The dose was increased until a persistent response was evident, toxicity was reached, or 175 mg twice a day was met. 8 patients achieved persistent responses with platelet counts greater than 50,000 mm3/L on more than 67% of their visits. 3 of these patients had not persistently responded to thrombopoietic agents. 4 others had nonsustained responses. Mean peak platelet count exceeded 100,000 mm3/L in these 12 patients. Toxicity was evidenced primarily in GI-related side effects, notable diarrhea, urgency, and vomiting. 2 patients developed transaminitis.Fostamatinib as a treatment for severe COVID19 complications has finished a Phase 2 trial, and is entering a Phase 3 trial. Rheumatoid arthritis
A phase II study of rheumatoid arthritis patients failing to respond to a biologic agent showed little efficacy as compared to placebo, but the drug was well tolerated. In patients with high inflammatory burden, measured by levels of C-reactive protein, ACR20 was achieved by a significantly higher portion of those in the fostamatinib group (42%) versus the placebo group (26%). Autoimmune thrombocytopenia
Immune thrombocytopenic purpura (ITP) is an autoimmune disease where the immune system attacks and destroys platelets in the blood, causing abnormally low platelet counts. It is characterized by the antibody-mediated destruction of platelets. Patients with ITP have accelerated clearance of circulating IgG-coated platelets via Fcγ receptor-bearing macrophages in the spleen and liver, leading to different levels of thrombocytopenia and variable degrees of mucocutaneous bleeding. Recent studies of ITP pathophysiology suggest decreased platelet production may also be an important component of the thrombocytopenia.
Thanatophoric dysplasia is a severe skeletal disorder characterized by a disproportionately small ribcage, extremely short limbs and folds of extra skin on the arms and legs. Symptoms and signs
Infants with this condition have disproportionately short arms and legs with extra folds of skin. Other signs of the disorder include a narrow chest, small ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes. Thanatophoric dysplasia is a lethal skeletal dysplasia divided into two subtypes. Type I is characterized by extreme rhizomelia, bowed long bones, narrow thorax, a relatively large head, normal trunk length and absent cloverleaf skull. The spine shows platyspondyly, the cranium has a short base, and, frequently, the foramen magnum is decreased in size. The forehead is prominent, and hypertelorism and a saddle nose may be present. Hands and feet are normal, but fingers are short. Type II is characterized by short, straight long bones and cloverleaf skull. It presents with typical telephone-handle shaped long bones and H-shaped vertebrae. Causes
It can be associated with missense mutations in fibroblast growth factor receptor-3. It is inherited in an autosomal dominant manner. Diagnosis
Classification
Infants with type 1 thanatophoric dysplasia also have curved thigh bones, flattened bones of the spine (platyspondyly) and shortened thoracic ribs. Note: Prenatal ultra-sound images of the ribs sometimes appear asymmetrical when in fact they are not. In certain cases, this has caused a misdiagnosis of Osteogenisis Imperfecta (OI) type II.An unusual head shape called kleeblattschädel ("cloverleaf skull") can be seen with type 2 thanatophoric dysplasia.