PD-1/ PD-L1

PD-1-IN-17, an analogue of CA-170, is a programmed cell death-1 (PD-1) inhibitor.

[1]. 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives as immunomodulators. WO2015033301A1.

CA-170 is a selective, small molecule inhibitor of PD-L1. PD-L1/PD-L2/VISTA Antagonist CA-170 is an orally bioavailable small molecule inhibitor of the immune checkpoint regulatory proteins programmed cell death ligand-1 (PD-L1; B7-H1; CD274), PD-L2, and V-domain immunoglobulin (Ig) suppressor of T-cell activation (VISTA; programmed death 1 homolog; PD1H; PD-1H), with potential negative immune checkpoint regulatory and antineoplastic activities. Upon oral administration, PD-L1/PD-L2/VISTA antagonist CA-170 targets and binds to PD-L1, PD-L2 and VISTA. This inhibits PD-L1/PD-L2/VISTA-mediated signaling, abrogates the PD-L1-, PD-L2- and VISTA-induced suppression of T-lymphocyte immune responses, enhances cytotoxic T-cell proliferation and activation against tumor cells, increases cytokine production by T-cells, and inhibits tumor cell growth. PD-L1, PD-L2 and VISTA, negative checkpoint molecules of immune activation, play key roles in the suppression of T-cell functions.

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CA-170 is currently the only small-molecule modulator in clinical trials targeting PD-L1 and VISTA proteins - important negative checkpoint regulators of immune activation. The reported therapeutic results to some extent mimic those of FDA-approved monoclonal antibodies overcoming the limitations of the high production costs and adverse effects of the latter. However, no conclusive biophysical evidence proving the binding to hPD-L1 has ever been presented. Using well-known in vitro methods: NMR binding assay, HTRF and cell-based activation assays, we clearly show that there is no direct binding between CA-170 and PD-L1. To strengthen our reasoning, we performed control experiments on AUNP-12 - a 29-mer peptide, which is a precursor of CA-170. Positive controls consisted of the well-documented small-molecule PD-L1 inhibitors: BMS-1166 and peptide-57.[Molecules. 2019 Aug 1;24(15):2804.]

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CA-170 is the first small-molecule inhibitor targeted at PD-L1 that was introduced to phase I and II clinical trials. We, however, unambiguously determined that there is in fact no direct binding between CA-170 and its peptidic precursor AUNP-12 to PD-L1. In the NMR binding assay, neither of these molecules showed any interactions with the one- or two-domain PD-L1 in the human and mice variants as well as human PD-1. CA-170 and AUNP-12 were also not able to dissociate complex formation in the isolated system of the HTRF assay and cell-based assay mimicking in vivo conditions. All measurements were cross-validated with positive controls: peptide-57 and small-molecule BMS-1166. Therefore, proposed mechanism of the direct blocking of hPD-1/hPD-L1 interactions with CA-170 has to be changed.[Molecules. 2019 Aug 1;24(15):2804.]

C13H22N6O7

374.3498

374.154

C, 41.71; H, 5.92; N, 22.45; O, 29.92

1673560-66-1

PD-1-IN-17 TFA

131998882

White to off-white solid powder

-6.7

7

10

10

26

507

4

O1C(C([H])(C([H])(C([H])([H])[H])O[H])N([H])[H])=NN=C1C([H])(C([H])([H])C([H])([H])C(N([H])[H])=O)N([H])C(N([H])C([H])(C(=O)O[H])C([H])([H])O[H])=O

SRNQPYBWRIETFQ-XKBZYTNZSA-N

InChI=1S/C13H22N6O7/c1-5(21)9(15)11-19-18-10(26-11)6(2-3-8(14)22)16-13(25)17-7(4-20)12(23)24/h5-7,9,20-21H,2-4,15H2,1H3,(H2,14,22)(H,23,24)(H2,16,17,25)/t5-,6+,7+,9+/m1/s1

(2S)-2-[[(1S)-4-amino-1-[5-[(1S,2R)-1-amino-2-hydroxypropyl]-1,3,4-oxadiazol-2-yl]-4-oxobutyl]carbamoylamino]-3-hydroxypropanoic acid

PD-1-IN-17; PD-1-IN-17 free base; PD1-IN-1; (2S)-2-[[(1S)-4-amino-1-[5-[(1S,2R)-1-amino-2-hydroxypropyl]-1,3,4-oxadiazol-2-yl]-4-oxobutyl]carbamoylamino]-3-hydroxypropanoic acid; (S)-2-(3-((S)-4-Amino-1-(5-((1S,2R)-1-amino-2-hydroxypropyl)-1,3,4-oxadiazol-2-yl)-4-oxobutyl)ureido)-3-hydroxypropanoic acid; CHEMBL4458504; SCHEMBL19450456;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

DMSO : ~125 mg/mL (~333.91 mM)
H2O : ≥ 100 mg/mL (~267.13 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.56 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 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL 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: ≥ 2.08 mg/mL (5.56 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 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.08 mg/mL (5.56 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 20.8 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.)