Syk Inhibition in MItigating Lung Allograft Rejection (SIMILAR): A Trial to Evaluate the Safety and Tolerability of Fostamatinib in Lung Transplant Patients With Donor-Specific Antibodies

Launched by NATIONAL HEART, LUNG, AND BLOOD INSTITUTE (NHLBI) · Apr 28, 2025

Keywords

ClinConnect Summary

The SIMILAR trial is studying a medication called fostamatinib to see if it can help lung transplant patients who have developed donor-specific antibodies (DSA). These antibodies can attack the new lungs, making the body more likely to reject the transplant. The goal of the study is to determine if fostamatinib is safe and can help prevent this rejection, potentially improving outcomes for these patients.

To participate in this trial, you must be at least 18 years old and have recently tested positive for DSA after receiving your first lung transplant. Participants will continue their usual care while taking the study medication, which is a pill taken by mouth. For two weeks, participants will take one pill daily, and then for the next six weeks, they will take two pills daily. Throughout the study, participants will have regular clinic visits every two weeks to monitor their health and respond to any questions. After finishing the medication, there will be a follow-up visit four weeks later. This study is not yet recruiting, so keep an eye out if you think you might be eligible!

Gender

ALL

Eligibility criteria

• * INCLUSION CRITERIA:
• Subjects who do not meet any of the following criteria during screening will not be randomized but will be counted toward study accrual. Screen failures may be rescreened at a later time if the reason for screening failure is revised. In order to be eligible to participate in this study, an individual must meet all of the following criteria:
• • First time LT recipients
• • Have provided signed written informed consent, prior to performing any study procedure, including screening procedures.
• • Age greater than or equal to 18 years
• • Patients who first test positive for class II DSA between day 21 and day 180 post-transplantation, and screened within 14 days of first testing positive.
• • No prior demonstration of DSA
• • Demonstrate no clinical or spirometry signs of allograft dysfunction at the time of enrollment.
• * Have adequate liver function, as defined by:
• • Serum aspartate aminotransferase (AST) \<=1.5 x Upper Limit of Normal (ULN) (unless the increased AST is assessed by the Investigator as due to hemolysis) and alanine aminotransferase (ALT) \<=1.5 x ULN.
• • Absolute neutrophil count \>=1.0 x 10\^9/L.
• • Hemoglobin \>= 9 g/dL
• • For women of reproductive potential, have a negative serum pregnancy test during the screening period. Women of reproductive potential are defined as sexually mature women who have not undergone a hysterectomy, bilateral oophorectomy, or tubal occlusion; or who have not been naturally postmenopausal (i.e., who have not menstruated at all for at least the preceding 1 year prior to signing informed consent unrelated to hormonal contraception).
• • For women of reproductive potential, be abstinent as part of their usual lifestyle, or agree to use 2 effective forms of contraception from the time of giving informed consent, during the study, and for 28 days following the last dose of study treatment. An effective form of contraception is defined as hormonal oral contraceptives, injectables, patches, intrauterine or subdermal contraceptive implants, and barrier methods.
• • Be willing to comply with all study procedures for the duration of the study.
• EXCLUSION CRITERIA:
• An individual who meets any of the following criteria will be excluded from participation in this study:
• * Have a significant medical condition that confers an unacceptable risk to participating in the study, and/or that could confound the interpretation of the study data. Such significant medical conditions include, but are not limited to the following:
• • History of neutropenia (benign ethnic neutropenia and/or acquired neutropenia).
• • History of posterior reversible encephalopathy syndrome (PRES)
• • History of poorly controlled hypertension or hypertensive crises (defined as systolic blood pressure \>=180 mmHg or average diastolic blood pressure \>=120 mmHg based on an average of 3 blood pressure readings despite adequate antihypertensive therapy) unless controlled for \>90 days prior to enrollment.
• • History of positive post-transplant active hepatitis C and/or hepatitis B viral infection.
• • History of drug-induced cholestatic hepatitis.
• • History of any primary malignancy.
• • Testing positive for human immunodeficiency virus 1 or 2 Ab with evidence for ongoing active infection (i.e., CD 4 count \<400/microliter and viral load \>100,000 copies/ml) on antiretroviral therapy.
• • Current or recent history of psychiatric disorder that, in the opinion of the Investigator or Medical Monitor, could compromise the ability of the subject to cooperate with study visits and procedures.
• • Are currently enrolled in another therapeutic clinical trial involving ongoing therapy with any investigational or marketed product or placebo.
• • Having had a prior lung or any organ transplant.
• • Currently pregnant or lactating.
• • Estimated glomerular filtration (eGFR) rate less than 30 mL/min.
• • Current or history of grade 3 diarrhea.
• • Subjects on strong CYP3A4 inducers.
• • Subjects who have received prior treatment for DSA.