WT ALK (IC50 = 1.01 nM); ALK(L1196M) (IC50 = 1.08 nM); ALK(G1202R) (IC50 = 1.26 nM); Trk receptor; ROS1

TPX-0005 is an orally available and potent ATP-competitive inhibitor that can be taken orally and is effective against clinically resistant mutants of ALK, ROS1, TRKA, TRKB, and TRKC recombinant kinases. Through the inhibition of target phosphorylation and concurrent inactivation of downstream effectors like ERK, AKT, and STAT3, TPX-0005 exhibits strong anti-proliferative activity in the range of sub-nanomolar to low nanomolar in a number of human cancer cell lines and engineered stable cell lines expressing the targeted oncogenes or their solvent front mutants[2]. Similar to saracatinib, TPX-0005 also inhibits H2228 cell migration in a wound healing assay. In addition to inhibiting a wide range of mutant ALKs and the wild-type ALK, TPX-0005 can suppress metastatic features by inhibiting SRC, which also helps it overcome primary resistance[1].

TPX-0005 treatment results in significant regression of tumors harboring the oncogenic ALK, ROS1 and TRKC fusions in patient derived xenograft tumor models. Additionally, via inhibition of target phosphorylation, TPX-0005 demonstrates strong anti-tumor activity in a number of mouse xenograft tumor models in tumors containing solvent front mutation-carrying oncogenes as well as tumors containing wildtype oncogenic targets[2].

TPX-0005 is a novel, rationally-designed, highly potent ALK/ROS1/TRK inhibitor, has IC50 values of 5.3 nM, 1.01 nM, 1.26 nM, and 1.08 nM for SRC, WT ALK, ALK G1202R, and ALK L1196M, in that order. It might possess anticancer properties. By significantly inhibiting the phosphorylation of EML4-ALK (IC50 13 nM) and the SRC substrate paxillin (IC50 107 nM), it successfully overcomes this primary resistance (IC50 100 nM in the cell proliferation assay). In a wound healing assay, PX-0005 inhibits H2228 cell migration with activity comparable to that of saracatinib. All things considered, TPX-0005 has a very promising profile and is capable of defeating several ALK resistance mechanisms, such as secondary mutations, bypass signaling activation, and EMT. As such, it deserves further clinical research.

TPX-0005 is also a potent SRC inhibitor (IC50 5.3 nM). In tests of cell proliferation, the increased SRC kinase activity in the H2228 lung cancer cell line confers resistance to crizotinib (IC50 1200 nM) and ceritinib (IC50 1000 nM). With strong inhibition of the phosphorylation of EML4-ALK (IC50 13 nM) and the SRC substrate paxillin (IC50 107 nM), as well as other downstream signaling targets, TPX-0005 effectively overcame this primary resistance (IC50 100 nM in cell proliferation assay). Similar to saracatinib, TPX-0005 inhibited H2228 cell migration in a wound healing assay.

Absorption, Distribution and Excretion
The geometric mean (CV%) of repotrectinib steady state peak concentration (Cmax,ss) is 713 (32.5%) ng/mL and the area under the time concentration curve (AUC0-24h,ss) is 7210 (40.1%) ng•h/mL following the approved recommended twice daily dosage in patients with cancer. Repotrectinib Cmax and AUC0-inf increases approximately dose-proportional (but less than linear with estimated slopes of 0.78 and 0.70, respectively) over the single dose range of 40 mg to 240 mg (0.25 to 1.5 times the approved recommended dosage). Steady-state PK was time-dependent with an autoinduction of CYP3A4. Steady-state is achieved within 14 days of daily administration of 160 mg. The geometric mean (CV%) absolute bioavailability of repotrectinib is 45.7% (19.6%). Peak repotrectinib concentration occurred at approximately 2 to 3 hours post a single oral dose of 40 mg to 240 mg (0.25 to 1.5 times the approved recommended dosage) under fasted conditions. No clinically significant differences in repotrectinib pharmacokinetics were observed in patients with cancer following administration of a high-fat meal (approximately 800-1000 calories, 50% fat).
Following a single oral 160 mg dose of radiolabeled repotrectinib, 4.84% (0.56% as unchanged) was recovered in urine and 88.8% (50.6% unchanged) in feces.
The geometric mean (CV%) apparent volume of distribution (Vz/F) was 432 L (55.9%) in patients with cancer following a single 160 mg oral dose of repotrectinib.
The geometric mean (CV%) apparent oral clearance (CL/F) was 15.9 L/h (45.5%) in patients with cancer following a single 160 mg oral dose of repotrectinib.

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Metabolism / Metabolites
Repotrectinib is primarily metabolized by CYP3A4 followed by secondary glucuronidation.

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Biological Half-Life
The repotrectinib mean terminal half-life is approximately 50.6 h for patients with cancer following a single dose. The steady-state repotrectinib terminal half-life is approximately 35.4 h for patients with cancer.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of repotrectinib during breastfeeding. Because repotrectinib is 94.5% bound to plasma proteins, the amount in milk is likely to be low and oral bioavailability is less than 50%; however, the drug’s half-life is about 50 hours in adults. The manufacturer recommends that breastfeeding be discontinued during repotrectinib therapy and for 10 days after the final 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.

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Protein Binding
Repotrectinib binding to plasma protein was 95.4% in vitro. The blood-to-plasma ratio was 0.56 in vitro.

[1]. Cancer Res (2016) 76 (14_Supplement): 2132.

[2]. Cancer Res (2017) 77 (13_Supplement): 3168.

Repotrectinib is an azamacrocycle with formula C18H18FN5O2. It is a tyrosine kinase inhibitor (highly potent against ROS1, TRKA-C, and ALK) used for the treatment of locally advanced or metastatic ROS1-positive non-small cell lung cancer. It has a role as an EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor and an antineoplastic agent. It is a member of monofluorobenzenes, a pyrazolopyrimidine, a cyclic ether, a secondary carboxamide and an azamacrocycle.
Repotrectinib is a next-generation tyrosine kinase inhibitor (TKI) specifically designed to address resistance in the treatment of non-small cell lung cancer (NSCLC), specifically due to mutations in the ROS1 gene. ROS1 mutations are one of the defined oncogenic drives of NSCLC, and the solvent-front mutation ROS1 G2032R is responsible for 50 to 60% of [crizotinib]-resistant cases. Repotrectinib possesses a compact macrocyclic structure that both limits adverse interactions with resistance mutation hotspots and targets mutations in the solvent-front region. Although resistance to multiple TKI has been reported, including [crizotinib], [lorlatinib], [taletrectinib], and [entrectinib], there has been no reported case of repotrectinib resistance. On November 15th, 2023, the FDA approved repotrectinib under the brand name Augtyro for the treatment of locally advanced or metastatic ROS1-Positive NSCLC. This approval is based on favorable results from the TRIDENT-1 study, where the objective response rate was 79% in TKI-naive patients and 38% in TKI-pretreated patients respectively.
Repotrectinib is a Kinase Inhibitor. The mechanism of action of repotrectinib is as a Proto-Oncogene Tyrosine-Protein Kinase ROS1 Inhibitor, and Tropomyosin Receptor Tyrosine Kinase A Inhibitor, and Tropomyosin Receptor Tyrosine Kinase B Inhibitor, and Tropomyosin Receptor Tyrosine Kinase C Inhibitor, and Cytochrome P450 3A4 Inducer.
Repotrectinib is an orally available inhibitor of multiple kinases, including the receptor tyrosine kinase anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), the neurotrophic tyrosine receptor kinase (NTRK) types 1, 2 and 3, the proto-oncogene SRC, and focal adhesion kinase (FAK), with potential antineoplastic activity. Upon oral administration, repotrectinib binds to and inhibits wild-type, point mutants and fusion proteins of ALK, ROS1, NTRK1-3, SRC, FAK and, to a lesser extent, other kinases. Inhibition of these kinases leads to the disruption of downstream signaling pathways and the inhibition of cell growth of tumors in which these kinases are overexpressed, rearranged or mutated.

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Drug Indication
Repotrectinib is indicated for the treatment of adult patients with locally advanced or metastatic ROS1-positive non-small cell lung cancer (NSCLC).
Treatment of all conditions included in the category of malignant neoplasms (except haematopoietic neoplasms)

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Mechanism of Action
Repotrectinib is an inhibitor of proto-oncogene tyrosine-protein kinase ROS1 (ROS1) and of the tropomyosin receptor tyrosine kinases (TRKs) TRKA, TRKB, and TRKC.

C18H18FN5O2

355.37

355.144

C, 60.84; H, 5.11; F, 5.35; N, 19.71; O, 9.00

1802220-02-5

1802220-02-5; 2058227-19-1

135565923

White to off-white solid powder

1.5±0.1 g/cm3

1.694

1.71

2

6

0

26

524

2

FC1C=CC2=C(C=1)[C@@H](C)NC1C=CN3C(=C(C=N3)C(NC[C@H](C)O2)=O)N=1

FIKPXCOQUIZNHB-WDEREUQCSA-N

InChI=1S/C18H18FN5O2/c1-10-8-20-18(25)14-9-21-24-6-5-16(23-17(14)24)22-11(2)13-7-12(19)3-4-15(13)26-10/h3-7,9-11H,8H2,1-2H3,(H,20,25)(H,22,23)/t10-,11+/m0/s1

(3R,11S)-6-fluoro-3,11-dimethyl-10-oxa-2,13,17,18,21-pentazatetracyclo[13.5.2.04,9.018,22]docosa-1(21),4(9),5,7,15(22),16,19-heptaen-14-one

Ropotrectinib; TPX0005; TPX-0005; TPX 0005; Augtyro

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)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.03 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.03 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.

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