Pre-Clinical Safety and Efficacy Evaluation of Amytrap, a Novel Therapeutic to Treat Alzheimer’s Disease

Abstract

Alzheimer's disease (AD) is the most common cause of dementia. Amyloid-␤ (A␤ 42) is implicated in AD pathogenesis. We have designed a non-immune based proprietary therapeutic, called Amytrap, a conjugate containing a retro-inverso peptide, polyethylene glycol, and human serum albumin. Amytrap not only binds A␤ 42 but also prevents and dissociates aggregated A␤ 42. Amytrap binds to the region in A␤ 42 known to trigger its self-aggregation, thus disrupting aggregation. we have obtained proof of concept on AmyTrap in a clinically relevant mouse model, namely, AD-APPSWE/Tg2576. We synthesized and characterized Amytrap and confirmed its authenticity. Efficacy evaluations were performed on young (5 months) and old (9 months) model mice. Amytrap was injected biweekly for a period of five months. Pharmacokinetics and safety toxicology were assessed in normal mice and rats, respectively. Post treatment, younger mice showed significant improvements in cognition and A␤ 42 levels in plasma, brain, and cerebrospinal fluid, while older mice showed less significant benefits. Immunohistochemistry of brain sections showed similar differences between young and old mice. They all had diminished size and number of plaques in the brain of Amytrap-treated mice. Further, treated mice did not develop antibodies to Amytrap, suggesting Amytrap is non-immunogenic. Safety toxicological studies in rats showed that Amytrap was well tolerated and therefore safe (even at 50 X the efficacy dose). Stability tests showed Amytrap is stable at 4 • C for up to one year. Efficacy and safety features make Amytrap a promising candidate for treating or modulating AD.

Novel API Coated Catheter Removes Amyloid-β from Plasma of Patients with Alzheimer’s Disease

“…We have been working on the development of a peptide-based compound, Amytrap, for amyloid reduction in circulation. Amytrap has been shown to bind Aβ42 in vitro and in vivo [ 12 ]. In a previous study we have shown that the device called Amytrapper column, containing the API (RI-peptide) coupled to sepharose beads, binds and removes Aβ in sera or plasma spiked with known amounts of Aβ42.…”

“…The microwells were then blocked with 3% gelatin in TBS for 1h at 37°C. Wells were probed with rabbit anti-RI-peptide antibody [ 12 ] at 1/2500 in TBST for 1h at 37°C, then washed 10 times with TBST. The wells were treated with goat anti-rabbit HRP antibody (1/5000, Invitrogen) for 1h at 37°C.…”

“…We have developed and studied Amytrap peptide, a retro inverso peptide (RI peptide: WKGEWTGR) that has been shown to sequester Aβ in both in vitro and in vivo studies [ 12 , 13 ]. The RI-peptide has a high binding affinity for Aβ.…”

“…The RI-peptide has a high binding affinity for Aβ. RI peptides are generally non-toxic, non-immunogenic, stable and offer higher resistance to proteolytic degradation [ 12 ]. In addition, non-immune based therapeutics are expected to circumvent the immunological side-effects.…”

Recent Applications of Retro-Inverso Peptides

“…Recently, the synthesis of Amytrap, a tetrameric RI analogue of the all-L peptide WKGEWTGR has been reported. Amytrap was pegylated and conjugated to human serum albumin (HSA) to enhance its bioavailability [67] and as such displayed high affinity for the GSNKG region of Aβ 1-42 , blocking oligomerization and aggregation of the full length polypeptide. Using this molecule, the authors observed a significant reduction of Aβ 1-42 levels in the brain as determined by immunohistochemical analyses of brain tissues.…”