Direct Comparison of Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes Targeting STAT3 in a Syngeneic Murine Model of TNBC

RNA interference (RNAi) molecules have tremendous potential for cancer therapy but are limited by insufficient potency after intravenous (IV) administration. We previously found that polymer complexes (polyplexes) formed between 3′-cholesterol-modified siRNA (Chol-siRNA) or DsiRNA (Chol-DsiRNA) and the cationic diblock copolymer PLL[30]-PEG[5K] greatly increase RNAi potency against stably expressed LUC mRNA in primary syngeneic murine breast tumors after daily IV dosing. Chol-DsiRNA polyplexes, however, maintain LUC mRNA suppression for ~48 h longer after the final dose than Chol-siRNA polyplexes, which suggests that they are the better candidate formulation. Here, we directly compared the activities of Chol-siRNA polyplexes and Chol-DsiRNA polyplexes in primary murine 4T1 breast tumors against STAT3, a therapeutically relevant target gene that is overexpressed in many solid tumors, including breast cancer. We found that Chol-siSTAT3 polyplexes suppressed STAT3 mRNA in 4T1 tumors with similar potency (half-maximal ED50 0.3 mg/kg) and kinetics (over 96 h) as Chol-DsiSTAT3 polyplexes, but with slightly lower activity against total Stat3 protein (29% vs. 42% suppression) and tumor growth (11.5% vs. 8.6% rate-based T/C ratio) after repeated IV administration of equimolar, tumor-saturating doses every other day. Thus, both Chol-siRNA polyplexes and Chol-DsiRNA polyplexes may be suitable clinical candidates for the RNAi therapy of breast cancer and other solid tumors.

Increase in Antibody Titers Following Sars-Cov-2 Vaccination Remains Limited for More Than 3 Years after Final Dose of Anti-CD20 Antibody

COVID-19, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a global pandemic. Patients with hematological disorders are known to be at high risk of morbidity and mortality from COVID-19, and vaccines against SARS-CoV-2 have been rapidly developed. Although mRNA vaccines against SARS-CoV-2 are reported to be effective, efficacy in patients with hematological malignancies who have received anti-CD20 antibody treatment remains unclear. Here, we prospectively evaluated the efficacy of BNT162b2 mRNA COVID-19 vaccine in patients with B-cell malignancies treated with anti-CD20 antibody. We first evaluated antibody titers in 12 healthy volunteers (median age 75.5 years, range 57-82) and three lymphoma patients undergoing R-CHOP therapy (73, 81, and 81 years old) who had received 2 vaccine doses of BNT162b2 at pre-vaccination, 21 days after the first dose and 14 days after the second dose of vaccination. IgG antibody titers for S1 protein were measured in serum samples by ELISA. In healthy control subjects, titers were clearly increased. In contrast, no patient treated with R-CHOP developed antibodies even after the second vaccination (Figure A). To determine the SARS-CoV-2-specific T-cell reactivity in these three patients, we evaluated interferon (IFN)-γ response to the SARS-CoV-2 spike peptide before and after the second vaccination dose, and detected IFN-γ responses after vaccination in all three patients (Figure B). Next, to investigate the duration of the effect of anti-CD20 antibody on antibody production to BNT162b2, we enrolled 36 patients (median age 74 years, range 50-87) who had received the final dose of anti-CD20 antibody 48-1320 (median 571) days before vaccination. S1 antibody titers were measured 14 days after the second dose of vaccination. Diagnoses included diffuse large B-cell lymphoma (n = 21), follicular lymphoma (n = 9), lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (n = 3), and mantle cell lymphoma (n = 3). Thirty-four patients had received rituximab-based and 2 had received obinutuzumab-based therapy, with a median of 6 (range 3-20) courses. No patient had received any chemotherapy after the last anti-CD20 antibody dose. No patient vaccinated within close to one year or sooner after the last anti-CD20 antibody administration showed an increase in titers. Furthermore, titers in most patients were lower than in healthy volunteers even among those vaccinated more than three years after the last administration (Figure C). Finally, we investigated surrogate markers of antibody production ability. We found no relationship between the percent of B-cells (CD19-positive cells) and S1 antibody titers (Figure D), whereas all patients (n = 9) with total IgG level below lower normal limit (< 870 mg/dl) had low S1 antibody titers (< 0.16), below the lowest optical density (O.D.) value in healthy donors (Figure E). These findings indicate that the antibody-mediated response to vaccination in patients following treatment with anti-CD20 antibody was considerably impaired for an extended time. Alternative protection strategies for these patients are therefore warranted. Although T-cell responses were detected, we recommend that these patients continue to wear a face mask and wash their hands to prevent COVID-19 even after vaccination. Figure 1 Figure 1. Disclosures Yakushijin: Chugai pharmaceutical Co. Ltd.: Research Funding; Jazz pharmaceuticals: Research Funding; Nippon Shinyaku: Honoraria. Kiyota: Bristol-Myers Squibb: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Astra-Zeneca: Honoraria, Research Funding; Roche Phamaceuticals: Research Funding; Merck Biopharma: Honoraria; Merck Sharp & Dohme: Honoraria; Eisai: Honoraria; Bayer: Honoraria. Matsuoka: Takeda Pharmaceutical Company: Research Funding; Sysmex: Research Funding. Minami: Behring: Research Funding; CSL: Research Funding; Yakult Honsha: Research Funding; Nippon Shinyaku: Research Funding; Astellas Pharma: Research Funding; Asahi-Kasei Pharma: Research Funding; Eli Lilly: Honoraria, Research Funding; Taiho Pharmaceutical: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; MSD: Honoraria, Research Funding; Merck Serono: Honoraria, Research Funding; Kyowa-Kirin: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; DaiichiSankyo: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Boehringer Ingelheim: Honoraria, Research Funding; Bayer Yakuhin: Honoraria, Research Funding; Nippon Kayaku: Research Funding; Celgene: Honoraria; Ohtsuka Pharmaceutical: Honoraria; Shire Japan: Honoraria; Genomic Health: Honoraria; Abbvie: Honoraria.

Infantil Hemangioma and Optimum Dose of Propranolol Treatment: A Retrospective Tertiary-Center Study

Background/Objectives: Propranolol is the mainstay treatment of infantile hemangioma, and the optimal dose is unclear. Few studies are comparing the efficacy of propranolol dose of 2 vs.3 mg/kg/day. We compared the efficacy between these two doses and propranolol groups with no treatment group. Methods: One hundred eight patients with infantile hemangioma (15 days-27 months of age) were examined. The patients with high-risk features and/or a score of >6 points are given propranolol with a final dose of 2 or 3 mg/kg/day according to tolerance for 6-12 months. The resolutions rates for propranolol vs. placebo and propranolol 2 mg/kg/day vs. 3 mg/kg/day are compared. Results: The demographic and clinical features of the groups ( the non-treatment, propranolol 2 mg/kg/day group, propranolol 3 mg/kg/day group) are similar. Propranolol is significantly efficent in infantil hemangioma treatment (p<0.001). The resolution rates are not statistically different between 2 mg/kg/day propranolol group vs 3 mg/kg/day propranolol group at the sixth (68,59 ± 28,95 vs 73,44 ± 32,54)(p=0,673) and twelfth month (p=0,673) (89,08 ± 46,58 vs 91,13 ± 37,46 respectively )of follow up. A milld (n=3)(4%) adverse event was reported with no need for cessation.Conclusions: Propranolol is a safe drug for treating infantile hemangioma with an ideal dose of 2 mg/kg/day rather than 3 mg/kg/day.

Pharmacokinetics of cannabichromene in a medical cannabis product also containing cannabidiol and Δ9-tetrahydrocannabinol: a pilot study

Purpose Cannabichromene (CBC) is a phytocannabinoid commonly found in cannabis, yet its acute post-dose pharmacokinetics (PK) have not been examined in humans. This is a secondary data analysis from a trial investigating Spectrum Yellow oil, an oral cannabis product used for medical purposes that contained 20 mg cannabidiol (CBD), 0.9 mg Δ9-tetrahydrocannabinol (THC), and 1.1 mg CBC, per 1 mL of oil. Methods Participants (N = 43) were randomized to one of 5 groups: 120 mg CBD, 5.4 mg THC, and 6.6 mg CBC daily; 240 mg CBD, 10.8 mg THC, and 13.2 mg CBC daily; 360 mg CBD, 16.2 mg THC, and 19.8 mg CBC daily; 480 mg CBD, 21.6 mg THC, and 26.4 mg CBC daily; or placebo. Study medication was administered every 12 h for 7 days. Plasma CBC concentrations were analyzed by a validated two-dimensional high-performance liquid chromatography–tandem mass spectrometry assay. Results After a single dose and after the final dose, the Cmax of CBC increased by 1.3–1.8-fold for each twofold increase in dose; the tmax range was 1.6–4.3 h. Based on the ratio of administered CBD, THC, and CBC to the plasma concentration, the dose of CBD was 18 times higher than the dose of CBC, yet the AUC0–t of CBD was only 6.6–9.8-fold higher than the AUC0–t of CBC; the dose of THC was similar to the dose of CBC, yet THC was quantifiable in fewer plasma samples than was CBC. Conclusions CBC may have preferential absorption over CBD and THC when administered together. Trial Registration: Australian New Zealand Clinical Trials Registry #ACTRN12619001450101, registered 18 October 2019.

Direct Comparison of Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes Targeting STAT3 in a Syngeneic Murine Model of TNBC

RNA interference (RNAi) molecules have tremendous potential for cancer therapy but are limited by insufficient potency after i.v. administration. We previously found that polymer complexes (polyplexes) formed between 3&rsquo;-cholesterol-modified siRNA (Chol-siRNA) or DsiRNA (Chol-DsiRNA) and the cationic diblock copolymer PLL[30]-PEG[5K] greatly increase RNAi potency against stably expressed LUC mRNA in primary syngeneic murine breast tumors after daily i.v. dosing. Chol-DsiRNA Polyplexes, however, maintain LUC mRNA suppression ~48 h longer after the final dose than Chol-siRNA Polyplexes, suggesting they are a better candidate formulation. Here, we directly compared the activities of Chol-siRNA and Chol-DsiRNA Polyplexes in primary murine 4T1 breast tumors against STAT3, a therapeutically relevant target gene overexpressed in many solid tumors including breast cancer. We found that Chol-siSTAT3 Polyplexes suppressed STAT3 mRNA in 4T1 tumors with similar potency (half-maximal ED50 0.3 mg/kg) and kinetics over 96 hours as Chol-DsiSTAT3 Polyplexes but with slightly lower activity against total Stat3 protein (29% vs. 42% suppression) and tumor growth (11.5% vs. 8.6% rate-based T/C ratio) after repeated i.v. administration of tumor-saturating doses every other day. Thus, both Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes may be suitable clinical candidates for RNAi therapy of breast cancer and other solid tumors.

482 Solriamfetol Titration & AdministRaTion (START): dosing and titration strategies in patients with narcolepsy starting solriamfetol

Introduction Solriamfetol (Sunosi®), a dopamine/norepinephrine reuptake inhibitor, is approved (US and EU) to treat excessive daytime sleepiness (EDS) in adults with narcolepsy (75–150 mg/day) or obstructive sleep apnea (OSA) (37.5–150 mg/day). Previous research examined the use of solriamfetol in clinical trial settings but research in real-world settings was not previously conducted. This study characterized real-world dosing and titration with solriamfetol. Methods This virtual, descriptive study included a quantitative retrospective patient chart review among US-based physicians prescribing solriamfetol. Target enrollment was 25 physicians treating patients with EDS associated with OSA or narcolepsy. Titration strategies were classified as de novo (no prior EDS medication), transition (switched/switching from existing EDS medications onto solriamfetol), or add-on (adding solriamfetol to current EDS medication). Results Twenty-six physicians participated. Seventy patients with narcolepsy were analyzed (type 1, n=24; type 2, n=46; mean±SD age, 40±11 years; 57% female; 6 also had OSA); EDS was primarily moderate (59%) or severe (36%). Solriamfetol initiation was de novo for 19 (27%) patients, transition for 31 (44%), and add-on for 20 (29%). Most patients (86%) started solriamfetol at 75 mg; 11% and 3% started at 37.5 mg and 150 mg, respectively. The final/stable dose was 150 mg for 76% (53/70) of patients and 75 mg for 24% (17/70). Most patients (67%) had 1 dose adjustment to reach their final dose; 4% had 2 adjustments, 4% had 3 adjustments, and 24% had none. Mean±SD time to reach a stable dose was 15.1±11.8 days overall, 19.4±9.3 days with de novo treatment, 15.0±13.7 days for transition, and 11.9±8.6 days for add-on. Physicians most frequently considered EDS severity (44% of patients) when titrating. Among patients transitioning, 14/22 (64%) taking a wake-promoting agent (WPA) discontinued it abruptly while 5/9 (56%) taking a stimulant were tapered off. Physicians were overall likely (n=33, 47%) or very likely (n=30, 43%) to recommend their approach for similar patients. Conclusion In a real-world study, the majority of physicians prescribing solriamfetol for patients with narcolepsy started at the 75-mg dose, tapered stimulants but abruptly discontinued WPAs, and made 1 adjustment to reach a stable dose across 15 days on average. Support (if any) Jazz Pharmaceuticals

Colitis presenting 5 months after the final dose of anti-PD-1: long-term monitoring is warranted after adjuvant therapy

Immune checkpoint inhibitors have been approved as adjuvant therapy. Adverse immune events occurred during the administration of treatment, and delayed immune-related events have low incidence. A 66-year-old man was treated for hypopharynx cancer in 2012. In 2019, he was treated for a new oropharynx cancer. After undergoing surgery and complete response, the patient received nivolumab as adjuvant treatment. 5 months after the last dose of nivolumab, he presented with grade III diarrhea and abdominal pain for 3 weeks. Rectoscopy showed infiltration of mucous by lymphocytes. Corticosteroid was started resulting in a rapid decrease in symptom severity. With the increasing immune checkpoint inhibitors in adjuvant therapy, strict surveillance and education of patient in remission is necessary.

A151 COMPARABLE NEONATAL AND PREGNANCY-RELATED OUTCOMES BETWEEN EARLY AND LATE DISCONTINUATION OF BIOLOGICS IN PREGNANT WOMEN WITH INFLAMMATORY BOWEL DISEASE

Background Inflammatory bowel disease (IBD) disease activity during pregnancy is related to adverse neonatal and pregnancy-related outcomes. Biologics are used to suppress disease activity, however, since there is known transplacental passage, the American Gastroenterology Association (AGA) recommends timing the final dose with drug-specific half-lives although there is little evidence demonstrating adverse outcomes. Aims We aim to assess the safety of early versus late discontinuation of biologics according to drug-specific half-lives by comparing various neonatal and pregnancy-related outcomes. Methods This is a REB approved single-center retrospective cohort study on all patients with IBD ≥18 years of age on a biologic agent prior to conception, have a documented final dose during pregnancy, and were seen at Mount Sinai Hospital from 2016–2019. Neonate and pregnancy-related outcomes were compared amongst the two groups (Table 1) using the student’s t-test (birthweight, gestational age, Apgar scores) and Fischer’s exact test (NICU admission, congenital anomalies, GBS, chorioamnionitis) analyzed in SPSS Version 27. The level of significance was set at p&lt;0.05. Results We identified 53 patients on biologics pre-conception. 26 patients had a documented final dose (19 early cohort, 7 late cohort) and were included in the analysis. Aside from mean birthweight (3014 vs 3561 g, p=0.036), there were no statistically significant differences between the early and late cohorts for gestational age (37.4 vs 39.0 weeks, p=0.20), 1- and 5-min Apgar scores (7.8 vs 8.8, p=0.37 and 8.5 vs 9.0, p=0.49), NICU admissions (p=0.54), congenital anomalies (p=1.00), GBS (p=0.55), and chorioamnionitis (p=1.00). Conclusions Overall, our study suggests that early and late discontinuation of biologics have comparable safety profiles based on various neonatal and pregnancy-related outcomes. In fact, we see significantly higher birthweights in the late cohort along with a consistent (non-statistically significant) trend of later gestational ages, and higher Apgar scores. Further, no cases involving NICU admissions, congenital abnormalities, GBS, or chorioamnionitis were seen in the late cohort. Next, we hope to verify our findings by conducting a prospective cohort study with a larger study population and more comprehensive data collection. This will provide higher statistical power and allow for additional subgroup analyses based on objective disease activity (FCP levels) and therapeutic drug monitoring (serum drug levels). Funding Agencies None

Exploration of the Optimal Desmopressin Treatment in Children With Monosymptomatic Nocturnal Enuresis: Evidence From a Chinese Cohort

Objectives: Nocturnal enuresis (NE) is a common pediatric condition, and desmopressin (dDAVP) is a first-line therapy for NE. The standard initial dosage of dDAVP is 0. 2 mg/day, and most guidelines recommend that the dose should be increased at 0.2 mg increments until dryness is achieved or to the maximal recommended dose. However, previous evidence has shown that this strategy seems insufficient to further improve efficacy and results in unnecessarily high doses for some patients. Our study aimed to assess the efficacy of our modified dDAVP treatment regimen in children with MNE in China and evaluate predictive factors associated with the dDAVP response.Methods: All MNE patients at the Department of Nephrology at Children's Hospital of Fudan University from January to December 2019 were prospectively and consecutively enrolled. dDAVP treatment comprised a dose titration period and a 3-month maintenance period. The efficacy of dDAVP was assessed according to the latest International Children's Continence Society criteria at the end of the study. Predictive factors were evaluated by logistic regression analysis.Results: Overall, 322 MNE patients were enrolled in our study, and 225 (69.9%) completed the study. The intention to treat analysis showed that the overall dDAVP response rate was 69.9%: among these patients 32.3% were complete responders, and 37.6% were partial responders. At the end of the study, 194/225 (86.2%) patients received a final dose of 0.2 mg, 24/225 (10.7%) patients received a final dose of 0.3 mg, and 7/225 (3.1%) patients received a final dose of 0.4 mg. Multivariate analysis showed that patients requiring lower doses to achieve responses were significantly more likely to experience complete response during the maintenance period [odds ratio (OR)=9.683; 95% confidence interval (CI), 2.770–33.846].Conclusions: Our results indicate that the dDAVP treatment regimen provides a comparable efficacy to the international conventional treatment regimen with a lower overall dose. Low-dose responders were likely to achieve a complete response without increasing the dose; in these cases, the maximum dose might not be necessary.