Small Molecule Tyrosine Kinase Inhibitors Research Articles

Pyrotinib for HER2-positive metastatic breast cancer: a systematic review and meta-analysis.

Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer patients continue to progress despite multiple anti-HER2-targeted treatments. A number of studies have found that Pyrotinib, a small-molecule pan-ErbB receptor tyrosine kinase inhibitor (TKI), is effective in treating patients with HER2-positive metastatic breast cancer. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of Pyrotinib in the treatment of HER2-positive metastatic breast cancer. PubMed, Embase, Web of Science, and Cochrane Library databases were searched until February 2022. Research on HER2-positive metastatic breast cancer being treated with Pyrotinib in any line of therapy was included, both prospective and retrospective. Statistical pooling and meta-analysis of data from the included studies were performed to explore the efficacy and safety of Pyrotinib in HER2-positive metastatic breast cancer. In this meta-analysis, 23 studies were included. The overall objective response rate was 0.49 (95% CI: 0.40, 0.58) for Pyrotinib in HER2-positive metastatic breast cancer and 0.52 (95% CI: 0.32, 0.71) in those with brain metastases. The objective response rate of Pyrotinib was superior to that of other second-line therapeutics in comparison (RR =1.38, 95% CI: 1.25, 1.52), but was relatively inferior to trastuzumab emtansine (T-DM1) (RR =0.82, 95% CI: 0.36, 1.85). The combined median progression-free survivals (PFSs) for Pyrotinib in metastatic breast cancer and those with brain metastases were 8.2 (95% CI: 6.8, 9.5) months and 8.9 (95% CI: 6.2, 11.7) months, respectively. The most common adverse reaction was diarrhea with an all-grade incidence of 0.84 (95% CI: 0.74, 0.92), followed by nausea and vomiting of 0.52 (95% CI: 0.36, 0.68). In any line of treatment for HER2-positive metastatic breast cancer, the Pyrotinib-containing regimens demonstrated considerable tumor response, disease control, and survival with manageable adverse effects.

Phase 1/1b first-in-human study of IDRX-42, a novel oral tyrosine kinase inhibitor (TKI), in patients with metastatic and/or unresectable gastrointestinal stromal tumors (GISTs).

TPS483 Background: The majority of GISTs are driven by constitutively activated kinases, either KIT or platelet-derived growth factor-alpha ( PDGFRA), and respond to TKI treatment (eg, imatinib, sunitinib, regorafenib, ripretinib). Most GISTs develop heterogeneous resistance to TKI during treatment, usually driven by secondary mutations in the primary kinase oncogene ( KIT or PDGFRA). Novel therapies are needed to prevent emergence of resistant subclones or to treat TKI-resistant GISTs. IDRX-42 (formerly M4205) is a potent, highly selective, orally administered small-molecule TKI targeting disease-specific oncogenic drivers and a range of clinically relevant resistance mutations of KIT. Nonclinical studies of IDRX-42 have demonstrated robust antitumor activity in patient and cell line-derived GIST xenograft models, including models with relevant KIT mutations and TKI resistance mutations (De Sutter et al AACR 2022). Methods: IDRX-42-001 is a phase 1/1b, first-in-human, open-label, multicenter study to evaluate single-agent IDRX-42 in participants with metastatic and/or surgically unresectable GISTs. Phase 1 dose escalation utilizes a 3+3 design to evaluate safety, tolerability, PK, and preliminary antitumor activity of IDRX-42 to establish the MTD and RP2D. Phase 1b will consist of exploratory cohorts with selected lines of prior therapy to assess the antitumor activity of IDRX-42 and further characterize its safety profile at RP2D. Eligible participants are ≥18 yr old with ECOG PS 0–1, documented pathogenic mutation in KIT or any PDGFRA mutation other than exon 18 mutations, and ≥1 measurable lesion per mRECIST v1.1 by investigator assessment. Phase 1 dose-escalation participants must have documented progression on at least imatinib. For phase 1b exploratory cohorts, cohort 1 participants must have progressed on imatinib only (2nd line); cohort 2 participants must have progressed on imatinib and sunitinib (3rd line) or progressed on imatinib, sunitinib, and an additional agent (ie, regorafenib or ripretinib; 4th line); cohort 3 participants must have progressed on imatinib, sunitinib, regorafenib, and ripretinib (≥5th line). IDRX-42 will be initiated at 120 mg PO QD in 28-d cycles until disease progression, unacceptable toxicity, or other reason. Primary endpoints are to determine the nature, incidence, & severity of IDRX-42 TEAEs and DLTs (phase 1), and to evaluate safety and determine ORR per investigator assessed mRECIST v1.1 (phase 1b). Secondary efficacy endpoints include PK parameters, DoR, PFS, and time to response related to IDRX-42. Exploratory endpoints will evaluate potential predictive and pharmacodynamic markers using ctDNA, as well as changes in KIT, PDGFRA, and other relevant gene mutant allele fractions and their correlation with clinical outcomes. Enrollment is ongoing (NCT05489237). Clinical trial information: NCT05489237 .

The efficacy and safety of epirubicin and cyclophosphamide combined with pyrotinib in neoadjuvant treatment for HER2-positive breast cancer: A real-world study.

Long-term survival benefit of anthracyclines for human epidermal growth factor receptor 2 (HER2)-positive breast cancer is clear. In the neoadjuvant treatment, compared with the monoclonal antibody such as trastuzumab and pertuzumab, the clinical benefit of pyrotinib, a new small-molecule tyrosine kinase inhibitor (TKI), as the main anti-HER2 strategy currently requires more research to determine. Our real-world study is the first prospective observational study in China to evaluate the efficacy and safety of epirubicin (E) and cyclophosphamide (C) with pyrotinib as anti-HER2 therapy in the neoadjuvant setting of patients with stage II-III HER2-positive breast cancer. From May 2019 to December 2021, 44 untreated patients with HER2-positive nonspecific invasive breast cancer who received 4 cycles of neoadjuvant EC with pyrotinib. The primary endpoint was pathological complete response (pCR) rate. Secondary endpoints included the overall clinical response, breast pathological complete response rate (bpCR), the rate of axillary lymph nodes pathological negativity and adverse events (AEs). Other objective indicators were the rate of surgical breast-conserving, the negative conversion ratios of tumor markers. Thirty-seven (84.1%) of 44 patients completed this neoadjuvant therapy, and 35 (79.5%) had surgery and were included in the primary endpoint assessment. The objective response rate (ORR) of 37 patients was 97.3%. Two patients reached clinical complete response, 34 obtained clinical partial response, 1 sustained stable disease, and no one had progressive disease. Eleven (31.4%) of 35 patients who had surgery achieved bpCR and the rate of axillary lymph nodes pathological negativity was 61.3%. The tpCR rate was 28.6% (95% CI: 12.8-44.3%). Safety was evaluated in all 44 patients. Thirty-nine (88.6%) had diarrhea, and 2 developed grade 3 diarrhea. Four (9.1%) patients had grade 4 leukopenia. All grade 3-4 AEs could be improved after symptomatic treatment. The regimen of 4 cycles of EC combined with pyrotinib presented some feasibility in the neoadjuvant setting for HER2-positive breast cancer with manageable safety. New regimens with pyrotinib should be evaluated for higher pCR in future. chictr.org Identifier: ChiCTR1900026061.

Inhibiting the glycerophosphodiesterase EDI3 in ER-HER2+ breast cancer cells resistant to HER2-targeted therapy reduces viability and tumour growth

BackgroundIntrinsic or acquired resistance to HER2-targeted therapy is often a problem when small molecule tyrosine kinase inhibitors or antibodies are used to treat patients with HER2 positive breast cancer. Therefore, the identification of new targets and therapies for this patient group is warranted. Activated choline metabolism, characterized by elevated levels of choline-containing compounds, has been previously reported in breast cancer. The glycerophosphodiesterase EDI3 (GPCPD1), which hydrolyses glycerophosphocholine to choline and glycerol-3-phosphate, directly influences choline and phospholipid metabolism, and has been linked to cancer-relevant phenotypes in vitro. While the importance of choline metabolism has been addressed in breast cancer, the role of EDI3 in this cancer type has not been explored.MethodsEDI3 mRNA and protein expression in human breast cancer tissue were investigated using publicly-available Affymetrix gene expression microarray datasets (n = 540) and with immunohistochemistry on a tissue microarray (n = 265), respectively. A panel of breast cancer cell lines of different molecular subtypes were used to investigate expression and activity of EDI3 in vitro. To determine whether EDI3 expression is regulated by HER2 signalling, the effect of pharmacological inhibition and siRNA silencing of HER2, as well as the influence of inhibiting key components of signalling cascades downstream of HER2 were studied. Finally, the influence of silencing and pharmacologically inhibiting EDI3 on viability was investigated in vitro and on tumour growth in vivo.ResultsIn the present study, we show that EDI3 expression is highest in ER-HER2 + human breast tumours, and both expression and activity were also highest in ER-HER2 + breast cancer cell lines. Silencing HER2 using siRNA, as well as inhibiting HER2 signalling with lapatinib decreased EDI3 expression. Pathways downstream of PI3K/Akt/mTOR and GSK3β, and transcription factors, including HIF1α, CREB and STAT3 were identified as relevant in regulating EDI3 expression. Silencing EDI3 preferentially decreased cell viability in the ER-HER2 + cells. Furthermore, silencing or pharmacologically inhibiting EDI3 using dipyridamole in ER-HER2 + cells resistant to HER2-targeted therapy decreased cell viability in vitro and tumour growth in vivo.ConclusionsOur results indicate that EDI3 may be a potential novel therapeutic target in patients with HER2-targeted therapy-resistant ER-HER2 + breast cancer that should be further explored.

Structure-Guided Strategies of Targeted Therapies for Patients with EGFR-Mutant Non-Small Cell Lung Cancer.

Oncogenic mutations within the EGFR kinase domain are well-established driver mutations in non-small cell lung cancer (NSCLC). Small-molecule tyrosine kinase inhibitors (TKIs) specifically targeting these mutations have improved treatment outcomes for patients with this subtype of NSCLC. The selectivity of these targeted agents is based on the location of the mutations within the exons of the EGFR gene, and grouping mutations based on structural similarities has proved a useful tool for conceptualizing the heterogeneity of TKI response. Structure-based analysis of EGFR mutations has influenced TKI development, and improved structural understanding will inform continued therapeutic development and further improve patient outcomes. In this review, we summarize recent progress on targeted therapy strategies for patients with EGFR-mutant NSCLC based on structure and function analysis.

Oral Squamous Cell Carcinoma Cells with Acquired Resistance to Erlotinib Are Sensitive to Anti-Cancer Effect of Quercetin via Pyruvate Kinase M2 (PKM2).

Oral squamous cell carcinoma (OSCC) frequently carries high epidermal growth factor receptor (EGFR) expression. Erlotinib, a small molecule tyrosine kinase inhibitor (TKI), is an effective inhibitor of EGFR activity; however, resistance to this drug can occur, limiting therapeutic outcomes. Therefore, in the current study, we aimed to unveil key intracellular molecules and adjuvant reagents to overcome erlotinib resistance. First, two HSC-3-derived erlotinib-resistant cell lines, ERL-R5 and ERL-R10, were established; both exhibited relatively higher growth rates, glucose utilization, epithelial-mesenchymal transition (EMT), and invasiveness compared with parental cells. Cancer aggressiveness-related proteins, such as N-cadherin, Vimentin, Twist, MMP-2, MMP-9, and MMP-13, and the glycolytic enzymes PKM2 and GLUT1 were upregulated in ERL-R cells. Notably, ERL-R cells were sensitive to quercetin, a naturally-existing flavonol phytochemical with anti-cancer properties against various cancer cells. At a concentration of 5 μM, quercetin effectively arrested cell growth, reduced glucose utilization, and inhibited cellular invasiveness. An ERL-R5-derived xenograft mouse model confirmed the growth-inhibitory efficacy of quercetin. Additionally, knock-down of PKM2 by siRNA mimicked the effect of quercetin and re-sensitized ERL-R cells to erlotinib. Furthermore, adding quercetin blocked the development of erlotinib-mediated resistance by enhancing apoptosis. In conclusion, our data support the application of quercetin in anti-erlotinib-resistant OSCC and indicate that PKM2 is a determinant factor in erlotinib resistance and quercetin sensitivity.

Efficacy and safety of apatinib in patients with recurrent uterine malignancy: a prospective, single-center, single-arm, phase 2 study.

Apatinib, a small-molecule tyrosine kinase inhibitor that selectively targets vascular endothelial growth factor receptor-2, has clinical activity in recurrent/advanced gynecological cancers. However, its efficacy in uterine malignancy remains unclear. This study aimed to determine the efficacy and safety of single-agent apatinib in patients with recurrent uterine malignancy. This is a prospective single-center, single-arm, phase 2 study that enrolled patients aged 18-70 years with histopathologically confirmed recurrent endometrial cancer (EC) and recurrent uterine sarcoma (US), received at least 2 chemotherapy regimens, and an Eastern Cooperative Group performance status of 0-1. Apatinib (500 mg) was administered orally once daily. A treatment cycle was defined as 4 weeks. The patients were followed up every 2 cycles for tumor radiological assessment until disease progression. The primary endpoint was the overall response rate (ORR). The secondary endpoints were progression-free survival (PFS) and overall survival (OS). Adverse events (AEs) were recorded throughout the treatment and within 30 days of the last study treatment and graded as per the National Cancer Institute Common Toxicity Criteria Version 4.0. A total of 33 patients (22 with EC and 11 with US) were enrolled between October 2018 and April 2021. Median follow-up duration was 11.7 months (interquartile range: 6.8-32.5 months). The patients received apatinib for a median of 4.79 cycles (range 2-13 cycles). In the EC and US cohorts, the ORRs were 27.2% [95% confidence interval (CI), 10.7% to 50.2%] and 9.1% (95% CI, 0.2% to 41.3%), the median PFS were 4.4 months (95% CI, 4.2 to 6.7 months) and 7.0 months (95% CI, 3.2 to 11.6 months), and the median OS were 11.7 months (95% CI, 6.8 months to not reached) and 18.1 months (95% CI, 9.2 months to not reached), respectively. The most common treatment-related AEs of all grades were hypertension (36.4%), proteinuria (33.3%), and hand-foot syndrome (30.3%). No treatment-related serious AEs or deaths occurred. To our knowledge, this is the first prospective study assessing the efficacy and safety of apatinib in patients with uterine malignancy. The results suggested that apatinib might be a potential treatment option for these patients.

Targeting the EGF receptor family in non-small cell lung cancer—increased complexity and future perspectives

Lung cancer remains the leading cause of cancer-associated mortality worldwide, but with the emergence of oncogene targeted therapies, treatment options have tremendously improved. Owing to their biological relevance, members of the ERBB receptor family, including the EGF receptor (EGFR), HER2, HER3 and HER4, are among the best studied oncogenic drivers. Activating EGFR mutations are frequently observed in non-small cell lung cancer (NSCLC), and small molecule tyrosine kinase inhibitors (TKIs) are the established first line treatment option for patients whose tumors bear "typical/classical" EGFR mutations (exon 19 deletions, L858R point mutations). Additionally, new TKIs are rapidly evolving with better efficacy to overcome primary and secondary treatment resistance (e.g., that due to T790M or C797S resistance mutations). Some atypical EGFR mutations, such as the most frequent exon 20 insertions, exhibit relative resistance to earlier generation TKIs through steric hindrance. In this subgroup, newer TKIs, such as mobocertinib and the bi-specific antibody amivantamab have recently been approved, whereas less frequent atypical EGFR mutations remain understudied. In contrast to EGFR, HER2 has long remained a challenging target, but better structural understanding has led to the development of newer generations of TKIs. The recent FDA approval of the antibody-drug conjugate trastuzumab-deruxtecan for pretreated patients with HER2 mutant NSCLC has been an important therapeutic breakthrough. HER3 and HER4 also exert oncogenic potential, and targeted treatment approaches are being developed, particularly for HER3. Overall, strategies to inhibit the oncogenic function of ERBB receptors in NSCLC are currently evolving at an unprecedented pace; therefore, this review summarizes current treatment standards and discusses the outlook for future developments.

Tyrosine kinase inhibitor-loaded biomimetic nanoparticles as a treatment for osteosarcoma

Small-molecule tyrosine kinase inhibitors (TKIs) represent a potentially powerful approach to the treatment of osteosarcoma (OS). However, dose-limiting toxicity, therapeutic efficacy, and targeting specificity are significant barriers to the use of TKIs in the clinic. Notably among TKIs, ponatinib demonstrated potent anti-tumor activity; however, it received an FDA black box warning for potential side effects. We propose ponatinib-loaded biomimetic nanoparticles (NPs) to repurpose ponatinib as an efficient therapeutic option for OS. In this study, we demonstrate enhanced targeting ability and maintain potent ponatinib nano-therapeutic activity, while also reducing toxicity. In in vitro two- and three-dimensional models, we demonstrate that ponatinib-loaded biomimetic NPs maintain the efficacy of the free drug, while in vivo we show that they can improve tumor targeting, slow tumor growth, and reduce evidence of systemic toxicities. Though there is limited Pon encapsulation within NPs, this platform may improve current therapeutic approaches and reduce dosage-related side effects to achieve better clinical outcomes in OS patients.Graphical

Elvn-001, a Next Generation ATP-Competitive ABL1 Tyrosine Kinase Inhibitor for the Treatment of Chronic Myeloid Leukemia

Of the six small-molecule ABL1 tyrosine kinase inhibitors (TKIs) that have received FDA-approval for the treatment of BCR-ABL1-driven Chronic Myeloid Leukemia (CML), five (Imatinib, Nilotinib, Dasatinib, Ponatinib, Bosutinib) target the ATP-binding site in the kinase domain. While each of these TKIs provides added value to the arsenal of treatments for CML, these agents suffer from selectivity issues, inhibiting a number of off-target kinases that drive an array of dose-limiting toxicities (DLTs) which constrain their ability to fully engage ABL1 and drive maximal efficacy. In addition, the emergence of on-target resistance against these TKIs, such as the highly prevalent T315I mutation at the gatekeeper position of the active site, is common and represents a significant clinical challenge. The recently approved ABL1 TKI Asciminib is an allosteric inhibitor that interacts with the unique myristoyl binding pocket of ABL1 and therefore possesses high kinome selectivity and an improved tolerability profile. Despite its unique binding mode, clinical activity against the T315I mutant requires a dose five times higher than that approved for the broader third-line or greater patient population, which leads to issues with tolerance. In addition, emergent on-target resistance remains a challenge, particularly with respect to mutations within the myristoyl pocket as well as select active site mutants. Here we report the discovery of ELVN-001, a potent ATP-competitive small-molecule ABL1 TKI which, unlike the majority of currently approved ABL1 TKIs, is highly selective in both biochemical and cell-based assays versus the kinome in general as well as the key off-target kinases KDR, c-KIT, PDGFR and SRC, which are associated with a variety of DLTs including myelosuppression, edema, pleural effusions, hypertension, and certain cardiovascular events. ELVN-001 exhibited potent pharmacodynamic (phosphorylated CRKL) and anti-proliferative activity in vitro against BCR-ABL1-driven CML cell lines with comparable or superior activity to the approved therapies. Evaluation of ELVN-001 against Ba/F3 cell lines expressing a panel of clinically relevant BCR-ABL1 TKI-resistant mutants demonstrated activity of ELVN-001 against many of these mutants, including T315I as well as two myristoyl pocket mutants (A334P, P465S) which are highly resistant to asciminib. Cell-based mutagenesis screens using Ba/F3 BCR-ABL1 cells confirmed a concentration-dependent reduction in outgrowth of resistant clones, which generally narrowed to a select subset of P-loop mutations. Consistent with previously reported findings for ponatinib, while ELVN-001 showed little to no activity against cells expressing a subset of T315I-inclusive BCR-ABL1 compound mutants, the addition of Asciminib resulted in varying degrees of re-sensitizing these mutants to ELVN-001. Importantly, ELVN-001 possessed a favorable absorption, distribution, metabolism, elimination, and toxicity profile, as determined from both in vitro and in vivo studies, that readily translated into favorable pharmacokinetic properties in all preclinical species evaluated. Accordingly, administration of doses of ELVN-001 corresponding to well-tolerated free drug exposures in rats and non-human primates readily translated to mouse in vivo tumor xenograft models of efficacy, including a model of T315I CML. These anti-tumor activities also compared favorably to currently approved therapies when evaluated head-to-head in these studies. Together, these findings support ELVN-001 as an extremely selective, novel ATP-competitive inhibitor of ABL1 kinase with superior pharmacokinetic and tolerability properties compared to currently approved TKIs and which retains activity against T315I and other key on-target resistance mutations, warranting its further investigation in patients with TKI-resistant/intolerant CML.

CTIM-04. PHASE I STUDY OF IBRUTINIB WITH RADIATION AND TEMOZOLOMIDE IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA

Abstract BACKGROUND Glioblastoma is associated with dismal outcomes with a survival of 15-18 months. A major challenge in glioblastoma is the inability to effectively target glioma stem cells (GSCs) that have the capacity for self-renewal. GSCs are resistant to radiation and traditional chemotherapy agents. Ibrutinib is a first-in-class, potent, small-molecule tyrosine kinase inhibitor of Bruton’s Tyrosine Kinase (BTK) and Bone marrow X-linked (BMX). BMX nonreceptor tyrosine kinase activates STAT3 signaling to maintain self-renewal and tumorigenic potential of GSCs. Hence a combination of ibrutinib with radiation and temozolomide in Glioblastoma is a promising approach. METHODS Unmethylated MGMT GBM patients received ibrutinib daily with 60 Gy radiation over 6 weeks (Arm 1). MGMT methylated patients received Temozolomide at 75 mg/m2 in addition to Ibrutinib and radiation (Arm 2). Starting dose of Ibrutinib (level 1) was 420 mg daily, level 2 dose was 560 mg daily and dose level -1 was 280 mg. Patients received adjuvant Ibrutinib (Arm 1) and ibrutinib and temozolomide (Arm 2). The primary endpoint included the maximum tolerated dose (MTD) of Ibrutinib with radiation (Arm 1), and ibrutinib, radiation, and temozolomide (Arm 2). Progression-free survival and overall survival are secondary endpoints. RESULTS 27 patients (15 males, 12 females), with a median age of 63 years (range, 34-77 years) were treated on two arms. Dose Limiting toxicity (DLT) in Arm 1 included grade 3 weakness, grade 4 transaminases, and grade 4 neutropenia. DLT in Arm 2 included grade 3 rash, grade 3 transaminases, grade 4 neutropenia, and thrombocytopenia. Ibrutinib was too toxic with radiation in Arm 1, MTD of 420 mg ibrutinib was confirmed in Arm 2. CONCLUSION MTD of Ibrutinib is 420 mg daily with Temozolomide and radiation. Efficacy outcomes (PFS and OS) will be presented.

Formulation development, optimization and characterization of Pemigatinib-loaded supersaturable self-nanoemulsifying drug delivery systems

BackgroundPemigatinib is a small molecule tyrosine kinase inhibitor of fibroblast growth factor receptor inhibitors. The oral bioavailability of Pemigatinib is constricted due to its limited solubility at physiological pH. It is essential to develop a novel formulation of Pemigatinib to improve the intrinsic solubility and to reduce the pharmacokinetic variability. Self-nanoemulsifying drug delivery system is an effective, smart and more adequate formulation approach for poorly soluble drugs. Different from conventional self-nanoemulsifying drug delivery system, a supersaturable self-nanoemulsifying drug delivery system of Pemigatinib was prepared by using a supersaturation promoter.ResultsAmong all the oils, Captex® 300 have shown maximum solubility of Pemigatinib. Considering the solubilization potential and emulsification ability Kolliphor®RH 40 was selected as surfactant. Transcutol®HP was selected as co-surfactant. The composition of oil, surfactant and co-surfactant was identified using phase diagrams and further adjusted by simplex-lattice design. HPMC K4M as precipitation inhibitor at 5% concentration resulted in effective supersaturating with increased self-emulsification time. The droplet of sSNEDDS ranges from 166.78 ± 3.14 to 178.86 ± 1.24 nm with PDI 0.212 – 0.256, which is significantly smaller than that observed with plain SNEDDS. TEM images revealed the spherical shape of the nanodroplets. The final optimized formulation formed spontaneous nanoemulsion within 15 secs when added to physiological fluids. The percent transmittance of the diluted formulation was found to be 99.12 ± 0.46. The viscosity was found to be 574 ± 26 centipoises indicating the good flow ability. FTIR and DSC studies indicated the amorphization of the drug. The dissolution profile of sSNEDDS indicated the faster release of drug compared to both pure drug suspension and SNEDDS formulation. The drug release rate is directly proportional to the concentration of the drug. The drug release from the insoluble matrix is a square root of time-dependent Fickian diffusion process. The formulation was found to be stable and transparent at all pH values and the percent transmittance was more than 95%. Any kind of separation or precipitation was not observed at different temperatures cycles. No significant difference was observed with all the samples exposed at different storage conditions.ConclusionsThis study demonstrated the feasibility of stabilizing and improving the in-vitro performance of self-nanoemulsifying drug delivery systems of Pemigatinib by incorporating HPMC K4M as precipitation inhibitor.

Pharmacokinetics of the Multi-kinase Inhibitor Pexidartinib: Mass Balance and Dose Proportionality.

Pexidartinib is an oral small-molecule tyrosine kinase inhibitor that selectively targets colony-stimulating factor 1 receptor. Two phase 1 single-center trials were conducted in healthy subjects to determine the absorption, distribution, metabolism, and excretion of pexidartinib using radiolabeled drug and to assess the dose proportionality of pexidartinib following single oral doses. In the mass balance study, eight male subjects received a single oral dose of [14 C]-pexidartinib 400mg with radioactivity assessed in plasma, urine, and feces samples taken at various timepoints postdose. In the dose-proportionality study, 18 subjects received single doses of pexidartinib 200, 400, and 600mg using randomization sequences. Peak pexidartinib and total radioactivity were observed at 1.75-2.0hours after the oral dose and then declined in a multiphasic manner. The overall mean recovery of administered radioactivity was 92.2% over 240hours with 64.8% in the feces and 27.4% in the urine. Major components detected in plasma were pexidartinib and glucuronide (M5, ZAAD-1006a), with M5 and pexidartinib detected in urine and feces, respectively. A glucuronide of dealkylated form (M1) in the urine and multiple oxidized forms (M2, M3, and M4) in feces were detected. The dose-proportionality study found dose-proportional drug exposure between the 200- and 400-mg doses and slightly less than proportional exposure between the 400- and 600-mg doses. These results from these studies provide insight into pexidartinib disposition after oral administration and support the development of dosing guidance in subjects with renal or hepatic impairment or subjects taking cytochrome P450 3A and uridine disphosphate-glucuronosyl transferase inhibitors and inducers.

Molecular mechanism of VEGF and its role in pathological angiogenesis.

Over the last seven decades, a significant scientific contribution took place in the delineation of the implications of vascular endothelial-derived growth factor (VEGF) in the processes of angiogenesis. Under pathological conditions, mainly in response to hypoxia or ischemia, elevated VEGF levels promote vascular damage and the growth of abnormal blood vessels. Indeed, the development of VEGF biology has revolutionized our understanding of its role in pathological conditions. Hence, targeting VEGF or VEGF-mediated molecular pathways could be an excellent therapeutic strategy for managing cancers and intraocular neovascular disorders. Although anti-VEGF therapies, such as monoclonal antibodiesand small-molecule tyrosine kinase inhibitors, have limited clinical efficacy, they can still significantly improve the overall survival rate. This thus demands further investigation through the development of alternative strategies in the management of VEGF-mediated pathological angiogenesis. This review article focuses on the recent developments towardthe delineation of the functional biology of VEGF and the role of anti-VEGF strategies in the management of tumor and eye pathologies. Moreover, therapeutic angiogenesis, an exciting frontier for the treatment of ischemic disorders, is highlighted in this review, including wound healing.

Strategies for the treatment of HER2+ advanced breast cancer based on clinical practice in Chinese patients: a roundtable discussion.

Human epithelial growth factor receptor 2-positive (HER2+) breast cancer is easy to relapse and metastasize in the early stage, and usually has more aggressive clinical behavior and worse patient survival outcomes as compared with estrogen receptor-positive (ER+), HER2-negative (HER2-) breast cancer. The HER2+ breast cancer has been significantly enhanced by trastuzumab and other multiple novel HER2 anti-tumor drugs. The dual combination regimen of trastuzumab + pertuzumab has been established as the standard first-line therapy for advanced HER2+ patients, and pyrotinib with capecitabine is the preferred second-line treatment in Chinese patients. However, no third- or later-line regimens are currently recommended, and thus, the treatment needs of these patients remain unmet. Margetuximab is a human/mouse chimeric anti-HER2 immunoglobulin G1 (IgG1) monoclonal antibody (mAb) based on the murine precursor of trastuzumab, has shown greater efficacy than trastuzumab in terms of its natural killer (NK) cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) effect and may become the preferred solution for HER2+ metastatic breast cancer (mBC) following progression on second-line therapy with small molecule tyrosine kinase inhibitors (TKIs). This paper explores discussion of therapeutic strategies of anti-HER2 drugs based on Chinese clinical practice, and summarizes the consensus and controversy in the post-anti-HER2 TKIs guideline recommendations, so as to provide certain guidance to HER2+ mBC patients pretreated with TKIs in the third or later lines.

63 (PB053) - Exposure-response relation in metastatic colorectal cancer organoids after high-dose short-term tyrosine kinase inhibitor exposure

A better understanding of the molecular basis of metastatic colorectal cancer (mCRC), has led to interest in small molecule tyrosine kinase inhibitors (TKIs) as its treatment option. However, most of the TKIs tested for mCRC in their standard dosing regimen, fail in early-phase clinical trials due to lack of efficacy or excessive toxicity. TKIs are known to have a broader kinase inhibitory potency at higher concentrations. Optimizing TKI dosing regimens aims at improved antitumor efficacy with acceptable toxicity.

Successes and failures of angiogenesis blockade in gastric and gastro-esophageal junction adenocarcinoma.

Gastric and gastro-esophageal junction adenocarcinoma (GEA) remains a considerable major public health problem worldwide, being the fifth most common cancer with a fatality-to-case ratio that stands still at 70%. Angiogenesis, which is a well-established cancer hallmark, exerts a fundamental role in cancer initiation and progression and its targeting has been actively pursued as a promising therapeutic strategy in GEA. A wealth of clinical trials has been conducted, investigating anti-angiogenic agents including VEGF-directed monoclonal antibodies, small molecules tyrosine kinase inhibitors and VEGF-Trap agents both in the resectable and advanced setting, reporting controversial results. While phase III randomized trials testing the anti-VEGFR-2 antibody Ramucirumab and the selective VEGFR-2 tyrosine kinase inhibitor Apatinib demonstrated a significant survival benefit in later lines, the shift of angiogenesis inhibitors in the perioperative and first-line setting failed to improve patients’ outcome in GEAs. The molecular landscape of disease, together with novel combinatorial strategies and biomarker-selected approaches are under investigation as key elements to the success of angiogenesis blockade in GEA. In this article, we critically review the existing literature on the biological rationale and clinical development of antiangiogenic agents in GEA, discussing major achievements, limitations and future developments, aiming at fully realizing the potential of this therapeutic approach.

Apatinib plus vinorelbine versus vinorelbine for metastatic triple-negative breast cancer who failed first/second-line treatment: the NAN trial

While therapies such as chemotherapy combined with immunotherapy, sacituzumab govitecan, and PARP inhibitors are available for metastatic TNBC, on disease progression after these therapies, the mainstay of therapy is chemotherapy. Apatinib is a small-molecule tyrosine kinase inhibitor that has promising anti-angiogenesis and antitumor activity for TNBC. We aimed to evaluate the safety and efficacy of adding apatinib to chemotherapy in patients with advanced TNBC with failed first/second-line treatment. A total of 66 patients were randomly assigned, in a 1:1 ratio, to receive vinorelbine or vinorelbine with apatinib in 28-day cycles. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), overall response rate (ORR) and safety. 33 received apatinib plus vinorelbine and 32 received vinorelbine (1 was withdrawal). Median PFS was significantly longer in the apatinib plus vinorelbine group than in the vinorelbine group (3.9 months vs. 2.0 months; hazard ratio, 1.82; 95% confidence interval [CI], 1.06 to 3.11; P = 0.026). Median OS was 11.5 months with apatinib plus vinorelbine and 9.9 months with vinorelbine (HR,1.01; 95% CI, 0.51 to 1.97; P = 0.985). The ORR was 9.1% in the apatinib plus vinorelbine group and 6.3% in the vinorelbine group (P = 0.667). The most common treatment-related hematologic grade 3–4 adverse events in apatinib plus vinorelbine group, were leukopenia, granulocytopenia, anemia, and thrombocytopenia. no treatment-related nonhematologic grade 4 adverse events or treatment-related deaths were observed. Collectively, adding apatinib to vinorelbine shows a promising benefit in PFS compared to vinorelbine monotherapy, with an excellent toxicity profile, warranting further exploration.

1250P Camrelizumab plus apatinib combined with POF in patients with untreated advanced gastric cancer (UAGC): A single-center, open-label, single-arm, phase II trial (SYLT-017)

Previous reports of POF demonstrated promising efficacy for patients with AGC (ASCO-GI 2019). Apatinib, a small molecule tyrosine kinase inhibitor, can be safely administered up to 850 mg daily combined with POF in AGC (ESMO 2019). The PD-1 inhibitor nivolumab provided superior OS, along with PFS benefit, in combination with chemotherapy in UAGC in the CheckMate-649 study. Camrelizumab, in combination with apatinib, has been demonstrated clinical benefits in multiple advanced solid tumors. On the basis of these results, we conducted this trial to evaluate the safety and efficacy of first-line camrelizumab plus apatinib combined with POF in patients with UAGC.

Cytochromes P450 2C8 and 3A Catalyze the Metabolic Activation of the Tyrosine Kinase Inhibitor Masitinib.

Masitinib is a small molecule tyrosine kinase inhibitor under investigation for the treatment of amyotrophic lateral sclerosis, mastocytosis, and COVID-19. Hepatotoxicity has been reported in some patients while taking masitinib. The liver injury is thought to involve hepatic metabolism of masitinib by cytochrome P450 (P450) enzymes to form chemically reactive, potentially toxic metabolites. The goal of the current investigation was to determine the P450 enzymes involved in the metabolic activation of masitinib in vitro. In initial studies, masitinib (30 μM) was incubated with pooled human liver microsomes in the presence of NADPH and potassium cyanide to trap reactive iminium ion metabolites as cyano adducts. Masitinib metabolites and cyano adducts were analyzed using reversed-phase liquid chromatography-tandem mass spectrometry. The primary active metabolite, N-desmethyl masitinib (M485), and several oxygenated metabolites were detected along with four reactive metabolite cyano adducts (MCN510, MCN524, MCN526, and MCN538). To determine which P450 enzymes were involved in metabolite formation, reaction phenotyping experiments were conducted by incubation of masitinib (2 μM) with a panel of recombinant human P450 enzymes and by incubation of masitinib with human liver microsomes in the presence of P450-selective chemical inhibitors. In addition, enzyme kinetic assays were conducted to determine the relative kinetic parameters (apparent Km and Vmax) of masitinib metabolism and cyano adduct formation. Integrated analysis of the results from these experiments indicates that masitinib metabolic activation is catalyzed primarily by P450 3A4 and 2C8, with minor contributions from P450 3A5 and 2D6. These findings provide further insight into the pathways involved in the generation of reactive, potentially toxic metabolites of masitinib. Future studies are needed to evaluate the impact of masitinib metabolism on the toxicity of the drug in vivo.