active than HD-IL2 alone in pts with ccRCC. Clinical trial information: NCT03501381 .

A phase II trial with safety lead-in to evaluate the addition of sotigalimab, a CD40 agonistic monoclonal antibody, to standard-of-care doxorubicin for the treatment of advanced sarcoma.

11565 Background: Immune checkpoint inhibitors have limited efficacy in soft tissue sarcoma (STS) due to insufficient T-cell activation and infiltration by immunosuppressive macrophages. Sotigalimab (S), a high-affinity humanized monoclonal antibody for CD40, promotes antigen presentation, stimulates T-cell responses, and reprograms immunosuppressive macrophages. Preclinical studies with CD40 agonists revealed efficacy in immune “cold” tumor types and synergy with chemotherapy. Standard first-line doxorubicin (D) provides objective response rate (ORR) &lt; 15% and median progression free survival (mPFS) of 4-6 mos in advanced STS. We therefore conducted this first-in-human study of D+S in STS. Methods: An open-label, single-arm, multi-center, phase 2 study evaluated D+S in advanced STS. Pts had ECOG PS ≤ 1 and any number of prior lines (but were anthracycline-naïve). The study initially enrolled all STS subtypes (except KS and GIST) but was amended in 12/2020 to limit enrollment to dedifferentiated liposarcoma (DDLPS), leiomyosarcoma (LMS), and undifferentiated pleomorphic sarcoma (UPS). Pts received D 75 mg/m2 IV D1 + S 0.3 mg/kg IV D1 for eight 21-day cycles, followed by S monotherapy. A safety lead-in was performed (first 6 patients). Primary endpoint was ORR. Secondary endpoints included PFS and safety. A Simon two-stage design was used. If ≥ 7/32 responded overall, the treatment would be considered promising (85% power, α = 0.05). A subset of patients underwent paired tumor biopsies. Results: 32 pts have enrolled (median age 62; 10 LMS, 10 UPS, 9 DDLPS, 3 other). 4 pts remain on treatment with median follow-up of 2.8 mos (1 UPS pt has not reached first imaging). D (75 mg/m2) + S (0.3 mg/kg) was safe and tolerable without dose limiting toxicity. Overall ORR was 16% (5/31). Objective responses occurred in UPS (2), LMS (1), other LPS (1), and epithelioid hemangioendothelioma (1). Overall mPFS was 7.5 mos (95% CI 5.6-14.9 mos) and PFS rate at 6 and 12-mos was 55% and 31%, respectively. mPFS by STS subtype was 11.9 mos (95% CI: 10.3 – NE) for DDLPS, 7.5 mos (95% CI: 1.4—NE) for UPS and 5.6 mos (95% CI: 1.3 – NE) for LMS. Overall, 17/31 (55%) pts experienced grade 3 or 4 adverse events (AEs): most commonly, neutropenia (32%), febrile neutropenia (19%), and anemia (16%). 16% of pts experienced cytokine release (all low-grade). Correlative analysis of biopsies with high-definition spatial proteomics is ongoing. Conclusions: D (75 mg/m2) + S (0.3 mg/kg) every 21 days is safe and tolerable in STS. Final analysis of the primary endpoint awaits further follow-up on recently enrolled patients. Subtype-specific analysis suggests improvement in median PFS for DDLPS over historical controls: 11.9 mos vs 4 mos (Stacchiotti S. Ann Oncol 2020; Livingston M. Sci Rep 2017). An expansion of the DDLPS cohort is planned. Clinical trial information: NCT03719430 .

IMRT followed by pembrolizumab in the adjuvant setting in anaplastic cancer of the thyroid (IMPAACT): Phase II trial adjuvant pembrolizumab after IMRT in ATC.

TPS6117 Background: Anaplastic thyroid carcinoma (ATC) has historically been an almost uniformly rapidly fatal disease. In patients with loco-regional disease with no distant metastasis (stage IVB), and without a targetable mutation, a combination of external beam radiation delivered via intensity modulated techniques (IMRT) +/- concurrent cytotoxic chemotherapy is the current standard of care. However, the relapse rate is very high within the first year of diagnosis. Our data show that 90% of ATCs express PD-L1, with 43% having expression levels greater than 50%. A clinical trial with an anti-PD1 drug in ATC patients with active disease showed that patients with ATC had a response rate of 19%. Additionally, as tumor PD-L1 expression has been linked to radioresistance and there is a need to target micrometastatic disease, using adjuvant checkpoint inhibitor is a rational strategy in these patients. Methods: This is an open label, single center, phase 2 trial of adjuvant pembrolizumab after external beam radiation to the primary tumor in patients with stage IVB ATC. The primary cohorts will include those with gross, locoregional disease who have completed treatment with IMRT +/- concurrent radiosensitizing chemotherapy. Patients will be treated with adjuvant pembrolizumab (400mg IV Q6 weeks for up to 9 cycles), 2-6 weeks after completion of radiation. Patients will be enrolled based on dose of radiation in cohort 1 (high dose group, &gt; 51 Gy), cohort 2 (palliative dose group, &lt; 50 Gy). Cohort 3, consisting of those who underwent surgery followed by IMRT plus concurrent chemotherapy will be an exploratory cohort. Restaging scans will be performed every 12 weeks after enrollment. MRI brain will be repeated every 6 months in the absence of evidence of progression. The primary endpoint is median PFS (from the start of adjuvant pembrolizumab) in cohorts 1 and 2. Secondary endpoint is median overall survival in cohorts 1 and 2. Cohort 3 (5 patients) will have an exploratory endpoint, to estimate the median disease-free survival (DFS). Statistics: Survival analyses will be performed using the Kaplan-Meier method. Based on historical data, the median PFS for unresected patients is 6.8 months. For an expected improvement of median PFS by 3.7 months, with a combined total of 30 evaluable patients in cohorts 1 and 2, we anticipate having 80.0% power using 1-sided 10% alpha for a one-sample log rank test. The trial began enrollment in July 2022. This trial is sponsored by philanthropic funds and Merck. ClinicalTrials.gov ID NCT05059470. Clinical trial information: NCT05059470 .

Dostarlimab for primary advanced or recurrent (A/R) endometrial cancer (EC): Outcomes by blinded independent central review (BICR) of the RUBY trial (ENGOT-EN6-NSGO/GOG-3031/RUBY).

5503 Background: RUBY (NCT03981796) evaluated the efficacy and safety of the anti–programmed death 1 (PD-1) dostarlimab + standard of care (SOC) carboplatin paclitaxel (CP) versus CP alone in A/R EC. The primary endpoint of PFS by investigator assessment (INV) per RECIST v1.1 was significantly longer with dostarlimab+CP than placebo (PBO)+CP in the mismatch repair deficient/microsatellite instability-high (dMMR/MSI-H; HR 0.28; 95% CI 0.162–0.495) and overall populations (HR 0.64, 95% CI 0.507–0.800). Here we present secondary efficacy endpoints by BICR. Methods: RUBY is a phase 3, global, randomized, double-blind, multicenter, PBO-controlled study. Patients (pts) with primary advanced stage III or IV or first recurrent EC were randomized 1:1 to receive dostarlimab 500 mg, or PBO, plus carboplatin AUC 5 and paclitaxel 175 mg/m2 Q3W (6 cycles), followed by dostarlimab 1000 mg, or PBO, monotherapy Q6W for up to 3 y. Secondary endpoints by BICR assessment per RECIST v1.1 were PFS, ORR, DOR, and DCR in the overall and dMMR/MSI-H populations. Results: 494 pts were randomized (245:dostarlimab+CP; 249:PBO+CP); 47.8% had recurrent disease, 18.6% and 33.6% had primary stage III and IV disease, respectively. PFS by BICR was longer with dostarlimab+CP than PBO+CP in the dMMR/MSI-H (HR 0.29; 95% CI 0.158–0.543) and overall populations (HR 0.66; 95% CI 0.517–0.853; Table). Consistent benefits were seen with dostarlimab+CP for ORR, DCR, and DOR by BICR in the dMMR/MSI-H and overall populations (Table). Safety was previously reported. Conclusions: Dostarlimab+CP showed clinically meaningful improvement in BICR-assessed PFS in the dMMR/MSI-H and overall populations compared with CP alone. The HRs for PFS per BICR and per INV were consistent, which supports the reliability of PFS by INV in EC trials. Benefits were seen in all BICR-assessed endpoints, which were consistent with INV. Dostarlimab+CP represents a new SOC for pts with primary A/R EC. Clinical trial information: NCT03981796 . [Table: see text]

Subgroup analyses of safety and efficacy by number and types of prior lines of treatment in FRESCO-2, a global phase III study of fruquintinib in patients with refractory metastatic colorectal cancer.

3604 Background: Effective treatment options are limited for patients (pts) with refractory metastatic colorectal cancer (mCRC). Fruquintinib (F), a highly selective, potent, oral tyrosine kinase inhibitor of VEGFR-1, -2, and -3, was evaluated in the global phase III FRESCO-2 study (NCT04322539) and demonstrated a clinically meaningful and statistically significant improvement in OS and PFS with a favorable safety profile. Here we report subgroup analyses of efficacy and safety by prior lines (PL) and types of anti-cancer treatment (Tx) for metastatic disease (MD). Methods: FRESCO-2 was conducted in the US, Europe, Japan &amp; Australia, comparing F + best supportive care (BSC) with Placebo (P) + BSC. Pts were given 5 mg PO, QD, 3 wks on, 1 wk off, in a 28-day cycle. Eligible pts received prior chemotherapy, anti-VEGF, and if RAS wild type, anti-EGFR therapies; if BRAFV600E mutant or MSI-H, and appropriate targeted regimen; and had progressed on, or were intolerant to, trifluridine/tipiracil (TAS-102) and/or regorafenib (R). Subgroup (sbgrps) analyses for efficacy and safety were performed according to number of prior lines of tx (LOT) and by types of therapy. Results: A total of 691 pts were randomized; F:461 vs P:230. The median number of prior lines of anti-cancer tx for metastatic disease F vs P was 4 (2, 16) vs 4 (2, 12). F improved OS and PFS compared to P for all sbgrps and prior tx for MD, consistent with those of the ITT population (pop). (Table: OS reported by sbgrps and prior tx for MD). Occurrence of adverse events (AEs) and serious adverse events were generally balanced between F vs P and consistent across all subgroups. The most common ≥ G3 AEs in ≥5% of pts on F within majority of sbgrps were hypertension, asthenia and palmar plantar erythrodysesthesia and were consistent with the overall safety population. Additional analyses based on duration of prior anti-VEGF and last therapy prior to F will be presented at the conference. Conclusions: F demonstrated clinically meaningful improvement in OS, PFS with an acceptable safety profile across all sbgrps. These results were consistent with the effect observed in the overall population; irrespective of previous tx with anti-VEGF, anti-EGFR, TAS-102 and R further supporting F as a potential new tx option for pts with refractory mCRC. Clinical trial information: NCT04322539 . [Table: see text]

FLORA-5/GOG3035: Chemo-immunotherapy (paclitaxel-carboplatin-oregovomab [PCO] vs chemotherapy (paclitaxel-carboplatin-placebo [PCP]) as front-line treatment in patients with advanced epithelial ovarian cancer (EOC)—Phase III, double blind, placebo controlled, global, multinational study.

TPS5625 Background: Oregovomab, a murine IgGκ1 monoclonal antibody with high affinity binding to tumor associated antigen CA125, renders the target antigen CA125 more immunogenic or “neoantigen-like”. The proposed mechanism action is enhanced antigen processing and presentation to specific T cells. This phenomenon is hypothesized to bypass tumor-associated immune suppression when oregovomab is combined with chemotherapy. In a randomized phase II study, oregovomab, in combination with paclitaxel and carboplatin, (PC) induced tumor immunity and demonstrated significant improvement in median PFS (41.8 months(m) PCO vs 12.2 m PC, HR 0.46, p = 0.0027) and median OS (N.E. PCO vs 43.2 m PCP, HR 0.35, p = 0.043) in patients with previously untreated EOC. Patients receiving adjuvant chemotherapy were included. Oregovomab combined with PC had a favorable toxicity profile. FLORA-5/GOG3035, the definitive confirmatory global registration trial, is currently recruiting patients in the front-line setting. Methods: In this phase 3, multicenter, double-blind, placebo-controlled trial, optimally debulked patients with FIGO III/IV EOC and serum CA125 ≥ 50 U/ml receiving adjuvant (Cohort 1) or patients receiving neoadjuvant chemotherapy post-interval cytoreductive surgery (Cohort 2) will be randomized to PC + oregovomab or placebo (PCO vs. PCP). Patients with germline BRCA1/2 mutations are excluded. Chemotherapy will be administered every 3 weeks in both cohorts. Oregovomab/placebo is administered simultaneously at cycles 1, 3, and 5 of chemotherapy with an additional dose at 12 weeks following cycle 5 in Cohort 1. Neoadjuvant patients will be administered oregovomab/placebo after debulking surgery at cycles 4 and 6 with two additional doses at 6- and 18-weeks following cycle 6 in Cohort 2. No other front-line maintenance therapy is permitted. The primary objective is PFS determined by RECIST 1.1. Cohort 1 will recruit 372 patients with a 90% power to detect a difference with an alpha of 0.025 and a hazard ratio of 0.65 when 252 PFS events have been observed. Cohort 2 will be analyzed separately recruiting 232 patients with a 90% power to detect a difference with an alpha of 0.025 and a hazard ratio of 0.60 when 165 PFS events have been observed. An interim futility analysis will be performed. Secondary objectives include OS, frequency and severity of AEs, and QoL. Exploratory objectives include iRECIST, TFST, TSST, PFS2, and evaluation of correlative biomarkers. The study is actively enrolling in the US, Canada, Belgium, Italy, Spain, Czech Republic, Hungary, Poland Korea, Taiwan, Mexico Argentina, India and Chile. 518 of the planned 602 patients were enrolled at the time of submission. Clinical trial information: NCT04498117 .

Deutenzalutamide, an oral deuterated androgen receptor inhibitor, vs placebo for patients with mCRPC who have experienced treatment failure with abiraterone and docetaxel: Results of the HC-1119-04 phase 3 trial.

5065 Background: Deutenzalutamide (HC-1119) is a novel deuterated derivative of enzalutamide with a different metabolic profile while maintaining biologic activity at a lower dose. Abiraterone and docetaxel are widely used in mCRPC, however, resistance mechanisms eventually occur. Methods: The HC-1119-04 (NCT03851640), a multicenter, randomized, double-blind phase 3 trial in China enrolled patients with mCRPC who have failed abiraterone, or failed or were not eligible for docetaxel. Patients were randomized 2:1 to deutenzalutamide (80 mg orally daily) or placebo. Stratification factors included lesion site (visceral/non-visceral), prior docetaxel treatment (yes/no). The primary endpoint was investigator-assessed radiographic PFS. Secondary endpoints included: OS, independent radiologic review committee (IRC)-assessed rPFS, ORR, and PSA response. The hazard ratio (HR) and its 95% confidence interval (CI) between the two groups were calculated using a stratified Cox proportional hazards model. Results: The HC-1119-04 study enrolled 417 subjects between April 2019 – Nov 2021, with 276 randomized to deutenzalutamide and 141 to placebo. Demographics and disease characteristics were well-balanced across treatment arms. All subjects were previously treated with abiraterone. Most of the subjects received docetaxel (68.8% vs. 68.1%); visceral lesions accounted for 27.9% in the deutenzalutamide and 27.7% in the placebo group. The study met its primary endpoint with a 42% reduction in the risk of progression or death in the deutenzalutamide arm (HR = 0.58 [95% CI: 0.439, 0.770]; P= 0.001. The median rPFS (95% CI) was 5.55 (4.830, 7.360) months for deutenzalutamide vs 3.71 (2.860, 5.490) months for placebo. Results in the pre-specified subgroups, including visceral metastases, and prior docetaxel were consistent with the overall outcome. The median OS (95% CI) was 14.98 (9.560, -) months and 11.24 (9.890, 15.510) months in the deutenzalutamide and placebo group, respectively, with an HR (95% CI) of 0.88 (0.577, 1.331). Common treatment-related adverse events (TEAE) ( &gt; 10%) with deutenzalutamide vs placebo included: weight decreased (23.4% vs 18.6%), platelet count decreased (12.8% vs 10.7%), lymphocyte count decreased (10.2% vs 7.9%), and hypercholesterolemia (10.9% vs 4.3%), mostly grade 1/2. The overall incidence of ≥ Grade 3 study drug related TEAEs in the deutenzalutamide group was not significantly different from placebo, except anemia (6.6% vs 2.9%) and hypertension (2.2% vs 0.7%). Conclusions: Deutenzalutamide demonstrated a statistically significant improvement of PFS vs placebo in a randomized phase 3 study in patients with mCRPC who have failed abiraterone, and who failed or were intolerant to docetaxel. Deutenzalutamide was well tolerated and has the potential as additional treatment option. Clinical trial information: NCT03851640 .