Multiple Myeloma Oligosecretory Relapse, a Non-Negligible Phenomenon. Frequency, Clinical Characteristics and Outcomes in a Single Center

Introduction: Multiple myeloma (MM) is malignancy of plasma cells, which secrete monoclonal antibodies that are detectable in the patient's (pt) serum and/or urine. Infrequently, MM may present as an oligosecretory disease, where monoclonal protein (M-protein) and involved free light chain (iFLC) are either not detected (=non-secretory) or are both below the threshold for measurable disease (=oligosecretory) as defined by International Myeloma Working Group (IMWG). The incidence of non-secretory MM at presentation has been estimated at 1-2% [Chawla, Eur J Haematol 2015], yet data regarding the frequency and clinical phenotype of oligosecretory relapse is lacking. These pts are typically excluded from most clinical trials. Methods: Pt's MM was classified as oligo-secretory, in the absence of measurable disease according to the IMWG criteria (M-protein≥1 gr/dL, or U-PEP > 200 mg/24 hrs or involved free light chain≥ 100 mg/L). Relapse was defined according to IMWG criteria, based on changes in monoclonal protein in the serum or urine, bone or extramedullary lesions on imaging, bone-marrow plasmacytosis, serum hemoglobin, creatinine and calcium levels. Pts treated at our center for MM, who had secretory (i.e., measurable disease) MM at diagnosis, and relapsed (secretory or non-secretory relapse) between January 2016 to July 2020, were included. MM baseline pt and disease characteristics, disease characteristics at relapse, treatment regimens and outcomes were documented. The first oligosecretory relapse (OSR) that any given pt experienced was defined as the index OSR for that pt. For each pt with an OSR, we identified the first 4 pts with a secretory relapse (SR) in the dataset, who matched the pt by the relapse index number and calendar year of relapse, to form a SR comparator group. We compared pt and disease characteristics, therapy patterns and outcomes between the OSR and SR groups. Results: One hundred and seventy-seven pts with relapse were identified; 8 (4.5%) had oligo-secretory disease at MM diagnosis and were excluded; 152 of the 169 pts who were secretory at presentation (89.9%) had secretory MM at all relapses; 17 (10.0%) had an OSR (4 non-secretory and 13 oligosecretory), the SR comparator group included 67 pts. Pts with OSR had similar characteristics compared to SR pts at MM presentation, in terms of demographics, FISH cytogenetics, ISS, levels of M-protein and involved FLC, frequency of extramedullary disease, target organ involvement; Treatment pattern and response to upfront therapy were comparable (Fig1 A). Oligosecretory disease was more frequent at relapse compared to newly diagnosed MM (10% vs 4.5%), proportion of OSR among pts with previously secretory MM increased in later relapses. The proportion of OSR from total 3 rd or 4 th relapses, was high as 20% and 17.6%, respectively (Fig 1B). OSR pts had a higher rate of new plasmacytoma (53% vs 9%, p<0.001) as the criteria for relapse, and a trended towards increase in LDH, and higher rate of extramedullary disease (17% vs 4.4%, p=0.09) whereas increase in monoclonal protein was more frequent in the SR group as a criterion for relapse. Overall response rate to therapy of the index relapse was similar between groups among evaluable pts (58% vs 64%), however, in 5/17 (29%) of the OSR, response was non evaluable from available documentation. Median follow up was 10.2 months [Q1 4.1- Q3 16.7]. Twelve-months progression free survival was 82.4% vs 73.8% (p=0.76), and 12-months overall survival was 60.2% vs 64.75% (p=0.60) in RS and OSR, respectively. Conclusions: Oligosecretory disease was more frequent in relapsed MM, compared to its rate at MM presentation, reaching 10% of the pts with relapsed MM and increasing in more advanced relapses. Pts with OSR and those with SR had similar clinical characteristics of their MM at presentation as well as comparable outcomes, but pts with OSR had higher rates of new skeletal and extramedullary lesions. As identification of the OSR may be challenging in the absence of serum and urine biomarkers, awareness and clinical alertness are warranted to avoid end organ damage. We suggest inclusion of OSR pts in clinical trials should be considered, despite some challenges in following their therapy response, as they comprise a non-negligible proportion of pts, in particular in the advanced relapse setting. Figure 1 Figure 1. Disclosures Avivi: Kite, a Gilead Company: Speakers Bureau; Novartis: Speakers Bureau. Cohen: Neopharm / promedico: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karophram: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees.

347 KEYNOTE-365 cohort C: pembrolizumab + enzalutamide in patients with abiraterone acetate–pretreated metastatic castration-resistant prostate cancer (mCRPC)—data after minimum of 22 months of follow-up

BackgroundPrevious data from cohort C of phase 1b/2 study KEYNOTE-365 (NCT02861573) showed that PD-1 inhibitor pembrolizumab + enzalutamide was well tolerated and showed antitumor activity in patients with abiraterone acetate–pretreated mCRPC. Updated data after a minimum of 22 months of follow-up are presented.MethodsPatients in the prechemotherapy mCRPC state who were intolerant to ≥4 weeks‘ treatment with abiraterone acetate or for whom this treatment failed, had progressive disease ≤6 months before screening, and had ECOG PS 0-2 were enrolled. Patients received pembrolizumab 200 mg IV Q3W + enzalutamide 160 mg orally QD. Primary end points were PSA response rate (decrease ≥50% from baseline), confirmed ORR per RECIST v1.1 by blinded independent central review (BICR), and safety. Secondary end points were time to PSA progression; DCR (CR or PR of any duration + SD or non-CR/non-PD ≥6 months) and DOR per RECIST v1.1 by BICR; rPFS per PCWG3-modified RECIST v1.1 by BICR; and OS.ResultsOf 103 enrolled patients, 102 were treated. Median age was 70.0 years (range, 43–87); 29.4% of patients were PD-L1+; 37.3% had RECIST-measurable disease. Median follow-up (time from enrollment to data cutoff) was 40.2 months (range, 22.3–49.9). Confirmed PSA response rate in patients with baseline PSA measurement (N = 101) was 23.8%. Median time to PSA progression was 4.0 months (95% CI, 3.5–4.4). In 38 patients with measurable disease, ORR was 10.5% (2 CR; 2 PR). Median DOR was 11.8 months (4.3 to 38.3+ months); 1 patient had a response ≥12 months. DCR for the total population was 33.3%. Median (95% CI) rPFS was 6.0 months (4.1–6.3); rPFS at 12 months was 30.1%. Median (95% CI) OS was 20.1 months (16.9–25.2); OS at 12 months was 76.2%. Treatment-related AEs (TRAEs) occurred in 92.2% of patients; most common (≥20%) were fatigue (39.2%), nausea (21.6%), and rash (21.6%). Grade 3–5 TRAEs occurred in 42.2%, most commonly rash (7.8%) and fatigue (5.9%). Four patients died of AEs: 1 death was treatment-related (unknown cause).ConclusionsAfter a minimum follow-up of 22 months, pembrolizumab + enzalutamide continued to show antitumor activity in abiraterone acetate–pretreated mCRPC. The safety profile of pembrolizumab + enzalutamide was generally consistent with individual profiles of each agent. There was a higher incidence than typically reported for the individual agents of all-grade (21.6%) and grade 3 (7.8%) rash, which resolved with standard-of-care treatment. The combination is being further evaluated in the phase 3 study KEYNOTE-641.AcknowledgementsMedical writing and/or editorial assistance was provided by Matthew Grzywacz, PhD, of ApotheCom (Yardley, PA, USA). This assistance was funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Funding for this research was provided by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.Trial RegistrationClinicalTrialsgov, identifier: NCT02861573Ethics ApprovalThe study and the protocol were approved by the Institutional Review Board or ethics committee at each site.

Combined CTLA-4 and PD-L1 blockade in patients with chemotherapy-naïve metastatic castration-resistant prostate cancer is associated with increased myeloid and neutrophil immune subsets in the bone microenvironment

BackgroundImmune checkpoint therapy (ICT) has low response rates in patients with metastatic castration-resistant prostate cancer (mCRPC), in part due to few T cells in the tumor microenvironment (TME). Anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) promotes intratumoral T cell infiltration but induces upregulation of PD-1 and programmed death ligand-1 (PD-L1) within the prostate TME. Combined anti-CTLA-4 plus anti-PD-1 can partly overcome this adaptive resistance and was recently shown to augment responses in patients with mCRPC with measurable disease. Although bone is the most common site of metastasis in prostate cancer, patients with bone-predominant disease are frequently excluded from trials because they lack measurable disease, which limits assessment of disease progression and tissue sampling. We therefore designed this study to investigate combined ICT in mCRPC to bone.HypothesisCombined anti-CTLA-4 (tremelimumab) plus anti-PD-L1 (durvalumab) is safe and well tolerated in patients with chemotherapy-naïve mCRPC to bone.Patients and methodsIn this single-arm pilot study, men with chemotherapy-naïve mCRPC to bone received tremelimumab (75 mg intravenous) plus durvalumab (1500 mg intravenous) every 4 weeks (up to four doses), followed by durvalumab (1500 mg intravenous) maintenance every 4 weeks (up to nine doses). The primary endpoint was incidence of adverse events. Secondary endpoints included serum prostate-specific antigen (PSA), progression-free survival (PFS), radiographic PFS (rPFS), and maximal PSA decline.ResultsTwenty-six patients were treated between August 8, 2017 and March 28, 2019. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 11 patients (42%), with no grade 4 or 5 events. TRAEs leading to discontinuation occurred in three patients (12%). PSA decline ≥50% occurred in three patients (12%). Six patients (24%) achieved stable disease for >6 months. At a median follow-up of 43.6 months, median rPFS was 3.7 months (95% CI: 1.9 to 5.7), and median overall survival was 28.1 months (95% CI: 14.5 to 37.3). Post-treatment evaluation of the bone microenvironment revealed transcriptional upregulation in myeloid and neutrophil immune subset signatures and increased expression of inhibitory immune checkpoints.ConclusionsTremelimumab plus durvalumab was safe and well tolerated in patients with chemotherapy-naïve mCRPC to bone, with potential activity in a small number of patients as measured by rPFS. Combination of CTLA-4 and PD-L1 blockade with therapies targeting the myeloid compartment or other inhibitory immune receptors may be necessary to overcome mechanisms of resistance within prostate bone microenvironment.Trial registration numberNCT03204812.

Outcomes for hospitalized cancer patients with COVID-19 during the height of pandemic in New York City.

10572 Background: Several reports have suggested that cancer patients are at increased risk for contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and suffering worse coronavirus disease 2019 (COVID-19) outcomes. However, little is known about the impact of cancer status on presentation and outcome. Here, we report on the association between cancer status and survival in hospitalized patients who tested positive for SARS-CoV-2 during the height of pandemic in New York City. Methods: Of the 6,724 patients who were hospitalized at NYU Langone Health (3/16/20 - 7/31/20) and tested positive for SARS-CoV-2, 580 had either active cancer (n = 221) or a history of cancer (n = 359). Patients were classified as having active malignancy if they either received treatment within six months of their COVID-19 diagnosis or they had measurable disease documented at the time of their hospitalization. Patients were categorized as having a history of cancer if there was no evidence of measurable disease or there were no treatments administered within six months of their COVID-19 diagnosis. We compared the baseline clinicodemographic characteristics and hospital courses of the two groups, and the relationship between cancer status and the rate of admission to the intensive care unit (ICU), use of invasive mechanical ventilation (IMV), and all-cause mortality. Results: There was no differences between the two groups in their baseline laboratory results associated with COVID-19 infection, incidence of venous thromboembolism, or incidence of severe COVID-19. Active cancer status was not associated with the rate of ICU admission ( P = 0.307) or use of IMV ( P = 0.236), but was significantly associated with worse all-cause mortality in both univariate and multivariate analysis with ORs of 1.48 (95% CI: 1.04-2.09; P = 0.028) and 1.71 (95% CI: 1.12-2.63; P = 0.014), respectively. Conclusions: Active cancer patients had worse survival outcomes compared to patients with a history of cancer despite similar COVID-19 disease characteristics in the two groups. Our data suggest that cancer care should continue with minimal interruptions during the pandemic to bring about response and remission as soon as possible. Additionally, these findings support the growing body of evidence that malignancy portends worse COVID-19 prognosis, and demonstrate that the risk may even apply to those without active disease.

Long-term results of the GEINO 1401 TRIAL: Randomizing patients to stop or to continue temozolomide until 12 cycles.

2013 Background: We previously presented our results of the GEINO 1401 trial that randomized patients diagnosed with glioblastoma and treated with chemoradiotherapy and adjuvant temozolomide (TMZ) followed by six cycles of TMZ, to receive an extended use of TMZ up to 12 cycles or to control. We found no differences in 6-months neither progression free survival (PFS) nor overall survival (OS). In this report we actualize our results and analyse long-term survivor patients (LTSP). Methods: The trial NCT02209948 randomized (ratio 1:1) 159 patients diagnosed with glioblastoma who had been treated with standard therapy to stop treatment or to continue up to 12 cycles of TMZ. Patients were stratified based on their O6-methylguanine-DNA-methyltransferasa (MGMT) methylation status and presence or absence of measurable disease at inclusion. We update here OS outcomes and analyse the data of LTSP defined as an OS over 30 months from diagnosis. Results: At a median follow-up of 20 months, 82.4% of the patients had died and 89.9% had progressed. The median OS from randomization was 22.0 months for the control arm and 18.2 for the experimental arm: HR 0.957 (95%CI 0.806-1.136, p = 0.615). At 2 years from randomization there were a 61% of survivors in the TMZ group and 62% in the control group. There were a 49.7% of LTSP showing no differences between TMZ and control group. We found a higher prevalence of methylated MGMT in LTSP, but no differences were shown in patients with or without measurable disease at inclusion, status of IDH and the use of bevacizumab after progression. Conclusions: Adding 6 cycles of TMZ after the first 6 adjuvant cycles confers no additional benefit in OS. Nearly 50% of the patients included in GEINO 1401 who had been previously treated with TMZ 6 cycles without progressing were LTSP. Clinical trial information: NCT02209948.

Decreased enrollment of patients with advanced lobular breast cancer compared to ductal breast cancer in interventional clinical trials.

1092 Background: Response Evaluation Criteria in Solid Tumors (RECIST) criteria are often used to measure tumor response in cancer trials, especially in the stage IV setting. However, RECIST requires measurable disease, which is less common in invasive lobular breast carcinoma (ILC) of the breast, a diffusely growing tumor type, compared to invasive ductal carcinoma (IDC). We examined the prevalence of RECIST in breast cancer clinical trials, and whether there are differential trial enrollment rates by histology and stage. Methods: We analyzed the clinicaltrials.gov database to evaluate the proportion of interventional, stage IV clinical trials that require measurable disease as inclusion criteria or outcome measures. We then performed an institutional cohort study comparing the proportion of patients in the University of California, San Francisco (UCSF) OnCore clinical trials management system (CTMS) to the UCSF Cancer Registry between 2000-2018, stratified by histology and stage. We hypothesized that the proportion of patients with ILC in the CTMS would be significantly lower than in the cancer registry. Results: There were 146 actively-recruiting, interventional clinical trials for stage IV breast cancer that were identified in our search on clinicaltrials.gov. Overall, 108 (74%) required measurable disease for study participation. The UCSF Cancer Registry included 8,679 patients, while the UCSF OnCore CTMS included 1,511 patients (Table). In those with early stage disease, where RECIST is not typically used, there was no difference in the proportion of ILC patients enrolled in clinical trials versus in the cancer registry. However, among those with stage IV disease, there was a significantly lower proportion of patients with ILC in the CTMS than in the cancer registry (9.2% versus 17.9%, p = 0.005). In contrast, patients with stage IV IDC were overrepresented in the clinical trials database compared to the cancer registry. Conclusions: Patients with metastatic ILC were significantly less likely to be enrolled in clinical trials than those with metastatic IDC. This decreased enrollment may be due to the widespread use of RECIST, and further investigation is needed to ensure equity in access to clinical trials.[Table: see text]

Trials in progress: A phase 1, open-label, dose-escalation, pharmacokinetic, safety and tolerability study of the selective TAM kinase inhibitor PF-07265807 in patients with advanced or metastatic solid tumors.

TPS2671 Background: MERTK is a receptor tyrosine kinase from the tumor-associated macrophage kinase (TAMK) family that regulates key aspects of immune homeostasis and responses to infection. MERTK inhibition may lower the threshold for immune activation thereby promoting anti-tumor activity. Agents with some degree of MERTK inhibitory activity have been investigated in the clinic, but are limited by poor potency in patients (pts) and significant off-targets effects. PF-07265807 (ARRY-067) is a selective small-molecule inhibitor of the TAMKs MERTK and AXL. In preclinical models, PF-07265807 monotherapy shows antitumor activity that results in long-term cures and resistance to tumor re-challenge when combined with anti-programmed cell death protein 1/programmed death-ligand 1 (anti-PD-1/PD-L1) antibodies. This first-in-human study will evaluate the safety, tolerability, pharmacokinetics (PK) and preliminary anti-tumor activity of PF-07265807 in pts with selected advanced or metastatic solid tumors. This study will also explore the potential utility of PF-07265807 in combination with anti-PD-1/PD-L1 antibodies. Methods: This is a phase 1, open-label, multi-center, dose-escalation study (NCT04458259) to evaluate the safety, PK and tolerability of PF-07265807. Eligible participants will be adult pts with selected advanced or metastatic solid tumors who are intolerant or resistant to standard therapy. Other key eligibility criteria: measurable disease by RECIST 1.1 or non-measurable disease; Eastern Cooperative Oncology Group performance status 0–2; adequate bone marrow, renal and liver function; and resolved acute effects of any prior therapy. Successive cohorts of pts will receive escalating doses of PF-07265807 starting from 25 mg QD. Each cycle will be 21 days in duration (14 days on/7 days off). Study drug treatment will continue until disease progression or unacceptable toxicity, whichever occurs first. For dose escalation, a Bayesian logistic regression model will be used to model the relationship of dose-limiting toxicities (DLTs) to PF-07265807 dose. This model, along with escalation with overdose control, will guide the dose escalation of PF-07265807 after the completion of the DLT observation period (first two cycles of treatment, i.e. 42 days) of each cohort, until determination of the maximum tolerated dose/recommended phase 2 dose (MTD/RP2D). After the MTD/RP2D is identified, the safety and efficacy of combined PF-07265807 and anti-PD1/PD-L1 treatment will be explored. Primary endpoints: incidence of DLTs, treatment-emergent adverse events and laboratory abnormalities. Secondary endpoints: PK parameters of PF-07265807, objective response rate and duration of response. The study began enrolling pts in September 2020 and is still recruiting. Clinical trial information: NCT04458259.

Outcome of patients with recurrent/refractory osteosarcoma enrolled in three recent phase II trials: A report from the Children’s Oncology Group.

11530 Background: Based on seven prior Phase 2 Children’s Oncology Group (COG) trials, the 4-month event-free survival(EFS) and associated confidence interval for relapsed osteosarcoma with measurable disease according to RECIST was determined to be 12% (95% CI 6 - 19%). Three prospective clinical trials were conducted using this historical benchmark to detect activity defined by an EFS improvement of double the upper confidence interval. This report summarizes the outcome of these studies, describes whether the historical data remains an accurate baseline, and considers implications for future phase II trial study design in relapsed osteosarcoma measurable according to RECIST. Methods: We conducted an analysis of outcome for patients with recurrent/refractory osteosarcoma enrolled in three recent prospective COG phase II trials; AOST1321 (unresected cohort), AOST1322 and AOST1521 that used EFS at 4 months as the primary endpoint. Patients were eligible if they had osteosarcoma that had recurred or become refractory after standard therapy and had measurable disease according to RECIST. We assessed whether risk of an EFS event is modified by age, sex, race/ethnicity, number of prior chemotherapy regimens, or time to first relapse. Results: In each of the three phase II trials (unresected group of AOST1321, AOST1322, AOST1521), the drugs tested (denosumab, eribulin and glembatumumab) were concluded to be not effective due to a failure of the patient populations to meet the prespecified active 4-month progression free survival endpoint. The 4-month EFS for the 57 evaluable patients enrolled on these trials was 7% (95% CI 2 – 16%), similar to the 4-month EFS for 96 patients in the previous seven phase II trials of 12% (95% CI 6 - 19%). The combined EFS at 4 months for all 10 studies is 10% (95% CI 6 – 15%).There was no significant difference in EFS across trials based on age, sex, ethnicity, number of prior treatment regimens, consistent with prior analysis. Data from AOST1321 and AOST1521 were analyzed to determine the impact of time to first recurrence on EFS. Two different quantifications were applied: 1 year or less versus 2 or more years; and 2 years or less versus 3 years or more. Neither categorization was statistically significant. Conclusions: The EFS at 4 months in the three new phase II trials is similar to the previous seven phase II single arm trials. The combined analysis of 153 patients from 10 trials tightens the confidence interval, moving the upper 95% CI to 15%. Modification to future study designs could be considered based on this updated analysis. EFS at 4 months remains a robust primary endpoint. Single-arm trials using this endpoint based on the historical benchmark have accrued rapidly and allowed assessment of multiple novel agents in osteosarcoma. The negative trial results and continued poor outcome highlight the need for new approaches for relapsed osteosarcoma. Clinical trial information: NCT02097238, NCT02470091, NCT02487979.

Efficacy and safety of zenocutuzumab in advanced pancreas cancer and other solid tumors harboring NRG1 fusions.

3003 Background: NRG1 fusion proteins are oncogenic drivers in pancreas cancer and other solid tumors. They bind HER3, leading to HER2/HER3 heterodimerization and oncogenic transformation. The activity of zenocutuzumab (MCLA-128; zeno), a bispecific antibody targeting NRG1 fusion signaling in NRG1 fusion positive ( NRG1+) cancers, is being evaluated in the ongoing global multicenter phase 2 part of the eNRGy study and a global early access program (EAP). Methods: Enrolled patients (pts) have advanced NRG1+ pancreas cancer, non-small cell lung cancer (NSCLC), and other solid tumors previously treated with standard therapy, are ≥ 18 years-old, have ECOG ≤1, adequate organ function, and measurable disease (RECIST v1.1). Zeno dosing: 750 mg IV every 2 weeks until progression or unacceptable toxicity. Primary endpoint: investigator (INV)-assessed objective response rate (ORR). Secondary endpoints: ORR per central independent radiologist review, duration of response (DOR), and safety. Tumor imaging is conducted every 8 weeks. Results: 51 pts with NRG1+ cancer have received zeno, 37 in the eNRGy study and 14 pts in the EAP. As of 12 Jan 2021, treatment is ongoing in 27/51 pts (8/13 pancreas, 10/25 NSCLC, 9/13 other solid tumors). Among the 51 pts, 10 pts with pancreas cancer, 18 pts with NSCLC, and 5 pts with other solid tumors had measurable disease and had the opportunity for ≥1 tumor assessment (TA) and are included in this analysis. Among the 10 pts with pancreas cancer, median age was 49 y (range 34-72), 50% were male, 6/4 pts had ECOG 0/1, and all had metastatic disease and were KRAS wild-type. The median number of prior therapies was 3 (range 1-6). The INV-assessed confirmed ORR was 40% (4/10; 90% CI, 15;70), and for this cohort of pts, responses occurred at the first TA. Tumor regression was seen in 7/10 pts, and the disease control rate was 90% (90% CI, 61-100). A CA 19-9 decline of ≥ 50% was observed in 9/9 (100%) pts. DOR is pending. In the overall NRG1+ population, tumor regression was observed in 25 of 33 pts and confirmed INV-assessed responses were seen in 9 of 33 pts (ORR 27%; 90% CI, 15;43), including in pts who previously received afatinib. Zeno was well tolerated with no pts requiring dose reduction for toxicity. Across all cohorts, for individual AEs, grade 3 events were reported in ≤5% of pts, and there was a notable lack of cardiotoxicity and severe gastrointestinal or skin toxicity. Updated data from all cohorts (pancreas, NSCLC, other solid tumors) will be presented. Conclusions: Zeno induces rapid and major radiologic tumor regression and biomarker responses in heavily-pretreated metastatic KRAS wild-type NRG1+ pancreas cancer, with minimal toxicity. Zeno is a promising novel targeted therapeutic option for pts with NRG1+ cancers. Clinical trial information: NCT02912949.

ADAGIO: A phase IIb, open-label, single-arm, multicenter study assessing the efficacy and safety of adavosertib (AZD1775) as treatment for recurrent or persistent uterine serous carcinoma.

TPS5612 Background: There is a high unmet medical need for therapies treating uterine serous carcinoma (USC), an aggressive type of endometrial carcinoma with an increased likelihood of recurrence and limited therapeutic options. 5-year overall survival (OS) for USC is estimated to be 35–50% for women with stage I–II disease and 0–15% for women with stage III–IV disease (Acharya et al. Lancet Oncol 2005). USC exhibits high rates of mutation in TP53 ( > 90% of cases), as well as mutations or amplifications in other cell-cycle regulators or oncogenes, including CCNE1, FBXW7, MYC, RB1, and KRAS/ NRAS (Zhao et al. PNAS 2013; Levine DA et al. Nature 2013), which may contribute to increased replication stress and susceptibility to inhibition of the tyrosine kinase WEE1. WEE1 inhibition is expected to release a tumor cell from DNA-damage-induced arrest at the G2/M boundary, so that unrepaired DNA damage may be taken into mitosis, leading to cell death. A Phase II study of the WEE1 inhibitor adavosertib in 34 women with recurrent or persistent USC reported an objective response rate (ORR) of 29.4% and a median duration of response (DoR) of 9.0 months; further correlative analysis and a translational biopsy cohort are planned (Liu et al. J Clin Oncol 2020). This Phase IIb study, ADAGIO, a single-arm, multicenter, global study (NCT04590248), aims to expand on these findings and will evaluate the efficacy and safety of adavosertib in women with recurrent or persistent USC who have previously received platinum-based chemotherapy. Methods: Women aged ≥18 years with histologically confirmed recurrent or persistent USC who have previously received at least one platinum-based chemotherapy regimen for the management of USC and have evidence of measurable disease according to RECIST v1.1 are eligible for this study. Participants with carcinosarcomas are not eligible. Prior receipt of immune checkpoint inhibitors, vascular endothelial growth factor inhibitors and human epidermal growth factor receptor 2 targeted therapy is permitted, with no restriction on the number of prior lines of systemic therapy a participant may have previously received. Approximately 120 eligible participants will receive oral adavosertib 300 mg qd on days 1–5 and 8–12 of a 21-day treatment cycle until disease progression, unacceptable toxicity, withdrawal of consent, or another discontinuation criterion is met. The primary outcome measure is ORR, defined as the percentage of patients with measurable disease at baseline who have a confirmed complete or partial response, as determined by blinded independent central review (RECIST v1.1 assessment every 6 weeks for the first 48 weeks, then every 9 weeks). Secondary outcome measures include DoR, depth of response, progression-free survival, OS, disease control rate, biomarkers, safety, tolerability, and pharmacokinetics. Clinical trial information: NCT04590248.