Preclinical evaluation of multiple species of PEGylated recombinant phenylalanine ammonia lyase for the treatment of phenylketonuria.
Phenylketonuria (PKU) is a metabolic disorder, in which loss of phenylalanine hydroxylase activity results in neurotoxic levels of phenylalanine. We used the Pah(enu2/enu2) PKU mouse model in short- and long-term studies of enzyme substitution therapy with PEGylated phenylalanine ammonia lyase (PEG-PAL conjugates) from 4 different species. The most therapeutically effective PAL (Av, Anabaena variabilis) species was one without the highest specific activity, but with the highest stability; indicating the importance of protein stability in the development of effective protein therapeutics. A PEG-Av-p.C503S/p.C565S-PAL effectively lowered phenylalanine levels in both vascular space and brain tissue over a >90 day trial period, resulting in reduced manifestations associated with PKU, including reversal of PKU-associated hypopigmentation and enhanced animal health. Phenylalanine reduction occurred in a dose- and loading-dependent manner, and PEGylation reduced the neutralizing immune response to the enzyme. Human clinical trials with PEG-Av-p.C503S/p.C565S-PAL as a treatment for PKU are underway.
Sarkissian
Christineh N
CN
Department of Biology, McGill University, Montreal, QC, Canada H3A 1B1.
Gámez
Alejandra
A
Wang
Lin
L
Charbonneau
Marilyse
M
Fitzpatrick
Paul
P
Lemontt
Jeffrey F
JF
Zhao
Bin
B
Vellard
Michael
M
Bell
Sean M
SM
Henschell
Carroll
C
Lambert
Amy
A
Tsuruda
Laurie
L
Stevens
Raymond C
RC
Scriver
Charles R
CR
D046870:Anabaena variabilis / Q000201:enzymology*; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004795:Enzyme Stability / Q000502:physiology; D006801:Humans; D051379:Mice; D008817:Mice, Mutant Strains; D009928:Organ Specificity / Q000187:drug effects; D010649:Phenylalanine / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D010661:Phenylketonurias / Q000188:drug therapy* / Q000378:metabolism; D011092:Polyethylene Glycols; D011994:Recombinant Proteins / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use
D000970:Antineoplastic Agents; D001426:Bacterial Proteins; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D010649:Phenylalanine; D010650:Phenylalanine Ammonia-Lyase