A Phase 3 study to evaluate the efficacy and safety of an investigational drug (fostamatinib) for the treatment of

Autoimmune Hemolytic Anemia

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Study Design

  • Randomized, double-blind, placebo-controlled group study
  • Patients will receive the study drug or placebo
  • Study dose is taken orally twice daily
  • Visit to your doctor every 2 weeks for 24 weeks
  • After completion of placebo-controlled study, all patients can receive fostamatinib in open label study

Study Objectives

  • Investigate if fostamatinib is effective at increasing the red blood cell count (hemoglobin) in people who have wAIHA and who have had an insufficient response to a previous treatment
  • Investigate the safety of fostamatinib in these patients

Key Inclusion Criteria

  • Age of 18 years or older
  • Must have a diagnosis of primary or secondary wAIHA, as with a positive direct antiglobulin test (DAT) specific for anti-IgG.
  • Did not respond to or did not tolerate at least one prior AIHA treatment regimen (e.g., prednisone, rituximab, splenectomy).
  • Have haptoglobin upper limit of normal (ULN) or lactate dehydrogenase (LDH) >ULN.
  • At screening, subject's hemoglobin level must be ≤9 g/dL OR if hemoglobin value >9 g/dL and <10 g/dL, subject must be on an allowed wAIHA treatment AND the subject must have documented symptoms related to anemia (e.g., weakness, dizziness, fatigue, shortness of breath, chest pain).
  • Subject's concurrent treatment for wAIHA may consist of no more than two of any of the following agents: azathioprine, steroids, erythropoiesis stimulating agent, mycophenolate mofetil, dapsone or danazol at a stable dose.

Key Exclusion Criteria

  • Subject with other types of AIHA (e.g., cold antibody AIHA, cold agglutinin syndrome, mixed type AIHA, or paroxysmal cold hemoglobinuria).
  • Subject has AIHA secondary to autoimmune disease, including systemic lupus erythematosus (SLE), or lymphoid malignancy if the underlying disease is not stable or is not well-controlled on current therapy, per investigator medical judgement.
  • Subject has uncontrolled or poorly controlled hypertension, defined as systolic blood pressure ≥135 mmHg or diastolic blood pressure ≥85 mmHg, whether or not the subject is receiving anti-hypertensive treatment.
  • Subject has one or more of the following laboratory abnormalities at screening: neutrophil count of <1,000/μL or platelet count of <30,000/μL, unless due to Evan syndrome; transaminase levels (i.e., alanine aminotransferase [ALT] or aspartate aminotransferase [AST]) >1.5 x ULN.
  • Has documented HIV infection or active hepatitis B or hepatitis C infection.

A Phase 3 study to evaluate preliminary efficacy and safety of an investigational drug (fostamatinib) in the treatment of

Autoimmune Hemolytic Anemia

Resources for Doctors

Contact: Gabrielle Khedr, (650) 624-1100, clinicaltrials@rigel.com

Contact: Sandra Jimenez, (650) 624-1100, clinicaltrials@rigel.com

Frequently Asked Questions:

1What is warm antibody autoimmune hemolytic anemia (wAIHA)?
Autoimmune hemolytic anemia (AIHA) is a rare, serious blood disorder in which the immune system produces antibodies that result in the destruction (hemolysis) of the body's own red blood cells (RBC). Approximately 1 to 3 in 100,000 adults are diagnosed with AIHA each year and this condition can create a severe, debilitating anemia. In AIHA, the body destroys RBCs at a greater rate than it can produce new RBCs, eventually leading to anemia (low levels of red blood cells), with symptoms such as fatigue, pale color, rapid heartbeat, and shortness of breath. In severe cases fever, chest pain, fainting, or heart failure may occur. Mild splenomegaly (enlargement of the spleen) is typical. wAIHA refers to the presence of antibodies that react with the red blood cell surface at body temperature. It is the most common form of AIHA and can be either primary or secondary to an underlying disease such as systemic lupus erythematosus (SLE) or a lymphoproliferative condition such as or chronic lymphocytic leukemia (CLL) or lymphoma.
2How is wAIHA diagnosed?
Patients with unexplained signs of anemia such as low hemoglobin may have a number of blood tests to confirm a diagnosis of wAIHA. These include:

  • Direct antibody (Coombs) test (DAT) positive for immunoglobulin G (IgG) antibodies. A positive DAT is a key signature of wAIHA.
  • Evidence of some or all of the following indicators of active red blood cell destruction/hemolysis: elevated lactate dehydrogenase, decreased haptoglobin, increased indirect bilirubin, and increased reticulocytes (immature red blood cells).
3What are the current treatment options for AIHA?
Treatment for AIHA varies widely, depending on medical need. A corticosteroid (such as prednisone) is the standard first line treatment given to patients. For patients that do not respond to corticosteroids, second line procedures/treatments include splenectomy (removal of the spleen), rituximab infusion, infusion of intravenous immunoglobulins (IVIG), erythropoietin, and/or danazol.

For patients with severe AIHA without a response to other treatments, immunosuppressive agents such as cyclosporine, mycophenolate mofetil, azathioprine, and cyclophosphamide may be used.

Some patients are not effectively treated by any available therapies due to lack of a stable response or due to side effects of treatment.

4What are the FDA-approved treatment options for AIHA?
Currently, there are no FDA-approved treatments for AIHA.
5What is the investigational drug fostamatinib?
Fostamatinib disodium hexahydrate (fostamatinib) is an oral drug designed to inhibit spleen tyrosine kinase (SYK), a key signaling component of the body's immune process that is believed to lead to red blood cell destruction in wAIHA.

Fostamatinib is commercially available in the U.S. for another indication.

6Has fostamatinib been tested in other diseases?
Yes, in addition to wAIHA, it has also been used in research studies as a potential treatment for rheumatoid arthritis, immune thrombocytopenia (ITP), IgA nephropathy, lymphoma and COVID-19. More information on these studies can be found at www.clinicaltrials.gov.

Fostamatinib is commercially available in the U.S. for another indication.

7What is a SYK inhibitor?
SYK stands for spleen tyrosine kinase, which is an enzyme that plays a very important role in cell signaling related to immune functions in the body. Abnormalities in this cell signaling can contribute to some autoimmune disorders, such as wAIHA and ITP.
8For a list of referenced literature that supported this FAQ section, click here:
  1. https://www.researchgate.net/publication/26732505_Therapeutic_prospect_of_Syk_inhibitors
  2. Klein NP, Ray P, Carpenter D, et al. Rates of autoimmune diseases in Kaiser Permanente for use in vaccine adverse event safety studies. Vaccine. 2010;28(4):1062-1068.
  3. Eaton WW, Rose NR, Kalaydjian A, Pedersen MG, Mortensen PB. Epidemiology of autoimmune diseases in Denmark. J Autoimmun. 2007;29(1):1-9.
  4. Lichtin, A.E., Autoimmune Hemolytic Anemia. Merck Manual (2013). Retrieved from: http://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-hemolysis/autoimmune-hemolytic-anemia
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119858/
  6. National Organization for Rare Disorders, Rare Disease Information for Patients and Families. Retrieved from: https://rarediseases.org/rare-diseases/anemia-hemolytic-acquired-autoimmune/ and https://rarediseases.org/rare-diseases/evans-syndrome/
  7. Lechner K, Jäger U. How I treat autoimmune hemolytic anemias in adults. Blood. 2010;16:1831-8.
  8. Zanella A, Barcellini W. Treatment of autoimmune hemolytic anemia. Haematologica 2014;99(10):1547-1554

The Phase 3 FORWARD study has completed enrollment. Results from the study are expected in mid-2022.