Methotrexate reduces antibody responses to recombinant humanα-galactosidase A therapy in a mouse model of Fabry disease

Abstract

SUMMARYTherapeutic enzymes are often recognized as foreign by the immune system of patients undergoing enzyme replacement therapy. The antibodies that develop may alter pharmacokinetics and biodistribution of the therapeutic protein, may be able to neutralize the activity of the enzyme, or may cause immune reactions in certain patients. We have explored treatment regimens to reduce the antibody response to human a -galactosidase A (r-h a GAL) in Fabry ( a GAL knock-out) and normal BALB/c mice. A wide variety of treatment modalities were tested, including high dose tolerance induction, increased frequency of therapeutic doses and immunosuppressive drugs in combination with administration of enzyme. The most substantial effects were observed in mice injected intravenously with rh a GAL in combination with methotrexate (MTX), which significantly lowered r-h a GAL-specific serum antibody levels. A short course of treatment with MTX was able to reduce antibody and spleen cell proliferative responses to long-term r-h a GAL treatment. MTX was able to suppress the development of r-h a GAL-specific IgG in antigen-primed mice. However, MTX was not effective in dampening robust ongoing antibody responses. These experiments provide a framework for the design of clinical protocols to prevent the drug-specific antibody responses of patients undergoing enzyme replacement therapy.

Transient Low-Dose Methotrexate Induces Tolerance to Murine Anti-Thymocyte Globulin and Together They Promote Long-Term Allograft Survival

“…In contrast to regimens of continual methotrexate dosing, our laboratory has demonstrated previously that a brief course of methotrexate can induce long-term, Ag-specific control of Ab responses throughout repeat administration of protein therapeutics in mice (11,12). This effect is being evaluated in the clinical setting where patients treated with a combination of rituximab and an immune tolerizing regimen of methotrexate appear to develop immune tolerance to the enzyme replacement therapy, Myozyme (38,39).…”

“…For these studies, methotrexate was tested as an immune tolerance inducing agent to mATG and was administered in a similar regimen to that used to tolerize Myozyme and Fabrazyme (11,12). Administration of 5 mg/kg methotrexate within 15 min of as well as 24 and 48 h following the initial three mATG treatments, significantly reduced anti-drug Ab titers by 69% through 6 mo of monthly mATG administration (Fig.…”

“…The mechanism by which methotrexate exerts these effects is presumed to be through killing proliferating cells by inhibiting dihydrofolate reductase and inducing immunosuppression (9,10). Our laboratory has also demonstrated that methotrexate can significantly reduce inflammatory responses against protein therapeutics (11,12). In particular, we have shown that methotrexate significantly decreases the development of antidrug Abs, however, not through immunosuppression but rather through the induction of immune tolerance because only a few short courses of methotrexate can significantly reduce Abs that develop in mice against the enzyme replacement therapies, Fabrazyme and Myozyme, for extended periods of time (11,12).…”

“…Our laboratory has also demonstrated that methotrexate can significantly reduce inflammatory responses against protein therapeutics (11,12). In particular, we have shown that methotrexate significantly decreases the development of antidrug Abs, however, not through immunosuppression but rather through the induction of immune tolerance because only a few short courses of methotrexate can significantly reduce Abs that develop in mice against the enzyme replacement therapies, Fabrazyme and Myozyme, for extended periods of time (11,12). We have also shown that in the context of Fabrazyme, methotrexateinduced control of anti-drug Abs is Ag specific (12).…”

Tolerating enzyme delivery

“…In both studies, a methotrexate regimen substantially reduced levels of antibody against enzyme replacement therapy compared with other immunosuppressant regimens, including the regimen used in the JCI paper. 3,4 Genzyme markets three enzyme replacement therapies: Cerezymeimiglucerase, Fabrazyme agalsidase beta and Myozyme alglucosidase alfa, to treat type 1 Gaucher's disease, Fabry's and Pompe's respectively.…”