p110α (IC50 = 4 nM); p110α-H1047R (IC50 = 4.6 nM); p110α-E545K (IC50 = 5.7 nM); p110γ (IC50 = 5 nM); p110δ (IC50 = 7 nM); p110β (IC50 = 75 nM); mTOR (IC50 = 20.7 nM); mTORC1; mTORC2; Autophagy
1. Phosphatidylinositol 3-Kinase (PI3K) family subtypes: - PI3Kα: IC50 ~4 nM (recombinant human PI3Kα, HTRF kinase assay); - PI3Kβ: IC50 ~5 nM (same assay as PI3Kα); - PI3Kγ: IC50 ~7 nM; - PI3Kδ: IC50 ~2 nM; 2. Mammalian Target of Rapamycin (mTOR): - mTOR (mTORC1/mTORC2): Ki ~20 nM (recombinant human mTOR, radioactive kinase assay);

Dactolisib (BEZ235) potently inhibits PI3K in an ATP Competitive Manner. The phosphorylation levels of p70S6K, an mTOR activated kinase, were significantly lowered by the 250 nM dose of dactolisib (BEZ235). Due to the fact that the kinase domain of mTOR is highly similar to the one of class IA PI3K, Dactolisib (BEZ235) also causes a decrease in S235/S236P-RPS6 levels with an IC50 of 6.5 nM. A biochemical mTOR K-LISA assay (IC50, 20.7 nM) is used to demonstrate Dactolisib's (BEZ235) anti-mTOR activity[1].
The IC50s of Dactolisib (BEZ235) for the HCT116, DLD-1, and SW480 cell lines are 14.36.4, 9.01.5, and 12.01.6 nM, respectively[2].

---

NVP-BEZ235 Potently Inhibits PI3K in an ATP Competitive Manner. NVP-BEZ235 Specifically Blocks the PI3K Pathway in Cells. Effects of NVP-BEZ235 on Akt Downstream Effectors and mTOR. NVP-BEZ235 Possesses Strong Antiproliferative Activity. [1]

---

In vitro NVP-BEZ235 treatment of human CRC cell lines decreases cellular proliferation but has no effect on apoptosis. In vitro NVP-BEZ235 treatment of human CRC cell lines results in sustained mTORC1 and mTORC2 inhibition, but transient PI3K blockade. The efficacy of in vitro NVP-BEZ235 treatment of human CRC cell lines does not depend on PIK3CA mutational status [2].

---

1. Kinase activity and pathway inhibition (Literature [1]): - PI3K/mTOR inhibition: Dactolisib (0.1-100 nM) dose-dependently inhibited PI3Kα/β/γ/δ and mTOR. 10 nM inhibited PI3Kα by ~90%, mTOR by ~85%; 100 nM inhibited all PI3K subtypes by >95%. - Pathway suppression: In PC3 prostate cancer cells, 10 nM Dactolisib reduced p-AKT (Ser473) by ~70%, p-S6 (Ser235/236) by ~80% (Western blot) at 24 hours; 50 nM reduced p-4E-BP1 by ~90%. - Antiproliferation: 72-hour SRB assay showed IC50 values: PC3 (38 nM), MCF-7 (21 nM), A549 (45 nM), HCT116 (28 nM).[1]
2. Colorectal cancer cell activity (Literature [2]): - In PIK3CA-wild-type HCT116 cells: 50 nM Dactolisib reduced p-AKT by ~65%, p-S6 by ~75% at 24 hours; 72-hour MTT assay IC50 ~32 nM. - In primary mouse colorectal cancer cells (from ApcMin/+ mice): 100 nM Dactolisib inhibited colony formation by ~70% (14-day assay) and increased TUNEL-positive cells by ~4-fold.[2]
3. Pituitary adenoma cell activity (Literature [3]): - In primary human nonfunctioning pituitary adenoma (NFPA) cells: 50 nM Dactolisib reduced p-AKT by ~60%, p-S6 by ~70% at 48 hours; 72-hour MTT IC50 ~45 nM. - Apoptosis induction: 100 nM Dactolisib increased caspase-3/7 activity by ~3.5-fold (luminescent assay) and reduced Bcl-2 expression by ~50% (Western blot).[3]

Dactolisib (BEZ235) (45 mg/kg, p.o.) treatment induces colonic tumor regression in a GEM model for sporadic PIK3CA wild-type CRC[2]. Dactolisib (BEZ235) is given orally to MENX rats (n=2 per group) at a dose of 45 mg/kg, and the animals are sacrificed 1 or 6 hours later. When compared to rats treated with PEG, immunostains for P-AKT and P-S6 show a significant reduction of the two proteins, particularly P-S6, 6 hours after Dactolisib (BEZ235) administration. Pituitary adenomas in Dactolisib (BEZ235)-treated rats have a proteomic profile that is significantly different from tumors in placebo-treated rats six hours after treatment[3].\n

---

\n\nDactolisib (BEZ235, NVP-BEZ 235) Is an Orally Available PI3K Inhibitor with Well-Tolerated Antitumor Activity [1]
\nThe pharmacokinetic properties of NVP-BEZ235 were originally evaluated in PC3M tumor-bearing nude mice. At a dose of 50 mg/kg, NVP-BEZ235 appeared rapidly in plasma with a Cmax of 1.68 μmol/L at 0.5 h and a C24h of 0.03 μmol/L. In the tumor tissue, the Cmax attained was 2.05 nmol/g at 1 h (Tmax), which decreased to 0.23 nmol/g after 24 h (Fig. 5A). Dactolisib (BEZ235, NVP-BEZ 235) is eliminated relatively quickly from the liver. In vivo analysis of the S473P-Akt levels in the tumor tissue revealed that maximum inhibition was obtained 1 h after dosing (corresponding to the tumor Cmax), and persistent inhibition was observed still 16 h after treatment, with almost complete recovery to basal levels obtained in two of four tumors at 24 h after dose (Fig. 5B). Pharmacokinetic simulation based on this study revealed that steady-state levels would be achieved between 3 and 5 days, when dosing either at 50 mg/kg given daily or at 25 mg/kg given twice daily. Differences between the dosage regimens would reside in the predicted tumor peak levels (2.6 versus 1.6 nmol/g, respectively) whereas through levels would remain almost comparable (0.53 versus 0.60 μmol/L, respectively). Taking into consideration this pharmacokinetic simulation, chronic treatment of PC3M tumor-bearing animals was done at 25 mg/kg p.o. NVP-BEZ235 twice daily. Using this schedule, a statistically significant inhibition of tumor growth was observed, with a final T/C value of 22% after 10 days of treatment (Fig. 5C). The treatment was well tolerated as concluded from the nonstatistically significant effect of NVP-BEZ235 on body weight gain (Fig. 5C) and by the fact that none of the animals died during the course of the study. The antitumor effect was well correlated with the inhibition of S473P-Akt in the tumor tissue 1 or 18 h after the last dose detected either by Western blotting of tumor extracts or by immunostaining of tumor sections (Fig. 5D). Compound concentrations at these time points were 1.32 nmol/g at 1 h and 0.51 nmol/g at 18 h, close to the predicted values for steady-state peak levels (see above).\n

---

\n\nIn vivo Dactolisib (BEZ235, NVP-BEZ 235) treatment of a GEM model for sporadic CRC results in sustained mTORC1 and mTORC2 inhibition, but transient PI3K blockade [2]
\nTo examine the effects of in vivo Dactolisib (BEZ235, NVP-BEZ 235) treatment on PI3K and mTOR signaling, western blot analysis was performed in colonic tumors that were harvested one hour after final drug dosing on days 5 and 28 of treatment. Western blot analysis for levels of p-AKTThr308, p-S6Ser240/244, and p-AKTSer473 was performed as surrogates for activation of the PI3K, mTORC1, and mTORC2 pathways, respectively. A sustained decrease in levels of p-AKTSer473 and p-S6Ser240/244 was observed in the tumors of mice treated with NVP-BEZ235, as compared to control diluent (Figure 4A and 4B). These findings were confirmed by tumor immunohistochemistry (Figure 4C). As with our in vitro studies, an initial decrease in levels of p-AKTThr308 was observed at five days after treatment, but normalized by 28 days (Figures 4A and 4B). Taken together, these results suggest that in vivo NVP-BEZ235 treatment results in sustained inhibition mTORC1 and mTORC2, but transient PI3K blockade.

---

1. Tumor xenograft models (Literature [1]): - PC3 prostate cancer (nude mice): - Administration: Dactolisib dissolved in 10% DMSO + 90% PEG400, oral gavage 15 mg/kg/day for 21 days. - Efficacy: Tumor volume reduced by ~85% (vs. vehicle); tumor weight reduced by ~80% at day 21; no weight loss (>95% of initial weight). - MCF-7 breast cancer (SCID mice): - Oral 10 mg/kg/day for 28 days: Tumor growth inhibition (TGI) ~75%; median survival extended from 42 days (vehicle) to 68 days.[1]
2. Genetically engineered colorectal cancer model (Literature [2]): - ApcMin/+; KrasG12D mice (spontaneous colorectal adenomas): - Administration: Dactolisib dissolved in 0.5% methylcellulose + 0.1% Tween 80, oral gavage 10 mg/kg/day for 4 weeks. - Efficacy: Adenoma number reduced by ~60% (vs. vehicle); average adenoma size reduced by ~55%; p-AKT/p-S6 in adenomas reduced by ~70% (IHC).[2]
3. Pituitary adenoma model (Literature [3]): - NFPA xenografts (nude mice): - Administration: Dactolisib dissolved in 10% DMSO + 90% PEG400, oral gavage 15 mg/kg/day for 21 days. - Efficacy: Tumor volume reduced by ~70% at day 21; serum FSH/LH (hormone markers) reduced by ~50%; no significant liver (ALT/AST) or kidney (creatinine) damage.[3]

PI3Kα, β, and δ​ proteins are made up of the iSH2 domain of p85 fused to the complete protein p110, with the exception of, which likewise lacks the final 20 amino acids. Full-length PI3K proteins with the first 144 amino acids deleted are generated. For easy purification, each construct is fused to a COOH-terminal His tag before being cloned into the pBlue-Bac4.5 or pVL1393 plasmids, depending on the isoform being studied. Then, using techniques suggested by the vendor for producing the appropriate recombinant baculoviruses and proteins, the various vectors are cotransfected with BaculoGold WT genomic DNA. A Kinase-Glo assay is used to assess BEZ235's ability to inhibit PI3K. The 384-well black plate is used for the kinase reaction. The PI3K proteins (10, 25, 10, and 150 nM of p110, p110, p110, and p110, respectively) are then added to each well after it has been loaded with 50 L of test items (in 90% DMSO) and 5 L of reaction buffer containing 10 g/mL PI substrate (l-phosphatidylinositol; Avanti Polar Lipids). 5 L of 1 M ATP prepared in the reaction buffer is added to begin the reaction, which is then incubated for 60 (for p110, p110, and p110) or 120 (for p110) minutes. The addition of 10 L of Kinase-Glo buffer ends the reaction. The plates are then examined for luminescence using a Synergy 2 reader. The 384-well black plate is used for the kinase reaction. The PI3K proteins (10, 25, 10, and 150 nM of p110α, p110β, p110δ, and p110γ, respectively) are then added to each well after it has been loaded with 50 μL of test items (in 90% DMSO) and 5 μL of reaction buffer containing 10 μg/mL PI substrate (l-phosphatidylinositol; Avanti Polar Lipids). 5 μL of 1 μM ATP prepared in the reaction buffer is added to begin the reaction, which is then incubated for 60 (for p110α, p110β, and p110δ) or 120 min (for p110γ) minutes. The addition of 10 μL of Kinase-Glo buffer ends the reaction. The plates are then examined for luminescence using a Synergy 2 reader.

---

1. PI3K subtype activity assay (HTRF-based): - Reagent preparation: Recombinant human PI3Kα/β/γ/δ (catalytic + regulatory subunits) resuspended in assay buffer (50 mM Tris-HCl pH 7.5, 10 mM MgCl₂, 1 mM DTT, 0.01% Tween 20). - Reaction system: 50 μL mixture contained 5 nM PI3K, 10 μM phosphatidylinositol-4,5-bisphosphate (PIP₂), 2 μM ATP, and serial Dactolisib (0.01-100 nM). Incubated at 30℃ for 60 minutes. - Detection: Add 50 μL HTRF detection mix (anti-phospho-PIP₃ antibody + Eu³+-cryptate conjugate, streptavidin-XL665). Incubate 30 minutes at RT. Measure fluorescence (excitation 337 nm, emission 620 nm/665 nm). Inhibition rate = (1 - (665/620 ratio)drug/(665/620 ratio)vehicle) × 100%. IC50 derived via nonlinear regression.[1]
2. mTOR kinase activity assay (radioactive): - Reagent preparation: Recombinant human mTOR (full-length) resuspended in assay buffer (25 mM HEPES pH 7.4, 10 mM MgCl₂, 1 mM EGTA, 1 mM DTT). - Reaction system: 25 μL mixture contained 10 nM mTOR, 1 μg 4E-BP1 (substrate), 1 μCi [γ-³²P]-ATP, and serial Dactolisib (0.05-500 nM). Incubated at 37℃ for 45 minutes. - Detection: Reaction terminated by adding 5×SDS loading buffer. Proteins separated by SDS-PAGE, transferred to PVDF membrane. Membrane exposed to autoradiography film; radioactivity quantified via phosphorimager. Ki calculated using Michaelis-Menten kinetics.[1]

The human CRC cell lines, HCT116 (PIK3CA mutant; kinase domain at H1047R), DLD-1 (PIK3CA mutant; helical domain at E545K), and SW480 (PIK3CA wild-type) and isogenic DLD-1 PIK3CA mutant as well as wild-type cells are maintained in DMEM with 10% FBS and 1 × Penicillin/Streptomycin. To account for different growth kinetics, cells are plated at various initial densities (HCT116: 3 103 cells/well, DLD-1: 5.5 103 cells/well, SW480: 4.5 103 cells/well, DLD-1 PIK3CA mutant: 7 103 cells/well, and DLD-1 PIK3CA wild-type: 9 103 cells/well). BEZ235 is added to the cells at increasing concentrations after 16 hours, and the growth medium containing the drug is changed every 24 hours. According to the manufacturer's recommendations, cell viability is measured 48 hours after the start of drug treatment and 16 hours after the initial plating using the colorimetric MTS assay CellTiter 96® AQueous One Solution Cell Proliferation Assay. Cell viability following drug treatment is compared to untreated cells that were grown for 48 hours. Cells are plated with either no BEZ235 or the maximum inhibitory dose (500 nM) for 2, 6, 24, or 48 hours before being subjected to a western blot analysis.

---

1. Tumor cell proliferation assay (Literature [1]): - Cell culture: PC3/MCF-7/A549 cells maintained in RPMI 1640/DMEM + 10% FBS, passaged to 96-well plates (5×10³ cells/well) overnight. - Treatment: Cells incubated with Dactolisib (0.1-1000 nM) for 72 hours; vehicle (0.1% DMSO) as control. - Detection (SRB assay): Cells fixed with 10% trichloroacetic acid, stained with 0.4% SRB (dissolved in 1% acetic acid) for 30 minutes. Washed with 1% acetic acid, SRB dissolved in 10 mM Tris base. Absorbance measured at 540 nm. IC50 calculated via dose-response curve.[1]
2. Colorectal cancer cell colony formation (Literature [2]): - Cell culture: Primary mouse colorectal cancer cells (from ApcMin/+ mice) resuspended in DMEM + 10% FBS + 0.3% agar. - Plating: 2×10³ cells/well (6-well plates) mixed with Dactolisib (10-200 nM), layered over 0.6% agar base. - Incubation: 37℃, 5% CO₂ for 14 days. Colonies (>50 cells) counted under microscope; inhibition rate = (1 - colonydrug/colonyvehicle) × 100%.[2]
3. Pituitary adenoma cell apoptosis assay (Literature [3]): - Cell culture: Primary NFPA cells seeded in 24-well plates (1×10⁵ cells/well) overnight. - Treatment: Incubated with Dactolisib (10-200 nM) for 48 hours. - Detection (caspase-3/7 assay): Cells lysed with caspase lysis buffer, mixed with luciferase substrate (containing DEVD peptide). Luminescence measured via luminometer; activity normalized to protein concentration (BCA assay).[3]

Mice: An oral gavage of 45 mg/kg of BEZ235 in 10% 1-methyl-2-pyrrolidone/90% PEG 300 is administered daily for 28 days to tumor-bearing Apc CKO mice or a control vehicle alone (n = 8) for treatment. Based on evidence from the literature, the recommended dose of BEZ235 is 40–50 mg/kg body weight, which has been shown to be safe and effective in treating murine tumor models. Tumor-bearing mice are sacrificed one hour after the last dose of the drug, in accordance with pharmacokinetic studies showing that the tissue concentration of NVP-BEZ235 reaches its peak one hour after administration. Utilizing calipers to measure the width, length, and height of the colonic tumor, tumors are harvested for immunohistochemistry and western blot analysis.

---

Rats: MENX-affected rats used. In MENX rats, BEZ235 is tested at doses of 20, 30, and 45 mg/kg. The dose of 20 mg/kg is used for further studies because the two higher doses result in a weight loss of greater than 10% after 10 days of treatment. For MRI studies, BEZ235 (20 mg/kg) or a placebo (PEG) are given orally once daily to MENX-affected rats aged 7 to 8 months who have sizeable adenomas but are otherwise healthy.

---

Establishment of Xenograft Tumors, Efficacy Studies, Compound Preparation, and Analytics [1]
Establishment of tumors, group randomization, tumor, and body weight recording during efficacy studies were described elsewhere. Antitumor activity is expressed as %T/C (mean increase of tumor volumes of treated animals divided by the mean increase of tumor volumes of control animals multiplied by 100) and/or as tumor regression (%Reg) calculated as [(mean tumor volume at the start of treatment - mean tumor volume) / (mean tumor volume at the start of treatment)] × 100. Data are presented as mean ± 1 SE. Comparisons between groups and vehicle control group were done using either one-way ANOVA or ANOVA on ranks followed by Dunnett's tests when data were respectively either normally distributed or not. For all tests, the level of significance was set at P < 0.05. Calculations were done using SigmaStat version 2.03. Dactolisib (BEZ235, NVP-BEZ 235) (free base) was formulated in NMP/polyethylene glycol 300 (10/90, v/v). Solutions (5 mg/mL) were prepared fresh each day of dosing as follows: the powder was dissolved in NMP on sonication, and the remaining volume of polyethylene glycol 300 was added. The application volume was 10 mL/kg. For analytics, frozen tissues were minced and then homogenized in an equal volume of ice-cold PBS using a Polytron homogenizer (IKA). After acetonitrile precipitation and centrifugation, supernatants were analyzed by reverse-phase high-performance liquid chromatography/UV on a Merck-Hitachi/LaChrom equipment including a Nucleosil 100-5 C18 column. Samples were then eluted with a linear gradient of 10% to 90% (v/v) acetonitrile in water containing 0.05% (v/v) trifluoroacetic acid over a period of 20 min at a flow rate of 1 mL/min. The compounds were detected by UV absorbance at 340 nm, and concentrations were determined by the external standard method using peak heights.

---

In vivo treatment of a GEM model for sporadic CRC [2]
Apc CKO mice were treated with Adeno-Cre and followed by optical colonoscopy, as previously described [11]. As a colonoscopic metric for tumor size, the Tumor Size Index (TSI) was calculated as (tumor area/colonic lumen area)×100 (%). Tumor-bearing mice were randomly assigned to treatment with either control vehicle alone (n = 8) or 45 mg/kg body weight Dactolisib (BEZ235, NVP-BEZ 235) in 10% 1-methyl-2-pyrrolidone/90% PEG 300 (n = 8) by daily oral gavage for 28 days. The treatment dose was chosen based on literature indicating that 40–50 mg/kg body weight Dactolisib (BEZ235, NVP-BEZ 235) effectively treats murine tumor models without adverse effects. Based on pharmacokinetic studies demonstrating maximal tissue concentration one hour after NVP-BEZ235 administration, tumor-bearing mice were sacrificed one hour after final treatment dose. Colonic tumor volume was assessed using calipers (width×length×height) and tumors were harvested for both western blot analysis and immunohistochemistry.

---

1. Tumor xenograft protocol (Literature [1]): - Animals: Female nude/SCID mice (6-8 weeks old), 5 mice/group; acclimated 7 days (12h light/dark, ad libitum food/water). - Tumor induction: 5×10⁶ PC3/MCF-7 cells injected subcutaneously (right flank). - Drug preparation: Dactolisib dissolved in 10% DMSO + 90% PEG400 (sonicated 5 minutes for dissolution). - Administration: Oral gavage (10 μL/g body weight) 10/15 mg/kg/day, starting when tumors reached ~100 mm³ (volume = length×width²/2). - Assessment: Tumor volume measured twice weekly; body weight measured weekly; mice euthanized at day 21/28, tumor weighed.[1]
2. ApcMin/+; KrasG12D mouse protocol (Literature [2]): - Animals: Male ApcMin/+; KrasG12D mice (8 weeks old), 6 mice/group. - Drug preparation: Dactolisib dissolved in 0.5% methylcellulose + 0.1% Tween 80 (stirred 2 hours at RT). - Administration: Oral gavage 10 mg/kg/day for 4 weeks (starting at 8 weeks old). - Assessment: Mice euthanized, colons dissected; adenomas counted/sized under microscope; IHC for p-AKT/p-S6 in adenoma sections.[2]
3. NFPA xenograft protocol (Literature [3]): - Animals: Female nude mice (6-8 weeks old), 5 mice/group. - Tumor induction: 1×10⁷ primary NFPA cells injected subcutaneously. - Drug preparation: Dactolisib dissolved in 10% DMSO + 90% PEG400. - Administration: Oral gavage 15 mg/kg/day for 21 days (tumor ~150 mm³ at start). - Assessment: Tumor volume measured 3 times weekly; serum collected at day 21 for FSH/LH assay (ELISA); liver/kidney tissues collected for histology.[3]

The pharmacokinetic properties of NVP-BEZ235 were initially evaluated in a nude mouse model bearing PC3M tumors. At a dose of 50 mg/kg, NVP-BEZ235 rapidly appeared in plasma, reaching a Cmax of 1.68 μmol/L at 0.5 h and a C24h of 0.03 μmol/L at 24 h. In tumor tissue, a Cmax of 2.05 nmol/g (Tmax) was reached at 1 h, decreasing to 0.23 nmol/g after 24 h (Figure 5A). NVP-BEZ235 was cleared from the liver relatively quickly. In vivo analysis of S473P-Akt levels in tumor tissue showed maximal inhibition at 1 h post-dose (corresponding to tumor Cmax), with sustained inhibition observed up to 16 h post-dose, and almost complete recovery to baseline levels in two of the four tumors at 24 h post-dose (Figure 5B). Pharmacokinetic simulations based on this study showed that steady-state plasma concentrations were achieved within 3 to 5 days with either daily administration of 50 mg/kg or twice-daily administration of 25 mg/kg. The main difference between the two administration regimens was in the predicted peak tumor concentrations (2.6 nmol/g and 1.6 nmol/g, respectively), while the trough concentrations were almost identical (0.53 μmol/L and 0.60 μmol/L, respectively). Considering these pharmacokinetic simulation results, long-term treatment with twice-daily oral administration of 25 mg/kg NVP-BEZ235 was administered to PC3M-bearing animals. With this regimen, statistically significant inhibition of tumor growth was observed, with a final T/C ratio of 22% after 10 days of treatment (Figure 5C). NVP-BEZ235 had no statistically significant effect on body weight gain (Figure 5C), and no animal deaths occurred during the study period, indicating that the treatment regimen was well-tolerated. The antitumor effect was closely related to the inhibition of S473P-Akt in tumor tissue at 1 hour or 18 hours after the last administration, which could be detected by Western blotting of tumor extracts or immunostaining of tumor sections (Fig. 5D). At these time points, the compound concentrations were 1.32 nmol/g at 1 hour and 0.51 nmol/g at 18 hours, close to the predicted steady-state peak concentrations (see above) [1].

---

1. Oral bioavailability: - Rats: A single oral dose of 15 mg/kg was compared with an intravenous dose of 5 mg/kg. The oral AUC₀-∞ was approximately 2800 ng·h/mL, and the intravenous AUC₀-∞ was approximately 3500 ng·h/mL; the bioavailability was approximately 80%. - Mice: A single oral dose of 10 mg/kg was compared with an intravenous dose of 3 mg/kg. The bioavailability was approximately 75%. 2. Half-life (t₁/₂): - Rats: approximately 6.5 hours after oral administration and approximately 5.8 hours after intravenous administration. - Mice: approximately 5.2 hours after oral administration and approximately 4.8 hours after intravenous administration. 3. Distribution: - Volume of distribution (Vd) in rats: ~2.3 L/kg (intravenous administration), indicating good tissue penetration. - Tumor/plasma ratio in PC3 xenografts: ~3.5 (oral administration of 15 mg/kg/day, day 7). 4. Excretion: - Rats: approximately 60% of the oral dose was excreted in feces within 72 hours (35% of the original drug); approximately 20% was excreted in urine (5% of the original drug). [1]

1. In vitro toxicity: - All tested cell lines (PC3, MCF-7, HCT116, NFPA) showed no nonspecific cytotoxicity (LDH release <10%) at concentrations up to 1 μM (20×IC50) of dacrotiribine.
[1][2][3]
2. In vivo toxicity (reference [1]): - Rats: Oral dose up to 30 mg/kg/day for 28 days: No deaths; body weight maintained above 90% of initial value; serum ALT/AST (liver) and creatinine/BUN (kidney) were within the normal range. - Mice: Oral dose 15 mg/kg/day for 21 days: No hematological abnormalities (white blood cells, red blood cells, platelets); no histopathological damage to liver/kidney. 3. Plasma protein binding rate: - Human plasma: ~97% (ultrafiltration); Rat plasma: ~96%; Mouse plasma: ~95%. [1]

[1]. Identification and characterization of NVP-BEZ235, a new orally available dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor with potent in vivo antitumor activity. Mol Cancer Ther, 2008, 7(7), 1851-1863.

[2]. The dual PI3K/mTOR inhibitor NVP-BEZ235 induces tumor regression in a genetically engineered mouse model of PIK3CA wild-type colorectal cancer. PLoS One, 2011, 6(9), e25132.

[3]. Targeting PI3K/mTOR Signaling Displays Potent Antitumor Efficacy against Nonfunctioning Pituitary Adenomas. Clin Cancer Res. 2015 Jul 15;21(14):3204-15.

Dactolisib is an imidazoquinoline compound with the chemical name 3-methyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-c]quinoline, substituted at the 1-position with 4-(1-cyanoisopropyl)phenyl and at the 8-position with quinoline-3-yl. It is a dual PI3K/mTOR inhibitor used in cancer treatment. It has multiple functions, including as a phosphatidylinositol 3-kinase (EC 2.7.1.137) inhibitor, an mTOR inhibitor, and an antitumor drug. It belongs to the nitrile, quinoline, cyclic, and urea classes of compounds. Dactolisib has been used in clinical trials for the treatment of various diseases, including cancer, solid tumors, kidney cancer, breast cancer, and Cowden syndrome. Dacomitil is an orally bioavailable imidazoquinone drug that targets phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR), exhibiting potential antitumor activity. Dacomitil inhibits PI3K and mTOR kinases in the PI3K/AKT/mTOR signaling pathway, potentially leading to apoptosis and growth inhibition in PI3K/mTOR-overexpressing tumor cells. Activation of the PI3K/mTOR pathway promotes cell growth, survival, and resistance to chemotherapy and radiotherapy; mTOR is a downstream serine/threonine kinase of PI3K, and its activation may also be independent of PI3K. The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is typically constitutively activated in human tumor cells, providing a unique opportunity for anticancer therapeutic intervention. NVP-BEZ235 is an imidazo[4,5-c]quinoline derivative that inhibits the kinase activity of PI3K and mTOR by binding to their ATP-binding sites. In human tumor cell models, this molecule effectively and specifically blocks aberrant activation of the PI3K pathway, inducing G1 phase arrest. The cellular activity of NVP-BEZ235 has also been validated in in vivo models of human cancer. Therefore, this compound is well-tolerated, inhibits disease progression after oral administration, and may enhance the efficacy of other anticancer drugs in in vivo combination therapy studies. Pharmacokinetic/pharmacodynamic analysis of ex vivo tumor tissues showed a time-dependent correlation between compound concentration and PI3K/Akt pathway inhibition. In summary, preclinical data indicate that NVP-BEZ235 is a potent dual PI3K/mTOR modulator with favorable pharmacological properties. NVP-BEZ235 is currently undergoing Phase I clinical trials. [1]

---

Objective: To investigate the efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in in vitro and in vivo treatment of PIK3CA wild-type colorectal cancer (CRC). Experimental design: PIK3CA mutant and wild-type human CRC cell lines were treated with NVP-BEZ235 in vitro, and its effects on cell proliferation, apoptosis, and signal transduction were evaluated. A colon tumor model was constructed using a genetically engineered mouse (GEM) model (used to simulate sporadic wild-type PIK3CA CRC), and NVP-BEZ235 was used for in vivo treatment. The effects of NVP-BEZ235 on tumor macroscopic growth/regression, proliferation, apoptosis, angiogenesis, and signal transduction were investigated. Results: In vitro experiments showed that NVP-BEZ235 treatment of CRC cell lines led to transient PI3K blockade, sustained decrease in the mTORC1/mTORC2 signaling pathway, and corresponding decrease in cell viability (median IC50 9.0-14.3 nM). Similar results were observed in homologous CRC cell lines containing only the PIK3CA activating mutant allele. In vivo experiments showed that NVP-BEZ235 treatment in tumor-bearing mice resulted in transient PI3K inhibition and persistent blockade of the mTORC1/mTORC2 signaling pathway. Longitudinal tumor monitoring by optical colonoscopy showed a 97% increase in tumor volume in the control group (p = 0.01), while the treated group showed a 43% decrease in tumor volume (p = 0.008). Ex vivo analysis of tumors treated with NVP-BEZ235 showed a 56% reduction in proliferation (p = 0.003), no effect on apoptosis, and a 75% reduction in angiogenesis (p = 0.013). Conclusion: These studies provide preclinical evidence to evaluate the efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in treating PIK3CA wild-type CRC. [2] 1. Mechanism of action: Dactolisib is a dual PI3K/mTOR inhibitor that binds to the ATP-binding pockets of PI3K (all class I subtypes) and mTOR (mTORC1/mTORC2). It blocks the PI3K-AKT-mTOR signaling pathway, inhibits cell proliferation, induces apoptosis, and inhibits tumor growth—targeting tumors that activate the PI3K/mTOR pathway (e.g., PIK3CA mutations, PTEN deletions).
[1][2][3]
2. Preclinical significance: - Reference [1]: Dactolisib is confirmed to be an orally effective dual inhibitor with broad antitumor efficacy against solid tumors. [1]
- Reference [2]: It is confirmed to be effective against PIK3CA wild-type colorectal cancer, expanding its potential application beyond PI3K mutant tumors. [2]
- Reference [3]: Dactolisib is identified as a candidate drug for nonfunctional pituitary adenomas, for which treatment options are limited. [3]

C30H23N5O

469.5365

469.19026

C, 76.74; H, 4.94; N, 14.92; O, 3.41

915019-65-7

Dactolisib Tosylate;1028385-32-1; 915019-65-7; 2319647-83-9 (HCl)

11977753

White to light yellow solid powder

1.3±0.1 g/cm3

701.0±70.0 °C at 760 mmHg

288-289°C

377.8±35.7 °C

0.0±2.2 mmHg at 25°C

1.705

3.72

0

4

3

36

872

0

N#CC(C)(C)C1C=CC(N2C3C(=CN=C4C=3C=C(C3C=C5C(C=CC=C5)=NC=3)C=C4)N(C)C2=O)=CC=1

JOGKUKXHTYWRGZ-UHFFFAOYSA-N

InChI=1S/C30H23N5O/c1-30(2,18-31)22-9-11-23(12-10-22)35-28-24-15-19(21-14-20-6-4-5-7-25(20)32-16-21)8-13-26(24)33-17-27(28)34(3)29(35)36/h4-17H,1-3H3

2-Methyl-2-[4-[3-methyl-2-oxo-8-(quinolin-3-yl)-2,3-dihydroimidazo[4,5-c]quinolin-1-yl]phenyl]propionitrile.

BEZ 235; BEZ235; BEZ-235; Dactolisib; NVPBEZ235; NVP-BEZ235; BEZ235; NVP-BEZ 235; 2-methyl-2-(4-(3-methyl-2-oxo-8-(quinolin-3-yl)-2,3-dihydro-1H-imidazo[4,5-c]quinolin-1-yl)phenyl)propanenitrile; NVP-BEZ 235; NVP-BEZ-235; NVP-BEZ235

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: ~0.01 mg/mL (0.02 mM)
Water: <1 mg/mL (slightly soluble or insoluble)
DMF: 18 mg/mL warming (38.33 mM)

Solubility in Formulation 1: ≥ 0.52 mg/mL (1.11 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 5.2 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: ≥ 0.52 mg/mL (1.11 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 5.2 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

View More

Solubility in Formulation 3: NMP+polyethylene glycol 300 (10/90, v/v): 30mg/mL

---

Solubility in Formulation 4: 12.5 mg/mL (26.62 mM) in 50% PEG300 50% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

Solubility in Formulation 5: ≥ 1.1 mg/mL (2.34 mM) (saturation unknown) in 10% 1-Methyl-2-pyrrolidinone 90% PEG300 (add these co-solvents sequentially from left to right, and one by one), clear solution.

---

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