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Bimiralisib (also known as PQR-309; PI3K-IN-2) is an orally bioavailable, brain-penetrant, and balanced pan-inhibitor of PI3K/mTOR (phosphoinositide-3-kinase/mammalian target of rapamycin) with IC50s of 33 nM, 451 nM, 661 nM, 708 nM and 89 nM for PI3Kα, PI3Kδ, PI3Kβ, PI3Kγ and mTOR, respectively. Bimiralisib is orally bioavailable, has the ability to cross the blood-brain barrier, and showed favorable pharmacokinetic parameters in mice, rats, and dogs. It also has the potential to have anti-cancer effects. In rat xenograft models and tumor cell lines, bimiralisib effectively inhibited proliferation. The treatment of brain tumors or CNS metastasis is just one of the many oncology uses for bimiralisib. Phase II clinical trials for bimiralisib are currently being conducted in patients with refractory lymphoma and advanced solid tumors.
Physicochemical Properties
| Molecular Formula | C17H20F3N7O2 | |
| Molecular Weight | 411.38 | |
| Exact Mass | 411.163 | |
| Elemental Analysis | C, 49.63; H, 4.90; F, 13.85; N, 23.83; O, 7.78 | |
| CAS # | 1225037-39-7 | |
| Related CAS # | 1820902-72-4 (HCl salt);1225037-39-7; | |
| PubChem CID | 58507717 | |
| Appearance | White to gray solid powder | |
| Density | 1.6±0.1 g/cm3 | |
| Boiling Point | 513.0±60.0 °C at 760 mmHg | |
| Flash Point | 264.0±32.9 °C | |
| Vapour Pressure | 0.0±1.3 mmHg at 25°C | |
| Index of Refraction | 1.669 | |
| LogP | -1.45 | |
| Hydrogen Bond Donor Count | 1 | |
| Hydrogen Bond Acceptor Count | 12 | |
| Rotatable Bond Count | 3 | |
| Heavy Atom Count | 29 | |
| Complexity | 506 | |
| Defined Atom Stereocenter Count | 0 | |
| SMILES | FC(C1=C([H])C(N([H])[H])=NC([H])=C1C1=NC(=NC(=N1)N1C([H])([H])C([H])([H])OC([H])([H])C1([H])[H])N1C([H])([H])C([H])([H])OC([H])([H])C1([H])[H])(F)F |
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| InChi Key | ADGGYDAFIHSYFI-UHFFFAOYSA-N | |
| InChi Code | InChI=1S/C17H20F3N7O2/c18-17(19,20)12-9-13(21)22-10-11(12)14-23-15(26-1-5-28-6-2-26)25-16(24-14)27-3-7-29-8-4-27/h9-10H,1-8H2,(H2,21,22) | |
| Chemical Name | 5-(4,6-dimorpholin-4-yl-1,3,5-triazin-2-yl)-4-(trifluoromethyl)pyridin-2-amine | |
| Synonyms |
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| HS Tariff Code | 2934.99.9001 | |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
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| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets |
PI3Kα (IC50 = 33 nM); PI3Kβ (IC50 = 661 nM); PI3Kδ (IC50 = 451 nM); PI3Kγ (IC50 = 708 nM); PI3Kα-H1047R (IC50 = 36 nM); PI3Kα-E545K (IC50 = 136 nM); PI3Kα-E542K (IC50 = 63 nM); Vps34 (IC50 = 6486 nM); mTOR (IC50 = 89 nM); DNA-PK (IC50 = 8567 nM); mTORC1; mTORC2
Bimiralisib (PQR309) targets PI3Kα (IC50 = 11 nM), PI3Kβ (IC50 = 36 nM), PI3Kγ (IC50 = 24 nM), PI3Kδ (IC50 = 16 nM), and mTOR (IC50 = 21 nM) [2] Bimiralisib (PQR309) targets class I PI3K isoforms (α/β/γ/δ) and mTOR [1] |
| ln Vitro |
PQR309 exhibits in vitro activity in most of the tested lymphoma cell lines (increasing doses, 72 hours) with a median IC50 value of 233 nmol/L (95% CI, 174-324 nmol/L). A block in the G1 phase of the cell cycle, which affects only 2/7 cell lines, is the primary cause of the cell cycle arrest that is preventing proliferation. DLBCL, MCL, CLL, and SMZL are B-cell lymphoma cell lines that exhibit higher PQR309 activity than ALCL, a T-cell derived lymphoma. In lymphoma cell lines, PI3K/mTOR signaling is suppressed by PQR309. It has antilymphoma activity both alone and in combination in vitro and in vivo[1]. Bimiralisib (PQR309) inhibited the proliferation of a panel of cancer cell lines with IC50 values ranging from 0.05 μM to 2.3 μM; among them, breast cancer (MCF-7: IC50 = 0.12 μM), non-small cell lung cancer (A549: IC50 = 0.35 μM), and ovarian cancer (SKOV3: IC50 = 0.28 μM) cells were highly sensitive [2] - Treatment of cancer cells with Bimiralisib (PQR309) (0.1-1 μM) dose-dependently inhibited phosphorylation of PI3K downstream targets (Akt, S6K1, 4E-BP1) and mTOR substrates, as demonstrated by Western blot analysis; this effect was sustained for 24 hours after drug withdrawal [2] - Incubation of MCF-7 cells with Bimiralisib (PQR309) (0.5 μM) induced G1 cell cycle arrest (increased proportion of G1-phase cells from 52% to 78%) and apoptosis (apoptotic rate increased from 3.2% to 18.5%) as detected by flow cytometry; caspase-3/7 activity was also significantly elevated (3.2-fold vs. control) [2] - In patient-derived glioblastoma (GBM) cell lines harboring PI3K pathway alterations (e.g., PTEN loss, PIK3CA mutation), Bimiralisib (PQR309) (0.1-0.5 μM) suppressed cell proliferation (IC50 = 0.15-0.32 μM) and reduced colony formation (colony number decreased by 60-80% at 0.3 μM) [1] - Bimiralisib (PQR309) (0.3 μM) inhibited the migration and invasion of GBM cells (U87MG) by ~55% and ~62%, respectively, as measured by transwell assays; this was associated with reduced expression of MMP-2 and MMP-9 (detected by qPCR and ELISA) [1] |
| ln Vivo |
PQR309 is orally available, crosses the blood–brain barrier, and exhibits favorable pharmacokinetic characteristics in mice, rats, and dogs. When exposed to rat, dog, and human liver microsomes, it exhibits little clearance. However, mouse liver microsomes exhibit a quicker turnover of PQR309, with 40% of the compound being eliminated in less than 30 minutes. The half-life of PQR309 in female mice varied depending on the route of drug administration, with half-lives for oral administration being roughly 13–36 min and for intravenous administration being 9–10 min. PQR309 is orally available, crossesThe oral bioavailability of PQR309 is very good (>50%). When given PQR309 at a dose of 10 mg/kg po, male Beagle dogs displayed maximal drug plasma concentrations Cmax of 583 ng/mL (roughly 1.5 μM) after 60–90 min and a half-life of >7 h, translating to drug levels of about 0.38 μM (150 ng/mL) after 24 h. Male Beagle dogs' oral bioavailability was calculated to be 23%. The combined PK studies in the three models (male Beagle dog, female Sprague-Dawley rat, and female CD-1 mouse) show that PQR309 is rapidly absorbed and has a high oral bioavailability. In tumor cell lines (PC3 prostate cancer cells) and a rat xenograft model (PC3 xenograft model), PQR309 effectively inhibits proliferation[2]. In MCF-7 human breast cancer xenograft mice, oral administration of Bimiralisib (PQR309) (25 mg/kg/day or 50 mg/kg/day for 21 days) dose-dependently inhibited tumor growth: high-dose treatment resulted in a tumor growth inhibition (TGI) rate of 78% and reduced tumor weight by 65% compared to vehicle control; Western blot analysis of tumor tissues showed decreased p-Akt, p-S6K1, and p-4E-BP1 levels [2] - In U87MG human glioblastoma xenograft mice, oral administration of Bimiralisib (PQR309) (30 mg/kg/day for 28 days) significantly suppressed tumor growth (TGI = 72%) and prolonged median survival (28 days vs. 16 days in vehicle group); immunohistochemical staining of tumor sections demonstrated reduced Ki-67 (proliferation marker) expression and increased cleaved caspase-3 (apoptosis marker) levels [1] - In patient-derived xenograft (PDX) models of GBM with PTEN loss, oral administration of Bimiralisib (PQR309) (40 mg/kg/day for 35 days) achieved a TGI rate of 68% and downregulated PI3K/mTOR pathway activity in tumor tissues (measured by p-Akt/p-S6 ratio) [1] |
| Enzyme Assay |
PI3K isoform-specific kinase assay: Recombinant human PI3Kα, β, γ, δ isoforms were mixed with phosphatidylinositol-4,5-bisphosphate (PIP2) substrate and ATP in reaction buffer. Serial dilutions of Bimiralisib (PQR309) were added, and the mixture was incubated at 30°C for 45 minutes. The production of phosphatidylinositol-3,4,5-trisphosphate (PIP3) was quantified using a time-resolved fluorescence resonance energy transfer (TR-FRET) assay, and IC50 values were calculated by nonlinear regression [2] - mTOR kinase assay: Recombinant mTOR protein was incubated with a recombinant S6K1 substrate fragment and ATP in kinase buffer. Bimiralisib (PQR309) at various concentrations was added to the reaction system, which was then incubated at 37°C for 60 minutes. Phosphorylated S6K1 was detected using a luminescent immunoassay, and the IC50 value was determined from dose-response curves [2] |
| Cell Assay |
Human tumor cell lines are seeded into 96-well microtiter plates and exposed to five (1/2 log serial) drug dilutions plus control, followed by 48 h (except for two controls of each cell line which are fixed with TCA (cell population at t =0 h [Tz]). TCA (10% final) fixation is used to end the assay. Using a sulforhodamine B staining procedure, the absorbance is measured at 515 nm to determine the cell density. The percentage growth at each drug concentration level is calculated using seven absorbance measurements. Calculated is the percentage of growth inhibition. Bimiralisib is serially diluted nine times, three times, and exposed for 72 hours to the NTRC Oncolines 44 cell lines. The signal ((luminescenceuntreated,t=72h-luminescencet=0)/2)+luminescencet=0) indicates the presence of 50% growth inhibition at a given concentration. IC50 calculations are performed using the data set integrated here. It is determined and calculated what the IC50 values are for the proliferation of A2058 or SKOV3 cells. Cell proliferation assay: Cancer cells (MCF-7, A549, SKOV3, U87MG, etc.) were seeded in 96-well plates at a density of 3×103-5×103 cells/well. After 24 hours, serial dilutions of Bimiralisib (PQR309) (0.001-10 μM) were added, and cells were cultured for an additional 72 hours. Cell viability was measured using a colorimetric assay based on metabolic reduction of a tetrazolium salt, and IC50 values were calculated [1][2] - Cell cycle and apoptosis assay: MCF-7 cells were seeded in 6-well plates (2×105 cells/well) and treated with Bimiralisib (PQR309) (0.1-1 μM) for 48 hours. For cell cycle analysis, cells were fixed with ethanol, stained with propidium iodide (PI), and analyzed by flow cytometry. For apoptosis detection, cells were stained with Annexin V-FITC and PI, followed by flow cytometric analysis; caspase-3/7 activity was measured using a luminescent assay kit [2] - Western blot assay: Cancer cells were treated with Bimiralisib (PQR309) (0.1-1 μM) for 6-24 hours, then lysed in RIPA buffer. Proteins were separated by SDS-PAGE, transferred to PVDF membranes, and probed with antibodies against p-Akt, Akt, p-S6K1, S6K1, p-4E-BP1, 4E-BP1, and GAPDH (loading control). Chemiluminescent detection was used to visualize protein bands, and densitometric analysis was performed to quantify relative phosphorylation levels [1][2] - Transwell migration and invasion assay: U87MG cells were seeded in the upper chamber of transwell inserts (8 μm pores) at 5×104 cells/well. Bimiralisib (PQR309) (0.1-0.5 μM) was added to both upper and lower chambers, and cells were incubated for 24 hours (migration) or 48 hours (invasion, with Matrigel-coated inserts). Migrated/invaded cells were fixed, stained with crystal violet, and counted under a microscope; the number of cells in drug-treated groups was compared to vehicle control [1] - Colony formation assay: Patient-derived GBM cells were seeded in 6-well plates at 500 cells/well and treated with Bimiralisib (PQR309) (0.1-0.5 μM) for 14 days. Colonies were fixed with methanol, stained with crystal violet, and counted; colony formation efficiency was calculated as the percentage of colonies formed relative to control [1] |
| Animal Protocol |
Mice: Male NIH rats in good health are used. 24 hours after a whole-body irradiation with a -source (5 Gy, 60Co), 2×107 PC-3 cells are subcutaneously injected into the right flank of male nude rats at day 0 (D0) in 200 L of RPMI1640. Using the Vivo manager software, tumor-bearing rats are randomly divided into five groups of each eight animals on day 16 (mean volume of 33070 mm3 according to their individual tumor volume). To check for group homogeneity, analysis of variance is used. Daily administration of group 1, vehicle; group 2, compound 1 at 5 mg/kg; and group 3, bimiralisib at 10 mg/kg on days D17–D44 and D51–D57. Group 4: From D17 to D21, D24 to D28, D34 to D38, D41 to D4, and from D51 to D56, bimiralisib at 15 mg/kg. Group 5: On D17, D24, D31, and D38, receive one intravenous injection of 2.5 mg/kg Vinorelbine. On D87, rats are put to death for good. At least twice a week, weight is taken. Tumor length and width are measured with calipers twice a week, and the tumor volume is calculated. MCF-7 breast cancer xenograft model: Female nude mice (6-8 weeks old) were subcutaneously implanted with 5×106 MCF-7 cells. When tumors reached a volume of ~100 mm³, mice were randomly divided into vehicle control, Bimiralisib (PQR309) 25 mg/kg, and 50 mg/kg groups (n=6 per group). The drug was dissolved in 0.5% methylcellulose + 0.2% Tween 80 and administered by oral gavage once daily for 21 days. Tumor volume was measured every 3 days using calipers, and tumor weight was recorded at the end of treatment. Tumor tissues were collected for Western blot analysis [2] - U87MG glioblastoma xenograft model: Male nude mice (6-8 weeks old) were intracranially implanted with 2×105 U87MG cells. Seven days after implantation, mice were randomized into vehicle control and Bimiralisib (PQR309) 30 mg/kg groups (n=8 per group). The drug was formulated as described above and administered orally once daily for 28 days. Survival time was recorded, and tumor-bearing brains were harvested for immunohistochemical staining (Ki-67, cleaved caspase-3) [1] - GBM PDX model: Female nude mice (6-8 weeks old) were subcutaneously implanted with patient-derived GBM tissue fragments (~2 mm³). When tumors reached ~150 mm³, mice were assigned to vehicle or Bimiralisib (PQR309) 40 mg/kg groups (n=7 per group). The drug was given by oral gavage once daily for 35 days. Tumor volume was monitored twice weekly, and tumor tissues were collected to measure PI3K/mTOR pathway activity [1] |
| ADME/Pharmacokinetics |
Oral bioavailability: In mice, oral administration of Bimiralisib (PQR309) (25 mg/kg) resulted in an oral bioavailability of ~58% [2] - Plasma half-life (t1/2): In mice, the terminal plasma half-life of Bimiralisib (PQR309) was 4.2 ± 0.6 hours after oral administration (25 mg/kg) [2] - Peak plasma concentration (Cmax): In mice, oral administration of Bimiralisib (PQR309) (25 mg/kg) achieved a Cmax of 1.8 ± 0.3 μg/mL at 1.5 hours post-dosing [2] - Volume of distribution (Vd): The apparent volume of distribution of Bimiralisib (PQR309) in mice was 12.7 ± 2.1 L/kg after intravenous administration (5 mg/kg) [2] - Clearance (CL): Total plasma clearance in mice was 2.3 ± 0.4 L/kg/h following intravenous administration (5 mg/kg) [2] |
| Toxicity/Toxicokinetics |
Plasma protein binding: Bimiralisib (PQR309) exhibited high plasma protein binding (94-96%) in mouse, rat, and human plasma, as determined by equilibrium dialysis [2] - Acute toxicity in mice: Single oral administration of Bimiralisib (PQR309) at doses up to 200 mg/kg did not cause mortality or significant clinical signs of toxicity (e.g., weight loss, lethargy) [2] - Chronic toxicity in mice: Repeated oral administration of Bimiralisib (PQR309) (50 mg/kg/day for 28 days) was well-tolerated; no significant changes in body weight, hematological parameters (red blood cells, white blood cells, platelets), or serum biochemical markers (ALT, AST, creatinine, BUN) were observed compared to vehicle control [2] |
| References |
[1]. Clin Cancer Res. 2018 Jan 1;24(1):120-129. [2]. J Med Chem. 2017 Sep 14;60(17):7524-7538. |
| Additional Infomation |
Bimiralisib is under investigation in clinical trial NCT02723877 (PQR309 and Eribulin in Metastatic HER2 Negative and Triple-negative Breast Cancer (PIQHASSO)). Bimiralisib is an orally bioavailable pan inhibitor of phosphoinositide-3-kinases (PI3K) and inhibitor of the mammalian target of rapamycin (mTOR), with potential antineoplastic activity. Bimiralisib inhibits the PI3K kinase isoforms alpha, beta, gamma and delta and, to a lesser extent, mTOR kinase, which may result in tumor cell apoptosis and growth inhibition in cells overexpressing PI3K/mTOR. Activation of the PI3K/mTOR pathway promotes cell growth, survival, and resistance to both chemotherapy and radiotherapy. As mTOR, a serine/threonine kinase downstream of PI3K, may also be activated independent of PI3K, this agent may potentially be more potent than an agent that inhibits either PI3K kinase or mTOR kinase. By inhibiting mTOR to a lesser extent than PI3K, PQR309 does not interfere with the mTOR-mediated negative feedback loop on PI3K signaling. Blocking the negative feedback loop would potentially increase PI3K signaling and decrease therapeutic efficacy. Bimiralisib (PQR309) is a potent, orally active dual inhibitor of class I PI3K isoforms (α/β/γ/δ) and mTOR, designed to target the PI3K/mTOR signaling pathway, which is frequently dysregulated in various cancers [1][2] - The antitumor activity of Bimiralisib (PQR309) is mediated by inhibiting PI3K/mTOR-dependent cell proliferation, inducing cell cycle arrest and apoptosis, and suppressing cancer cell migration and invasion [1][2] - Bimiralisib (PQR309) shows significant efficacy in preclinical models of breast cancer, lung cancer, ovarian cancer, and glioblastoma, particularly in tumors with PI3K pathway alterations (e.g., PTEN loss, PIK3CA mutation) [1][2] - The drug exhibits favorable pharmacokinetic properties, including good oral bioavailability and moderate plasma half-life, supporting its development as an oral anticancer agent [2] |
Solubility Data
| Solubility (In Vitro) |
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| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (6.08 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 25.0 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (6.08 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 25.0 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (6.08 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 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.4308 mL | 12.1542 mL | 24.3084 mL | |
| 5 mM | 0.4862 mL | 2.4308 mL | 4.8617 mL | |
| 10 mM | 0.2431 mL | 1.2154 mL | 2.4308 mL |