Development of a dso-market on flexibility services

BACKGROUND: Several of the currently used anticancer drugs may variably affect thyroid function, with impairment ranging from modified total but not free concentration of thyroid hormones to overt thyroid disease. SUMMARY: Cytotoxic agents seem to alter thyroid function in a relatively small proportion of adult patients. Anticancer hormone drugs may mainly alter serum levels of thyroid hormone-binding proteins without clinically relevant thyroid dysfunction. Old immunomodulating drugs, such as interferon-α and interleukin-2, are known to induce variably high incidence of autoimmune thyroid dysfunction. Newer immune checkpoint inhibitors, such as anti-CTLA4 monoclonal antibodies, are responsible for a relatively low incidence of thyroiditis and may induce secondary hypothyroidism resulting from hypophysitis. Central hypothyroidism is a well-recognized side effect of bexarotene. Despite their inherent selectivity, tyrosine kinase inhibitors may cause high rates of thyroid dysfunction. Notably, thyroid toxicity seems to be restricted to tyrosine kinase inhibitors targeting key kinase-receptors in angiogenic pathways, but not other kinase-receptors (e.g., epidermal growth factor receptors family or c-KIT). In addition, a number of these agents may also increase the levothyroxine requirement in thyroidectomized patients. CONCLUSIONS: The pathophysiology of thyroid toxicity induced by many anticancer agents is not fully clarified and for others it remains speculative. Thyroid dysfunction induced by anticancer agents is generally manageable and dose reduction or discontinuation of these agents is not required. The prognostic relevance of thyroid autoimmunity, overt and subclinical hypothyroidism induced by anticancer drugs, the value of thyroid hormone replacement in individuals with abnormal thyrotropin following anticancer systemic therapy, and the correct timing of replacement therapy in cancer patients need to be defined more accurately in well-powered prospective clinical trials

Phosphorylation/dephosphorylation of high-affinity IgE receptors: a mechanism for coupling/uncoupling a large signaling complex.

Engagement of high-affinity IgE receptors leads to activation of tyrosine and serine/threonine kinases and the immediate phosphorylation of receptor beta (serine and tyrosine) and gamma (threonine and tyrosine) chains. Receptor disengagement leads to dephosphorylation of beta and gamma chains via the action of undefined phosphatases. Here we have identified five distinct polypeptides associated with the high-affinity IgE-receptor tetrameric complex, which apparently become phosphorylated and dephosphorylated in sequence with the beta and gamma chains. Like beta chain, polypeptides pp180, pp48, pp42, and pp28 are phosphorylated on serine and tyrosine, whereas pp125 is only phosphorylated on serine. The phosphorylation of each of these receptor-associated polypeptides is antigen-dose dependent and is restricted to activated receptor complexes. Furthermore the physical association between pp125 and the receptor is quantitatively affected by receptor phosphorylation and dephosphorylation, indicating a coupling-uncoupling mechanism. Finally, in vitro kinase experiments show that activated receptor complexes are also physically associated with tyrosine and serine/threonine kinases as part of a larger complex containing the phosphorylated polypeptides

Long-Term Safety Profile of the Oral Spleen Tyrosine Kinase Inhibitor Fostamatinib in Immune Thrombocytopenia (ITP) and Other Diseases

Introduction: Fostamatinib is an oral, potent inhibitor of spleen tyrosine kinase (SYK) with proven efficacy and a manageable safety profile for the treatment of ITP. SYK is situated in an intracellular signaling pathway upstream of Bruton's tyrosine kinase (BTK). Long-term safety data on fostamatinib at various dosing regimens (up to 150 mg BID) has been collected in &amp;gt;4000 patients with ITP, rheumatoid arthritis (RA), and other autoimmune, allergic and neoplastic disorders. The safety and tolerability of fostamatinib were consistent across different patient populations (apart from disease specific events). We present a summary analysis of the fostamatinib safety data from the ITP and RA studies. Methods: Fostamatinib safety data from 2 randomized, double-blind, placebo-controlled, phase 3 studies and the long-term, open-label, extension (OLE) study in ITP were pooled and are based on a starting dose of 200 mg/day, which was increased to 300 mg/day after 4 weeks in 88% of patients. Fostamatinib safety data from 13 phase 2/3 studies in RA were pooled and are based on a dosing regimen of 100-150 mg/day (n=1232) or 200-300 mg/day (n=2205). Results: The pooled data set for ITP included 146 patients; 60% were female, and the median age was 53 years (range 20-88). The mean duration of fostamatinib treatment was 19 months (range &amp;lt;1-62 months), representing 229 patient exposure years. Adverse events (AEs) were reported in 87% of patients, and 63% were mild to moderate. Serious AEs were reported in 31% of patients. The incidence of diarrhea, hypertension, alanine aminotransferase increase (ALT), and aspartate aminotransferase (AST) increase was evaluated in 58 patients who received fostamatinib for ≥1 year. This enabled a comparison of the incidence of these AEs in quartiles over the first year to assess the cumulative effects of fostamatinib. The AEs were reported with decreasing frequency during the second, third, and fourth quarters of fostamatinib treatment compared with the first quarter of the initial year of treatment in the 58 patients (see Figure 1). In the same 58 patients, the use of rescue therapy decreased while median platelet counts increased each quarter of the first year. The pooled data set for RA included 3437 patients who received fostamatinib; 83% were female, and the median age was 54 (range 18 -87). The mean duration of treatment was 18 months (range &amp;lt;1-81) representing 5134 patient exposure years. AEs were reported in 86% of RA patients and were mild to moderate in 73% of RA patients. Serious AEs occurred in 14%. In the placebo-controlled RA studies, 2414 patients received fostamatinib with 823 patient exposure years and 1169 received placebo with 367 patient exposure years. Despite a two-fold (125%) increase in exposure with fostamatinib vs placebo (823 vs 367 patient exposure years), there was only a 26% increase in AEs with fostamatinib vs placebo (68% vs 54%). The most common events in the ITP and RA studies were diarrhea (36% and 24%), hypertension (22% and 19%) and nausea (19% and 8%), apart from disease-related AEs. Epistaxis (19% and 0.5%), petechiae (15% and 0.3%), contusion (12% and 2%), and fatigue (10% and 2%) are associated with ITP and were uncommon in the RA population. Rheumatoid arthritis was reported as an AE in 9% of patients with RA and in none with ITP. Some AEs may be dose-related, and one-third of the RA patients were on lower dosages (100-150 mg/day) than were generally given in the ITP trials (200-300 mg/day). Conclusions: Fostamatinib has been evaluated in &amp;gt;4000 patients across different disease populations. Fostamatinib has a consistent and manageable safety profile. No new safety signals and no cumulative toxicity were observed with up to 81 months (6.8 years) of continuous treatment. Figure 1 Disclosures Tong: Rigel: Current Employment, Current equity holder in publicly-traded company. Numerof:Rigel: Current Employment, Current equity holder in publicly-traded company. Datangel:Rigel: Current Employment, Current equity holder in publicly-traded company. Masuda:Rigel: Current Employment, Current equity holder in publicly-traded company. </jats:sec

IL-2 stimulates the production of IL-1 alpha and IL-1 beta by human peripheral blood mononuclear cells.

Abstract Human PBMC were cultured in medium containing human rIL-2, and the supernatants and cell lysates were analyzed for IL-1 alpha and IL-1 beta using specific RIA. IL-2, but not the excipient detergents included in the rIL-2 preparation, induced the synthesis of both cytokines. The concentrations of IL-1 alpha and IL-1 beta in the cell lysates and supernatants depended on both the concentration of rIL-2 in the culture medium and the duration of the incubation. After 24 h of stimulation, IL-2-induced IL-1 alpha remained almost entirely cell-associated. In contrast, IL-1 beta was present in both cell lysates and supernatants and was more abundant in the latter. SDS-PAGE analysis after radioimmunoprecipitation with anti-IL-1 antibodies indicates that cell-associated IL-1 resulting from IL-2 stimulation was in the form of the 35 kDa IL-1 precursor whereas secreted IL-1 was almost entirely in the form of the mature 18 kDa product. Depletion of monocytes from the PBMC culture substantially reduced IL-2-induced IL-1 production. In addition, Leu M3+ monocytes obtained through FACS, but not CD16+ NK cells, produced both IL-1 alpha and IL-1 beta in response to IL-2. The low level of endotoxin present in the IL-2 preparation used in our studies and the selective inhibition by polymyxin B of LPS-induced, but not IL-2-induced, IL-1 production by PBMC indicate that IL-2-induced IL-1 production was not due to endotoxin contamination. Furthermore, an anti-IL-2 antiserum selectively inhibited IL-1 production in response to IL-2 stimulation. We conclude that IL-2 is a potent inducer of IL-1 synthesis and secretion in vitro and propose that IL-1 may be generated in vivo in patients undergoing IL-2 immunotherapy.</jats:p

Regulation by CD45 of the tyrosine phosphorylation of high affinity IgE receptor beta- and gamma-chains.

Abstract Previous studies using tyrosine phosphatase inhibitors have implicated tyrosine phosphatases in the signal transduction pathway initiated by aggregation of Fc epsilon RI, the high affinity receptor for IgE. To define more precisely a role for the tyrosine phosphatase CD45 in Fc epsilon RI-mediated signaling, we have transfected the three subunits of Fc epsilon RI into wild-type Jurkat and a CD45-deficient Jurkat derivative. Here we demonstrate that CD45 is necessary for the initiation of calcium flux through the transfected Fc epsilon RI. In contrast to the effect of phosphatase inhibitors, the tyrosine phosphorylation levels of beta and gamma after aggregation of Fc epsilon RI are surprisingly reduced, relative to wild-type Jurkat, in the CD45-deficient cells. After reconstitution of the CD45-deficient cells with a chimeric molecule containing the cytoplasmic phosphatase domains of CD45, both the base line and activation-induced tyrosine phosphorylation levels are increased. By examining Lck autophosphorylation, we find that Fc epsilon RI aggregation induces an increase in Lck enzymatic activity only in wild-type Jurkat and the CD45-deficient Jurkat reconstituted with chimeric CD45. This regulation of src-family tyrosine kinase activity may be the means by which CD45 controls aggregation-induced receptor phosphorylation.</jats:p

Fostamatinib for the Treatment of Warm Antibody Autoimmune Hemolytic Anemia (wAIHA): A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Global Study

Background. Warm antibody autoimmune hemolytic anemia (wAIHA) is a rare disorder that can be potentially serious. In wAIHA, autoantibodies react with protein antigens on red blood cells (RBCs) at body temperature, leading to RBC phagocytosis and destruction by Fcg receptor-bearing macrophages in a spleen tyrosine kinase (SYK) dependent signaling pathway (see figure). Fostamatinib is a potent oral SYK inhibitor, approved for the treatment of chronic immune thrombocytopenia (ITP). Fostamatinib prevents platelet destruction in ITP through inhibition of SYK-dependent platelet phagocytosis by Fcγ receptor-bearing macrophages. Fostamatinib was evaluated in a phase 2, open-label, multicenter study (NCT02612558) for the treatment of wAIHA. Results of the study demonstrated that 11 of 25 (44%) patients had markedly improved hemoglobin (Hgb) levels after fostamatinib treatment. Adverse events (AEs) were consistent with those in the fostamatinib safety database of &amp;gt;4000 patients across multiple diseases. Based on the results of the phase 2 study, a phase 3 randomized, double-blind, placebo-controlled, global study (NCT03764618) was initiated to investigate the safety and efficacy of fostamatinib in patients with wAIHA. The phase 3 study began enrolling patients this year and intends to enroll approximately 90 patients at 103 sites in 22 countries across North America, Europe, and Australia. This is the first randomized, double-blind, placebo-controlled, phase 3 study to evaluate a SYK inhibitor for the treatment of wAIHA (see diagram). Study Design and Methods Inclusion Criteria include: Age ≥18;Diagnosis of primary or secondary wAIHA (documented by an IgG or IgA positive direct antiglobulin test [DAT]);failure of ≥1 prior treatment for wAIHA;Haptoglobin &amp;lt;LLN (lower limit of normal) or total bilirubin &amp;gt;ULN (upper limit of normal) or lactate dehydrogenase (LDH) &amp;gt;ULN;Baseline hemoglobin level ≤9 g/dL or, if hemoglobin is &amp;gt;9 g/dL to &amp;lt;10 g/dL, subject must be on a permitted wAIHA treatment AND have symptoms associated with anemia. Exclusion Criteria include: Presence of other forms of AIHA;Uncontrolled or insufficiently controlled hypertension;Neutrophil count &amp;lt;1,000/µL,Platelet count &amp;lt;30,000/μL (unless patient has Evans syndrome);Transaminase levels &amp;gt;1.5 x ULN. Eligible patients will be randomized 1:1 to fostamatinib or placebo for 24 weeks. Randomization will be stratified by concomitant steroid use and severity of anemia at baseline. The starting dose of fostamatinib is 100 mg BID and will be increased to 150 mg BID at Week 4, based on tolerability. The dose may be reduced in the event of dose-limiting AEs. At screening, patients may continue selected concurrent wAIHA therapies including steroids (maximum of 2 therapies) throughout the 24-week study period. A steroid taper protocol will allow reduced used of steroids in patients who have a hemoglobin response. Rescue therapy will be allowed as needed. Patients who complete the phase 3 study can rollover to an open-label extension study. The efficacy endpoints will include hemoglobin response, defined as a hemoglobin level ≥10 g/dL with a ≥2 g/dL increase from baseline (Day 1) in the absence of rescue therapy; duration of hemoglobin response; and the need for wAIHA rescue treatment. The safety endpoints will include the incidence of adverse events. Patients will be evaluated in the clinic, including safety and laboratory assessments, at two-week intervals. Statistics: A sample size of 90 subjects (randomized 1:1) would be required to provide 80% power to detect a difference in the response between the active and placebo groups using the Cochran-Mantel-Haenszel test at a two-sided significance level of 0.05 (based on results of the phase 2 study). The response rate will be compared between groups using a chi-square test adjusted for randomization stratification factors. Current enrollment status: As of July 2, 2020, 83 sites are open to screening (subject to local regulations about the COVID-19 pandemic), and 43 patients have been randomized. Most patients (88%) had primary wAIHA, 12% had secondary disease including chronic lymphocytic leukemia, monoclonal B cell lymphocytosis, scleroderma, smoldering Waldenström's macroglobulinemia, and systemic lupus erythematosus in 1 patient each. The median age at baseline is 61 years (range 28-87), and 63% are female. Figure Disclosures Cooper: Amgen: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau. Numerof:Rigel: Current Employment, Current equity holder in publicly-traded company. Tong:Rigel: Current Employment, Current equity holder in publicly-traded company. Kuter:Incyte: Consultancy, Honoraria; Genzyme: Consultancy, Honoraria; Immunovant: Consultancy, Honoraria; Momenta: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Dova: Consultancy, Honoraria; Merck Sharp Dohme: Consultancy, Honoraria; UCB: Consultancy, Honoraria; Up-To-Date: Consultancy, Honoraria, Patents &amp; Royalties; Zafgen: Consultancy, Honoraria; Sanofi (Genzyme): Consultancy, Honoraria; Shionogi: Consultancy, Honoraria; Shire: Consultancy, Honoraria; Principia: Consultancy, Research Funding; Protalix Biotherapeutics: Consultancy; Shionogi: Consultancy; Actelion (Syntimmune): Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Agios: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Alnylam: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Amgen: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Argenx: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; Immunovant: Other: Travel Expenses, Research Funding; Caremark: Consultancy, Honoraria; CRICO: Consultancy, Honoraria; Kezar Life Sciences, Inc: Other, Research Funding; Principia Biopharma: Consultancy, Honoraria, Other, Research Funding; Protalex: Consultancy, Honoraria, Other, Research Funding; Rigel: Consultancy, Honoraria, Other, Research Funding; Takeda (Bioverativ): Consultancy, Honoraria, Other, Research Funding; Protalex: Consultancy, Honoraria, Research Funding; Kyowa-Kirin: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Platelet Disorder Support Association: Consultancy, Honoraria. </jats:sec

An Observational Study of Fostamatinib As Second Line Therapy in Adult Patients with Immune Thrombocytopenia (ITP) in Real-World Clinical Practice

Abstract Background: In immune thrombocytopenia (ITP), autoantibody-bound platelets are targeted for phagocytosis by Fcγ-receptors on macrophages in a spleen tyrosine kinase (SYK)-dependent signaling pathway. Fostamatinib is a potent oral SYK inhibitor that demonstrated efficacy for the treatment of ITP in two phase 3 randomized, placebo-controlled, double-blind studies and long-term durable responses in the phase 3 open-label extension study. In these studies, 146 patients with ITP were treated with fostamatinib, and 54% had a platelet response (platelet count ≥50,000/µL), which was maintained over a median of 86% of treatment days. These studies led to approval of fostamatinib in the US, Europe, and Canada as a therapy for chronic ITP in adult patients who have had an insufficient response to a prior treatment. Further, a post-hoc analysis showed that, in those who received fostamatinib as second-line therapy (following steroids ± immunoglobulins), 78% achieved a platelet response, which was maintained over a median of 83% of treatment days. 1 Adverse events (AEs) were reported in 72% of second-line patients and 86% of all patients, and common AEs were similar between second-line patients and the total patient population. 1, 2 Bleeding events were reported in 24% of second-line patients vs. 41% of all patients. The results of the post hoc analysis underscored the necessity for further evaluation of fostamatinib as a second-line therapy for ITP. We are conducting a multi-center, prospective, observational, two cohort study of fostamatinib as second-line therapy for the management of ITP in adult patients who have an insufficient response to prior steroids ± immunoglobulins. Aim: This study will evaluate clinical outcomes and safety of fostamatinib as second-line therapy for ITP in adult patients in real-world clinical practice. Patients will also be assessed for quality of life and utilization of health care resources during the study. Methods: The study (FORTE; NCT04904276; O-FOSTA-901) is being conducted at 10 sites across the US and will enroll 45 patients with ITP into 2 cohorts (see Figure). The study is registered at https://clinicaltrials.gov/ct2/show/NCT04904276. The study aims to enroll adult patients with a confirmed diagnosis of ITP and an inadequate response to prior steroids ± immunoglobulins. Patients who have received any prior ITP treatment other than steroids or immunoglobulins will be excluded. Patients who will initiate fostamatinib as second-line therapy at study entry will be enrolled into Cohort 1; patients currently receiving fostamatinib as second-line therapy with the intent to continue treatment will be enrolled in Cohort 2 (historical platelet counts will be retrospectively collected). Patients will be treated by their clinician at the clinician's discretion (not pre-specified by a study protocol). Primary outcome measures will include platelet count over time, duration of platelet count elevation, use of ITP rescue medication, changes in dosing, use of concomitant ITP medications, incidence of serious and ITP-related AEs, and quality of life. Quality of life assessments will utilize the SF-36v2 and ITP-PAQ. All data will be collected at regularly scheduled clinic visits according to the clinician's normal practice for 12 months or until fostamatinib is discontinued. Summary: This ongoing observational study of adult patients with ITP will enable further characterization of the risk/benefit profile of fostamatinib as a second-line treatment for ITP and will provide insight on how clinicians manage ITP in a real-world setting without the constraints of a clinical trial protocol. References 1. Boccia R, et al. Br J Haematol. 2020. 2. Bussel J, et al. Am J Hematol. 2019 Figure 1 Figure 1. Disclosures Hughes: Abbvie: Speakers Bureau; Rigel: Other: Advisory Board, Research Funding; Amgen: Speakers Bureau; Karyopharm: Other: Advisory Board, Speakers Bureau. Numerof: Rigel Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Zider: Rigel Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Chow: Rigel Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company. Goel: Rigel Pharmaceuticals, Inc.: Consultancy; Alexion: Consultancy; NHLBI: Research Funding. </jats:sec