Citations

Abstract Most patients with coronavirus disease 2019 (COVID-19) have mild to moderate illness not requiring hospitalization. However, no study has detailed the evolution of symptoms in the first month of illness. At our institution, we conducted remote (telephone and video) visits for all adult outpatients diagnosed with COVID-19 within 24 h of a positive nasopharyngeal polymerase chain test for SARS-CoV-2. We repeated regular video visits at 7, 14, and 28 days after the positive test, retrospectively reviewed the prospective data collected in the remote visits, and constructed a week by week profile of clinical illness, through week 4 of illness. We reviewed the courses of 458 symptomatic patients diagnosed between March 12, 2020, and June 22, 2020, and characterized their weekly courses. Common initial symptoms included fever, headache, cough, and chest pain, which frequently persisted through week 3 or longer. Upper respiratory or gastrointestinal symptoms were much shorter lived, present primarily in week 1. Anosmia/ageusia peaked in weeks 2 to 3. Emergency department visits were frequent, with 128 visits in the 423 patients who were not hospitalized and 48 visits among the 35 outpatients (7.6%) who were eventually hospitalized (2 subsequently died). By the fourth week, 28.9% said their illness had completely resolved. After the 4-week follow up, 20 (4.7%) of the 423 nonhospitalized patients had further medical evaluation and management for subacute or chronic COVID-19 symptoms. Mild to moderate outpatient COVID-19 is a prolonged illness, with evolving symptoms commonly lasting into the fourth week of illness.

Substantial evidence indicates the importance of elevated cAMP in polycystic kidney disease (PKD). Preclinical and clinical trials have shown the feasibility of therapies (vasopressin V2 receptor antagonists and somatostatin analogs) acting on G protein coupled receptors to inhibit adenylyl cyclase activity and production of cAMP. An additional or alternative approach could be to increase phosphodiesterase (PDE) mediated hydrolysis of cAMP. Of the large PDE superfamily, PDE1 is the only family activated by calcium, which is reduced in PKD cells. To assess the contribution of PDE1A to renal cyst formation, we depleted PDE1A levels using antisense morpholinos in zebrafish. We identified two splice isoforms with alternative starts corresponding to human PDE1A1 and PDE1A5. Two splice‐blocking morpholinos targeting the common hydrolase domain of both isoforms induced renal cysts. Two additional morpholinos, targeting each start, also induced renal cysts with dose dependence and additive effects. Co‐injection of the start 1 morpholino with pkd2 morpholino increased the severity of hydrocephalus, renal cysts, and body curvature, demonstrating functional interaction of PDE1A and PC2. Overall, data implicate PDE1A in PKD pathogenesis and validate further investigation of PDE1A as a therapeutic target in PKD.

Lower body negative pressure (LBNP) is often used to simulate blood loss in humans. However, it is unknown if the effects of actual blood loss (BL) on cerebral blood flow regulation is analogous to simulated blood loss during LBNP. Nine healthy men (32±6 y) were studied at baseline, during 3 levels of LBNP (5 min each at ‐15, ‐30, ‐45 mmHg), and during 3 levels of blood loss (5 min each at 333, 667, 1000 mL). LBNP and BL conditions were randomized. Intra‐arterial mean arterial pressure (MAP) was similar during LBNP compared with BL (p>0.20). Central venous pressure (CVP; 2.8±0.7 vs. 4.0±0.8, 1.2±0.6 vs. 3.5±0.8, 0.2±0.9 vs. 2.1±0.9 mmHg for level 1, 2, and 3; p<0.01) and stroke volume (71±4 vs. 80±3, 60±3 vs. 74±3, 51±2 vs. 68±4 mL for level 1, 2, and 3; p<0.01) were lower during LBNP compared with BL. Despite differences in CVP, middle cerebral artery velocity (MCAv) and cerebrovascular conductance index (CVCi) were similar between LBNP and BL at each level (MCAv at level 3: 62±6 vs. 66±5 cm/s; p=0.37; CVCi at level 3: 0.72±0.05 vs. 0.73±0.05 cm/s/mmHg; p=0.29). Furthermore, the slope of the relationship between MAP and MCAv was not different between LBNP and BL (1.06 vs. 1.07 cm/s/mmHg). Our results suggest that the cerebral hemodynamic responses to LBNP are similar to actual blood loss. Grant Funding Source : Supported by U.S. Army MRMC Combat Casualty Care Research Program Grant # W81XWH‐11‐1‐0823

Hospitalized patients with COVID-19 show increased serum concentrations of neurofilament light chain that correlate with worse clinical outcomes.

Context.— It is unclear if preimplantation frozen section biopsy correlates with outcomes after deceased donor kidney transplantation. Objective.— To assess if chronic histologic changes on the preimplant frozen section correlates with graft loss and estimated glomerular filtration rate independently of kidney donor profile index (KDPI). Design.— Seven hundred three preimplantation biopsies were reviewed and a Banff sum score was calculated using glomerular sclerosis, interstitial fibrosis, vascular intimal thickening, and arteriolar hyalinosis. The posttransplant outcomes were compared for preimplantation biopsy Banff sum 0-1, 2-3, and 4-9. The cohort was also stratified by KDPI 85 or less versus more than 85. Results.— For the entire biopsy cohort, graft survival, estimated glomerular filtration rate at 1 year, and chronic changes on a 1-year posttransplant biopsy were superior in the group with preimplantation Banff sum 0-1. After stratifying by KDPI, the Banff sum no longer correlated with graft survival. In a univariate mode, using the Banff sum score as a continuous variable, a higher Banff sum score was significantly associated with graft failure (P = .03); however, after adjusting the KDPI, the Banff sum score no longer correlated with graft failure (P = .45). The 1-year estimated glomerular filtration rate and 1-year biopsy changes were superior in the group with Banff sum 0-1 only in the cohort with KDPI 85 or less. Conclusions.— In donor kidneys used for transplant, preimplantation biopsy chronic changes correlate with estimated glomerular filtration rate and biopsy findings at 1 year, but biopsies with mostly mild chronicity and Banff sum scores less than or equal to 5 did not impact graft survival beyond KDPI.

7050 Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm manifesting as unifocal, multifocal, multisystem (MS) or pulmonary LCH (smoking-related). In pediatric LCH, somatic BRAFV600E prevalence is reported at 55-70%, and associated with increased risk of multisystem disease and early treatment failure. Our aim was to describe the prevalence of BRAFV600E mutation and evaluate its association with clinical manifestations and outcomes in adults with LCH. Methods: A retrospective review of adult patients diagnosed with LCH consecutively seen at Mayo Clinic from 2011 to 2020 was performed.Evaluation of association of BRAFV600E mutational status and clinical factors was conducted by the Chi-square test for independence. Progression-free survival (PFS) and overall survival (OS) were analyzed via the Kaplan Meier method and compared with the log-rank test to assess the effect of BRAFV600E. Results: Of the total LCH cohort ( n= 128), 88 patients with available BRAFV600E results were included in the study. Median age at diagnosis was 41y (range 19 - 88); 52.3% were male. 40 (45.5%) patients had a BRAFV600E mutation. Increasing age was associated with BRAFV600E (10-year increase OR 1.42, 95%CI 1.07-1.89; p= 0.017). No correlation was observed between BRAFV600E status and site of disease, risk organ (RO: liver, spleen, marrow) involvement, or MS disease. Patients with BRAFV600E were 4 times more likely to receive targeted therapy ( BRAF inhibitor) than non- BRAFV600E patients ( p= 0.018). After a median follow up of 46 mo (95% CI 30.8-61.2), PFS was similar between BRAFV600E and non- BRAFV600E patients ( p= 0.167). However, patients with BRAFV600E had a worse 3-year OS compared with non- BRAFV600E patients (84% vs. 97.1%, p= 0.027). Patients who died had a significantly higher age at LCH diagnosis (median 62 vs. 38 years; p= 0.0002). Conclusions: In our cohort of adults with LCH, BRAFV600E was less frequent than reported in pediatric literature and was associated with worse OS. The frequency of BRAFV600E was positively correlated with increasing age. Contrary to reports in pediatric LCH, there were no significant associations between BRAFV600E and high-risk or multisystem disease.[Table: see text]

TPS3616 Background: METamp is a secondary, or co-driving, genetic change in pts with mCRC and acquired resistance to anti-EGFR therapy, which can contribute to disease progression. In EGFR-resistant pts with mCRC and METamp, MET inhibition + an anti-EGFR agent may achieve disease control by targeting emerging MET pathway activation and maintaining EGFR pathway inhibition. Tepotinib is an oral, once-daily, highly selective, potent MET tyrosine kinase inhibitor (TKI), recently approved in the US for NSCLC harboring MET exon 14 skipping. Tepotinib + gefitinib demonstrated improved outcomes in pts with EGFR-mutant METamp NSCLC and acquired EGFR TKI resistance vs chemotherapy (INSIGHT: NCT01982955). In these pts, progression-free survival (PFS) was 16.6 vs 4.2 months (HR = 0.13; 90% CI: 0.04, 0.43) and overall survival (OS) was 37.3 vs 13.1 months (HR = 0.08; 90% CI: 0.01, 0.51). In pts with mCRC and acquired resistance to anti-EGFR antibody therapy due to METamp, tepotinib + anti-EGFR antibody cetuximab may be active and provide an effective therapeutic option. Methods: This Phase II, multicenter, single-arm, open-label study will assess preliminary safety and tolerability, antitumor activity, and explore pharmacokinetic (PK) profiles of tepotinib + cetuximab in pts with RAS/BRAF wild-type left-sided mCRC and acquired resistance to anti-EGFR antibody-targeted therapy due to METamp (NCT04515394). A safety run-in (6–12 pts) will evaluate the recommended Phase II dose of tepotinib to be used in combination with cetuximab (endpoint: dose-limiting toxicities). Enrollment is based on a confirmed advanced left-sided CRC diagnosis ( RAS/BRAF wild-type), documented previous anti-EGFR therapy and acquired resistance on most recent anti-EGFR antibody and METamp confirmed by liquid and/or tissue biopsy. Pts must be ≥18 years old, have ECOG PS of 0/1 and normal organ function. The study will screen sufficient pts to account for setting-specific heterogenecity in reported METamp incidence. Approximately 42 pts are planned to receive study treatment: ̃22 in Cohort A (second-line, outside US) and 20 in Cohort B (≥third-line, US only). Primary endpoint: investigator-assessed objective response (RECIST 1.1). Secondary endpoints are investigator-assessed duration of response (DoR), PFS (RECIST 1.1) and OS, tolerability and safety (NCI-CTCAE v5.0), and cetuximab immunogenicity (measured by antidrug antibody assays at the start and end of treatment). Additional endpoints include assessment of tepotinib and cetuximab PK profiles, and expression of biomarkers of resistance (from blood and/or tissue samples). Retrospective assessment of best overall response, DoR and PFS by an independent review committee may be conducted. No formal statistical hypothesis will be tested in this exploratory study. Clinical trial information: NCT04515394.

3040 Background: Pembrolizumab was recently FDA approved across solid tumors for TMB scores ≥ 10mut/Mb as assessed by next-generation sequencing (NGS) of tissue (tTMB). A prior study of advanced cancer patients treated with immunotherapy found that higher somatic TMB, as defined by the 80th percentile in each histology, was associated with better overall survival. Previously, bTMB assessed by ctDNA from patients with newly diagnosed advanced NSCLC at a score of 16 mut/MB correlated with a tTMB score of 10 mut/MB. TMB levels vary by cancer type, line of treatment, and therapy received; the distribution of bTMB scores across solid tumor types has not been well characterized. Here we report the distribution of bTMB scores in patients with advanced malignancies. Methods: We queried 5,610 samples from patients with different cancer types undergoing clinical cell-free DNA testing (Guardant360; Redwood City, CA) and assessed bTMB scores from October 2020 - January 2021. bTMB score was derived via a previously described computational algorithm examining the total number of synonymous and non-synonymous SNVs and indels across a 1.0MB genomic footprint. We assessed the success rate of bTMB evaluation, overlap with microsatellite instability (MSI) status, and defined the distribution of bTMB levels across indications in this dataset. Results: bTMB score was successfully assessed in 4,275/5,610 (76.3%) samples (Table). The majority of samples (58%) were tested at disease progression as compared to initial diagnosis (42%). The median turnaround time from sample receipt to clinical reporting was 11 days and decreased to 9 days over the course of the study. For the majority of cancer types the 80th percentile TMB was ≥ 16 mut/MB tissue equivalency. Conclusions: Our analysis demonstrates the feasibility of measuring bTMB using a commercially available liquid biopsy assay. bTMB scores trended higher than tTMB previously reported in these cancer types, reflecting the ability of ctDNA to better capture tumor heterogeneity. cfDNA may allow for exploration of bTMB evolution throughout treatment. TMB should be interpreted in the context of disease, treatment, and method; these data establish a pan-cancer benchmark for bTMB which will serve as a resource for further studies.[Table: see text]

7049 Background: Langerhans cell histiocytosis (LCH) can manifest as single system (SS) disease, multisystem (MS) disease, or pulmonary LCH (smoking-related). There is a paucity of data on prognostic factors including risk organ (RO) involvement (liver, spleen, and bone marrow) in adult LCH, which we sought to address in this study. Methods: Single-center retrospective study of patients ≥18y diagnosed with LCH from 1998 to 2020. Univariate and multivariate analyses for progression free survival (PFS) and overall survival (OS) were conducted using age, sex, organ involvement, LCH subtype, year of diagnosis, BRAF V600E status, and treatments. Results: We included 219 patients with LCH; median age 43y (range 19-88), females 51%, SS unifocal (23%), SS multifocal (6%), pulmonary (31%) and MS (40%). Commonly involved organs included lung (53%), bone (42%), skin (24%), pituitary (16%), and CNS (12%). BRAF V600E was positive in 40/88 (46%). Median follow-up duration was 6.1y (95% CI, 5.1- 7.1). On univariate analysis, factors associated with worse PFS were bone LCH, RO involvement, multifocal/MS LCH, and radiation therapy alone; those with worse OS included RO involvement, MS disease, BRAF V600E+, and age ≥45y at diagnosis. In multivariate analysis, BRAF V600E and age ≥45y at diagnosis were associated with worse mortality (Table). Median PFS was not reached (NR-NR) for SS unifocal LCH, 5mo (0-12.7) for SS multifocal LCH, 110mo (84.7-135.3) for pulmonary LCH, and 27mo (17.2-36.8) for MS LCH. 5-year OS was 97.4% for SS unifocal LCH, 100% for SS multifocal LCH, 96.1% for pulmonary LCH, and 79.9% for MS LCH. 41 (18.7%) developed a second primary malignancy (SPM), of which 11 were hematologic neoplasms. There was a trend towards a higher prevalence of SPMs in patients with BRAF V600E (28% vs. 17%; p = 0.22). Conclusions: In our large single-center study, PFS for multifocal and MS LCH was worse than SS unifocal or pulmonary LCH. RO involvement was not associated with outcomes in multivariate analysis. Overall prognosis was excellent for all subtypes except MS LCH. BRAF V600E and older age were associated with worse OS. The prevalence of SPMs was very high and needs to be explored further.[Table: see text]

Abstract Background This secondary image analysis of a randomized trial of proton radiotherapy (PT) versus photon intensity-modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment versus Response Assessment in Neuro-Oncology (RANO). Methods Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. “Clinical progression” was based on a clinical radiology report of progression and/or change in treatment for progression. Results Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (range: 9.4–14.7) months; 10.8 months IMRT versus 11.2 months PT (P = .14). Median RANO-PFS was 8.2 (range: 6.9, 12): 8.9 months IMRT versus 6.6 months PT (P = .24). RANO-PFS was significantly shorter than clinical PFS overall (P = .001) and for both the IMRT (P = .01) and PT (P = .04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria. Conclusions Based on this secondary analysis of a trial of PT versus IMRT for glioblastoma, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.