Analogous to an assembly line, we employed a modular design for the high-throughput study of 1,536 structurally distinct nanoparticles with cationic cores and variable shells. This enabled elucidation of complexation, internalization, and delivery trends that could only be learned through evaluation of a large library. Using robotic automation, epoxide-functionalized block polymers were combinatorially cross-linked with a diverse library of amines, followed by measurement of molecular weight, diameter, RNA complexation, cellular internalization, and in vitro siRNA and pDNA delivery. Analysis revealed structure-function relationships and beneficial design guidelines, including a higher reactive block weight fraction, stoichiometric equivalence between epoxides and amines, and thin hydrophilic shells. Cross-linkers optimally possessed tertiary dimethylamine or piperazine groups and potential buffering capacity. Covalent cholesterol attachment allowed for transfection in vivo to liver hepatocytes in mice. The ability to tune the chemical nature of the core and shell may afford utility of these materials in additional applications.

Background : CD47 is a transmembrane protein ubiquitously expressed in human cells. CD47 is overexpressed in various malignancies and is correlated with negative prognosis in AML and MDS (Chao et al. Curr Opin Immunol.2012; Majeti et al. Cell.2009). Interaction of CD47 with signal-regulatory protein alpha (SIRPα) expressed on macrophages inhibits phagocytosis (Kim et al. Leukemia.2012). CC-90002, a humanized anti-CD47 monoclonal antibody, blocks CD47/SIRPα interactions, thereby enabling macrophage-mediated killing of tumor cells. In preclinical studies, CC-90002 demonstrated antibody-mediated phagocytosis of several hematologic cancer cell lines, including AML cells. CC-90002 also demonstrated a rapid and substantial reduction in tumor burden in AML xenograft models. Herein, we report results from CC-90002-AML-001 evaluating CC-90002 in patients (pts) with R/R AML and high-risk MDS. Methods : In this phase I multicenter study (NCT02641002), CC-90002 was administered intravenously once/week for 4 weeks of each 42-day cycle during cycles 1−4 then once every 4 weeks during a maintenance phase of 28-day cycles. Pts were enrolled in cohorts of escalating dose levels using a modified 3+3 design. The primary objectives were to determine preliminary safety and tolerability, non-tolerated dose (NTD), maximum tolerated dose (MTD), and/or recommended phase 2 dose. Secondary objectives were to measure preliminary efficacy, pharmacokinetics, and the presence and frequency of anti-drug antibodies (ADAs). Results: As of July 18, 2018, 24 pts with R/R AML and 4 pts with high-risk R/R MDS were enrolled. Pts received CC-90002 at 0.1 mg/kg (n=6), 0.3 mg/kg (n=6), 1 mg/kg (n=6), 2 mg/kg (n=4), and 4 mg/kg (n=6). Median age was 70 years (range, 28-85) and 16 (57%) were male. The most common AML subtypes were AML with myelodysplasia-related changes (n=9) and AML not otherwise specified (n=9). All 4 pts with MDS were classified as having refractory anemia with excess blasts-2 and high- or very high-risk disease per the Revised International Prognostic Index Scoring System. The median number of prior systemic anticancer regimens was 3 (range, 1-10), and 29% of pts had prior stem cell transplants. The median treatment duration was 6.9 weeks (range, 2-44). Four pts experienced a dose-limiting toxicity, consisting of grade 4 disseminated intravascular coagulation and grade 4 cerebral hemorrhage in 1 pt (0.1 mg/kg), grade 3 purpura in 1 pt (0.3 mg/kg), grade 4 congestive cardiac failure and grade 4 acute respiratory failure in 1 pt (1 mg/kg), and grade 4 sepsis in 1 pt (4 mg/kg). The most common (≥30%) any-grade treatment-emergent adverse events (TEAEs) were diarrhea (46%); thrombocytopenia (39%); febrile neutropenia and aspartate aminotransferase increased (36% each); and anemia, alanine aminotransferase increased, and cough (32% each). A total of 23 pts (82%) had serious TEAEs with febrile neutropenia (n=10), bacteremia (n=4), pneumonia (n=4), and general physical health deterioration (n=3) occurring in>2 pts. No TEAEs led to dose reductions; however, 7 pts (25%) discontinued due to TEAEs. Overall, 82% of pts were dependent on red blood cell (RBC) transfusions and CC-90002 treatment did not interfere with continued RBC transfusion in pts on study. No pts experienced hemolysis, tumor lysis syndrome, or macrophage activation/cytokine release syndrome. Sixteen pts died during the study. The best overall response observed was stable disease in 2 pts with MDS. CC-90002 serum exposures appeared to increase with doses above 0.3−4.0 mg/kg and the terminal half-life ranged from 4.6−17.0 hours. Development of ADAs targeting CC-90002 occurred at all dose levels tested and the proportion of pts testing positive for ADAs in cycle 1 increased over time (4/27 pts at day 8, 6/25 pts at day 15, and 8/22 pts at day 22). ADAs continued to be present across different doses with increases in median serum ADA titers after cycle 1. No apparent dose-ADA relationship was observed. Conclusion: CC-90002 showed a lack of objective responses in pts with R/R AML and high-risk MDS. The MTD and NTD were not established. The CC-90002-AML-001 study was discontinued in dose escalation for lack of preliminary monotherapy activity and evidence of ADAs in most pts. CC-90002 in combination with rituximab is being explored in CD20+ NHL to enhance efficacy of CD47 blockade while reducing ADAs (CC-90002-ST-001; NCT02367196). Disclosures Zeidan: BeyondSpring: Honoraria; Seattle Genetics: Honoraria; Acceleron Pharma: Consultancy, Honoraria, Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Medimmune/AstraZeneca: Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Research Funding; Jazz: Honoraria; Ariad: Honoraria; Agios: Honoraria; Novartis: Honoraria; Astellas: Honoraria; Daiichi Sankyo: Honoraria; Cardinal Health: Honoraria. DeAngelo:Novartis: Consultancy, Research Funding; Jazz Pharmaceuticals Inc: Consultancy; Shire: Consultancy; Incyte: Consultancy; Blueprint: Consultancy, Research Funding; Pfizer: Consultancy; Amgen: Consultancy; GlycoMimetics: Research Funding; Celgene: Consultancy; Abbvie: Research Funding; Takeda Pharmaceuticals: Consultancy. Seet:University of California, Los Angeles: Employment. Tallman:Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; Cellerant: Research Funding; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biosight: Research Funding; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biosight: Research Funding; Biosight: Research Funding; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biosight: Research Funding; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; UpToDate: Patents & Royalties; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biosight: Research Funding; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; UpToDate: Patents & Royalties; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biosight: Research Funding. Wei:Celgene Corp.: Employment, Equity Ownership. Li:Celgene Corp.: Employment, Equity Ownership. Hock:Celgene Corp.: Employment, Equity Ownership. Burgess:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties: Patent - CD47 antibodies and methods of use thereof; University of California: Other: Volunteer clinical faculty, without salary, Patents & Royalties: Patent - T315A and F317I mutations of BCR-ABL kinase domain. Hege:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties; Mersana Therapuetics: Membership on an entity's Board of Directors or advisory committees; Arcus Biosciences: Membership on an entity's Board of Directors or advisory committees; Society for Immunotherapy of Cancer: Membership on an entity's Board of Directors or advisory committees. Stock:Agios: Membership on an entity's Board of Directors or advisory committees; Research to Practice: Honoraria; UpToDate: Honoraria; Daiichi: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Kite, a Gilead Company: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees.

Background: Cluster of differentiation 47 (CD47), a widely expressed cell-surface ligand,is overexpressed in various malignancies and is correlated with worse outcomes in NHL. Interaction of CD47 and signal regulatory protein-α (SIRPα) delivers an antiphagocytic 'don't eat me' signal to promote tumor cell evasion from macrophages. CC-90002 is a humanized IgG4-PE CD47 antibody that inhibits CD47-SIRPα interaction and enabled phagocytosis across a panel of cancer cell lines (Narla et al. AACR.2017). In addition to high binding affinity, CC-90002 is potentially differentiated from other CD47 immunotherapies by its lack of ability to induce hemagglutination of red blood cells or hemolysis in nonclinical studies. CD47 antibodies can synergize with the CD20 antibody rituximab to induce phagocytosis of NHL cells in vitroand to eliminate lymphoma in mouse models (Chao et al. Cell.2010). We therefore examined CC-90002 plus rituximab for treatment of R/R NHL. Methods: This 2-part, phase I, multicenter study (CC-90002-ST-001; NCT02367196) is evaluating CC-90002 in subjects with advanced solid and hematologic malignancies. Part B of the study (reported here) is examining CC-90002 in combination with rituximab in subjects with CD20-positive R/R NHL. Dose escalation followed a modified 3+3 design. Subjects received escalating doses of CC-90002 intravenously at 4, 8, 15, 20, or 30 mg/kg every 2 weeks (Q2W) on days 1 and 15 plus rituximab 375 mg/m2 given on days −15, −8, and −1 and day 8 of cycles 1-6, 8, 10, and 12 in 28-day cycles. Primary endpoints are dose-limiting toxicities (DLTs), nontolerated dose (NTD), and maximimum tolerated dose. Secondary endpoints are pharmacokinetics, preliminary efficacy per International Working Group Response Criteria for NHL (Cheson et al. J Clin Oncol.2014), and frequency of antidrug antibodies. Results: Overall, 28 subjects have been enrolled and 24 were treated. As of July 5, 2019, 20 subjects had discontinued the study, most commonly for progressive disease (PD; n=9) or death (n=7). The median age at enrollment was 64 years (range, 27−81), and subjects had received a median of 3 prior systemic therapies (range, 2−9). Subjects received a median of 2 cycles of CC-90002 plus rituximab (range, 1−18). There were no CC-90002 dose reductions but 7 subjects had their dose interrupted, mostly because of thrombocytopenia and neutropenia. The NTD was established as 30 mg/kg Q2W.DLTs occurred in 3 subjects; 1 subject developed dyspnea attributed to an infusion-related reaction at 15 mg/kg Q2W CC-90002 and 2 subjects had grade 3 thrombocytopenia requiring platelet transfusion occurring at 30 mg/kg Q2W CC-90002. The most common adverse events (AEs) were hematologic (Table). Although anemia was common, there was no evidence of hemolysis. The most frequent grade 3/4 AEs were neutropenia (38%) and thrombocytoenia (21%). Seven deaths occurred on study or in follow-up, 6 from PD or complications related to NHL and 1 due to an AE (cytokine release syndrome in a subject who discontinued CC-90002 for PD and enrolled in another trial within the follow-up period). There were no treatment-related deaths. The overall response rate was 13% (95% CI, 2.7−32.4) and the disease control rate was 25% (95% CI, 9.8−46.7; Figure). One subject achieved a durable complete response (8 mg/kg; ongoing in cycle 18) and 2 had partial responses (15 mg/kg and 20 mg/kg); 3 subjects had stable disease. Among responders, the median duration of response was 3.9 months (95% CI, 1.9−3.9). CC-90002 exhibited linear pharmacokinetics at doses ≥15 mg/kg, suggesting target saturation at 15 mg/kg. In addition, a longer half-life was observed at higher (≥15 mg/kg) versus lower doses (t1/2≈ 3−7 days vs 1 day). Conclusions: The CD47-SIRPα checkpoint inhibitor, CC-90002,plus rituximab demonstrated tolerability and modest clinical activity in this early-phase study of heavily pretreated R/R NHL subjects. AEs were predominantly grade 1/2; cytopenias were the most common AEs with dose-limiting thrombocytopenia observed at 30 mg/kg Q2W. In contrast to other CD47-targeting immunotherapies and consistent with results of preclinical studies of CC-90002, hemolysis at a starting dose of up to 30 mg/kg CC-90002 was not observed. These preliminary data support further evaluation of targeting the CD47-SIRPα pathway in combination with rituximab in NHL. Disclosures Abrisqueta: Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau; Roche: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau. Sancho:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Other: Advisory board; Novartis: Honoraria; Kern Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Celltrion: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squib: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy; F. Hoffmann-La Roche Ltd: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cordoba:Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Speakers Bureau; Kyowa-Kirin: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Research Funding, Speakers Bureau; Roche: Honoraria, Speakers Bureau; FUNDACION JIMENEZ DIAZ UNIVERSITY HOSPITAL: Employment; Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy. Persky:Sandoz: Consultancy; Morphosys: Other: Member, Independent Data Monitoring Committee; Debiopharm: Other: Member, Independent Data Monitoring Committee; Bayer: Consultancy. Andreadis:Juno: Research Funding; Pharmacyclics: Research Funding; Roche: Equity Ownership; Novartis: Research Funding; Jazz Pharmaceuticals: Consultancy; Celgene: Research Funding; Kite: Consultancy; Gilead: Consultancy; Merck: Research Funding; Genentech: Consultancy, Employment. Huntington:Pharmacyclics: Honoraria; Genentech: Consultancy; Bayer: Consultancy, Honoraria; DTRM Biopharm: Research Funding; AbbVie: Consultancy; Celgene: Consultancy, Research Funding. Carpio:University Hospital Vall D'Hebron: Employment. Morillo Giles:Hospital Universitario Fundacion Jimenez Diaz: Honoraria. Wei:Celgene Corp.: Employment, Equity Ownership. Li:Celgene Corp.: Employment, Equity Ownership. Zuraek:Celgene Corp.: Employment, Equity Ownership, Other: Travel, Accommodations, Expenses. Burgess:University of California: Other: Volunteer clinical faculty, without salary, Patents & Royalties: Patent - T315A and F317I mutations of BCR-ABL kinase domain; Celgene Corporation: Employment, Equity Ownership, Patents & Royalties: Patent - CD47 antibodies and methods of use thereof. Hege:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties; Arcus Biosciences: Membership on an entity's Board of Directors or advisory committees; Mersana Therapuetics: Membership on an entity's Board of Directors or advisory committees; Society for Immunotherapy of Cancer: Membership on an entity's Board of Directors or advisory committees. Martín:iQone: Consultancy; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Other: Travel Expenses; Celgene: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Kiowa Kirin: Consultancy; Servier: Honoraria, Other: Travel Expenses; Teva: Research Funding; Janssen: Honoraria, Other: Travel Expenses, Research Funding.

Asciminib (Scemblix) is a first-in-class BCR::ABL1 inhibitor that works by specifically targeting the ABL myristoyl pocket (STAMP) and has potent activity against the T315I mutation. This study aimed to characterize the effect of asciminib exposure on disease progression and to elucidate factors influencing efficacy. Our analysis included 303 patients with chronic myeloid leukemia in chronic phase recruited in a phase I study with dose ranging from 10 to 200 mg twice a day (b.i.d.) or 40 to 200 mg once a day (q.d.) (NCT02081378) and in the phase III ASCEMBL (Study of Efficacy of CML-CP Patients Treated With ABL001 Versus Bosutinib, Previously Treated With 2 or More TKIs) study receiving asciminib 40 mg b.i.d. (NCT03106779). A total of 67 patients harbored the T315I mutation. A longitudinal pharmacokinetic/pharmacodynamic model was developed to characterize the exposure-efficacy relationship, in which the efficacy was assessed through BCR::ABL1 transcript levels over time. Specifically, a three-compartment model representing quiescent leukemic stem cells, proliferating bone marrow cells, and resistant cells was developed. Drug killing of the proliferating cells by asciminib was characterized by a power model. A subgroup analysis was performed on the patients with the T315I mutation using a maximum drug effect model to characterize the drug effect. The model demonstrated the appropriateness of a total daily dose of asciminib 80 mg in patients without the T315I mutation and 200 mg b.i.d. in patients with the T315I mutation with further validation in light of safety data. This model captured key characteristics of patients' response to asciminib and helped inform dosing rationale for resistant and difficult-to-treat populations.Chronic myeloid leukemia (CML) is driven by the constitutively active ABL1 tyrosine kinase domain of BCR::ABL1, 1 and studies have shown that BCR::ABL1 transcript levels are correlated with long-term outcomes to tyrosine kinase inhibitors (TKIs) among patients with CML. 2,3 Therefore, BCR::ABL1 and its derived major molecular response (MMR) rate (proportion of patients with BCR::ABL1 ≤ 0.1%), used in phase III studies as a primary end point, is an established surrogate marker to evaluate