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Futibatinib (formerly also known as TAS 120; TAS-120) is a novel, potent, irreversible and orally bioavailable inhibitor of the fibroblast growth factor receptor (FGFR) with potential anticancer activity. Its IC50 values for inhibiting FGFR 1-4 are 3.9, 1.3, 1.6, and 8.3 nM, in that order. TAS-120 specifically and irreversibly binds to FGFR, inhibiting it. This may lead to increased cell death in tumor cells overexpressing FGFR, as well as the inhibition of the FGFR-mediated signal transduction pathway and tumor cell proliferation. Many different types of tumor cells express FGFR, a receptor tyrosine kinase that is critical to the growth, differentiation, and survival of tumor cells. Futibatinib is an anticancer agent with demonstrated anti-tumour activity in mouse and rat xenograft models of human tumours with activating FGFR genetic alterations. Futibatinib is not expected to affect cell lines with no FGFR genomic aberrations. It suppresses the growth of tumours in a dose-dependent manner.
Physicochemical Properties
| Molecular Formula | C22H22N6O3 |
| Molecular Weight | 418.4485 |
| Exact Mass | 418.18 |
| Elemental Analysis | C, 63.15; H, 5.30; N, 20.08; O, 11.47 |
| CAS # | 1448169-71-8 |
| PubChem CID | 71621331 |
| Appearance | Off-white to light beige solid powder |
| Density | 1.0±0.1 g/cm3 |
| Boiling Point | 244.0±0.0 °C at 760 mmHg |
| Flash Point | 87.5±21.3 °C |
| Vapour Pressure | 0.0±0.4 mmHg at 25°C |
| Index of Refraction | 1.490 |
| LogP | 2.39 |
| Hydrogen Bond Donor Count | 1 |
| Hydrogen Bond Acceptor Count | 7 |
| Rotatable Bond Count | 6 |
| Heavy Atom Count | 31 |
| Complexity | 723 |
| Defined Atom Stereocenter Count | 1 |
| SMILES | O=C(C=C)N1CC[C@@H](C1)N1C2C(=C(N)N=CN=2)C(C#CC2C=C(C=C(C=2)OC)OC)=N1 |
| InChi Key | KEIPNCCJPRMIAX-HNNXBMFYSA-N |
| InChi Code | InChI=1S/C22H22N6O3/c1-4-19(29)27-8-7-15(12-27)28-22-20(21(23)24-13-25-22)18(26-28)6-5-14-9-16(30-2)11-17(10-14)31-3/h4,9-11,13,15H,1,7-8,12H2,2-3H3,(H2,23,24,25)/t15-/m0/s1 |
| Chemical Name | 1-[(3S)-3-[4-amino-3-[2-(3,5-dimethoxyphenyl)ethynyl]pyrazolo[3,4-d]pyrimidin-1-yl]pyrrolidin-1-yl]prop-2-en-1-one |
| Synonyms | Futibatinib; TAS-120; TAS 120; 1448169-71-8; Lytgobi; UNII-4B93MGE4AL; 4B93MGE4AL; Futibatinib [USAN]; TAS120 |
| 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 |
| 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 |
FGFR1 (IC50 = 3.9 nM); FGFR2 (IC50 = 1.3 nM); FGFR3 (IC50 = 1.6 nM); FGFR4 (IC50 = 8.3 nM); wild-type FGFR2 (IC50 = 0.3 nM); FGFR2 V5651 (IC50 = 1-3 nM); FGFR2 N550H (IC50 = 3.6 nM); FGFR2 E566G (IC50 = 2.4 nM) Futibatinib (TAS-120) is an irreversible pan-FGFR inhibitor that covalently binds to a highly conserved cysteine residue (C492 in FGFR2-IIIb isoform) within the ATP-binding pocket of FGFR1–4. It exhibits low nanomolar in vitro potency against wild-type FGFR1–4 and retains activity against multiple secondary FGFR2 kinase domain mutations (e.g., N550K, E566A, K660M, L618V, H683L), except for the V565F gatekeeper mutation which confers high-level resistance (103‑fold increase in IC50). [1] |
| ln Vitro |
Futibatinib (TAS-120) is a permanent fibroblast growth factor receptor (FGFR) inhibitor that inhibits all four FGFR subtypes, with enzyme half-lives (IC50) for FGFR1, FGFR2, FGFR3, and FGFR4 being 1.8 nM, 1.4 nM, 1.6 nM, and 3.7 nM, respectively. Futibatinib shows potent anti-proliferative activity in FGFR-driven intrahepatic cholangiocarcinoma (ICC) cell lines. In ICC13‑7 cells (harboring FGFR2‑OPTN fusion) and CCLP‑1 cells (overexpressing wild‑type FGFR1), the IC50 values were 0.6–1.5 nM, while FGFR‑independent cell lines exhibited IC50 values of 300–8000 nM. [1] Treatment with 50 nM Futibatinib effectively suppressed phosphorylation of FRS2 (Y196), SHP2 (Y542), MEK1/2 (S217/221), and ERK1/2 (T202/Y204) in ICC13‑7 and CCLP‑1 cells, indicating durable inhibition of the MEK/ERK pathway without reactivation for up to 3 days. No significant inhibition of PI3K/AKT signaling (pAKT T308/S473) was observed. [1] In engineered CCLP‑1 cells expressing FGFR2‑PHGDH fusions with various kinase domain mutations, Futibatinib maintained activity (2‑ to 7‑fold IC50 increase) against mutations that confer resistance to ATP‑competitive inhibitors (BGJ398, Debio1347), except for V565F (103‑fold IC50 increase). [1] A pooled clone system containing 1% of each mutant FGFR2‑PHGDH clone and 90% wild‑type cells was treated with 10 nM Futibatinib for 14 days. ddPCR analysis showed outgrowth of V565F, and to a lesser extent E566A and N550K, while other mutants were suppressed. [1] |
| ln Vivo |
TAS-120 (3, 30, 100 mg/kg/day, p.o.) exerts an anti-tumor effect in mice. By lowering the blood phosphorus level's sustained elevation and weight suppression, as well as by intermittently administering the drug every other day and twice a week, TAS-120 exhibits anti-tumor effects. Its daily administration is also effective. To corroborate these results in vivo, we screened a collection of patient-derived xenograft (PDX) models of ICC for FGFR alterations, and identified a model harboring a FGFR2-KIAA1217 fusion (designated MG69) (Supplemental Figure S1G). Treatment of MG69 PDX tumors with Futibatinib (TAS-120) (starting when the volume reached ~500 mm3) led to tumor regression and complete proliferative arrest, with prominent effects evident within three days and persisting over a 14-day course (Figure 2E, F). Moreover, FGFR inhibition suppressed MEK/ERK and SHP2 activity, but not PI3K signaling, in MG69 PDX tumors (Figure 2G). Thus, FGFR activated ICC models are highly dependent on FGFR activity to sustain growth and maintain MEK/ERK signaling in vitro and in vivo [1]. In a patient‑derived xenograft (PDX) model of ICC harboring an FGFR2‑KIAA1217 fusion (MG69), oral administration of Futibatinib (25 mg/kg daily) induced tumor regression and complete proliferative arrest within 3 days, effects that persisted over a 14‑day treatment course. [1] Immunoblot analysis of PDX tumors after 14 days of Futibatinib treatment showed suppression of pFRS2, pSHP2, pMEK, and pERK, but not PI3K/AKT signaling, consistent with in vitro findings. [1] |
| Enzyme Assay | 1-[(3S)-3-[4-Amino-3-[2-(3,5-dimethoxyphenyl)ethynyl]-1H-pyrazolo[3,4-d]pyrimidin-1-yl]-1-pyrrolidinyl]-2-propen-1-one (TAS-120) is an irreversible inhibitor of the fibroblast growth factor receptor (FGFR) family, and is currently under phase I/II clinical trials in patients with confirmed advanced metastatic solid tumours harbouring FGFR aberrations. This inhibitor specifically targets the P-loop of the FGFR tyrosine kinase domain, forming a covalent adduct with a cysteine side chain of the protein. Our mass spectrometry experiments characterise an exceptionally fast chemical reaction in forming the covalent complex. The structural basis of this reactivity is revealed by a sequence of three X-ray crystal structures: a free ligand structure, a reversible FGFR1 structure, and the first reported irreversible FGFR1 adduct structure. We hypothesise that the most significant reactivity feature of TAS-120 is its inherent ability to undertake conformational sampling of the FGFR P-loop. In designing novel covalent FGFR inhibitors, such a phenomenon presents an attractive strategy requiring appropriate positioning of an acrylamide group similarly to that of TAS-120 [2]. |
| Cell Assay |
Overexpressing FGFR in a human gastric cancer cell line The Dulbecco's Modified Eagle (OCUM-2MD3) cells, which contain 10% fetal bovine serum (FBS) in medium (DMEM), are routinely passaged at a cell density of no more than 80%. In order to test the cytostatic activity, 3,000 cells per well are seeded in each well of 96-well flat-bottom plates. The cells are then suspended in the DMEM medium above and cultured for one day at 37°C in an incubator with 5% carbon dioxide gas. It is stage-diluted to 100 times the final concentration of the test compound in DMSO the following day. The test compound is diluted with DMSO solution and added to a final concentration of DMSO in each well of a culture plate containing cells at a rate of 0.5%, 5% carbon dioxide gas incubator, and then cultured for 72 hours at 37°C. Following the suggested protocols provided by Dojindo Laboratories, the number of cells is measured using a cell counting kit-8 72 hours after the test compound is added to the culture. The reagent kit is added to each plate, and the color reaction is carried out for a predetermined amount of time at 37°C in an incubator with 5% carbonic acid gas. A microplate reader is used to measure the absorbance at 450 nm after the reaction is finished. GI50 (nM) is the concentration of the test compound at which 50% inhibition occurs, which is calculated by applying the growth inhibition rate formula. For cell viability assays, cells were dissociated and seeded into 384‑well plates (200 viable cells/well). After 24 hours, Futibatinib was added over a 15‑point concentration range using a digital drug dispenser. Cells were cultured for 5 days, and viability was assessed by adding Cell Titer‑Glo reagent, incubating for 20 minutes, and measuring luminescence. IC50 values were determined using a 4‑parameter dose‑response model. [1] For immunoblot analysis, cells were treated with drugs in 6‑well plates for 5–8 hours. Lysates were prepared in RIPA buffer containing protease and phosphatase inhibitors. Proteins were separated by SDS‑PAGE, transferred, and probed with specific antibodies against phospho‑FRS2 Y196, phospho‑SHP2 Y542, phospho‑MEK1/2 S217/221, phospho‑ERK1/2 T202/Y204, phospho‑AKT T308/S473, and total proteins. [1] For the clonal pool growth modeling, cell pools containing 1% of each mutant FGFR2‑PHGDH clone and 90% wild‑type cells were seeded in 6‑well plates. Drugs (or DMSO) were added 24 hours later and refreshed every 3–4 days. After 1, 7, or 14 days, genomic DNA was extracted and analyzed by ddPCR to determine fractional abundance of mutant alleles. [1] |
| Animal Protocol |
The old 6-week-old male nude rats with an intermittent administration schedule are transplanted to the right chest of the anti-tumor effect human gastric cancer strain (OCUM-2MD3). Measuring the tumor's volume after implantation and its major and minor axes in millimeters: The day 0 of the days that are conducted in groups of (n=5) is determined by allocating the mouse average TV to each group after the tumor volume TV has been calculated. Futibatinib (TAS-120) is prepared so that it contains 3 mg/kg/day and 30 mg/kg/day. 3 mg/kg/day is taken orally every day, while 30 mg/kg/day is taken orally every other day. 100 mg/kg/day is taken orally twice a week starting on day 1, with a 14-day evaluation period and a 15-day final valuation date. PDX treatment studies [1] To develop an FGFR2 fusion human PDX, we obtained tissue from a fresh resection specimen from a patient with an FGFR2-KIAA1217 fusion ICC tumor, per our IRB-approved protocol. The tissue was rinsed in HBSS and cut into 0.3–0.5 mm3 pieces with sterile razor blades. These tumor pieces were implanted subcutaneously into 6–8-week old female NSG mice. Tumor size was measured with a digital caliper. Upon reaching ~500 mm3, mice were randomized to either vehicle control or 25 mg/kg Futibatinib (TAS-120) (in hydroxypropyl methyl cellulose solution) by oral gavage daily for three and fourteen days prior to harvest. NSG mice bearing subcutaneous PDX tumors (FGFR2‑KIAA1217 fusion) were randomized when tumor volume reached approximately 500 mm³. Futibatinib was administered orally at 25 mg/kg daily, formulated in hydroxypropyl methyl cellulose solution, for 3 or 14 days before tumor harvest. Control mice received vehicle alone. Tumor size was measured with digital calipers. [1] For histology and immunohistochemistry, harvested tumors were fixed in 4% buffered formaldehyde, embedded in paraffin, sectioned, and stained with hematoxylin & eosin or an anti‑Ki‑67 antibody (1:400 dilution) to assess proliferation. [1] |
| ADME/Pharmacokinetics |
Absorption, Distribution and Excretion Tmax ranges from 1.2 to 22.8 hours, with a median value of two hours. In healthy subjects, a high-fat and high-calorie meal (900 to 1000 calories with approximately 50% of total caloric content from fat) decreased futibatinib AUC by 11% and Cmax by 42%. Following a single oral dose of 20 mg radiolabeled futibatinib, approximately 91% of the total recovered radioactivity was observed in feces and 9% in urine, with negligible unchanged futibatinib in urine or feces. The geometric mean (CV%) apparent volume of distribution (Vc/F) is 66 L (18%). The geometric mean (CV%) apparent clearance (CL/F) is 20 L/h (23%). Metabolism / Metabolites _In vitro_, futibatinib is primarily metabolized by CYP3A and to a lesser extent by CYP2C9 and CYP2D6. Unchanged futibatinib is the major drug-related moiety in plasma (accounting for 59% of radioactivity) in healthy subjects. Biological Half-Life The mean (CV%) elimination half-life (t1/2) of futibatinib is 2.9 hours (27%). The study mentions that the irreversible binding mode of Futibatinib permanently disables FGFR2 enzymatic activity, potentially allowing extended pharmacodynamic duration without maintaining high drug levels. [1] |
| Toxicity/Toxicokinetics |
Hepatotoxicity In the open label clinical trials of futibatinib, adverse events were common and led to dose interruptions in 66%, dose reductions in 58%, and drug discontinuation in 5% of patients but only a small proportion of these were due to serum aminotransferase elevations. In preregistration trials in 103 patients with cholangiocarcinoma, ALT elevations arose in 50% and to above 5 times ULN in 7%. The elevations were typically self-limited and resolved rapidly with or without dose adjustments. No patients developed clinically apparent liver injury or jaundice. Publications on the efficacy and safety of futibatinib rarely mentioned serum ALT elevations or hepatotoxicity. Since its approval, there have been no reports clinically apparent liver injury attributed to futibatinib. However, the total clinical experience with its use has been limited and the frequency of serum aminotransferase elevations during therapy suggest that clinically significant liver injury may occur. Likelihood score: E (unproven, but possible rare cause of clinically apparent liver injury). Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation No information is available on the clinical use of futibatinib during breastfeeding. Because futibatinib is 95% bound to plasma proteins, the amount in milk is likely to be low. The manufacturer recommends that breastfeeding be discontinued during futibatinib therapy and for 1 week after the last dose. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date. Protein Binding Futibatinib is 95% bound to human plasma protein at 0.2 to 5 µmol/L _in vitro_, primarily to albumin and α1-acid glycoprotein. Hyperphosphatemia was observed as a class effect of FGFR inhibition due to on‑target blockade of FGF23‑FGFR1 signaling in renal tubules. In the clinical cohort, one patient on Futibatinib required a dose hold due to hyperphosphatemia, and two patients on BGJ398 required dose holds for the same reason. [1] Other adverse events leading to dose modifications in patients receiving Futibatinib included grade 3 motor neuropathy, grade 2 ALT/AST elevation, and grade 4 creatine kinase elevation. [1] |
| References |
[1]. TAS-120 Overcomes Resistance to ATP-Competitive FGFR Inhibitors in Patients with FGFR2 Fusion-Positive Intrahepatic Cholangiocarcinoma. Cancer Discov. 2019 Aug;9(8):1064-1079. [2]. TAS-120 Cancer Target Binding: Defining Reactivity and Revealing the First Fibroblast Growth Factor Receptor 1 (FGFR1) Irreversible Structure. ChemMedChem. 2019 Feb 19;14(4):494-500. [3]. Molecular targeted therapies: Ready for "prime time" in biliary tract cancer [published online ahead of print, 2020 Mar 12]. J Hepatol. 2020;S0168-8278(20)30165-3. |
| Additional Infomation |
Pharmacodynamics Futibatinib is an anticancer agent with demonstrated anti-tumour activity in mouse and rat xenograft models of human tumours with activating FGFR genetic alterations. Futibatinib is not expected to affect cell lines with no FGFR genomic aberrations. It suppresses the growth of tumours in a dose-dependent manner. Futibatinib is a third‑generation, irreversible FGFR inhibitor designed to overcome acquired resistance to ATP‑competitive FGFR inhibitors (e.g., BGJ398/infigratinib, Debio1347) in FGFR2 fusion‑positive intrahepatic cholangiocarcinoma. [1] In a phase I basket trial, Futibatinib showed an overall response rate of 25.0% and a disease control rate of 78.6% in 28 patients with ICC harboring FGFR2 fusions, including some previously treated with ATP‑competitive FGFR inhibitors. [1] Resistance to Futibatinib can emerge via the FGFR2 V565F gatekeeper mutation, but no mutations at the covalent binding site (C492) were identified in the studied patients. [1] The study supports the strategic sequencing of FGFR inhibitors guided by serial ctDNA and tumor biopsies to prolong benefit in FGFR2‑altered ICC. [1] |
Solubility Data
| Solubility (In Vitro) | DMSO: ≥ 29 mg/mL (~69.3 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: 2.08 mg/mL (4.97 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication. 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. Solubility in Formulation 2: 2.08 mg/mL (4.97 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (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 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. Solubility in Formulation 3: ≥ 2.08 mg/mL (4.97 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. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.3898 mL | 11.9489 mL | 23.8977 mL | |
| 5 mM | 0.4780 mL | 2.3898 mL | 4.7795 mL | |
| 10 mM | 0.2390 mL | 1.1949 mL | 2.3898 mL |