Abstract: Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub ( https://covid19forecasthub.org/ ) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks.

Abstract: Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages.

Abstract: Purpose: HSP90 is a chaperone protein required for the stability of a variety of client proteins. 17-Demethoxygeldanamycin (17-AAG) is a natural product that binds to HSP90 and inhibits its activity, thereby inducing the degradation of these clients. In preclinical studies, HER2 is one of the most sensitive known client proteins of 17-AAG. On the basis of these data and activity in a phase I study, we conducted a phase II study of 17-AAG (tanespimycin) with trastuzumab in advanced trastuzumab-refractory HER2-positive breast cancer. Experimental Design: We enrolled patients with metastatic HER2+ breast cancer whose disease had previously progressed on trastuzumab. All patients received weekly treatment with tanespimycin at 450 mg/m2 intravenously and trastuzumab at a conventional dose. Therapy was continued until disease progression. The primary endpoint was response rate by Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Results: Thirty-one patients were enrolled with a median age of 53 years and a median Karnofsky performance status (KPS) of 90%. The most common toxicities, largely grade 1, were diarrhea, fatigue, nausea, and headache. The overall response rate was 22%, the clinical benefit rate [complete response + partial response + stable disease] was 59%, the median progression-free survival was 6 months (95% CI: 4–9), and the median overall survival was 17 months (95% CI: 16–28). Conclusions: This is the first phase II study to definitively show RECIST-defined responses for 17-AAG in solid tumors. Tanespimycin plus trastuzumab has significant anticancer activity in patients with HER2-positive, metastatic breast cancer previously progressing on trastuzumab. Further research exploring this therapeutic interaction and the activity of HSP90 inhibitors is clearly warranted. Clin Cancer Res; 17(15); 5132–9. ©2011 AACR.

Abstract: This phase I study examined whether a heat shock protein (Hsp) 90 inhibitor tanespimycin (17-AAG; KOS-953) could be administered safely in combination with trastuzumab at a dose that inhibits Hsp90 function in vivo in lymphocytes. Patients and Methods Patients with an advanced solid tumor progressing during standard therapy were eligible. Patients were treated with weekly trastuzumab followed by intravenous tanespimycin, assessed in escalating dose levels. Results Twenty-five patients were enrolled onto four tanespimycin dose levels: 225 (n = 4), 300 (n = 3), 375 (n = 8), and 450 mg/m 2 (n = 10). Dose-limiting toxicity (DLT) was observed at the third and fourth cohort (1 patient each): more than 2-week delay for grade 4 fatigue/grade 2 nausea and anorexia (375 mg/m 2 ); more than 2-week delay for thrombocytopenia (450 mg/m 2 ). Drug-related grade 3 toxicity included emesis, increased ALT, hypersensitivity reactions (two patients each), and drug-induced thrombocytopenia (n = 1). Common mild to moderate toxicities included fatigue, nausea, diarrhea, emesis, headache, rash/pruritus, increased AST/ALT, and anorexia. Pharmacokinetic analysis demonstrated no difference in tanespimycin kinetics with or without trastuzumab. Pharmacodynamic testing showed reactive induction of Hsp70 (a marker of Hsp90 inhibition) in lymphocytes at all dose levels. Antitumor activity was noted (partial response, n = 1; minor response, n = 4; stable disease ≥ 4 months, n = 4). Tumor regressions were seen only in patients with human epidermal growth factor receptor 2 (HER-2)-positive metastatic breast cancer. Conclusion Tanespimycin plus trastuzumab is well tolerated and has antitumor activity in patients with HER-2+ breast cancer whose tumors have progressed during treatment with trastuzumab. These data suggest that Hsp90 function can be inhibited in vivo to a degree sufficient to cause inhibition of tumor growth.

Abstract: Increased bone marrow angiogenesis and vascular endothelial growth factor (VEGF) levels are adverse prognostic features in patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDSs). VEGF is a soluble circulating angiogenic molecule that stimulates signaling via receptor tyrosine kinases (RTKs), including VEGF receptor 2 (VEGFR-2). AML blasts may express VEGFR-2, c-kit, and FLT3. SU5416 is a small molecule RTK inhibitor (RTKI) of VEGFR-2, c-kit, and both wild-type and mutant FLT3. A multicenter phase 2 study of SU5416 was conducted in patients with refractory AML or MDS. For a median of 9 weeks (range, 1-55 weeks), 55 patients (33 AML: 10 [30%] primary refractory, 23 [70%] relapsed; 22 MDS: 15 [68%] relapsed) received 145 mg/m2 SU5416 twice weekly intravenously. Grade 3 or 4 drug-related toxicities included headaches (14%), infusion-related reactions (11%), dyspnea (14%), fatigue (7%), thrombotic episodes (7%), bone pain (5%), and gastrointestinal disturbance (4%). There were 11 patients (20%) who did not complete 4 weeks of therapy (10 progressive disease, 1 adverse event); 3 patients (5%) who achieved partial responses; and 1 (2%) who achieved hematologic improvement. Single agent SU5416 had biologic and modest clinical activity in refractory AML/MDS. Overall median survival was 12 weeks in AML patients (range, 4-41 weeks) and not reached in MDS patients. Most observed toxicities were attributable to drug formulation (polyoxyl 35 castor oil or hyperosmolarity of the SU5416 preparation). Studies of other RTKI and/or other antiangiogenic approaches, with correlative studies to examine biologic effects, may be warranted in patients with AML/MDS.

Abstract: Previous data suggests that anti-OX40 mAb can elicit anti-tumor effects in mice through deletion of Tregs. However, OX40 also has powerful costimulatory effects on T cells which could evoke therapeutic responses. Human trials with anti-OX40 antibodies have shown that these entities are well tolerated but to date have delivered disappointing clinical responses, indicating that the rules for the optimal use of anti-human OX40 (hOX40) antibodies is not yet fully understood. Changes to timing and dosages may lead to improved outcomes; however, here we focus on addressing the role of agonism versus depleting activity in determining therapeutic outcomes. We investigated a novel panel of anti-hOX40 mAb to understand how these reagents and mechanisms may be optimized for therapeutic benefit. Methods This study examines the binding activity and in vitro activity of a panel of anti-hOX40 antibodies. They were further evaluated in several in vivo models to address how isotype and epitope determine mechanism of action and efficacy of anti-hOX40 mAb. Results Binding analysis revealed the antibodies to be high affinity, with epitopes spanning all four cysteine-rich domains of the OX40 extracellular domain. In vivo analysis showed that their activities relate directly to two key properties: (1) isotype—with mIgG1 mAb evoking receptor agonism and CD8+ T-cell expansion and mIgG2a mAb evoking deletion of Treg and (2) epitope—with membrane-proximal mAb delivering more powerful agonism. Intriguingly, both isotypes acted therapeutically in tumor models by engaging these different mechanisms. Conclusion These findings highlight the significant impact of isotype and epitope on the modulation of anti-hOX40 mAb therapy, and indicate that CD8+ T-cell expansion or Treg depletion might be preferred according to the composition of different tumors. As many of the current clinical trials using OX40 antibodies are now using combination therapies, this understanding of how to manipulate therapeutic activity will be vital in directing new combinations that are more likely to improve efficacy and clinical outcomes.

Abstract: Defibrotide improves day +100 survival and CR in patients with VOD and MOF compared with a historical control. The historical control selection methodology offers a novel approach for investigation of a life-threatening orphan disease.

Abstract: Introduction Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS), is a rare and potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT). Severe cases, historically defined by multi-organ dysfunction (MOD), may be associated with mortality rates of 〉 80%. There is no FDA-approved treatment for VOD/SOS. Defibrotide (DF) has a proposed mechanism of action that includes stabilization of endothelial cells and restoration of thrombo-fibrinolytic balance. Earlier analyses of a pivotal phase 3 trial of DF in VOD/SOS plus MOD (Richardson et al. Blood. 2009;114:Abstract 654) underpinned approval of DF in the EU to treat severe hepatic VOD/SOS after HSCT. Additional data were obtained at the request of US health authorities. Here we present the final analysis: day +100 survival (primary endpoint) and complete response (CR; secondary). Methods This was a multicenter, open-label, phase 3 historical control (HC) study assessing DF. Eligible patients met Baltimore VOD/SOS criteria (total bilirubin ≥2.0 mg/dL with ≥2 of: hepatomegaly, ascites, or 5% weight gain) by day +21 post-HSCT, plus MOD (renal [trebling of creatinine levels, reduced creatinine clearance, or dialysis] and/or pulmonary [oxygen saturation ≤90%, need for oxygen supplementation/ventilator dependence] ) by day +28 post-HSCT. Exclusion criteria included severe graft-versus-host disease (GvHD) of liver or gut, clinically significant bleeding, or need for ≥2 pressors. HC patients were reviewed for inclusion/exclusion criteria in a sequential review of medical charts starting 6 months prior to use of DF at each site; a blinded medical review committee made the final determination of HCs unequivocally meeting criteria for VOD/SOS with MOD. DF dose was 25 mg/kg/d in 4 divided 2-hour IV infusions q6h; recommended treatment duration was ≥21 days. Primary endpoint was day +100 survival. CR by day +100 was a secondary endpoint. Treatment difference in survival and CR rates and their 95% confidence intervals were estimated using propensity-stratified and weighted (Koch-adjusted) estimates of differences in proportions that account for baseline prognostic factors of survival (ie, ventilator and/or dialysis dependency at entry, age ≤/ 〉 16 years, transplant type, and prior HSCT). Analyses included patients treated with DF and HCs. Results There were 102 patients in the DF group and 32 cases selected as HCs. Baseline characteristics were similar in the DF and HC groups: mean age (26 and 25 years; 43% and 44% ≤16 years), allogeneic graft (88% and 84%), prior HSCT (13% and 9%), ventilator- and/or dialysis-dependent at study entry (33% and 22%), myeloablative conditioning (87% and 94%), and the most common underlying diseases (acute leukemias: 45% and 47%), respectively. In the DF-treated group, common GvHD medications included tacrolimus (49%), methotrexate (41%), and cyclosporine (38%); in the HC group, common medications were cyclosporine (72%) and methotrexate (63%). Survival at day +100 in the DF and HC groups was 38% and 25%, respectively. The propensity-stratified difference in survival was 23.0% (95.1% CI, 5.2-40.8, P = .0109). Respective observed CR rates by day +100 were 25.5% and 12.5%, and the propensity-stratified difference in CR was 19.0% (95.1% CI, 3.5-34.6, P = .0160). Comparing the earlier EU and final analyses, the survival rates at day +100 in each group did not vary; however, the propensity adjusted final analysis provided a different level of statistical significance. Day +100 CR rates in the original analysis were slightly lower in both arms at 24% and 9% due to increased data capture to investigate CR; the P value was essentially unchanged. For the DF group, 45% had an adverse event (AE) at least possibly related to study drug, and 21% had a serious AE at least possibly related to study drug. In this very sick population, percentages of patients with ≥1 AE leading to death were similar between DF and HC patients (64% and 69%), as were hemorrhagic AEs (64%, 75%) and hypotension (39%, 50%). Conclusions Based on observed study data and using a propensity-adjusted rate difference estimator, patients treated with DF had a 23% reduction in risk of death by day +100 and 19% improvement in CR rate. Overall incidence of hemorrhage and fatal AEs were similar between groups with AEs consistent with those expected in this critically ill population. Support: Jazz Pharmaceuticals. Disclosures Richardson: Novartis: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Gentium S.p.A.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Takeda: Membership on an entity's Board of Directors or advisory committees. Off Label Use: Marizomib, pmalidomide, and low dose dexamethasone in RR MM. Defibrotide is an investigational treatment for hepatic veno-occlusive disease/sinusoidal obstruction syndrome in the United States. . Kernan:Gentium S.p.A.: Research Funding. Grupp:Novartis: Consultancy, Research Funding. Guinan:Gentium SpA/Jazz Pharmaceuticals: Other: My institution received fees for research.. Martin:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Gentium SpA/Jazz Pharmaceuticals: Research Funding. Steinbach:Gentium SpA/Jazz Pharmaceuticals: Research Funding. Krishnan:Celgene: Consultancy, Speakers Bureau; BMS: Consultancy; Janssen: Consultancy; Onyx: Speakers Bureau; Jazz: Consultancy; Millenium: Speakers Bureau. Giralt:SANOFI: Consultancy, Honoraria, Research Funding; CELGENE: Consultancy, Honoraria, Research Funding; AMGEN: Consultancy, Research Funding; JAZZ: Consultancy, Honoraria, Research Funding, Speakers Bureau; TAKEDA: Consultancy, Honoraria, Research Funding. Rodriguez:Gentium SpA/Jazz Pharmaceuticals: Research Funding. Doyle:Gentium SpA/Jazz Pharmaceuticals: Research Funding. Antin:Gentium SpA/Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. D'Agostino:Gentium SpA/Jazz Pharmaceuticals: Consultancy. Massaro:Gentium SpA/Jazz Pharmaceuticals: Consultancy. Miloslavsky:Jazz Pharmaceuticals: Employment, Equity Ownership. Hume:Jazz Pharmaceuticals: Employment, Equity Ownership. Iacobelli:Gentium SpA: Employment. Nejadnik:Jazz Pharmaceuticals: Employment, Equity Ownership. Hannah:Gentium SpA: Other: Personal fees during conduct of the study.. Soiffer:Gentium SpA/Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.