CLINICAL PHARMACOLOGY
Mechanism Of Action
Migalastat is a pharmacological
chaperone that reversibly binds to the active site of the alpha-galactosidase A
(alpha-Gal A) protein (encoded by the galactosidase alpha gene, GLA), which is
deficient in Fabry disease. This binding stabilizes alpha-Gal A allowing its
trafficking from the endoplasmic reticulum into the lysosome where it
exerts its action. In the lysosome, at a lower pH and at a higher concentration
of relevant substrates, migalastat dissociates from alpha-Gal A allowing it to
break down the glycosphingolipids globotriaosylceramide (GL-3) and
globotriaosylsphingosine (lyso-Gb3). Certain GLA variants (mutations) causing
Fabry disease result in the production of abnormally folded and less stable
forms of the alpha-Gal A protein which, however, retain enzymatic activity.
Those GLA variants, referred to as amenable variants, produce alpha-Gal A
proteins that may be stabilized by migalastat thereby restoring their
trafficking to lysosomes and their intralysosomal activity.
In Vitro Amenability Assay
In an in vitro assay (HEK-293 assay), Human Embryonic
Kidney (HEK-293) cell lines were transfected with specific GLA variants
(mutations) which produced mutant alpha-Gal A proteins. In the transfected
cells, amenability of the GLA variants was assessed after a 5-day incubation
with 10 micromol/L migalastat. A GLA variant was categorized as amenable if the
resultant mutant alpha-Gal A activity (measured in the cell lysates) met two
criteria: 1) it showed a relative increase of at least 20% compared to the
pre-treatment alpha-Gal A activity, and 2) it showed an absolute increase of at
least 3% of the wild-type (normal) alpha-Gal A activity.
The in vitro assay did not evaluate trafficking of the
mutant alpha-Gal A proteins into the lysosome or the dissociation of migalastat
from the mutant alpha-Gal A proteins within the lysosome. Also, the in vitro
assay did not test whether a GLA variant causes Fabry disease or not.
The GLA variants which are amenable to treatment with
GALAFOLD, based on the in vitro assay data, are shown in Table 2. Inclusion of GLA
variants in this table does not reflect interpretation of their clinical
significance in Fabry disease. Whether a certain amenable GLA variant in a
patient with Fabry disease is disease-causing or not should be determined by
the prescribing physician (in consultation with a clinical genetics
professional, if needed) prior to treatment initiation. Consultation with a
clinical genetics professional is strongly recommended in cases where the
amenable GLA variant is of uncertain clinical significance (VUS, variant of
uncertain significance) or may be benign (not causing Fabry disease).
Table 2: Amenable GLA Variants Based on the In Vitro
Assay
DNA Change (Long) |
DNA Change (Short) |
Protein Change (1-letter Code) |
Protein Change (3-letter Code) |
c.7C>G |
c.C7G |
p.(L3V) |
p.(Leu3Val) |
c.8T>C |
c.T8C |
p.(L3P) |
p.(Leu3Pro) |
c.[11G>T; 620A>C] |
c.G11T/A620C |
p.(R4M/Y207S) |
p.(Arg4Met/Tyr207Ser) |
c.37G>A |
c.G37A |
p.(A13T) |
p.(Ala13Thr) |
c.37G>C |
c.G37C |
p.(A13P) |
p.(Ala13Pro) |
c.43G>A |
c.G43A |
p.(A15T) |
p.(Ala15Thr) |
c.44C>G |
c.C44G |
p.(A15G) |
p.(Ala15Gly) |
c.53T>G |
c.T53G |
p.(F18C) |
p.(Phe18Cys) |
c.58G>C |
c.G58C |
p.(A20P) |
p.(Ala20Pro) |
|
|
|
|
c.59C>A |
c.C59A |
p.(A20D) |
p.(Ala20Asp) |
c.65T>G |
c.T65G |
p.(V22G) |
p.(Val22Gly) |
c.70T>C or c.70T>A |
c.T70C or c.T70A |
p.(W24R) |
p.(Trp24Arg) |
c.70T>G |
c.T70G |
p.(W24G) |
p.(Trp24Gly) |
c.72G>C or c.72G>T |
c.G72C or c.G72T |
p.(W24C) |
p.(Trp24Cys) |
c.95T>C |
c.T95C |
p.(L32P) |
p.(Leu32Pro) |
c.97G>T |
c.G97T |
p.(D33Y) |
p.(Asp33Tyr) |
c.98A>G |
c.A98G |
p.(D33G) |
p.(Asp33Gly) |
c. 100A>C |
c.A100C |
p.(N34H) |
p.(Asn34His) |
c. 100A>G |
c.A100G |
p.(N34D) |
p.(Asn34Asp) |
c.101A>C |
c.A101C |
p.(N34T) |
p.(Asn34Thr) |
c.101A>G |
c.A101G |
p.(N34S) |
p.(Asn34Ser) |
c.102T>G or c.102T>A |
c.T102G or c.T102A |
p.(N34K) |
p.(Asn34Lys) |
c.103G>C or c.103G>A |
c.G103C or c.G103A |
p.(G35R) |
p.(Gly35Arg) |
c. 104G>A |
c.G104A |
p.(G35E) |
p.(Gly35Glu) |
c.104G>T |
c.G104T |
p.(G35V) |
p.(Gly35Val) |
c.107T>C |
c.T107C |
p.(L36S) |
p.(Leu36Ser) |
c.107T>G |
c.T107G |
p.(L36W) |
p.(Leu36Trp) |
c.108G>C or c.108G>T |
c.G108C or c.G108T |
p.(L36F) |
p.(Leu36Phe) |
c.109G>A |
c.G109A |
p.(A37T) |
p.(Ala37Thr) |
c.110C>T |
c.C110T |
p.(A37V) |
p.(Ala37Val) |
c.122C>T |
c.C122T |
p.(T41I) |
p.(Thr41Ile) |
c. 124A>C or c.124A>T |
c.A124C or c.A124T |
p.(M42L) |
p.(Met42Leu) |
c. 124A>G |
c.A124G |
p.(M42V) |
p.(Met42Val) |
c.125T>A |
c.T125A |
p.(M42K) |
p.(Met42Lys) |
c.125T>C |
c.T125C |
p.(M42T) |
p.(Met42Thr) |
c.125T>G |
c.T125G |
p.(M42R) |
p.(Met42Arg) |
c. 126G>A or c.126G>C or c. 126G>T |
c.G126A or c.G126C or c.G126T |
p.(M42I) |
p.(Met42Ile) |
c.137A>C |
c.A137C |
p.(H46P) |
p.(His46Pro) |
|
|
|
|
c.142G>C |
c.G142C |
p.(E48Q) |
p.(Glu48Gln) |
c.152T>A |
c.T152A |
p.(M51K) |
p.(Met51Lys) |
c.153G>A or c.153G>T or c.153G>C |
c.G153A or c.G153T or c.G153C |
p.(M51I) |
p.(Met51Ile) |
c.[157A>C; 158A>T] |
c.A157C/A158T |
p.(N53L) |
p.(Asn53Leu) |
c.157A>G |
c.A157G |
p.(N53D) |
p.(Asn53Asp) |
c.160C>T |
c.C160T |
p.(L54F) |
p.(Leu54Phe) |
c.161T>C |
c.T161C |
p.(L54P) |
p.(Leu54Pro) |
c. 164A>G |
c.A164G |
p.(D55G) |
p.(Asp55Gly) |
c. 164A>T |
c.A164T |
p.(D55V) |
p.(Asp55Val) |
c.[164A>T; 170A>T] |
c.A164T/A170T |
p.(D55V/Q57L) |
p.(Asp55Val/Gln57Leu) |
c.167G>A |
c.G167A |
p.(C56Y) |
p.(Cys56Tyr) |
c.167G>T |
c.G167T |
p.(C56F) |
p.(Cys56Phe) |
c. 170A>T |
c.A170T |
p.(Q57L) |
p.(Gln57Leu) |
c.175G>A |
c.G175A |
p.(E59K) |
p.(Glu59Lys) |
c.178C>A |
c.C178A |
p.(P60T) |
p.(Pro60Thr) |
c.178C>T |
c.C178T |
p.(P60S) |
p.(Pro60Ser) |
c.179C>T |
c.C179T |
p.(P60L) |
p.(Pro60Leu) |
c.196G>A |
c.G196A |
p.(E66K) |
p.(Glu66Lys) |
c.197A>G |
c.A197G |
p.(E66G) |
p.(Glu66Gly) |
c.207C>A or c.207C>G |
c.C207A or c.C207G |
p.(F69L) |
p.(Phe69Leu) |
c.214A>G |
c.A214G |
p.(M72V) |
p.(Met72Val) |
c.216G>A or c.216G>T or c.216G>C |
c.G216A or c.G216T or c.G216C |
p.(M72I) |
p.(Met72Ile) |
c.218C>T |
c.C218T |
p.(A73V) |
p.(Ala73Val) |
c.227T>C |
c.T227C |
p.(M76T) |
p.(Met76Thr) |
c.239G>A |
c.G239A |
p.(G80D) |
p.(Gly80Asp) |
c.239G>T |
c.G239T |
p.(G80V) |
p.(Gly80Val) |
c.247G>A |
c.G247A |
p.(D83N) |
p.(Asp83Asn) |
c.253G>A |
c.G253A |
p.(G85S) |
p.(Gly85Ser) |
c.[253G>A; 254G>A] |
c.G253A/G254A |
p.(G85N) |
p.(Gly85Asn) |
c.[253G>A; 254G>T; 255T>G] |
c.G253A/G254T/T255G |
p.(G85M) |
p.(Gly85Met) |
c.254G>A |
c.G254A |
p.(G85D) |
p.(Gly85Asp) |
c.261G>C or c.261G>T |
c.G261C or c.G261T |
p.(E87D) |
p.(Glu87Asp) |
c.265C>T |
c.C265T |
p.(L89F) |
p.(Leu89Phe) |
c.272T>C |
c.T272C |
p.(I91T) |
p.(Ile91Thr) |
c.288G>A or c.288G>T or c.288G>C |
c.G288A or c.G288T or c.G288C |
p.(M96I) |
p.(Met96Ile) |
c.289G>C |
c.G289C |
p.(A97P) |
p.(Ala97Pro) |
c.290C>T |
c.C290T |
p.(A97V) |
p.(Ala97Val) |
c.305C>T |
c.C305T |
p.(S102L) |
p.(Ser102Leu) |
c.311G>T |
c.G311T |
p.(G104V) |
p.(Gly104Val) |
c.316C>T |
c.C316T |
p.(L106F) |
p.(Leu106Phe) |
c.320A>G |
c.A320G |
p.(Q107R) |
p.(Gln107Arg) |
c.322G>A |
c.G322A |
p.(A108T) |
p.(Ala108Thr) |
c.326A>G |
c.A326G |
p.(D109G) |
p.(Asp109Gly) |
c.334C>G |
c.C334G |
p.(R112G) |
p.(Arg112Gly) |
c.335G>A |
c.G335A |
p.(R112H) |
p.(Arg112His) |
c.337T>A |
c.T337A |
p.(F113I) |
p.(Phe113Ile) |
c.337T>C or c.339T>A or c.339T>G |
c.T337C or c.T339A or c.T339G |
p.(F113L) |
p.(Phe113Leu) |
c.352C>T |
c.C352T |
p.(R118C) |
p.(Arg118Cys) |
c.361G>A |
c.G361A |
p.(A121T) |
p.(Ala121Thr) |
c.368A>G |
c.A368G |
p.(Y123C) |
p.(Tyr123Cys) |
c.373C>T |
c.C373T |
p.(H125Y) |
p.(His125Tyr) |
c.374A>T |
c.A374T |
p.(H125L) |
p.(His125Leu) |
c.376A>G |
c.A376G |
p.(S126G) |
p.(Ser126Gly) |
c.383G>A |
c.G383A |
p.(G128E) |
p.(Gly128Glu) |
c.399T>G |
c.T399G |
p.(I133M) |
p.(Ile133Met) |
c.404C>T |
c.C404T |
p.(A135V) |
p.(Ala135Val) |
c.408T>A or c.408T>G |
c.T408A or c.T408G |
p.(D136E) |
p.(Asp136Glu) |
c.416A>G |
c.A416G |
p.(N139S) |
p.(Asn139Ser) |
c.419A>C |
c.A419C |
p.(K140T) |
p.(Lys140Thr) |
c.427G>A |
c.G427A |
p.(A143T) |
p.(Ala143Thr) |
c.431G>A |
c.G431A |
p.(G144D) |
p.(Gly144Asp) |
c.431G>T |
c.G431T |
p.(G144V) |
p.(Gly144Val) |
c.434T>C |
c.T434C |
p.(F145S) |
p.(Phe145Ser) |
c.436C>T |
c.C436T |
p.(P146S) |
p.(Pro146Ser) |
c.437C>G |
c.C437G |
p.(P146R) |
p.(Pro146Arg) |
c.454T>C |
c.T454C |
p.(Y152H) |
p.(Tyr152His) |
c.454T>G |
c.T454G |
p.(Y152D) |
p.(Tyr152Asp) |
c.455A>G |
c.A455G |
p.(Y152C) |
p.(Tyr152Cys) |
c.466G>A |
c.G466A |
p.(A156T) |
p.(Ala156Thr) |
c.466G>T |
c.G466T |
p.(A156S) |
p.(Ala156Ser) |
c.467C>T |
c.C467T |
p.(A156V) |
p.(Ala156Val) |
c.471G>C or c.471G>T |
c.G471C or c.G471T |
p.(Q157H) |
p.(Gln157His) |
c.484T>G |
c.T484G |
p.(W162G) |
p.(Trp162Gly) |
c.493G>C |
c.G493C |
p.(D165H) |
p.(Asp165His) |
c.494A>G |
c.A494G |
p.(D165G) |
p.(Asp165Gly) |
c.496_497delinsTC |
c.496_497delinsTC |
p.(L166S) |
p.(Leu166Ser) |
c.496C>G |
c.C496G |
p.(L166V) |
p.(Leu166Val) |
c.[496C>G; 497T>G] |
c.C496G/T497G |
p.(L166G) |
p.(Leu166Gly) |
c.499C>G |
c.C499G |
p.(L167V) |
p.(Leu167Val) |
c.506T>C |
c.T506C |
p.(F169S) |
p.(Phe169Ser) |
c.511G>A |
c.G511A |
p.(G171S) |
p.(Gly171Ser) |
c.520T>C |
c.T520C |
p.(C174R) |
p.(Cys174Arg) |
c.520T>G |
c.T520G |
p.(C174G) |
p.(Cys174Gly) |
c.525C>G or c.525C>A |
c.C525G or c.C525A |
p.(D175E) |
p.(Asp175Glu) |
c.539T>G |
c.T539G |
p.(L180W) |
p.(Leu180Trp) |
c.540G>C or c.540G>T |
c.G540C or c.G540T |
p.(L180F) |
p.(Leu180Phe) |
c.548G>A |
c.G548A |
p.(G183D) |
p.(Gly183Asp) |
c.548G>C |
c.G548C |
p.(G183A) |
p.(Gly183Ala) |
c.550T>A |
c.T550A |
p.(Y184N) |
p.(Tyr184Asn) |
c.551A>G |
c.A551G |
p.(Y184C) |
p.(Tyr184Cys) |
c.553A>G |
c.A553G |
p.(K185E) |
p.(Lys185Glu) |
c.559_564dup |
c.559_564dup |
p.(M187_S188dup) |
p.(Met187_Ser188dup) |
c.559A>G |
c.A559G |
p.(M187V) |
p.(Met187Val) |
c.560T>C |
c.T560C |
p.(M187T) |
p.(Met187Thr) |
c.561G>T or c.561G>A or c.561G>C |
c.G561T or c.G561A or c.G561C |
p.(M187I) |
p.(Met187Ile) |
c.567G>C or c.567G>T |
c.G567C or c.G567T |
p.(L189F) |
p.(Leu189Phe) |
c.572T>A |
c.T572A |
p(L191Q) |
p.(Leu191Gln) |
c.581C>T |
c.C581T |
p.(T194I) |
p.(Thr194Ile) |
c.584G>T |
c.G584T |
p.(G195V) |
p.(Gly195Val) |
c.586A>G |
c.A586G |
p.(R196G) |
p.(Arg196Gly) |
c.593T>C |
c.T593C |
p.(I198T) |
p.(Ile198Thr) |
c.595G>A |
c.G595A |
p.(V199M) |
p.(Val199Met) |
c.596T>C |
c.T596C |
p.(V199A) |
p.(Val199Ala) |
c.596T>G |
c.T596G |
p.(V199G) |
p.(Val199Gly) |
c.599A>G |
c.A599G |
p.(Y200C) |
p.(Tyr200Cys) |
c.602C>A |
c.C602A |
p.(S201Y) |
p.(Ser201Tyr) |
c.602C>T |
c.C602T |
p.(S201F) |
p.(Ser201Phe) |
c.608A>T |
c.A608T |
p.(E203V) |
p.(Glu203Val) |
c.609G>C or c.609G>T |
c.G609C or c.G609T |
p.(E203D) |
p.(Glu203Asp) |
c.611G>T |
c.G611T |
p.(W204L) |
p.(Trp204Leu) |
c.613C>A |
c.C613A |
p.(P205T) |
p.(Pro205Thr) |
c.613C>T |
c.C613T |
p.(P205S) |
p.(Pro205Ser) |
c.614C>T |
c.C614T |
p.(P205L) |
p.(Pro205Leu) |
c.619T>C |
c.T619C |
p.(Y207H) |
p.(Tyr207His) |
c.620A>C |
c.A620C |
p.(Y207S) |
p.(Tyr207Ser) |
c.623T>G |
c.T623G |
p.(M208R) |
p.(Met208Arg) |
c.628C>T |
c.C628T |
p.(P210S) |
p.(Pro210Ser) |
c.629C>T |
c.C629T |
p.(P210L) |
p.(Pro210Leu) |
c.638A>G |
c.A638G |
p.(K213R) |
p.(Lys213Arg) |
c.638A>T |
c.A638T |
p.(K213M) |
p.(Lys213Met) |
c.640C>T |
c.C640T |
p.(P214S) |
p.(Pro214Ser) |
c.641C>T |
c.C641T |
p.(P214L) |
p.(Pro214Leu) |
c.643A>G |
c.A643G |
p.(N215D) |
p.(Asn215Asp) |
c.644A>G |
c.A644G |
p.(N215S) |
p.(Asn215Ser) |
c. [644A>G; 937G>T*] |
c.A644G/G937T* |
p.(N215S/D313Y*) |
p.(Asn215Ser/Asp313Tyr*) |
c.644A>T |
c.A644T |
p.(N215I) |
p.(Asn215Ile) |
c.646T>G |
c.T646G |
p.(Y216D) |
p.(Tyr216Asp) |
c.647A>G |
c.A647G |
p.(Y216C) |
p.(Tyr216Cys) |
c.655A>C |
c.A655C |
p.(I219L) |
p.(Ile219Leu) |
c.656T>A |
c.T656A |
p.(I219N) |
p.(Ile219Asn) |
c.656T>C |
c.T656C |
p.(I219T) |
p.(Ile219Thr) |
c.659G>A |
c.G659A |
p.(R220Q) |
p.(Arg220Gln) |
c.659G>C |
c.G659C |
p.(R220P) |
p.(Arg220Pro) |
c.662A>C |
c.A662C |
p.(Q221P) |
p.(Gln221Pro) |
c.671A>C |
c.A671C |
p.(N224T) |
p.(Asn224Thr) |
c.671A>G |
c.A671G |
p.(N224S) |
p.(Asn224Ser) |
c.673C>G |
c.C673G |
p.(H225D) |
p.(His225Asp) |
c.683A>G |
c.A683G |
p.(N228S) |
p.(Asn228Ser) |
c.687T>A or c.687T>G |
c.T687A or c.T687G |
p.(F229L) |
p.(Phe229Leu) |
c.695T>C |
c.T695C |
p.(I232T) |
p.(Ile232Thr) |
c.712A>G |
c.A712G |
p.(S238G) |
p.(Ser238Gly) |
c.713G>A |
c.G713A |
p.(S238N) |
p.(Ser238Asn) |
c.716T>C |
c.T716C |
p.(I239T) |
p.(Ile239Thr) |
c.717A>G |
c.A717G |
p.(I239M) |
p.(Ile239Met) |
c.720G>C or c.720G>T |
c.G720C or c.G720T |
p.(K240N) |
p.(Lys240Asn) |
c.724A>G |
c.A724G |
p.(I242V) |
p.(Ile242Val) |
c.724A>T |
c.A724T |
p.(I242F) |
p.(Ile242Phe) |
c.725T>A |
c.T725A |
p.(I242N) |
p.(Ile242Asn) |
c.725T>C |
c.T725C |
p.(I242T) |
p.(Ile242Thr) |
c.728T>G |
c.T728G |
p.(L243W) |
p.(Leu243Trp) |
c.729G>C or c.729G>T |
c.G729C or c.G729T |
p.(L243F) |
p.(Leu243Phe) |
c.730G>A |
c.G730A |
p.(D244N) |
p.(Asp244Asn) |
c.730G>C |
c.G730C |
p.(D244H) |
p.(Asp244His) |
c.733T>G |
c.T733G |
p.(W245G) |
p.(Trp245Gly) |
c.740C>G |
c.C740G |
p.(S247C) |
p.(Ser247Cys) |
c.747C>G or c.747C>A |
c.C747G or c.C747A |
p.(N249K) |
p.(Asn249Lys) |
c.749A>C |
c.A749C |
p.(Q250P) |
p.(Gln250Pro) |
c.749A>G |
c.A749G |
p.(Q250R) |
p.(Gln250Arg) |
c.750G>C |
c.G750C |
p.(Q250H) |
p.(Gln250His) |
c.758T>C |
c.T758C |
p.(I253T) |
p.(Ile253Thr) |
c.758T>G |
c.T758G |
p.(I253S) |
p.(Ile253Ser) |
c.760-762delGTT or c.761-763del |
c.760 762delGTT or c.761_763del |
p.(V254del) |
p.(Val254del) |
c.769G>C |
c.G769C |
p.(A257P) |
p.(Ala257Pro) |
c.770C>G |
c.C770G |
p.(A257G) |
p.(Ala257Gly) |
c.770C>T |
c.C770T |
p.(A257V) |
p.(Ala257Val) |
c.772G>C or c.772G>A |
c.G772C or c.G772A |
p.(G258R) |
p.(Gly258Arg) |
c.773G>T |
c.G773T |
p.(G258V) |
p.(Gly258Val) |
c.776C>A |
c.C776A |
p.(P259Q) |
p.(Pro259Gln) |
c.776C>G |
c.C776G |
p.(P259R) |
p.(Pro259Arg) |
c.776C>T |
c.C776T |
p.(P259L) |
p.(Pro259Leu) |
c.779G>A |
c.G779A |
p.(G260E) |
p.(Gly260Glu) |
c.779G>C |
c.G779C |
p.(G260A) |
p.(Gly260Ala) |
c.781G>A |
c.G781A |
p.(G261S) |
p.(Gly261Ser) |
c.781G>C |
c.G781C |
p.(G261R) |
p.(Gly261Arg) |
c.781G>T |
c.G781T |
p.(G261C) |
p.(Gly261Cys) |
c.788A>G |
c.A788G |
p.(N263S) |
p.(Asn263Ser) |
c.790G>T |
c.G790T |
p.(D264Y) |
p.(Asp264Tyr) |
c.794C>T |
c.C794T |
p.(P265L) |
p.(Pro265Leu) |
c.800T>C |
c.T800C |
p.(M267T) |
p.(Met267Thr) |
c.805G>A |
c.G805A |
p.(V269M) |
p.(Val269Met) |
c.806T>C |
c.T806C |
p.(V269A) |
p.(Val269Ala) |
c.809T>C |
c.T809C |
p.(I270T) |
p.(Ile270Thr) |
c.810T>G |
c.T810G |
p.(I270M) |
p.(Ile270Met) |
c.811G>A |
c.G811A |
p.(G271S) |
p.(Gly271Ser) |
c.[811G>A; 937G>T*] |
c.G811A/G937T* |
p.(G271S/D313Y*) |
p.(Gly271Ser/Asp313Tyr*) |
c.812G>A |
c.G812A |
p.(G271D) |
p.(Gly271Asp) |
c.823C>G |
c.C823G |
p.(L275V) |
p.(Leu275Val) |
c.827G>A |
c.G827A |
p.(S276N) |
p.(Ser276Asn) |
c.829T>G |
c.T829G |
p.(W277G) |
p.(Trp277Gly) |
c.831G>T or c.831G>C |
c.G831T or c.G831C |
p.(W277C) |
p.(Trp277Cys) |
c.832A>T |
c.A832T |
p.(N278Y) |
p.(Asn278Tyr) |
c.835C>G |
c.C835G |
p.(Q279E) |
p.(Gln279Glu) |
c.838C>A |
c.C838A |
p.(Q280K) |
p.(Gln280Lys) |
c.840A>T or c.840A>C |
c.A840T or c.A840C |
p.(Q280H) |
p.(Gln280His) |
c.844A>G |
c.A844G |
p.(T282A) |
p.(Thr282Ala) |
c.845C>T |
c.C845T |
p.(T282I) |
p.(Thr282Ile) |
c.850A>G |
c.A850G |
p.(M284V) |
p.(Met284Val) |
c.851T>C |
c.T851C |
p.(M284T) |
p.(Met284Thr) |
c.860G>T |
c.G860T |
p.(W287L) |
p.(Trp287Leu) |
c.862G>C |
c.G862C |
p.(A288P) |
p.(Ala288Pro) |
c.866T>G |
c.T866G |
p.(I289S) |
p.(Ile289Ser) |
c.868A>C or c.868A>T |
c.A868C or c.A868T |
p.(M290L) |
p.(Met290Leu) |
c.869T>C |
c.T869C |
p.(M290T) |
p.(Met290Thr) |
c.870G>A or c.870G>C or c.870G>T |
c.G870A or c.G870C or c.G870T |
p.(M290I) |
p.(Met290Ile) |
c.871G>A |
c.G871A |
p.(A291T) |
p.(Ala291Thr) |
c.877C>A |
c.C877A |
p.(P293T) |
p.(Pro293Thr) |
c.881T>C |
c.T881C |
p.(L294S) |
p.(Leu294Ser) |
c.884T>G |
c.T884G |
p.(F295C) |
p.(Phe295Cys) |
c.886A>G |
c.A886G |
p.(M296V) |
p.(Met296Val) |
c.886A>T or c.886A>C |
c.A886T or c.A886C |
p.(M296L) |
p.(Met296Leu) |
c.887T>C |
c.T887C |
p.(M296T) |
p.(Met296Thr) |
c.888G>A or c.888G>T or c.888G>C |
c.G888A or c.G888T or c.G888C |
p.(M296I) |
p.(Met296Ile) |
c.893A>G |
c.A893G |
p.(N298S) |
p.(Asn298Ser) |
c.897C>G or c.897C>A |
c.C897G or c.C897A |
p.(D299E) |
p.(Asp299Glu) |
c.898C>T |
c.C898T |
p.(L300F) |
p.(Leu300Phe) |
c.899T>C |
c.T899C |
p.(L300P) |
p.(Leu300Pro) |
c.901C>G |
c.C901G |
p.(R301G) |
p.(Arg301Gly) |
c.902G>A |
c.G902A |
p.(R301Q) |
p.(Arg301Gln) |
c.902G>C |
c.G902C |
p.(R301P) |
p.(Arg301Pro) |
c.902G>T |
c.G902T |
p.(R301L) |
p.(Arg301Leu) |
c.907A>T |
c.A907T |
p.(I303F) |
p.(Ile303Phe) |
c.908T>A |
c.T908A |
p.(I303N) |
p.(Ile303Asn) |
c.911G>A |
c.G911A |
p.(S304N) |
p.(Ser304Asn) |
c.911G>C |
c.G911C |
p.(S304T) |
p.(Ser304Thr) |
c.919G>A |
c.G919A |
p.(A307T) |
p.(Ala307Thr) |
c.922A>G |
c.A922G |
p.(K308E) |
p.(Lys308Glu) |
c.924A>T or c.924A>C |
c.A924T or c.A924C |
p.(K308N) |
p.(Lys308Asn) |
c.925G>C |
c.G925C |
p.(A309P) |
p.(Ala309Pro) |
c.926C>T |
c.C926T |
p.(A309V) |
p.(Ala309Val) |
c.928C>T |
c.C928T |
p.(L310F) |
p.(Leu310Phe) |
c.931C>G |
c.C931G |
p.(L311V) |
p.(Leu311Val) |
c.935A>G |
c.A935G |
p.(Q312R) |
p.(Gln312Arg) |
c.936G>T or c.936G>C |
c.G936T or c.G936C |
p.(Q312H) |
p.(Gln312His) |
c.937G>T* |
c.G937T* |
p.(D313Y*) |
p.(Asp313Tyr*) |
c.[937G>T*; 1232G>A] |
c.G937T*/G1232A |
p.(D313Y*/G411D) |
p.(Asp313Tyr*/Gly411Asp) |
c.938A>G |
c.A938G |
p.(D313G) |
p.(Asp313Gly) |
c.946G>A |
c.G946A |
p.(V316I) |
p.(Val316Ile) |
c.947T>G |
c.T947G |
p.(V316G) |
p.(Val316Gly) |
c.950T>C |
c.T950C |
p.(I317T) |
p.(Ile317Thr) |
c.955A>T |
c.A955T |
p.(I319F) |
p.(Ile319Phe) |
c.956T>C |
c.T956C |
p.(I319T) |
p.(Ile319Thr) |
c.958A>C |
c.A958C |
p.(N320H) |
p.(Asn320His) |
c.959A>T |
c.A959T |
p.(N320I) |
p.(Asn320Ile) |
c.962A>G |
c.A962G |
p.(Q321R) |
p.(Gln321Arg) |
c.962A>T |
c.A962T |
p.(Q321L) |
p.(Gln321Leu) |
c.963G>C or c.963G>T |
c.G963C or c.G963T |
p.(Q321H) |
p.(Gln321His) |
c.964G>A |
c.G964A |
p.(D322N) |
p.(Asp322Asn) |
c.964G>C |
c.G964C |
p.(D322H) |
p.(Asp322His) |
c.966C>A or c.966C>G |
c.C966A or c.C966G |
p.(D322E) |
p.(Asp322Glu) |
c.967C>A |
c.C967A |
p.(P323T) |
p.(Pro323Thr) |
c.968C>G |
c.C968G |
p.(P323R) |
p.(Pro323Arg) |
c.973G>A |
c.G973A |
p.(G325S) |
p.(Gly325Ser) |
c.973G>C |
c.G973C |
p.(G325R) |
p.(Gly325Arg) |
c.978G>C or c.978G>T |
c.G978C or c.G978T |
p.(K326N) |
p.(Lys326Asn) |
c.979C>G |
c.C979G |
p.(Q327E) |
p.(Gln327Glu) |
c.980A>T |
c.A980T |
p.(Q327L) |
p.(Gln327Leu) |
c.983G>C |
c.G983C |
p.(G328A) |
p.(Gly328Ala) |
c.989A>G |
c.A989G |
p.(Q330R) |
p.(Gln330Arg) |
c.1001G>A |
c.G1001A |
p.(G334E) |
p.(Gly334Glu) |
c.1010T>C |
c.T1010C |
p.(F337S) |
p.(Phe337Ser) |
c.1012G>A |
c.G1012A |
p.(E338K) |
p.(Glu338Lys) |
c.1013A>T |
c.A1013T |
p.(E338V) |
p.(Glu338Val) |
c.1016T>A |
c.T1016A |
p.(V339E) |
p.(Val339Glu) |
c.1027C>A |
c.C1027A |
p.(P343T) |
p.(Pro343Thr) |
c.1028C>T |
c.C1028T |
p.(P343L) |
p.(Pro343Leu) |
c.1033T>C |
c.T1033C |
p.(S345P) |
p.(Ser345Pro) |
c. 1046G>C |
c.G1046C |
p.(W349S) |
p.(Trp349Ser) |
c.1055C>G |
c.C1055G |
p.(A352G) |
p.(Ala352Gly) |
c.1055C>T |
c.C1055T |
p.(A352V) |
p.(Ala352Val) |
c.1061T>A |
c.T1061A |
p.(I354K) |
p.(Ile354Lys) |
c.1066C>G |
c.C1066G |
p.(R356G) |
p.(Arg356Gly) |
c.1066C>T |
c.C1066T |
p.(R356W) |
p.(Arg356Trp) |
c.1067G>A |
c.G1067A |
p.(R356Q) |
p.(Arg356Gln) |
c.1067G>C |
c.G1067C |
p.(R356P) |
p.(Arg356Pro) |
c.1072G>C |
c.G1072C |
p.(E358Q) |
p.(Glu358Gln) |
c.1073A>C |
c.A1073C |
p.(E358A) |
p.(Glu358Ala) |
c.1073A>G |
c.A1073G |
p.(E358G) |
p.(Glu358Gly) |
c.1074G>T or c.1074G>C |
c.G1074T or c.G1074C |
p.(E358D) |
p.(Glu358Asp) |
c.1076T>C |
c.T1076C |
p.(I359T) |
p.(Ile359Thr) |
c.1078G>A |
c.G1078A |
p.(G360S) |
p.(Gly360Ser) |
c.1078G>T |
c.G1078T |
p.(G360C) |
p.(Gly360Cys) |
c.1079G>A |
c.G1079A |
p.(G360D) |
p.(Gly360Asp) |
c.1082G>A |
c.G1082A |
p.(G361E) |
p.(Gly361Glu) |
c.1082G>C |
c.G1082C |
p.(G361A) |
p.(Gly361Ala) |
c.1084C>A |
c.C1084A |
p.(P362T) |
p.(Pro362Thr) |
c.1085C>T |
c.C1085T |
p.(P362L) |
p.(Pro362Leu) |
c.1087C>T |
c.C1087T |
p.(R363C) |
p.(Arg363Cys) |
c.1088G>A |
c.G1088A |
p.(R363H) |
p.(Arg363His) |
c.1102G>A |
c.G1102A |
p.(A368T) |
p.(Ala368Thr) |
c.1117G>A |
c.G1117A |
p.(G373S) |
p.(Gly373Ser) |
c.1124G>A |
c.G1124A |
p.(G375E) |
p.(Gly375Glu) |
c.1139C>T |
c.C1139T |
p.(P380L) |
p.(Pro380Leu) |
c.1153A>G |
c.A1153G |
p.(T385A) |
p.(Tyr385Ala) |
c.1168G>A |
c.G1168A |
p.(V390M) |
p.(Val390Met) |
c.1172A>C |
c.A1172C |
p.(K391T) |
p.(Lys391Thr) |
c.1184G>A |
c.G1184A |
p.(G395E) |
p.(Gly395Glu) |
c.1184G>C |
c.G1184C |
p.(G395A) |
p.(Gly395Ala) |
c.1192G>A |
c.G1192A |
p.(E398K) |
p.(Glu398Lys) |
c. 1202_1203insGACTTC |
c. 1202_1203insGACTTC |
p.(T400_S401dup) |
p.(Thr400_Ser401dup) |
c.1208T>C |
c.T1208C |
p.(L403S) |
p.(Leu403Ser) |
c.1225C>A |
c.C1225A |
p.(P409T) |
p.(Pro409Thr) |
c.1225C>G |
c.C1225G |
p.(P409A) |
p.(Pro409Ala) |
c.1225C>T |
c.C1225T |
p.(P409S) |
p.(Pro409Ser) |
c.1228A>G |
c.A1228G |
p.(T410A) |
p.(Thr410Ala) |
c.1229C>T |
c.C1229T |
p.(T410I) |
p.(Thr410Ile) |
c.1232G>A |
c.G1232A |
p.(G411D) |
p.(Gly411Asp) |
c.1234A>C |
c.A1234C |
p.(T412P) |
p.(Thr412Pro) |
c.1235C>A |
c.C1235A |
p.(T412N) |
p.(Thr412Asn) |
c.1253A>G |
c.A1253G |
p.(E418G) |
p.(Glu418Gly) |
c.1261A>G |
c.A1261G |
p.(M421V) |
p.(Met421Val) |
* Based on available published
data, the GLA variant c.937G>T, (p.(D313Y)) is considered benign (not
causing Fabry disease). Consultation with a clinical genetics professional is
strongly recommended in patients with Fabry disease who have this GLA variant
as additional evaluations may be indicated. |
If a GLA variant does not
appear in Table 2, it is either non-amenable (if tested) or has not been tested
for in vitro amenability. For further information, please contact Amicus
Medical Information at 1-877-4AMICUS or [email protected]
Pharmacodynamics
In Study 1, 31 of 50 patients
with amenable GLA variants (18 on GALAFOLD, 13 on placebo) had lyso-Gb3 assessments
available after 6 months of treatment. The median change from baseline to month
6 in plasma lyso-Gb3 (nmol/L) was -2.37 (range -69.7, 1.8) in patients on GALAFOLD
and 0.53 (range -21.5, 16.3) in patients on placebo. In the open-label
treatment phase of Study 1, the 13 patients who were initially on placebo for 6
months and who switched to GALAFOLD for another 6 months had a median change in
lyso-Gb3 (nmol/L) of -2.72 (range -61.1, -0.3) . The 18 patients who were
treated with GALAFOLD for 6 months and then continued GALAFOLD in the
open-label treatment phase of Study 1 for an additional 6 months had no further
changes in plasma lyso-Gb3.
In Study 2, 46 of 56 patients with amenable GLA variants
(31 on GALAFOLD, 15 on enzyme replacement therapy (ERT)) had lyso-Gb3 assessments
available after 18 months of treatment. The median change from baseline to
month 18 in plasma lyso-Gb3 (nmol/L) was 0.53 (range -2.27, 28.3) in patients
on GALAFOLD and -0.03 (range -11.9, 2.57) in patients on ERT.
Cardiac Electrophysiology
At a dose approximately 8 times the recommended dose,
GALAFOLD did not prolong the QT interval to any clinically relevant extent.
Pharmacokinetics
Absorption
Following a single GALAFOLD oral dose of 123 mg, the
absolute bioavailability (AUC) of migalastat was approximately 75% and the time
to peak plasma concentration was approximately 3 hours. Plasma migalastat
exposure (AUC0-∞ and Cmax) demonstrated dose-proportional increases at
oral doses from 75 mg to 1250 mg (doses from 0.5 to 8.3-fold of the approved
recommended dosage). Migalastat does not accumulate following administration of
123 mg GALAFOLD every other day.
Effect Of Food
Administration of GALAFOLD one hour before a high-fat
(850 calories; 56% from fat) or light meal (507 calories; 30% from fat), or one
hour after a light meal, reduced the mean migalastat AUC0-∞ by 37% to 42%
and Cmax by 15% to 39% compared to the fasting state [see DOSAGE AND
ADMINISTRATION].
Distribution
The apparent volume of distribution (Vz/F) of migalastat
in Fabry patients was approximately 89 L (range: 77 to 133 L) at steady state. There
was no detectable plasma protein binding following administration of [14C]-migalastat
in the concentration range between 1 to 100 microM.
Elimination
Metabolism
Based upon in vivo data, migalastat is a substrate for
uridine diphosphate glucuronosyltransferase (UDPGT), a minor elimination
pathway.
Excretion
In a mass balance study in healthy male subjects,
following oral administration of 123 mg [14C]-migalastat,
approximately 77% of the total radiolabeled dose was recovered in urine and 20%
of the total radiolabeled dose was recovered in feces with an overall total
recovery of 98% within 96 hours post-dose. In urine, unchanged migalastat
accounted for 80% of the radioactivity, which equates to 62% of the
administered dose. In feces, unchanged migalastat was the only drug-related
component. In plasma, unchanged migalastat accounted for approximately 77% of
the plasma radioactivity and three dehydrogenated O-glucuronide conjugated
metabolites, M1 to M3, together accounted for approximately 13% of the plasma
radioactivity, none of which comprised more than 6% of the radiolabeled dose.
Approximately 9% of the total radioactivity in plasma was unassigned.
Following a single oral dose of 123 mg GALAFOLD,
migalastat is cleared from plasma with a mean half-life (t½) of approximately 4
hours and apparent clearance of 12.5 L/hr.
Specific Populations
Male and Female Patients
The pharmacokinetic characteristics of migalastat were
not significantly different between healthy male and female subjects or
patients with Fabry disease.
Racial Or Ethnic Groups
Clinical data indicate no ethnic differences in patient
populations studied with migalastat.
Patients With Renal Impairment
In a single-dose study in subjects with varying degrees
of renal impairment, exposure to migalastat (AUC) was increased by 1.2-, 1.8-,
and 4.3-fold in subjects with mild (eGFR 60 to 90 mL/min/1.73 m²), moderate
(eGFR 30 to 59 mL/min/1.73 m²), and severe renal impairment (eGFR less than 30
mL/min/1.73 m²), respectively, while the Cmax remained unchanged with severity
of renal impairment [see Use In Specific Populations].
Drug Interaction Studies
Migalastat is not a known inhibitor or inducer of
cytochrome P450 (CYP450) enzymes, nor is it an inhibitor of BCRP, MDR1,
P-glycoprotein (P-gp), or BSEP human efflux transporters, or OATP1B1, OATP1B3,
OAT1, OAT3, OCT1, OCT2, MATE1, or MATE2-K human uptake transporters. Migalastat
is not a substrate of P-gp, BCRP, MDR1 or MATE1, MATE2-K, OAT1, OAT3, or OCT2.
Migalastat showed low affinity for SGLT1, as both a substrate and an inhibitor,
and showed no activity for SGLT2.
Clinical Studies
Study AT1001-011 (referred to as Study 1; NCT00925301)
included a 6-month randomized, double-blind, placebo-controlled phase followed
by a 6-month open-label treatment phase and a 12-month open-label extension
phase. Patients received the recommended dosage of 123 mg GALAFOLD every other
day taken without consuming food 2 hours before and 2 hours after each dose to
give a minimum 4 hour fast [see DOSAGE AND ADMINISTRATION]. A total of
67 patients with Fabry disease who were naïve to GALAFOLD and enzyme
replacement therapy (ERT) or were previously treated with ERT (agalsidase beta
or non-U.S. approved agalsidase alfa) and had been off ERT for at least 6
months were randomized in a 1:1 ratio to receive either GALAFOLD 123 mg every
other day or placebo for the first 6 months. In the second 6 months, all
patients were treated with GALAFOLD. Of the 67 enrolled patients, 50 patients
(32 females, 18 males) had amenable GLA variants based on the in vitro
amenability assay [see CLINICAL PHARMACOLOGY]. The median age of the
population was 45 years and 97% were Caucasian. The major efficacy outcome
measure of the average number of GL-3 inclusions per kidney interstitial
capillary (KIC) in renal biopsy samples was assessed by light microscopy before
and after treatment. Efficacy was evaluated after 6 months of treatment in 45
of 50 patients (29 females and 16 males) with available histology data both at
baseline and month 6. Of the 45 evaluable patients, 25 received GALAFOLD (18
females, 7 males) and 20 received placebo (11 females, 9 males). The proportion
of patients with ≥ 50% reduction from baseline in the average number of
GL-3 inclusions per KIC and the median changes from baseline in the average
number of GL-3 inclusions per KIC after 6 months of treatment in Study 1 are
shown in Table 3.
Table 3: Changes from Baseline to Month 6 in Average
Number of GL-3 Inclusions per KIC in Adults with Fabry Disease with Amenable GLA
Variants in Study 1 (N = 45)
|
GALAFOLD
n/N (%) with ≥ 50% reduction Median change from baseline (range) |
Placebo
n/N (%) with ≥ 50% reduction Median change from baseline (range) |
All patients (N = 45) |
13/25 (52%)
-0.04 (-1.94, 0.26) |
9/20 (45%)
-0.03 (-1.00, 1.69) |
Females (N = 29) |
8/18 (44%)
-0.02 (-0.46, 0.26) |
5/11 (46%)
-0.03 (-0.35, 0.10) |
Males (N = 16) |
5/7 (71%)
-1.10 (-1.94, -0.02) |
4/9 (44%)
-0.03 (-1.00, 1.69) |
Patients with baseline GL-3 ≥ 0.3 (N = 17; 9 males, 8 females) |
7/9 (78%)
-0.91 (-1.94, 0.19) |
2/8 (25%)
-0.02 (-1.00, 1.69) |
Patients with baseline GL-3 < 0.3 (N = 28; 7 males, 21 females) |
6/16 (38%)
-0.02 (-0.10, 0.26) |
7/12 (58%)
-0.05 (-0.16, 0.14) |
In Study 1, patients with
non-amenable GLA variants (n = 17) had no change from baseline in the average
number of GL-3 inclusions per KIC after 6 months of treatment.