The current landscape of quinazoline derivatives with in vivo anticancer therapeutic potential–part I

ABSTRACT

With the development of new technology, cancer has already transformed from a catastrophic disease to a treatable and sometimes curable disease. Chemotherapeutics is critical for cancer therapy, but multidrug resistance and severe side effects often lead to treatment failure, creating an urgent demand to develop innovative and efficient therapeutic interventions. Quinazoline hybrids could arrest the cell cycle, induce apoptosis, inhibit angiogenesis, and disrupt cell migration. Moreover, several quinazoline hybrids, exemplified by Fruquintinib (quinazoline-benzofuran hybrid) and Barasertib (quinazoline-pyrazole hybrid), have already been applied in clinics for cancer therapy, indicating that the rational design of quinazoline hybrids may provide valuable chemotherapeutics for cancer therapy. This review outlines the current scenario of the in vivo anticancer therapeutic potential of quinazoline hybrids, together with modes of action, toxicity, and pharmacokinetic properties, developed from 2015 onwards, aiming to provide promising candidates for further preclinical/clinical evaluations and to facilitate further rational design.

GRAPHICAL ABSTRACT

The current review outlines the current landscape of quinazoline hybrids with in vivo antitumor therapeutic effects, along with pharmacokinetic properties, toxicity and modes of action, covering articles published from 2015 onwards, to shed light on the development of more effective and multitargeted candidates.

1. Introduction

Cancer, which can spread or metastasize to other parts of the body through blood vessels and lymph vessels, is one of the most prevalent and deadliest diseases across the world [1,2]. The International Agency for Research on Cancer (IARC) estimated that around 20.0 million new cases and approximately 10 million cancer-related deaths occurred in 2022, and the numbers are projected to increase to above 29.5 million and 16.3 million by 2040 [3,4]. Chemotherapy is the mainstay for cancer therapy, but multidrug resistance and severe adverse effects are surmountable obstacles for effective cancer therapy and are responsible for over 90% mortality of cancer patients, creating an urgent need to develop innovative and efficient therapeutic interventions [5,6].

Quinazoline derivatives could act on various enzymes, proteins, and receptors in cancer cells, including folate-dependent enzymes, growth factor receptor (EGFR), EGFR tyrosine kinase (EGFR-TK), vascular endothelial growth factor receptor (VEGFR), human epidermal growth factor receptor 2 (HER2), protein kinases, phosphoinositide 3-kinase (PI3K), and microtubule polymerization [7,8]. Mechanistically, Quinazoline derivatives could interfere with DNA replication and transcription (through intercalating into the DNA double helix structure, altering the spatial conformation of DNA, thereby hindering the normal binding and interaction of DNA polymerase, RNA polymerase, and other enzymes with DNA), induce apoptosis (by regulating the permeability of the mitochondrial membrane, causing mitochondria to release apoptosis-related factors, affecting the expression levels of apoptosis-related proteins), and inhibit tumor angiogenesis (through inhibiting the signaling pathway mediated by VEGF and VEGFR, reducing the proliferation, migration, and differentiation of vascular endothelial cells). Accordingly, quinazoline derivatives are useful scaffolds for the development of novel anticancer agents.

In particular, quinazoline hybrids, which consist of quinazoline and other anticancer pharmacophores, could inhibit multiple targets simultaneously and have potential advantages in improving anticancer therapeutic efficacy, reducing adverse effects, and circumventing drug resistance [9,10]. It was worth to notice that several quinazoline hybrids which are exemplified by Lapatinib (quinazoline-furan-sulfone hybrid), Fruquintinib (quinazoline-benzofuran hybrid), Cediranib (quinazoline-indole hybrid), Tandutinib (quinazoline-urea hybrid), Idelalisib (quinazolin-4(3H)-one-purine hybrid), and Barasertib (quinazoline-pyrazole hybrid) have already been developed as anticancer therapeutics [11,12], demonstrating that rational design of quinazoline hybrids is a promising strategy to develop valuable therapeutic interventions for cancer therapy.

This review focuses on the current state of quinazoline hybrids, including quinazoline-pyridine/quinoline/quinolone hybrids, quinazoline-pyridazine/pyrimidine/pyrazine hybrids, quinazoline-indole/pyrrole/furan/thiophene hybrids, and quinazoline-azole hybrids, that exhibit in vivo antitumor therapeutic effects. This review comprehensively explores their pharmacokinetic properties, toxicity profiles, and mechanisms of action, and encompasses articles published since 2015. The primary objectives are to offer a broader range of candidates for subsequent pre-clinical or clinical assessments and to assist in the rational design of anticancer agents that are more effective and less toxic.

2. Quinazoline-pyridine/quinoline/quinolone hybrids

Quinazoline-pyridine hybrid 1 (Figure 1; half maximal inhibitory concentration/IC₅₀: 0.11–0.13 μM) was 39.4–54.0 times superior to ABT-751 (IC₅₀: 4.73–5.94 μM) against HepG2, KB, HCT-8, and MDA-MB-231 cancer cell lines [13]. Mechanistically, hybrid 1 disrupted the intracellular microtubule network, caused G2/M phase arrest, induced cell apoptosis, and depolarized mitochondria of K562 cells. Moreover, hybrid 1 also reduced cell migration and disrupted capillary-like tube formation of human umbilical vein endothelial cells (HUVECs). In the H22 ×enografted mice model, hybrid 1 (30 mg/kg, oral administration) resulted in a 62.6% reduction of tumor growth, and no significant differences in body weight or other adverse effects were found.

Figure 1.

Structures of quinazoline-pyridine/quinoline/quinolone hybrids 1–11.

BPR1R024 (2, IC₅₀: 0.53 nM), a quinazoline-urea-pyridine hybrid, exhibited potent colony-stimulating factor-1 receptor (CSF1R) inhibitory activity and specific inhibited CSF1-induced M2-like macrophage (IC₅₀: 31 nM) [14]. The bioavailability of BPR1R024 was ~10%, while BPR1R024 mesylate salt showed 34.9% of bioavailability. Moreover, the half-life (t_1/2) of BPR1R024 mesylate salt (25 mg/kg, oral administration) was 11.6 h, peak time (t_max) was 0.5 h, dose-normalized maximum plasma concentration (DNC_max) was 68 ng/mL, and dose-normalized area under the curve from zero to time infinity (DNAUC_0-∞) was 558 h•ng/mL. In the MC38 ×enografted mice model, BPR1R024 mesylate salt (100 mg/kg, oral administration) suppressed 59% of tumor growth, and no severe body weight loss was observed during the treatment period. Overall, BPR1R024 mesylate salt was capable of inhibiting the tumor growth by remodeling the tumor microenvironment and deserved further evaluations.

Quinazoline-pyridine hybrid 3 in dark (IC₅₀: 4.26–69.8 nM) and in the photostationary states (PSS₃₆₅) upon irradiation with 365 nm light (IC₅₀: 2.26–40.0 nM) showed favorable PI3Kα/β/γ/δ inhibitory effects [15]. Upon administration in the PSS_dark, hybrid 3 (10 mg/kg, oral administration) showed a moderate half-life (t_1/2: 3.14 h), high oral exposure (area under the curve/AUC_0‑∞: 51996 h•ng/mL), and reasonable oral bioavailability (F%: 40.3%). In the HGC-27 ×enografted zebrafish model, hybrid 3 showed significant anticancer efficacy in the PSS₃₆₅ at 156 ng/fish. In the HGC-27 ×enografted mice model, hybrid 3 (oral administration) in the PSS_dark demonstrated robust antitumor efficacy with a tumor growth inhibition (TGI) value of 64.6% at 40 mg/kg. Collectively, hybrid 3, as a photoswitchable PI3K inhibitor, could act as not only a chemical tool to study the PI3K pathway but also a potential therapeutic agent merited further development toward precise cancer treatment.

Quinazoline-pyridine hybrid 4 and 5,6-dihydro‑4H‑pyrido[2,3,4-de]quinazoline-pyridine hybrid 5 were excellent dual inhibitors of EGFR (IC₅₀: 2.85 and 2.22 nM) and HER2 (IC₅₀: 2.67 and 2.96 nM), and hybrid 5 (IC₅₀: 1.63 and 1.49 nM) exhibited pronounced antiproliferative activity against NCI-N87 and BaF3 cells harboring HER2^insYVMA mutation [16]. Hybrids 4 (10 mg/kg, oral administration) and 5 (10 mg/kg, oral administration) also possessed acceptable pharmacokinetic properties with t_1/2 of 4.10 and 6.46 h, t_max of 3.67 and 0.50 h, peak concentration (C_max) of 124 and 23.8 ng/mL, AUC_0-∞ of 1296 and 157 h•ng/mL, and bioavailability of 30.4% and 7.43%, respectively. In the BaF3 hER2 A775_G776insYVMA xenografted mice model, hybrids 4 and 5 showed significant tumor inhibition with TGI values of 109.5% and 110.7% at 30 mg/kg by oral administration. No deaths, morbidity, or significant body weight loss were observed, indicating that there was no systemic toxicity associated with the administration of hybrids 4 and 5.

Quinazoline-pyridone hybrid 6, as a dual inhibitor of G9 (IC₅₀: 2.90 nM) and enhancer of zeste homologue 2 (EZH2, IC₅₀: 4.35 nM), showed considerable antiproliferative activity (IC₅₀: 19.63 and 19.91 μM) against RD and SW982 cancer cell lines [17]. Following intravenous (10 mg/kg) and oral (30 mg/kg) administration, hybrid 6 demonstrated favorable pharmacokinetic properties with t_1/2 of 3.47 and 4.02 h, t_max of 0.17 and 0.69 h, clearance rate (CL) of 908.70 and 3581.88 mL/h/kg, volume of distribution (Vz) of 4542.90 and 17,518.00 mL/kg, C_max of 1384.80 and 3184.14 ng/mL, AUC_0-∞ of 2476.02 and 11,389.71 h•ng/mL, and oral bioavailability of 91.97%. In the RD xenografted mice model, the tumor suppression effect of hybrid 6 (TGI: 86.6% at 20 mg/kg through intraperitoneal injection) was more effective than that of Tazemetostat (TGI: 69.2% at 20 mg/kg through intraperitoneal injection), and hybrid 6 could inhibit tumor growth by specifically inhibiting EZH2 and G9a. No mortality or significant weight fluctuations, or obvious toxic and side effects on major organs were observed, and the median lethal dose (LD₅₀) value was 98.11 mg/kg with intraperitoneal injection, demonstrating its excellent safety profile. Accordingly, hybrid 6 was a potential candidate for the treatment of malignant rhabdoid tumor.

Quinazolinone-imidazo[1,2-a]pyridine hybrid 7 exhibited potent inhibitory activity against Aurora A (IC₅₀: 84.41 nM) and Aurora B (IC₅₀: 14.09 nM) and was highly potent against HCC827, MHCC-97 h, BGC823, and SH-SY5Y cancer cell lines with IC₅₀ values in a range of 50–70 nM [18]. Mechanistic studies revealed that hybrid 7 inhibited receptor tyrosine kinase-like orphan receptor 1 (ROR1), arrested the cell cycle at the G2/M phase, and induced apoptosis. In the SHSY5Y xenografted mice model, hybrid 7 could remarkably inhibit the tumor growth with a TGI of 52.66% at 20 mg/kg via oral administration, and no significant loss of body weight or obvious toxicity in major organs (liver, lung, kidney, and spleen) was observed. Overall, hybrid 7 could serve as a potential candidate for the development of chemotherapeutic agents for the treatment of cancers with aberrant expression of ROR1 and Aurora kinases by simultaneously targeting ROR1 and Aurora kinases.

Quinazoline-1,2,3,4-tetrahydroisoquinoline hybrid 8 exhibited multidrug-resistant reversal activity, and the IC₅₀ value of Doxorubicin against MCF-7/Adr cancer cells decreased from 492.7 μM to 5.9 μM in the presence of 0.1 μM of hybrid 8 [19]. Further studies demonstrated that hybrid 8 increased the accumulation of Doxorubicin and rhodamine 123 (Rh123), increased Doxorubicin-induced apoptosis, and inhibited the proliferation, migration, and invasion of MCF-7/Adr. In the MCF-7/Adr xenografted mice model, hybrid 8 (2.0 mg/kg, intraperitoneal injection) significantly inhibited the growth with a TGI of 69.68% by increasing the sensitivity of Doxorubicin (10 mg/kg, intraperitoneal injection) without causing obvious liver and kidney cell necrosis, whereas combination of Tariquidar (2.0 mg/kg, intraperitoneal injection) with Doxorubicin (10 mg/kg, intraperitoneal injection) resulted in 49.42% reduction in tumor growth. Overall, hybrid 8 has the potential to be a reversal agent to overcome multidrug resistance in cancer treatment.

Quinazoline-1,6-naphthyridinone hybrid 9 exhibited excellent against anexelekto (AXL) inhibitory activity (IC₅₀: 1.1 nM) and profound antiproliferative activity (IC₅₀: 820 nM) against Ba/F3-TEL-AXL cells [20]. Further studies indicated that hybrid 9 significantly inhibited AXL-driven cell proliferation, suppressed 4T1 cell migration and invasion, and induced apoptosis. Following intravenous (5.0 mg/kg) and oral (10 mg/kg) administration, hybrid 9 demonstrated acceptable pharmacokinetic properties with t_1/2 of 3.71 and 4.35 h, t_max of 0.033 and 2.44 h, CL of 60.39 and 587.31 mL/h/kg, Vz of 327.21 and 2252.61 mL/kg, C_max of 52,320 and 3920 ng/mL, AUC_0-∞ of 83,030 and 23,990 h•ng/mL, and oral bioavailability of 14.4%. In the BaF3/TEL-AXL xenografted mice model, hybrid 9 (80 mg/kg, oral administration) substantially inhibited tumor growth with a TGI value of 77%, and no apparent body weight loss, mortality, or damage in major organs (heart, liver, spleen, lung, and kidney) occurred.

Quinazoline-1,6-naphthyridinone hybrid 10 (IC₅₀: 9.0 nM) was a potent inhibitor of mesenchymal-epithelia transition factor (MET) and possessed high maximal plasma concentration (C_max: 25100 ng/mL), long half-life (t_1/2: 12.5 h), high plasma exposure (AUC_0-∞: 427000 h•ng/mL), low total clearance (CL: 0.02 L/h/kg), and good oral bioavailability (F%: 42%) [21]. In the MET-positive human glioblastoma U-87 MG xenografted mice model, hybrid 10 could inhibit tumor growth in a dose-dependent manner and suppress 81% of tumor growth at 75 mg/kg via oral administration. Taken together, hybrid 10 was a promising anti-glioblastoma candidate and was worthy of further preclinical evaluations.

Quinazoline-4-quinolone hybrid 11 (IC₅₀: 10 and 5.0 nM) exhibited pronounced antiproliferative activity against MDA-MB-231 and MDA-MB-468 breast cancer cell lines and showed potent inhibitory activity on the AXL signaling, proliferation, migration, and invasion of AXL-expressed breast cancer cells [22]. In the MDA-MB-231 ×enografted mice model, hybrid 11 exhibited excellent antitumor efficacy with TGI values of 40.9% and 62.5% at 10 and 20 mg/kg, respectively. Moreover, no mortality or significant body weight loss was observed during the experiment, demonstrating its good safety profile. Accordingly, hybrid 11 was a promising therapeutic candidate for breast cancer therapy.

In conclusion, quinazoline-pyridine/quinoline/quinolone hybrids could disrupt the intracellular microtubule network and inhibit CSF1R, PI3K, MET, ROR1, G9, EGFR as well as HER2. Hence, quinazoline-pyridine/quinoline/quinolone hybrids have shown robust in vivo antitumor efficacy against a wide spectrum of cancers, such as lung cancer, neuroblastoma, glioblastoma, liver cancer, colon cancer, gastric cancer, and breast cancer.

3. Quinazoline-pyridazine/pyrimidine/pyrazine hybrids

10H-pyridazino[1,6-b]quinazolin-10-one 12 (Figure 2; IC₅₀: 1.39–2.33 µM) was not inferior to Cisplatin (IC₅₀: 1.16–4.52 µM) and Doxorubicin (IC₅₀: 0.62–1.89 µM) against SK-OV-3, CNE-2, MGC-803, and NCI-H460 cancer cell lines [23]. Mechanistically, hybrid 12 could arrest the cell cycle at the G2 phase and induce apoptosis in MGC-803 cells in a dose-dependent manner. In the MGC-803 ×enografted mice model, hybrid 12 (TGI: 55.9% at 20 mg/kg through intraperitoneal injection) showed obvious tumor growth inhibition, and no signs of morbidity or apparent body weight loss were observed. Hence, hybrid 12 was a promising therapeutic candidate for gastric cancer therapy and deserved further evaluations.

Figure 2.

Structures of quinazoline-pyridazine/pyrimidine/pyrazine hybrids 12–20.

Phthalazino[1,2‑b]quinazolinone 13 (IC₅₀: 3.09–6.10 µM) exhibited promising broad-spectrum antiproliferative activity against T24, HepG2, NCI-H460, MGC-803, and HeLa cancer cell lines [24]. Mechanistic studies demonstrated that hybrid 13 caused cell cycle arrest at the S/G2 phase, induced apoptosis, changed cell size, and led to cell death by increasing the proportion of sub-G1 cells. In the HepG2 and T24 ×enografted mice models, hybrid 13 (12 mg/kg, intraperitoneal injection) remarkably inhibited tumor growth with TGI values of 61.3% and 54.2% without obvious toxicity. Therefore, hybrid 13 holds potential as a promising candidate for the development of innovative anticancer therapeutics.

BP44 (14, IC₅₀: 238 and 197 nM), a quinazolinone-phthalazinone hybrid, was a dual bromodomain-containing protein 4 (BRD4) and poly(ADPribose) polymerase 1 (PARP1) inhibitor and showed potential antiproliferative activity (IC₅₀: 6.61 and 3.01 µM) against MDA-MB-231 and MDA-MB-468 breast cancer cell lines [25]. Further studies indicated that BP44 inhibited the homologous recombination in triple-negative breast cancer and triggered synthetic lethality, thus leading to cell cycle arrest and DNA damage. After oral administration, BP44 (10 mg/kg, oral administration) showed acceptable pharmacokinetic properties with t_1/2 of 3.33 h, C_max of 242 ng/mL, AUC_0-∞ of 1530 ng•h/mL, and bioavailability of 23.8%. In the MDA-MB-468 ×enografted mice model, BP44 (TGI: 68.7% at 80 mg/kg through intragastric administration) substantially inhibited tumor growth without significant body weight loss, and no obvious toxicity was found in the heart, liver, spleen, lung, and kidney.

Pyrimidino[2,1-b]quinazolin-6-one 15 exhibited great inhibitory activity (IC₅₀: 812 nM) against tubulin assembly and excellent broad-spectrum antiproliferative activity (GI₅₀: <10–66.9 nM) against the NCI 60 cancer cell lines [26]. Mechanistically, hybrid 15 blocked the cell cycle in the G2/M phase, disrupted microtubule formation, and displayed good antivascular properties as inhibition of cell migration, invasion, and endothelial tube formation. In the B16F10 ×enografted mice model, hybrid 15 (5.0 mg/kg, oral administration) showed a significant decrease in tumor growth and angiogenesis with a TGI of 58.3% and a 60% decrease in the percentage of microvessel number. Moreover, no significant difference in mice average weight between the hybrid 15-treated group and the vehicle, revealing its good safety profile.

8H-Quinazolino[4,3-b]quinazoline SIPI6473 (16, IC₅₀: 0.23, 230, 440, and 200 nM) was a multi-targeted inhibitor of EGFR, Fms-like tyrosine kinase 3 (FLT3), VEGFR2, and platelet-derived growth factor receptor α (PDGFRα) [27]. SIPI6473 (IC₅₀: 10.46 µM) displayed weak inhibitory activity against human ether-a-go-go related gene (hERG), similar to that of Erlotinib (IC₅₀: 14.26 µM), and exhibited low toxicity to mice with a maximum tolerated dose (MTD) value of >1,500 mg/kg by oral administration. SIPI6473 (20 mg/kg, oral administration) also showed acceptable pharmacokinetic properties with t_1/2 of 2.32 h, t_max of 0.44 h, C_max of 743.93 ng/mL, and oral bioavailability of 21.08%. In the A549 ×enografted mice model, SIPI6473 (150 mg/kg, oral administration) resulted in 66.1% tumor growth inhibition, which was superior to that of Erlotinib (TGI: 55.4%) under the same conditions.

Quinazolinone-purine hybrids 17 (IC₅₀: 0.39 nM) and 18 (IC₅₀: 0.09 nM) exhibited profound inhibitory effects against PI3K and excellent antiproliferative activity (IC₅₀: 14.59–63.15 nM) against MOLT-4 and SUDHL-5 cancer cell lines [28]. Hybrids 17 and 18 induced apoptosis and suppressed signal transduction during cancer cell proliferation and survival. In the MOLT-4 ×enografted mice model, hybrids 17 and 18 (10 mg/kg, oral administration) suppressed 55.1% and 56.7% tumor growth without inducing body weight loss. Hybrid 17 (3.0 mg/kg, oral administration) also showed promising pharmacokinetic properties with t_1/2 of 7.7 h, t_max of 1.0 h, C_max of 41.89 ng/mL, and AUC_0-∞ of 255.0 ng•h/mL.

Quinazoline-pyrazine hybrid 19 showed potent inhibitory activity (IC₅₀: 39.5 nM) against p97 and promising antiproliferative activity (IC₅₀: 3.48, 5.24, and 1.04 µM) against HCT-116, RPMI-8226, and S180 cancer cell lines [29]. Mechanistically, hybrid 19 arrested the cell cycle at the G2/M phase and suppressed p97 signaling. In the S180 ×enografted mice model, hybrid 19 (TGI: ~40% at a dose of 90 mg/kg by oral administration) effectively inhibited the tumor growth and reduced the p97 concentration in the serum and tumor, and almost no obvious side effects were observed.

Quinazoline-4-oxo-4,5-dihydropyrrolo[1,2-a]quinoxaline hybrid 20 (IC₅₀: 7.41 nM) was a potent Bruton’s tyrosine kinase (BTK) inhibitor and was comparable to Ibrutinib (IC₅₀: 8.0 and 8.8 µM vs 4.5 and 10.7 µM) against U937 and Romas cancer cell lines [30]. Mechanistically, hybrid 20 inhibited the growth of U937 cells mainly by arresting the cell cycle at the G1 phase and inducing cell apoptosis. In the U937 ×enografted mice model, hybrid 20 (TGI: 65.61% at 50 mg/kg by intraperitoneal injection) showed higher in vivo efficacy than Ibrutinib (TGI: 43.06% at 25 mg/kg by oral administration). Thus, hybrid 20 could be a promising lead compound for further development of novel noncovalent BTK inhibitors.

To sum up, quinazoline-pyridazine/pyrimidine/pyrazine hybrids were capable of inducing synthetic lethality, impeding microtubule assembly, blocking signal transduction pathways, halting the cell cycle at various phases, and inducing apoptosis. Through these multifaceted mechanisms of action, these hybrid compounds have demonstrated outstanding therapeutic efficacy against a diverse range of malignancies, including bladder, liver, gastric, lung, and breast cancers, as well as melanoma, lymphoma, sarcoma, and leukemia.

4. Quinazoline-indole/pyrrole/furan/thiophene hybrids

YS-363 (21, Figure 3; IC₅₀: 0.96 and 0.67 nM), a quinazoline-indole hybrid, was comparable to Gefitinib (IC₅₀: 1.0 and 1.3 nM) and Afatinib (IC₅₀: 0.3 and 0.7 nM) in inhibition of EGFR and EGFR^L858R and showed reversible inhibitory effect on cellular EGFR signaling as well as excellent inhibitory activity on cell proliferation and migration [31]. In addition, YS-363 arrested the cell cycle at the G0/G1 phase and induced apoptosis. Pharmacokinetic studies showed that the t_max of YS-363 (40 mg/kg, oral administration) was 3.0 h, C_max was 372 ng/mL, but bioavailability (F%: 11.2%) was relatively low. In the A431 ×enografted mice model, YS-363 (TGI: 87.6% and 95.3%, respectively, at 10 and 40 mg/kg by oral administration) was not inferior to Gefitinib (TGI: 94.5% at 10 mg/kg by oral administration), and no obvious changes in body weight were observed.

Figure 3.

Structures of quinazoline-indole/pyrrole/furan/thiophene hybrids 21–37.

YS-67 (22, IC₅₀: 5.2, 9.6 and 1.9 nM) was a highly potent inhibitor of EGFR^wt, EGFR^d764–750 and EGFR^L858R and exhibited promising antiproliferative activity (IC₅₀: 4.1, 0.5 and 2.1 µM) against A549, PC-9 and A431 cancer cell lines [32]. Further studies revealed that YS-67 could cause colony formation inhibition, arrest cell cycle progression at the G0/G1 phase, and induce apoptosis. In the A431 ×enografted mice model, YS-67 (40 mg/kg, oral administration) showed effective tumor growth suppression with a TGI of ~70% without significant change in body weight.

Quinazoline-indole hybrid 23 (IC₅₀: 0.90 and 0.90 nM) showed equal antiproliferative activity against MCF-7 and Doxorubicin-resistant MCF-7/Adr breast cancer cell lines, and the activity was superior to that of Combretastatin A-4 (IC₅₀: 4.8 and 3.1 nM) [33]. Mechanistically, hybrid 23 inhibited tubulin polymerization, depolarized the mitochondrial membrane potential, induced reactive oxygen species (ROS) production, arrested cell cycle at the G2/M phase, and induced cell apoptosis. In addition, hybrid 23 could inhibit the proliferation of MCF-7 cells by synergistically antagonizing microtubule polymerization and aryl hydrocarbon receptor (AhR) expression. In the MCF-7 ×enografted mice model, hybrid 23 (1.0 mg/kg, intravenous injection) reduced the tumor weight by 81.1%, which was comparable to that of Paclitaxel (TGI: 84.2% at 10 mg/kg by intravenous injection) and Combretastatin A-4 (TGI: 37.5% at 20 mg/kg by intravenous injection).

Quinazoline-indole hybrid 24 (IC₅₀: 201 and 750 nM) displayed selective inhibition of PI3Kα and PI3Kγ and could inhibit phospho-Akt levels in MCF-7 and PC-3 cancer cell lines [34]. In addition, hybrid 24 (half-maximal growth inhibition concentration/GI₅₀: 7.0 µM) showed considerable antiproliferative activity against MCF-7 breast cancer cells and was nontoxic to normal fR2, HEK293, and hGF cell lines with a GI₅₀ value > 50 µM. In the ECA and EST xenografted mice models, hybrid 24 (25 mg/kg, intraperitoneal injection) reduced 62% and 37% of tumor growth without causing any mortality or change in body weight.

SKLB-194 (25, IC₅₀: 13 nM), as a potent Rad3-related (ATR) kinase inhibitor, was highly active against ataxia-telangiectasia mutated (ATM)-deficient LoVo, Granta-519, OVCAR-3, NCI-H23, and SW620 cancer cell lines [35]. SKLB-194 (10 mg/kg, oral administration) also possessed promising pharmacokinetic properties with t_1/2 of 1.14 h, C_max of 895.28 ng/mL, AUC_0-∞ of 2719.61 ng•h/mL, and bioavailability of 43.1%. In the LoVo xenografted mice model, SKLB-194 (100 mg/kg, oral administration) reduced 72.8% tumor growth, and no significant body weight loss, toxicity, or damage in the vital organs (heart, liver, spleen, lung, and kidney) was found. Collectively, SKLB-194 was a promising candidate for colon cancer therapy and was worthy of further evaluation.

Quinazoline-indole hybrids C5 (26, IC₅₀: 0.38, 2.2, 3.5 and 1.6 nM) and C6 (27, IC₅₀: 0.72, 8.2, 7.5 and 2.0 nM) were potent multi-targeted inhibitors of EGFR^wt, EGFR^L858R, HER2, and HER4 and were highly active against A431, H1975, HCC827, SK-BR-3 and BT-474 cancer cell lines [36]. Furthermore, hybrids C5 and C6 could arrest the cell cycle mainly at the G1 phase and induce caspase-dependent apoptosis. In the A431 ×enografted mice model, hybrids C5 (TGI: ~85% at 80 mg/kg via oral administration) and C6 (TGI: ~50% at 80 mg/kg via oral administration) significantly inhibited tumor growth without obvious changes in body weight. In a nutshell, the hybrids C5 and C6 were promising pan-HER inhibitors and useful candidates for human epidermal cancer therapy.

8,14-Dihydroindolo[2‘,3:’3,4]pyrido[2,1-b]quinazolin-5(7H)-one dehydroevodiamine (DeHE, 28; IC₅₀: 96.10 and 49.88 µM) isolated from the traditional Chinese herb Evodiae fructus exhibited considerable antiproliferative activity against PANC-1 and MIA PaCa-2 pancreatic cancer cell lines [37]. Mechanistic studies showed that DeHE could directly interact with recombinant DNA damage inducible transcript 3 (DDIT3), thereby inhibiting the activation of the PI3K/AKT/mammalian target of rapamycin (mTOR) pathway. In the PANC-1 ×enografted mice model, DeHE (TGI: ~50% at a dose of 50 mg/kg through oral administration) remarkably suppressed tumor growth without hepatotoxicity and nephrotoxicity, and the in vivo efficacy was higher than that of Gemcitabine (TGI: ~20%) under the same conditions. Collectively, DeHE was a useful template for the treatment of pancreatic cancer.

Indolo[2,1-b]quinazoline-6,12-dione 29 (IC₅₀: 20 and 90 nM) was a dual inhibitor of indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) and could significantly augment the proliferation of T cells as well as block the kynurenine pathway [38]. In the LLC and H22 ×enografted mice models, hybrid 29 (45 mg/kg, oral administration) exhibited great in vivo therapeutic efficacy with TGI values of 56.2% and 47.3%, respectively. Therefore, hybrid 29 was an attractive IDO1 and TDO dual inhibitor and merited further preclinical evaluations for solid tumor therapy.

2,3-Dihydroquinazolin-4(1H)-one-indole hybrid 30 (IC₅₀: 0.093–11.81 µM) was more potent than 5-Fluorouracil (IC₅₀: 24.73–180.03 µM) against HepG2, U251, PANC-1, A549, and A375 cancer cell lines [39]. Further studies demonstrated that hybrid 30 could inhibit tubulin polymerization, disrupt cell microtubule networks, arrest the cell cycle at G2/M phase, and induce apoptosis through upregulating the expression of cleaved poly(adenosine diphosphate/ADP-ribose)polymerase 1 (PARP-1) and caspase-3. In the HepG2 ×enografted mice model, hybrid 30 (TGI: 42.9% at 80 mg/kg via oral gavage) was comparable to 5-Fluorouracil (TGI: 43.3% at 25 mg/kg via intraperitoneal injection) in reduction of tumor growth, and no significant body weight loss or overt organ-related toxicities were observed. Moreover, spontaneous locomotor activities remained unimpaired at a dose of 200 mg/kg by oral administration, and no mortality events or pathological anomalies in major organs occurred, demonstrating the low toxicity of hybrid 30.

4-Oxo-1,4,5,6-tetrahydropyrrolo[3,4-b]pyrrol-2-yl)quinazolinone 31 (IC₅₀: 0.2 nM) exhibited a profound inhibitory effect against the proviral insertion site of Moloney murine leukemia virus kinase 2 (Pim-2) and excellent antiproliferative activity (IC₅₀: 31 nM) against KMS-12 BM multiple myeloma cells [40]. Hybrid 31 (IC₅₀: >30 µM) also showed low hERG inhibitory activity, indicating its low cardiotoxicity potential. Besides, hybrid 31 (2.0 mg/kg for intravenous injection and 5.0 mg for oral administration) possessed good permeability (P_app: 44 × 10⁻⁶ cm/s), low clearance (CL: 0.3 L/h/kg), and high oral bioavailability (F%: 39%) in rats. In the KMS-12 BM xenografted mice model, hybrid 31 (TGI: 93% at a dose of 50 mg/kg via oral administration) remarkably suppressed tumor growth without overt toxicity, highlighting its potential for the treatment of multiple myeloma.

4-Oxo-1,4,5,6-tetrahydropyrrolo[3,4-b]pyrrol-2-yl)quinazolinone 32 (IC₅₀: 0.05 and 0.05 nM), an analogue of hybrid 31, was highly active against Pim-1 and Pim-2, and demonstrated pronounced antiproliferative activity (IC₅₀: 2.0–667 nM) against multiple myeloma (KMS-12 BM, RPMI-8226, and OPM-2) and acute myeloid leukemia (EOL-1 and OCI-M1) cell lines [41]. As hybrid 31, hybrid 32 (2.0 mg/kg for intravenous injection and 5.0 mg/kg for oral administration) also exhibited good permeability (P_app: 40 × 10⁻⁶ cm/s), long half-life (t_1/2: 11.2 h), low clearance (0.14 L/h/kg), and excellent oral bioavailability (F%: 56%) in rats. In the KMS-12 BM xenografted mice model, hybrid 32 (oral administration) led to 100% tumor growth inhibition at 50 mg/kg and 33% tumor regression at 100 mg/kg without obvious toxicity. Taken together, hybrid 32 was a potent and selective Pim-1/2 kinase inhibitor and was a valuable template for hematological malignancies therapy.

2,3-Dihydropyrrolo[2,1-b]quinazolin-9(1H)-one 33 (K_d: 2.0 nM) showed high specific binding affinity to NM23-H2 and could disrupt the interaction of NM23-H2 with G-quadruplex, down-regulate cMYC transcription, arrest cell cycle at the G0/G1 phase, and induce apoptosis [42]. In the SiHa BM xenografted mice model, hybrid 33 (intraperitoneal injection) resulted in a significant reduction in tumor growth with TGI values of 48.0% at 2.5 mg/kg and 64.8% at 5.0 mg/kg, whereas Doxorubicin (1.0 mg/kg, intraperitoneal injection) inhibited 67.6% tumor growth. Moreover, all of the animals in the hybrid 33-treated group appeared healthy with no significant body weight loss, visible signs of pain, distress, or discomfort, while toxicity was apparent in the Doxorubicin-treated group as evidenced by body weight loss. Overall, hybrid 33 was a potential candidate for cervical squamous cancer therapy and deserved further evaluation.

PVHD303 (34, IC₅₀: 13 nM), a quinazoline-furan hybrid, demonstrated excellent antiproliferative activity against A549 cancer cells and disturbed microtubule formation at the centrosomes [43]. In the HCT-116 ×enografted mice model, PVHD303 (20 mg/kg, intravenous injection) significantly inhibited tumor growth with a TGI of 62.9%. Hybrid 35 (IC₅₀: 6.15 and 9.78 nM) was a dual-target inhibitor of EGFR and HER2, more potent than that of Lapatinib (IC₅₀: 8.41 and 9.41 nM) [44]. Hybrid 35 (IC₅₀: 0.78–1.33 µM) showed prominent antiproliferative activity against A549, NCI-H1975, SK-BR-3, and MCF-7 cancer cell lines and could inhibit the migration, arrest the cell cycle in the G0/G1 phase, and induce apoptosis. In the SK-BR-3 ×enografted mice model, hybrid 35 (30 mg/kg, intragastric administration) reduced 68.98% tumor growth without obvious toxicity.

KS-19 (36, IC₅₀: 460 and 870 nM) exhibited eminent antiproliferative activity against KRAS G12C-mutated NCI-H358 and NCI-H23 cancer cell lines and could inhibit the formation of NCI-H358 and NCI-H23 tumor colonies [45]. In addition, KS-19 could decrease the active form of KRAS G12C (KRAS G12C-GTP) and phosphorylated extracellular regulated protein kinase (ERK), leading to NCI-H358 cancer cell apoptosis. In the NCI-H358 ×enografted mice model, KS-19 (TGI: 47% at 40 mg/kg by intraperitoneal injection) was comparable to ARS-1620 (TGI: 50%) in suppression of tumor growth under the same conditions. Besides, no bone marrow suppression or obvious morphological abnormalities in major organs were observed in the KS-19-treated group, revealing its good safety profile.

ERAS-5024 (37, IC₅₀: 2.1 nM), a quinazoline-benzothiophene hybrid, showed excellent inhibitory effect against ERK1/2 phosphorylation (pERK) and profound antiproliferative activity (IC₅₀: 0.2–10.6 nM) against AsPC-1, GP2d, AGS, SK-LU-1, HPAC, LS513, HPAF-1, Panc04.03 and RI G12D cancer cell lines [46]. In the AsPC-1 harboring KRAS G12D mutation xenografted mice model, ERAS-5024 (intraperitoneal injection) inhibited tumor growth by 77% at 10 mg/kg and induced tumor regression by 54% at 20 mg/kg. Moreover, no substantial alterations in the body weight of the mice were observed during the treatment, revealing its good safety profile.

In summary, quinazoline-indole/pyrrole/furan/thiophene hybrids could act as powerful inhibitors of multiple crucial targets such as EGFR, EGFR^L858R, EGFR^d764–750, tubulin, PI3K, ATR, HER2/4, AKT, mTOR, ODO1, TDO, Pim1/2 and ERK1/2. Owing to their broad-spectrum inhibitory activity, these hybrid molecules have shown robust in vivo anticancer efficacy against a wide array of malignancies, including pancreatic, breast, lung, liver, cervical, esophageal, and colon cancers, as well as myeloma, epidermoid carcinoma. Moreover, these hybrids also demonstrated excellent safety profile, revealing their potential as novel antitumor candidates.

5. Quinazoline-azole hybrids

CZh-124 (38, Figure 4), a quinazolinone-pyrazole hybrid, as a pan-tyrosine kinase (TRK) inhibitor (IC₅₀: 12, 9, and 12 nM), was not inferior to Larotrectinib (IC₅₀: 4.1, 6.6, and 4.5 nM) in inhibition of TRKA, TRKB, and TRKC [47]. In addition, CZh-124 (IC₅₀: 12, 250, 46, and 20 nM) was comparable to Larotrectinib (IC₅₀: 7.1, 2200, 850, and 260 nM) against Km-12, and drug-resistant BaF3-TRKA^G595R, BaF3-TRKA^G667C, as well as BaF3-TRKA^F589L cell lines. CZh-124 possessed good liver microsomal stability with t_1/2 of 70.5 min and CL_int of 17.7 µL/min/mg and showed weak inhibitory activity (IC₅₀: 5.49->50 μM) against five major cytochrome P450 proteins (CYPs, including CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4), indicating that CZh-124 had a low risk of drug–drug interaction. In the Km-12 ×enografted mice model, CZh-124 (TGI: 71% at 40 mg/kg by oral administration) was comparable to Larotrectinib (TGI: 78% at 40 mg/kg by oral administration), and no substantial alterations in the body weight of the mice were observed.

Figure 4.

Structures of quinazoline-pyrazole/indazole hybrids 38–49.

Quinazolinone-pyrazole hybrid 39, the prodrug of CZh-226, was not only stable under both acidic and neutral conditions but also could be quickly converted to the parent drug CZh-226 in rat plasma and liver S9 fraction [48]. Hybrid 39 (13.5 mg/kg, oral administration) possessed acceptable pharmacokinetic profiles with t_1/2 of 20.1 h, t_max of 0.083 h, C_max of 87.6 ng/L, and AUC_0-∞ of 995.7 h•ng/mL. In the HCT-116 and B16F10 ×enografted mice models, hybrid 39 (50 mg/kg, oral gavage) remarkably reduced tumor growth with TGI values of 65% and 63% respectively, and no mortality or body weight loss was observed.

Quinazolinone-pyrazole hybrid 40 (IC₅₀: 38 nM) was a highly potent Aurora A inhibitor and showed promising antiproliferative activity (IC₅₀: 0.45–2.40 µM) against K562, MCF-7, HeLa, DU145, MOLT-4, MDA-MB-231, and SK-BR-3 cancer cell lines [49]. In addition, hybrid 40 (IC₅₀: >10 µM) showed low hERG inhibitory activity, arrested cell cycle at the G2/M phase, and induced apoptosis. In the MDA-MB-231 ×enografted mice model, hybrid 40 (30 mg/kg, intragastric administration) inhibited 45% tumor growth, and no evident loss of body weight or damage in vital organs was observed, indicating its excellent safety profile.

5‑Azaquinazoline-pyrazole hybrid 41 (IC₅₀: 27 and 4.0 nM) exhibited great inhibitory activity against interleukin-1 receptor-associated kinase 1 (IRAK1) and IRAK4, and at a concentration of 0.3 μM, resulted in the complete suppression of IκBα phosphorylation [50]. In the OCI-LY10 ×enografted mice model, hybrid 41 reduced ~35% tumor growth at 100 mg/kg by oral administration, while Ibrutinib (12 mg/kg, oral administration) inhibited ~65% tumor growth. Notably, the combination of hybrid 41 (100 mg/kg, oral administration) with Ibrutinib (12 mg/kg, oral administration) led to robust tumor regression.

TS-41 (42, IC₅₀: 68.1 and 0.26 nM), a quinazoline-pyrazolone hybrid, displayed excellent inhibitory activity against EGFR^L858R and cellular-mesenchymal epithelial transition factor (c-Met) kinases and potent antiproliferative activity (IC₅₀: 1.48–2.76 µM) against A549^−P, H1975, and PC-9 lung cancer cell lines [51]. Mechanistic studies demonstrated that TS-41 arrested the cell cycle at G0/G1 phase, induced apoptosis, and significantly downregulated the phosphorylation of EGFR, c-Met, and downstream AKT. In the A549^−P xenografted mice model, TS-41 (60 mg/kg, intragastric administration) resulted in 55.3% tumor growth inhibition, higher than that of Afatinib (TGI: 46.4%). Moreover, no obvious hemolytic toxicity and organ toxicity were observed even at 100 mg/kg via intragastric administration, indicating its good biosafety profile.

Quinazoline-pyrazolone hybrid 43 (IC₅₀: 3.5 nM) exhibited a great inhibitory effect against AXL and was superior to Bemcentinib (IC₅₀: <0.1 nM vs 95.1 nM) against BaF3/TEL-AXL cancer cells [52]. Additionally, hybrid 43 could inhibit GAS6/AXL-mediated cancer cell invasion, migration, and wound healing. Further studies revealed that hybrid 43 (10 mg/kg, oral administration) possessed promising pharmacokinetic properties with t_1/2 of 3.24 h, t_max of 2.0 h, C_max of 2970 ng/mL, AUC_0-∞ of 16,007 ng•h/mL, and bioavailability of 22.9%. In the BaF3/TEL-AXL xenografted mouse model, hybrid 43 (oral administration) markedly suppressed tumor growth in a dose-dependent manner with TGI values of 89.5% at 4.0 mg/kg and 93.4% at 20 mg/kg, superior to that of Bemcentinib (TGI: 92.0% at 50 mg/kg through oral administration).

CN210 (44, K_d: 70 nM; IC₅₀: 0.94 µM) and CN017 (45, K_d: 230 nM; IC₅₀: 1.66 µM), pyrazole-quinazoline-isoxazole hybrids, were highly active in inhibition of BRD4 and showed promising antiproliferative activity against MV4–11 cells [53]. CN210 (10 mg/kg, oral administration) and CN017 (10 mg/kg, oral administration) possessed desirable pharmacokinetic profiles in mouse with t_1/2 of 1.7 and 1.8 h, C_max of 2163 and 2043 ng/mL, AUC_0-∞ of 18,927 and 15,013 h•ng/mL, and bioavailability of 75% and 89%, respectively. In the Kasumi-1 acute myelogenous leukemia xenografted mice model, CN210 (40 mg/kg, oral administration) and CN017 (40 mg/kg, oral administration) effectively decreased tumor volume and tumor weight with TGI values of 98.6% and 98.8%, and no obvious changes in body weight were observed.

Pyrazolo[4,3-h]quinazoline 46 (IC₅₀: 0.66 and 5.0 nM) was superior to Onvansertib (IC₅₀: 1.08 and 45 nM) in inhibition of Polo-like kinase 1 (PLK1) and against HCT-116 cancer cells and could arrest cell cycle at the G2/M phase [54]. Besides, the cellular permeability and efflux ratio were significantly improved when compared with Onvansertib (P_appA→B: 2.03 × 10⁻⁶ cm/s vs 0.345 × 10⁻⁶ cm/s and efflux ratio: 1.65 vs 94.7). In the HCT-116 ×enografted mice model, hybrid 46 (TGI: 116.2% at 60 mg/kg through oral administration) induced significant tumor regression, which was far superior to that of Onvansertib (TGI: 43.0%) under the same conditions. Furthermore, hybrid 46 could significantly accumulate in the colorectum, pancreas, and lung compared with Onvansertib, manifesting its potential against multiple types of tumors.

Quinazoline-pyrimidine-indazole hybrid 47 (IC₅₀: 1.0–4.9 nM) showed balanced and selective inhibitory effects against cyclin-dependent kinases (CDKs) 1/2/4/8/9 and possessed excellent broad-spectrum antiproliferative activity (IC₅₀: 28–835 nM) against a panel of 21 cancer cell lines [55]. Mechanistically, hybrid 47 could arrest the cell cycle at G0/G1 phase and induce apoptosis through activating PARP and caspase-3. Hybrid 47 (10 mg/kg, oral administration) also possessed acceptable pharmacokinetic profiles in mice with t_max of 2.00 h, C_max of 113 ng/mL, MRT of 3.55 h, AUC_0-∞ of 534 h•ng/mL, and bioavailability of 23.3%. In the MOLT-4 (15 mg/kg) and MV4–11 (30 mg/kg) xenografted mice models, hybrid 47 (oral administration) showed delightful antitumor efficacy with a TGI of ~60%, and the body weight of mice showed no obvious fluctuations during the administration.

Quinazoline-indazole hybrid 48 (IC₅₀: 77 nM) was a potent KRAS G12C inhibitor and showed profound antiproliferative activity (IC₅₀: 120 nM) against H1373 cancer cells [56]. In addition, hybrid 48 possessed good stability in human and mouse liver microsomes with CL_int values of 37 and 115 mL/min/kg, respectively. After a single subcutaneous administration of hybrid 48 (33 mg/kg), the inhibition rate of ERK phosphorylation in H1373 tumors at 6 h was 63% as compared with the vehicle control. In the H1373 ×enografted mice model, hybrid 77 showed an antitumor effect close to 100% growth inhibition without significant body weight loss after subcutaneous administration at 30 mg/kg.

ASP6918 (49, IC₅₀: 28 and 6.1 nM), an analogue of hybrid 48, exhibited pronounced activity against KRAS G12C and H1373 cancer cell lines and demonstrated excellent stability in human and mouse liver microsomes with CL_int values of 130 and 210 mL/min/kg, respectively [57]. In the H1373 ×enografted mice model, ASP6918 (oral administration) could completely suppress tumor growth with a TGI of > 100% at 40 mg/kg and resulted in tumor regression of 49% at 40 mg/kg and 73% at 60 mg/kg without obvious body weight loss.

Quinazolinone-thiazole hybrid 50 (Figure 5; IC₅₀: 3.0 and 20 nM) exhibited great inhibitory effects against EGFR^L858R/T790M and EGFR^{L858R/T790M/C797S}, and possessed acceptable half-life (t_1/2: 3.5 h), moderate clearance (CL: 30 mL/min/kg), and moderate oral bioavailability (F%: 24%) in rats [58]. In the H1975 harboring EGFR^L858R/T790M mutation xenografted mice model, hybrid 50 could completely inhibit tumor growth at 50 mg/kg by oral administration, and no apparent toxicity was observed during the treatment.

Figure 5.

Structures of quinazoline-thiazole/imidazole/triazole hybrids 50–62.

7H-Pyrrolo[3,2-f]quinazoline-benzothiophene hybrids 51 (IC₅₀: 0.001–0.11 µM) and 52 (IC₅₀: 0.18–1.95 µM) exhibited promising antiproliferative activity against MCF-7, HGC27, HCT-116 and HepG2 cancer cell lines [59]. Besides, hybrid 52 possessed good stability (t_1/2: 82.0 min, CL_int: 16.9 mL/min/kg) in mouse liver microsomes and desirable pharmacokinetic profiles (t_1/2: 9.81 h, t_max: 0.83 h, and AUC_0-∞: 2280.12 h•ng/mL at 10 mg/kg via intraperitoneal injection). In the EMT6 ×enografted mice model, hybrids 51 (10 mg/kg, intraperitoneal injection) and 52 (2.5 mg/kg, intraperitoneal injection) reduced 71.1% and 71.0% tumor growth, respectively, which were more potent than that of Taxol (TGI: 53.2% at 24 mg/kg by intraperitoneal injection). However, hybrid 51 (10 mg/kg, intraperitoneal injection) caused weight loss and death during the treatment period, while hybrid 52 demonstrated a good biosafety profile.

Quinazoline-1,2,3-triazole hybrid 53 (IC₅₀: 0.36–2.79 µM) was more potent than 5-Fluorouracil (IC₅₀: 4.89 and 4.53 µM) against HCT-116, A375, HepG2, MCF-7, MDA-MB-231, MGC-803, and A549 cancer cell lines and could arrest the cell cycle at G2/M phase and induce apoptosis [60]. Hybrid 53 (10 mg/kg, intraperitoneal injection) demonstrated excellent pharmacokinetic profiles with t_1/2 of 31.0 h, C_max of 39.87 ng/mL, CL of 16,554.3 mL/h/kg, and AUC_0-∞ of 408.18 h•ng/mL. Moreover, no death or diarrhea was found in the ≤50 mg/kg dose groups by intraperitoneal injection, and the MTD of hybrid 53 was 50 mg/kg. In the HCT-116 ×enografted mice model, hybrid 53 (TGI: ~65% at 10 mg/kg via intraperitoneal injection) suppressed tumor growth by promoting apoptosis in xenografted tumorigenesis without significant body weight loss.

Quinazoline-1,2,4-triazole hybrid 54 (IC₅₀: 690 nM) was a potent inhibitor of histone lysine-specific demethylase 1 (LSD1) and was not inferior to Erlotinib (IC₅₀: 9.21 μM vs 10.78 μM) against MGC-803 gastric cancer cells [61]. Mechanistic studies revealed that hybrid 54 could inhibit colony formation, suppress migration, and induce apoptosis. In the MGC-803 ×enografted mouse model, hybrid 54 (TGI: 81.6% and 96.1% at 40 and 80 mg/kg via intravenous injection) led to a remarkable reduction in tumor growth, and no apparent body weight loss or ocular toxicity was observed.

Quinazoline-1,2,4-triazole hybrids 55 (IC₅₀: 5.90 and 36.78 nM) and 56 (IC₅₀: 0.69 and 67.84 nM) were not inferior to Vandetanib (IC₅₀: 19.76 and 33.26 nM) in inhibition of EGFR and VEGFR-2 kinase [62]. In the A549 ×enografted mouse model, hybrids 55 (TGI: 80.5% at 50 mg/kg via oral administration) and 56 (TGI: 76.3% at 50 mg/kg via oral administration) significantly suppressed tumor growth without obvious body weight loss. Therefore, hybrids 55 and 56 were valuable scaffolds for non-small cell lung cancer therapy.

Quinazoline-pyrazole-benzimidazole hybrid 57 (IC₅₀: 0.52 nM) was highly active in the inhibition of spleen tyrosine kinase (Syk) and exhibited good activity (IC₅₀: 1.5–719 nM) against MV4–11, Ramos, REC-1, DOHH-2, SU-DHL-6, Daudi, and TMD8 lymphoma as well as leukemia cell lines [63]. Further studies showed that hybrid 57 (1.0 mg/kg via intravenous injection) had acceptable metabolic stability (t_1/2: 112.8 min) in human liver microsomes and possessed promising pharmacokinetic properties with t_1/2 of 6.4 h, CL of 33.3 mL/kg/min, and steady-state volume of distribution (V_ss) of 8.92 L/kg. In the MV4–11 ×enografted mice model, hybrid 57 (TGI: 99.33% at 1.0 mg/kg by intravenous injection) remarkably reduced tumor growth, and no obvious body weight loss or mortality was observed during the treatment period.

8-Azaquinazoline fused imidazole hybrids 58 and 59, as excellent CDKs 4,6 (IC₅₀: 0.8–4.8 nM) inhibitors, demonstrated profound antiproliferative activity (IC₅₀: 49.3–255.6 nM) against Colo-205 and U87MG cancer cell lines [64]. Mechanistic studies illustrated that hybrids 58 and 59 could arrest the cell cycle at the G0/G1 phase and induce apoptosis. In addition, hybrids 58 and 59 (6.0 mg/kg, oral administration) possessed desirable pharmacokinetic profiles in rats with t_1/2 of 4.96 and 4.44 h, C_max of 110 and 170 ng/mL, AUC_0-∞ of 1118 and 1775 ng•h/mL, and bioavailability of 65.2% and 66.9%, respectively. Hybrids 58 (TGI: 85% at 30 mg/kg by oral administration in the Colo-205 ×enografted mice model) and 59 (TGI: 70% at 10 mg/kg by oral administration in the U87MG xenografted mice model) exhibited remarkably in vivo antitumor efficacy, acceptable range of body weight loss (<20%) and controllable overt signs of toxicity in the two xenografted models. Moreover, the body weight could increase to a normal level after stopping drug dosing.

Imidazo[2,1-b]quinazoline 60 (IC₅₀: 1.47–5.96 μM) exhibited promising antiproliferative activity against MDA-MB-231, DU-145, HCT-116, SKOV-3, HOS and SAOS-2 cancer cell lines [65]. Mechanistically, hybrid 60 could arrest the cell cycle at the G0/G1 phase and induce apoptosis. In the C26 ×enografted mice model, hybrid 60 (100 mg/kg, oral administration) inhibited 75.36% tumor growth without overt toxicity, and the lethal dose (LD₅₀) was as high as 250 mg/kg.

Oxazolo[4,5-g]quinazolin-2(1H)-one 61 (IC₅₀: 8.7 nM) as a potent EGFR inhibitor was superior to Erlotinib (IC₅₀: 3.7 and 7.6 μM vs 16.6 and 25.6 μM) against KB and A498 cancer cell lines [66]. In the LLC xenografted mice model, hybrid 61 (TGI: ~85% at 100 mg/kg through oral administration) significantly suppressed tumor growth, and distinguishly extended the survival period of the tumor-bearing mice (from 29 days to 55 days), higher than that of Erlotinib (TGI: ~70% and the survival period was 45 days). Moreover, no evident body weight loss was observed, revealing its good safety profile.

Oxazolo[4,5-g]quinazolin-2(1H)-one 62 (IC₅₀: 19 and 35 nM) as a dual inhibitor of EGFR and HER2 was comparable to Lapatinib (IC₅₀: 4.49 and 0.47 μM vs 6.74 and 0.49 μM) against A549 and SK-BR-3 cancer cell lines and was nontoxic (IC₅₀: >100 μM) toward normal HELF cells [67]. In the LLC xenografted mice model, hybrid 62 (100 mg/kg, oral administration) inhibited ~ 65% tumor growth without affecting body weight, whereas Lapatinib suppressed ~ 50% tumor growth under the same conditions.

Conclusively, quinazoline-azole hybrids have emerged as highly effective inhibitors of a diverse set of key targets, including AXL, Aurora A, BRD4, CDKs, c-Met, EGFR, EGFR^L858R/T790M, EGFR^{L858R/T790M/C797S}, HER2, IRAK1/4, LSD1, PLK1, KRAS G12C, Syk, TRK, and VEGFR-2. Due to their potent inhibitory capabilities, these hybrids have shown outstanding in vivo efficacy against a range of cancers, including lung, gastric, and colon cancers, glioblastoma, and leukemia. Beyond their therapeutic potential, quinazoline-azole hybrids also exhibited favorable characteristics in terms of metabolic stability, possessing desirable pharmacokinetic properties that ensure proper distribution, metabolism, and elimination in the body. Additionally, these hybrids have demonstrated an excellent safety profile, indicating their potential as well tolerated and reliable candidates for further evaluation.

6. Conclusions

Multidrug resistance and severe side effects are surmountable obstacles to effective cancer therapy, highlighting the urgent need to develop novel anticancer chemotherapeutics. Quinazoline hybrids could inhibit dual/multiple targets simultaneously in cancer cells and have potential advantages in improving anticancer therapeutic efficacy, reducing adverse effects, and circumventing drug resistance. Moreover, some of them have already been applied in clinics as anticancer therapeutics, demonstrating that the rational design of quinazoline hybrids may provide valuable therapeutic intervention in cancer control.

This review emphasizes the current landscape of quinazoline hybrids, including quinazoline-pyridine/quinoline/quinolone hybrids, quinazoline-pyridazine/pyrimidine/pyrazine hybrids, quinazoline-indole/pyrrole/furan/thiophene hybrids, and quinazoline-azole hybrids with in vivo antitumor therapeutic effects, along with pharmacokinetic properties, toxicity, and modes of action, covering articles published from 2015 onwards. To sum up, these quinazoline hybrids possessed excellent broad-spectrum in vivo anticancer therapeutic potential against various cancers, low toxicity, and desirable pharmacokinetic properties; quinazoline hybrids showed promising efficacy in multidrug-resistant cancer xenografted mice models, demonstrating that quinazoline hybrids can overcome multidrug resistance.

7. Future perspectives

The following areas could serve as focal points for future research endeavors: (1) Explore the hybridization of innovative anticancer pharmacophores with pyrimidine, aiming to develop a larger pool of compounds worthy of in-depth investigation. This approach may unveil novel chemical entities with enhanced biological activities. (2) Conduct systematic and rational modifications to the existing lead compounds. The objectives are to significantly boost their in vivo therapeutic efficacy, optimize their pharmacokinetic profiles, and minimize potential toxicity. Such refinements can improve the overall druggability of these candidates. (3) Undertake more extensive preclinical evaluations. These comprehensive studies will help identify and validate a greater number of promising compounds that can progress to clinical trials, thereby accelerating the development of new anticancer therapies.

Funding Statement

The work was not funded.

Article highlights

• Quinazoline moiety is deemed a useful antitumor pharmacophore.

• The quinazoline hybrids could act on diverse biological targets in cancer cells.

• The mentioned quinazoline hybrids demonstrated robust in vivo antitumor efficacy in various tumor xenografted mice models.

• Most of the mentioned quinazoline hybrids possessed desirable pharmacokinetic properties and excellent toxicity profiles.

Declaration of Interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.