Fostamatinib is a tyrosine kinase inhibitor with demonstrated activity against spleen tyrosine kinase (SYK). The major metabolite of fostamatinib, R406, inhibits signal transduction of Fc-activating receptors and B-cell receptor. The fostamatinib metabolite R406 reduces antibody-mediated destruction of platelets.
Molecular weight: 580.47
Formula: C23H26FN6O9P
CLOGP: 1.56
LIPINSKI: 2
HAC: 15
HDO: 4
TPSA: 186.72
ALOGS: -4.05
ROTB: 10
Status: ONP
Legend: OFP - off patent OFM - off market ONP - on patent
Drug dosage:
Dose
Unit
Route
0.20
g
O
ADMET properties:
None
Approvals:
Date
Agency
Company
Orphan
Jan. 9, 2020
EMA
Instituto Grifols S.A.
April 17, 2018
FDA
RIGEL PHARMS INC
Dec. 23, 2022
PMDA
Kissei Pharmaceutical Co., Ltd.
FDA Adverse Event Reporting System (Female)
MedDRA adverse event term
Likelihood ratio
Likelihood ratio threshold
Patients taking drug having adverse event
Patients taking drug not having adverse event
Patients not taking drug having adverse event
Patients not taking drug not having adverse event
Platelet count decreased
88.42
44.43
31
352
116091
63372548
Platelet count
78.80
44.43
8
375
18
63488621
FDA Adverse Event Reporting System (Male)
MedDRA adverse event term
Likelihood ratio
Likelihood ratio threshold
Patients taking drug having adverse event
Patients taking drug not having adverse event
Patients not taking drug having adverse event
Patients not taking drug not having adverse event
Platelet count decreased
67.50
51.57
26
201
119691
34837013
FDA Adverse Event Reporting System (Geriatric)
MedDRA adverse event term
Likelihood ratio
Likelihood ratio threshold
Patients taking drug having adverse event
Patients taking drug not having adverse event
Patients not taking drug having adverse event
Patients not taking drug not having adverse event
Platelet count
65.38
40.13
7
283
56
79744042
Platelet count decreased
62.24
40.13
24
266
194640
79549458
FDA Adverse Event Reporting System (Pediatric)
None
Pharmacologic Action:
Source
Code
Description
ATC
B02BX09
BLOOD AND BLOOD FORMING ORGANS ANTIHEMORRHAGICS VITAMIN K AND OTHER HEMOSTATICS Other systemic hemostatics
Acid dissociation constants calculated using MoKa v3.0.0
Dissociation level
Dissociation constant
Type (acidic/basic)
pKa1
1.54
acidic
pKa2
6.59
acidic
pKa3
5.0
Basic
pKa4
4.34
Basic
Orange Book patent data (new drug applications)
Formulation strength
Trade name
Applicant
Application number
Approval date
Type
Dose form
Route
Patent number
Patent expiration date
Patent use
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
9266912
Jan. 19, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
9266912
Jan. 19, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
7538108
March 28, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
7538108
March 28, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
7989448
June 12, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
7989448
June 12, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8163902
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8912170
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
9283238
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8163902
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8912170
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
9283238
June 17, 2026
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8951504
July 27, 2032
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
8951504
July 27, 2032
TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
Orange Book exclusivity data (new drug applications)
Formulation strength
Trade name
Applicant
Application number
Approval date
Type
Dose form
Route
Exclusivity date
Description
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
April 17, 2023
NEW CHEMICAL ENTITY
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
April 17, 2023
NEW CHEMICAL ENTITY
EQ 100MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
April 17, 2025
FOR THE TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT
EQ 150MG BASE
TAVALISSE
RIGEL PHARMS INC
N209299
April 17, 2018
RX
TABLET
ORAL
April 17, 2025
FOR THE TREATMENT OF THROMBOCYTOPENIA IN ADULT PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIA (ITP) WHO HAVE HAD AN INSUFFICIENT RESPONSE TO A PREVIOUS TREATMENT