Lufotrelvir is cleaved into PF-00835231 when given intravenously, which then goes on to work as an antiviral agent. The cardiovascular safety profile of lufotrelvir is favorable [1]. Intravenous lofetrelvir is administered to rats, dogs, and monkeys. It formed 68%, 81%, and 76% of PF-00835231 in rats, dogs, and monkeys, respectively, compared with the systemic exposure obtained by intravenous injection of PF00835231, indicating higher systemic clearance and shorter half-life [1].

[1]. Considerations for the discovery and development of 3-chymotrypsin-like cysteine protease inhibitors targeting SARS-CoV-2 infection. Curr Opin Virol. 2021 Apr 27;49:36-40.

[2]. Title: Discovery of a Novel Inhibitor of Coronavirus 3CL Protease as a Clinical Candidate for the Potential Treatment of COVID-19 Short Title: Novel 3CL Protease Inhibitor for COVID-19.

PF-07304814 is an indolecarboxamide, formed by the condensation of the carboxyl group of 4-methoxy-1H-indole-2-carboxylic acid with the primary amino group of N-[(2S)-3-oxo-1-[(3S)-2-oxopyrrolidine-3-yl]-4-(phosphonooxy)but-2-yl]-L-leucine. It is a phosphate prodrug of the anticoronavirus drug PF-00835231. It is both a prodrug and an EC 3.4.22.69 (SARS coronavirus main protease) inhibitor and an anticoronavirus drug. It is an aromatic ether, indolecarboxamide, secondary formamide, pyrrolidine-2-one compound, L-leucine derivative, and phosphate monoester. It is functionally related to PF-00835231. PF-07304814 is a small molecule prodrug that targets the 3CLpro protease (Mpro), which is essential for the assembly and replication of viruses such as SARS-CoV-2. After intravenous infusion, the compound is cleaved into PF-00835231, thereby exerting its antiviral effect. PF-07304814, developed by Pfizer, was initially discovered during the 2002-2003 SARS outbreak; however, its use was subsequently suspended as the outbreak was brought under control. It is now being tested against the novel SARS-CoV-2 virus, including studies in combination with remdesivir for the treatment of COVID-19 infection; in vitro data show a synergistic effect in articles published on preprint servers. A Phase 1b study is also exploring the safety and tolerability of PF-07304814 in hospitalized COVID-19 patients (NCT04535167). Rufortrevir is the phosphate prodrug of PF-00835231, a broad-spectrum coronavirus 3CL protease (3CLpro) inhibitor with potential antiviral activity against multiple coronaviruses, including SARS-related coronavirus (SARS-CoV) and SARS-CoV-2. After administration, rufortrevir is converted to its active moiety, PF-00835231, which selectively targets and inhibits the activity of coronavirus 3CLpro. This compound inhibits the proteolytic cleavage of viral polyproteins and the formation of various viral proteins, including helicases, single-stranded RNA-binding proteins, RNA-dependent RNA polymerases, 20-O-ribose methyltransferases, ribonucleases, and exonucleases. This prevents viral transcription and replication.

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Mechanism of Action
PF-07304814 contains a phosphate group in its structure, enabling it to dissolve and subsequently be cleaved by alkaline phosphatases in tissues.
This step releases PF-00835231, a compound with antiviral activity against the SARS-CoV-2 3CL protease. The active compound PF-00835231 has been shown to have potent and broad-spectrum inhibitory activity against the 3CL protease of various coronaviruses.

C24H33N4O9P

552.51398730278

552.198

2468015-78-1

154699467

White to off-white solid powder

0.5

6

9

13

38

927

3

P(=O)(O)(O)OCC([C@H](C[C@H]1C(NCC1)=O)NC([C@H](CC(C)C)NC(C1=CC2C(=CC=CC=2N1)OC)=O)=O)=O

FQKALOFOWPDTED-WBAXXEDZSA-N

InChI=1S/C24H33N4O9P/c1-13(2)9-18(28-24(32)19-11-15-16(26-19)5-4-6-21(15)36-3)23(31)27-17(10-14-7-8-25-22(14)30)20(29)12-37-38(33,34)35/h4-6,11,13-14,17-18,26H,7-10,12H2,1-3H3,(H,25,30)(H,27,31)(H,28,32)(H2,33,34,35)/t14-,17-,18-/m0/s1

(S)-3-((S)-2-(4-methoxy-1H-indole-2-carboxamido)-4-methylpentanamido)-2-oxo-4-((S)-2-oxopyrrolidin-3-yl)butyl dihydrogen phosphate

PF-07304814Lufotrelvir PF 07304814 Lufotrelvirum PF07304814

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~130 mg/mL (~235.29 mM)
H2O : ~50 mg/mL (~90.50 mM)

Solubility in Formulation 1: ≥ 3.25 mg/mL (5.88 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 32.5 mg/mL clear DMSO stock solution to 400 μL of PEG300 and mix evenly; then add 50 μL of Tween-80 to the above solution and mix evenly; then add 450 μL of normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 3.25 mg/mL (5.88 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 32.5 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 3: 3.25 mg/mL (5.88 mM) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 32.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)