Efficacy, Safety, and Tolerability of Tivozanib in Heavily Pretreated Patients With Advanced Clear Cell Renal Cell Carcinoma.

BACKGROUND: Tivozanib has been approved as a third-line or later therapy for advanced renal cell carcinoma based on the TIVO-3 trial, which was conducted before immune checkpoint therapies (ICT), cabozantinib, and lenvatinib/everolimus became incorporated in the current sequential treatment paradigm for advanced clear cell RCC (ccRCC). METHODS: We performed a retrospective study of patients with advanced ccRCC treated with tivozanib at MD Anderson Cancer Center during 6/2021-7/2023. A blinded radiologist assessed tumor response by RECIST v1.1. We assessed overall response rate (ORR), clinical benefit rate (CBR) [percentage of all treated patients who achieved radiologic response or stable disease (SD) for ≥ 6 months], progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Of 30 analyzed patients, 23% had performance status ≥ 2; 47% had International Metastatic RCC Database Consortium (IMDC) poor-risk disease. Median number of prior therapies was 4 (range 1-8). All patients received prior ICT, 87% cabozantinib and 60% lenvatinib ± everolimus. Of 26 evaluable patients, 2 patients had confirmed partial response (ORR 7.7%); 5 patients had SD for ≥ 6 months (CBR 23.3%). Median PFS was 3.8 months (range 0.7-13.9); median OS was 14.1 months (range 0.3-28.5). Fifteen patients (50%) had ≥ 1 treatment-related adverse event (TRAE). There were 6 grade ≥ 3 TRAEs [hypertension, congestive heart failure (3), mucositis, and GI perforation (grade 5)]. CONCLUSIONS: In this cohort of heavily pretreated patients with advanced ccRCC, tivozanib yielded a modest clinical benefit in a minority of patients who received prior ICT, cabozantinib, and lenvatinib ± everolimus. TRAEs were consistent with previously published reports.

Long-Term Survival in Patients With Relapsed/Refractory Advanced Renal Cell Carcinoma Treated With Tivozanib: Analysis of the Phase III TIVO-3 Trial.

BACKGROUND: Tivozanib is an oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) with efficacy in advanced renal cell carcinoma (RCC). Long-term exploratory analyses from the TIVO-3 trial in relapsed/refractory (R/R) RCC including patients (26%) with prior immuno-oncology (IO) therapy are reported. METHODS: Patients with R/R advanced RCC that progressed with 2 or 3 prior systemic therapies (≥1 VEGFR TKI) were randomized to tivozanib 1.5 mg QD or sorafenib 400 mg BID, stratified by IMDC risk and previous therapy. Safety, investigator-assessed long-term progression-free survival (LT-PFS), and serial overall survival (OS) were assessed. RESULTS: Mean time on treatment was 11.0 months with tivozanib (n = 175) and 6.3 months with sorafenib (n = 175). Fewer grade ≥3 treatment-related adverse events occurred with tivozanib (46%) than sorafenib (55%). Dose modification rates were lower with tivozanib than sorafenib across age/prior IO subgroups; prior IO therapy did not impact dose reductions or discontinuations in either arm. Landmark LT-PFS rates were higher with tivozanib (3 years: 12.3% vs 2.4%; 4 years: 7.6% vs 0%). After 22.8 months mean follow-up, the OS HR was 0.89 (95% CI, 0.70-1.14); when conditioned on 12-month landmark PFS, tivozanib showed significant OS improvement over sorafenib (HR, 0.45; 95% CI, 0.22-0.91; 2-sided P = .0221). CONCLUSIONS: Tivozanib demonstrated a consistent safety profile and long-term survival benefit in patients with R/R advanced RCC who were alive and progression free at 12 months. These post hoc exploratory analyses of LT-PFS and conditional OS support a clinically meaningful improvement with tivozanib versus sorafenib in this advanced RCC population.

VEGF-A165a and angiopoietin-2 differently affect the barrier formed by retinal endothelial cells.

Exposure to VEGF-A165a over several days leads to a persistent dysfunction of the very tight barrier formed by immortalized endothelial cells of the bovine retina (iBREC). Elevated permeability of the barrier is indicated by low cell index values determined by electric cell-substrate impedance measurements, by lower amounts of claudin-1, and by disruption of the homogenous and continuous staining of vascular endothelial cadherin at the plasma membrane. Because of findings that suggest modulation of VEGF-A's detrimental effects on the inner blood-retina barrier by the angiogenic growth factor angiopoietin-2, we investigated in more detail in vitro whether this growth factor indeed changes the stability of the barrier formed by retinal endothelial cells or modulates effects of VEGF-A. In view of the clinical relevance of anti-VEGF therapy, we also studied whether blocking VEGF-A-driven signaling is sufficient to prevent barrier dysfunction induced by a combination of both growth factors. Although angiopoietin-2 stimulated proliferation of iBREC, the formed barrier was not weakened at a concentration of 3 nM: Cell index values remained high and expression or subcellular localization of claudin-1 and vascular endothelial cadherin, respectively, were not affected. Angiopoietin-2 enhanced the changes induced by VEGF-A165a and this was more pronounced at lower concentrations of VEGF-A165a. Specific inhibition of the VEGF receptors with tivozanib as well as interfering with binding of VEGF-A to its receptors with bevacizumab prevented the detrimental effects of the growth factors; dual binding of angiopoietin-2 and VEGF-A by faricimab was marginally more efficient. Uptake of extracellular angiopoietin-2 by iBREC can be efficiently prevented by addition of faricimab which is also internalized by the cells. Exposure of the cells to faricimab over several days stabilized their barrier, confirming that inhibition of VEGF-A signaling is not harmful to this cell type. Taken together, our results confirm the dominant role of VEGF-A165a in processes resulting in increased permeability of retinal endothelial cells in which angiopoietin-2 might play a minor modulating role.

Combination immune checkpoint and targeted protein kinase inhibitors for the treatment of renal cell carcinomas.

Kidney cancers comprise about 3% of all new malignancies in the United States. Renal cell carcinomas (RCCs) are the most common type of renal malignancy making up about 85% of kidney cancer cases. Signs and symptoms of renal cell carcinomas can result from local tumor growth, paraneoplastic syndromes, or distant metastases. The classic triad of presentation with flank pain, hematuria, and a palpable abdominal mass occurs in fewer than 10% of patients. Most diagnoses result from incidental imaging findings (ultrasonography or abdominal CT imaging) performed for another reason. Localized disease is treated by partial nephrectomy, total nephrectomy, or ablation (tumor destruction with heat or cold). When the tumors have metastasized, systemic therapy with protein-tyrosine kinase antagonists including sorafenib, sunitinib, pazopanib, and tivozanib that target vascular endothelial, platelet-derived, fibroblast, hepatocyte, and stem cell factor growth factor receptors (VEGFR, PDGFR, FGFR, MET, and Kit) were prescribed after 2005. The monoclonal antibody immune checkpoint inhibitor nivolumab (targeting programed cell death protein 1, PD1) was approved for the treatment of RCCs in 2015. It is usually used now in combination with ipilimumab (targeting CTLA-4) or cabozantinib (a multikinase blocker). Other combination therapies include pembrolizumab (targeting PD1) and axitinib (a VEGFR and PDGFR blocker) or lenvatinib (a multikinase inhibitor). Since the KEYNOTE-426 clinical trial, the use of immune checkpoint inhibitors in combination with protein-tyrosine kinase inhibitors is now the standard of care for most patients with metastatic renal cell carcinomas and monotherapies are used only in those individuals who cannot receive or tolerate immune checkpoint inhibitors.

Tivozanib-induced activation of the mitochondrial apoptotic pathway and suppression of epithelial-to-mesenchymal transition in oral squamous cell carcinoma.

The potential of tivozanib as a treatment for oral squamous cell carcinoma (OSCC) was explored in this study. We investigated the effects of tivozanib on OSCC using the Ca9-22 and CAL27 cell lines. OSCC is a highly prevalent cancer type with a significant risk of lymphatic metastasis and recurrence, which necessitates the development of innovative treatment approaches. Tivozanib, a vascular endothelial growth factor receptor inhibitor, has shown efficacy in inhibiting neovascularization in various cancer types but has not been thoroughly studied in OSCC. Our comprehensive assessment revealed that tivozanib effectively inhibited OSCC cells. This was accompanied by the suppression of Bcl-2, a reduction in matrix metalloproteinase levels, and the induction of intrinsic pathway-mediated apoptosis. Furthermore, tivozanib contributed to epithelial-to-mesenchymal transition (EMT) inhibition by increasing E-cadherin levels while decreasing N-cadherin levels. These findings highlight the substantial anticancer potential of tivozanib in OSCC and thus its promise as a therapeutic option. Beyond reducing cell viability and inducing apoptosis, the capacity of tivozanib to inhibit EMT and modulate key proteins presents the possibility of a paradigm shift in OSCC treatment.

Activity of Tivozanib in Non-clear Cell Renal Cell Carcinoma: Subgroup Analysis From a Phase II Randomized Discontinuation Trial.

BACKGROUND: Non-clear cell renal cell carcinoma (nccRCC) is a blanket term for a collection of heterogeneous and biologically diverse RCC histologies, including but not limited to papillary, chromophobe, and unclassified subtypes. Tivozanib is a selective vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) that demonstrated activity in RCC with clear cell component. The objective of this analysis was to determine the efficacy of tivozanib in histologically unclassified/mixed RCC. METHODS: We identified patients with nccRCC enrolled in Study 201 (NCT00502307) between October 2007 and July 2008. This was a phase II randomized discontinuation trial of tivozanib in patients with RCC who had no prior VEGFR-targeted treatment. Clinical outcomes including investigator-assessed objective response rate (ORR), disease control rate (DCR, defined by complete response + partial response + stable disease), and progression-free survival (PFS) were examined. RESULTS: Of the 272 patients enrolled, 46 (16.9%) patients had nccRCC: 11 (4%) papillary, 2 (0.7%) chromophobe, 2 (0.7%) collecting duct, and 31 (11.4%) mixed/unclassified. Of the 46 patients with nccRCC, 38 were continuously treated with tivozanib and the best ORR was 21.1% (confirmed) and 31.6% (confirmed and unconfirmed). The DCR was 73.7% and median PFS was 6.7 months (95% confidence interval, 125-366 days). There were no new safety signals compared to the ITT population. Limitations include the small number of individual nccRCC subtypes and the randomized discontinuation design. CONCLUSION: Tivozanib demonstrated activity and a favorable safety profile in patients with nccRCC. These data add to the body of evidence supporting the use of VEGFR-TKI in advanced nccRCC.

Tivozanib in Patients with Advanced Renal Cell Carcinoma Previously Treated With Axitinib: Subgroup Analysis from TIVO-3.

BACKGROUND: In phase III TIVO-3 trial, tivozanib improved progression-free survival (PFS) compared to sorafenib for patients with metastatic renal cell carcinoma (mRCC). However, the effectiveness of this drug after exposure to other selective VEGFR agents has not yet been defined. Herein, we characterize the clinical efficacy of tivozanib in patients with mRCC previously treated with axitinib. METHODS: We identified patients from the intention to treat (ITT) population, in the TIVO-3 trial, who received treatment with axitinib before enrolment in the study and evaluated PFS, response rate (RR), and safety. RESULTS: Out of 350 patients, 172 (83:89, tivozanib:sorafenib) had received prior treatment with axitinib in TIVO-3. In this subgroup, PFS was 5.5 months with tivozanib and 3.7 months with sorafenib (HR 0.68). RR was 13% and 8% favoring tivozanib. CONCLUSIONS: Tivozanib is active in the treatment of patients with mRCC who have progressed on prior therapies, including axitinib.

Rule of five violations among the FDA-approved small molecule protein kinase inhibitors.

Because genetic alterations including mutations, overexpression, translocations, and dysregulation of protein kinases are involved in the pathogenesis of many illnesses, this enzyme family is the target of many drug discovery programs in the pharmaceutical industry. Overall, the US FDA has approved 74 small molecule protein kinase inhibitors, nearly all of which are orally effective. Of the 74 approved drugs, thirty-nine block receptor protein-tyrosine kinases, nineteen target nonreceptor protein-tyrosine kinases, twelve are directed against protein-serine/threonine protein kinases, and four target dual specificity protein kinases. The data indicate that 65 of these medicinals are approved for the management of neoplasms (51 against solid tumors such as breast, colon, and lung cancers, eight against nonsolid tumors such as leukemia, and six against both types of tumors). Nine of the FDA-approved kinase inhibitors form covalent bonds with their target enzymes and they are accordingly classified as TCIs (targeted covalent inhibitors). Medicinal chemists have examined the physicochemical properties of drugs that are orally effective. Lipinski's rule of five (Ro5) is a computational procedure that is used to estimate solubility, membrane permeability, and pharmacological effectiveness in the drug-discovery setting. It relies on four parameters including molecular weight, number of hydrogen bond donors and acceptors, and the Log of the partition coefficient. Other important descriptors include the lipophilic efficiency, the polar surface area, and the number of rotatable bonds and aromatic rings. We tabulated these and other properties of the FDA-approved kinase inhibitors. Of the 74 approved drugs, 30 fail to comply with the rule of five.

Tivozanib in renal cell carcinoma: a systematic review of the evidence and its dissemination in the scientific literature.

BACKGROUND: Tivozanib (Fotivda) is an anti-angiogenic tyrosine kinase inhibitor that was denied access to the US market by the Food and Drug Administration (FDA). In contrast, it was granted approval by the European Medicines Agency (EMA) for the treatment of Renal Cell Carcinoma in adults. Given the conflicting decisions from these regulatory agencies, the objectives of the following study are (i) to critically review the evidence supporting the approval of tivozanib; (ii) to analyse the dissemination of this evidence in the literature by way of a citation analysis. METHODS: Pivotal trials were searched by two independent reviewers using Medline, Cochrane Library, ClinicalTrials.gov and the European Public Assessment Report. The risk of bias for each trial was then inductively assessed. Articles citing any of these trials were identified using Web of Sciences. Finally, the quality of the citations was evaluated by two independent reviewers according to standard data extraction methods. RESULTS: The search for primary evidence identified two pivotal studies: TIVO-1 upon which the FDA and the EMA decisions were based, and TIVO-3 which was conducted after the agencies' decisions had been issued. The TIVO-1 trial presented several limitations that compromised causal inference, in relation to (i) design (absence of blinding, inappropriate comparator, and one-way crossover), (ii) poor internal consistency in the results for the primary endpoint, (iii) a discrepancy between a benefit observed for progression-free survival (HR: 0.80, 95% CI [0.64-0.99]) and the absence of difference for overall survival (HR: 1.25, 95% CI [0.95 - 1.62]). Our citation search protocol identified 229 articles that cited TIVO-1 in the 7 years following its publication, among which 151 (65.9%) citing articles discussing efficacy. Presence of spin was identified in 64 (42.4%) of these 151 citing articles, and 39 (25.8%) additional articles citing results without providing enough elements to interpret the TIVO-1 results. CONCLUSION: EMA's approval was based on a single pivotal trial presenting critical limitations, rendering the results from the trial potentially inconclusive. The broad dissemination of TIVO-1 results in the scientific literature may have been affected by spin or results were presented in an inadequate critical manner.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2022 update.

Owing to the dysregulation of protein kinase activity in many diseases including cancer, this enzyme family has become one of the most important drug targets in the 21st century. There are 68 FDA-approved therapeutic agents that target about two dozen different protein kinases and six of these drugs were approved in 2021. Of the approved drugs, twelve target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), thirteen block nonreceptor protein-tyrosine kinases, and 39 target receptor protein-tyrosine kinases. The data indicate that 58 of these drugs are prescribed for the treatment of neoplasms (49 against solid tumors including breast, lung, and colon, five against nonsolid tumors such as leukemias, and four against both solid and nonsolid tumors: acalabrutinib, ibrutinib, imatinib, and midostaurin). Three drugs (baricitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases including rheumatoid arthritis. Of the 68 approved drugs, eighteen are used in the treatment of multiple diseases. The following six drugs received FDA approval in 2021 for the treatment of these specified diseases: belumosudil (graft vs. host disease), infigratinib (cholangiocarcinomas), mobocertinib and tepotinib (specific forms of non-small cell lung cancer), tivozanib (renal cell carcinoma), and trilaciclib (to decrease chemotherapy-induced myelosuppression). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and the newly approved trilaciclib. This review summarizes the physicochemical properties of all 68 FDA-approved small molecule protein kinase inhibitors including lipophilic efficiency and ligand efficiency.