Internal Pfizer Documents Prove Knowledge that Lipid Nanoparticles (in mice subjects) do not Remain in Muscle but ‘Were Shown to be Rapidly Distributed in the Blood to the Liver”
BNT162b2 (BioNTech code number: BNT162, Pfizer code number: PF-07302048) is a severe acute call. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike glycoprotein (S protein) full length It is a modified nucleoside mRNA (modRNA) that encodes against SARS-CoV-2 infection. Development is underway as the essence of the mRNA vaccine. When formulating BNT162b2, there are two Functional lipids ALC-0315 (aminolipid) and ALC-0159 (PEG lipid) and two structural lipids By mixing with DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine) and cholesterol Masking location: Adjusting PFIZER CONFIDENTIAL Page 3 Lipid nanoparticles (LNP) that encapsulate BNT162b2 are formed (hereinafter, “BNT162b2-encapsulated LNP”). ALC-0315 and ALC-0315 contained in LNP to evaluate the nonclinical pharmacokinetics of BNT162b2 encapsulated LNP In vivo and in vitro studies assessing absorption (PK), metabolism and excretion of ALC-0159 and BNT162b2 Biodistribution studies using luciferase or radiolabeled lipids as an alternative reporter for Was carried out.
Based on the fact that the development of vaccines aimed at preventing infectious diseases does not require evaluation of systemic exposure. (WHO, 2005; Non-clinical study guidelines for infectious disease preventive vaccines) 1 , 2 , BNT162b2 Encapsulated LNP muscle No internal PK study was performed. In addition, two other types of lipids (choleste) contained in this drug Rolls and DSPCs) are naturally occurring lipids that are thought to be metabolized and excreted in the same way as endogenous lipids. available. In addition, BNT162b2 is degraded by ribonucleases in the cells that have taken it up, resulting in nucleic acid charges. Apologize, the S protein from BNT162b2 is expected to undergo proteolysis. From the above, It was considered unnecessary to evaluate the metabolism and excretion of these components again.
LNP (Luciferase) encapsulating RNA encoding luciferase as an alternative reporter for BNT162b2 Lase RNA is encapsulated in an LNP having the same lipid composition as the BNT162b2-encapsulated LNP: In a PK study in which ZeRNA-encapsulated LNP “) was intravenously administered to Wistar Han rats, plasma, urine, feces and Liver samples were collected over time and the concentrations of ALC-0315 and ALC-0159 in each sample were measured. The conclusion As a result, ALC-0315 and ALC-0159 were shown to be rapidly distributed from the blood to the liver. Also, About 1% and about 50% of the doses of ALC-0315 and ALC-0159 are excreted in feces as unchanged drug, respectively. All of them were below the detection limit in urine.
In the biodistribution test, luciferase RNA-encapsulated LNP was intramuscularly administered to BALB / c mice. That As a result, the expression of luciferase was observed at the administration site, and the expression level was lower than that in the liver. Was also recognized. Expression at the administration site of luciferase was observed from 6 hours after administration, and 9 days after administration. Disappeared. Expression in the liver was also observed 6 hours after administration and disappeared by 48 hours after administration. Also, Intramuscular administration of radiolabeled LNP containing luciferase RNA to rats to quantify biodistribution Upon evaluation, the radioactivity concentration was the highest at the administration site. Liver is highest except at the administration site It was good (up to 18% of the dose).
Metabolism of ALC-0315 and ALC-0159 in CD-1 / ICR mice, Wistar Han or Sprague Dawley rats, In vitro using cynomolgus monkey or human blood, liver microsomes, liver S9 fraction and hepatocytes evaluated. In addition, plasma, urine, feces and liver samples collected in the above rat intravenous administration PK test were used. We also examined in vivo metabolism. From these in vitro and in vivo studies, ALC-0315 and ALC-0159 was added to ester and amide bonds in all animal species tested.
The solution showed that it was slowly metabolized.
From the above nonclinical pharmacokinetic evaluation, it was shown that LNP that reached the circulating blood is distributed in the liver. In addition, metabolism and fecal excretion may be involved in the disappearance of ALC-0315 and ALC-0159, respectively. It was suggested.