Addition Of Pazopanib Research Articles

Outcomes After Preoperative Chemoradiation With or Without Pazopanib in Non-Rhabdomyosarcoma Soft Tissue Sarcoma: A Report From Children's Oncology Group and NRG Oncology.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.ARST1321 was a phase II study designed to compare the near complete pathologic response rate after preoperative chemoradiation with/without pazopanib in children and adults with intermediate-/high-risk chemotherapy-sensitive body wall/extremity non-Rhabdomyosarcoma Soft Tissue Sarcoma (ClinicalTrials.gov identifier: NCT02180867). Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary aim of the study, the outcome data for this cohort were analyzed. Eight-five eligible patients were randomly assigned to receive (regimen A) or not receive (regimen B) pazopanib in combination with ifosfamide and doxorubicin + preoperative radiotherapy followed by primary resection at week 13 and then further chemotherapy at week 25. As of December 31, 2021, at a median survivor follow-up of 3.3 years (range, 0.1-5.8 years), the 3-year event-free survival for all patients in the intent-to-treat analysis was 52.5% (95% CI, 34.8 to 70.2) for regimen A and 50.6% (95% CI, 32 to 69.2) for regimen B (P = .8677, log-rank test); the 3-year overall survival was 75.7% (95% CI, 59.7 to 91.7) for regimen A and 65.4% (95% CI, 48.1 to 82.7) for regimen B (P = .1919, log-rank test). Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib, outcomes were not statistically significantly different between the two regimens.

Abstract PS2-19: Circulating tumor cell (CTC) enumeration in a phase II trial of pazopanib in addition to endocrine therapy in patients with hormone resistant advanced breast cancer (ABC)

Abstract Background: CTCs are detectable in approximately 50% of pts with metastatic breast cancer, and elevated CTC levels are an independent negative prognostic factor. CTCs have been shown to play a valuable role in predicting outcomes in pts with ABC treated with chemotherapy or endocrine therapy. This phase II trial was conducted to evaluate the clinical benefit (CB) of pazopanib, a VEGF receptor tyrosine kinase inhibitor (TKI) combined with nonsteroidal aromatase inhibitors (NSAIs) in pts with ABC resistant to NSAIs. As an exploratory analysis, we hypothesized that CTC levels might be correlated with response to pazopanib plus endocrine therapy. Methods: Eligibility included postmenopausal women with hormone receptor positive (HR+) ABC and progressive disease after at least one month of NSAIs. Treatment was pazopanib 800 mg/day plus either letrozole or anastrozole. The primary endpoint was clinical benefit rate at 12 weeks (CBR12, wks). Secondary endpoints included progression free survival (PFS), safety, and the impact of pazopanib and NSAI on CTCs. A CBR of 20% was considered a clinically meaningful comparison to the expected CBR of <5% with continued NSAIs after PD. Blood samples were collected for CTC analysis at baseline, then every 4 wks while on treatment. The presence of CTCs was assessed using the FDA-cleared CellSearch System; CTCs were defined as EPCAM-positive, CD45-negative nucleated cells. Samples with 5 CTCs per 7.5 mLs of blood were considered CTC-positive. Results: 32 pts were enrolled; 28 are evaluable for study endpoints. The median age was 58 years (range: 41-77). Pts were heavily pre-treated, with a median of 2 prior hormone therapies (range 1-6) and 1 prior chemotherapy (range 0-8). 8 pts (28.6%) stopped treatment due to adverse events, and 6 pts progressed before wk 12. CBR12 was 46.4% (12 SD, 1 PR), and CBR24 was 25% (5 SD, 2 PR). Safety has been presented (ASCO 2020). Median PFS was 20 wks, and median PFS for pts with CBR12 was 24 wks. Five (22%) of 23 pts with CTC data were CTC-positive (5 CTC/7.5 mL). There was no significant association between CBR12 and CTC status at baseline, or between CBR12 and change in CTC status (baseline to 4 wks after initiation of treatment). 7 pts had non-CBR12 and CTC data; 4 pts (n=4/7; 57%) were CTC positive at either baseline, week 4 or both. 11 pts had CBR12 and CTC data; all patients were CTC negative at baseline and remained negative at 4 wks. 7 pts had PFS >6 months (24, 32, 36, 36, 48, 184 and 274 wks), and 6 had CTC data: all were CTC-negative at baseline and 4 wks, then remained negative at 12 wks. Based on baseline values only, CTC-positive pts had a shorter median PFS compared to CTC-negative pts, but the difference was not statistically significant (11 wks vs 14 wks, p=0.18). Persistently CTC negative patients had significantly longer PFS compared to patients who were CTC positive at any time during study treatment (36 wks vs 11 wks, p=0.01). Conclusions: The addition of pazopanib to NSAIs resulted in a CBR12 of 46.4%, and a CBR24 of 25% in pts with heavily pre-treated ABC resistant to NSAIs. These results support clinical efficacy of antiangiogenic TKI in HR+ ABC and suggest benefit in hormone resistant disease. Consistently negative CTCs correlated with response and response duration. PFS was significantly longer in patients who were consistently CTC negative, further defining the prognostic role of CTCs in HR+ ABC. (NCT01466972) Citation Format: Ozge Gumusay, Mark Jesus M. Magbanua, Melanie C. Majure, Travis Deal, Jonathan R. Renslo, Chiara A. Wabl, Michelle E. Melisko, A. Jo Chien, Andrei Goga, Mark M. Moasser, John W. Park, Jimmy Hwang, Hope S. Rugo. Circulating tumor cell (CTC) enumeration in a phase II trial of pazopanib in addition to endocrine therapy in patients with hormone resistant advanced breast cancer (ABC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-19.

Pazopanib (PZ) plus endocrine therapy as treatment for hormone resistant advanced breast cancer (ABC).

1068 Background: A major limitation of endocrine therapy in hormone receptor positive (HR+) ABC is the development of resistance. Preclinical data suggests that higher levels of vascular endothelial growth factor (VEGF) are associated with endocrine therapy resistance. We conducted a phase II trial to evaluate the clinical benefit (CB) of PZ, a VEGF receptor tyrosine kinase inhibitor (TKI) combined with nonsteroidal aromatase inhibitors (NSAIs) in pts with ABC resistant to NSAIs. Methods: Eligibility included postmenopausal women with HR+ ABC and progressive disease (PD) after at least one month of NSAIs. Treatment was PZ 800 mg/day plus either letrozole or anastrozole. The primary endpoint was clinical benefit rate at 12 weeks (CBR12, wks). Secondary endpoints were PFS and safety. A CBR of 20% was considered a clinically meaningful comparison to the expected CBR of < 5% with continued NSAIs after PD. Using a 2-stage design, stable disease in at least 1 of the first 13 pts allowed continued enrollment to a planned 28. Results: 32 pts were enrolled; 28 are evaluable for study endpoints and all patients completed the study. The median age was 58 years (range: 41-77). Pts were heavily pre-treated, with a median of 2 prior hormone therapies (range 1-6) and 1 prior chemotherapy (range 0-8). 8 pts (28.6%) stopped treatment due to adverse events (AE) including hypertension (HTN), fever, transaminitis, nausea, vomiting, rash, hand foot syndrome and pulmonary embolism (PE); 6 pts progressed before wk 12. CBR12 was 46.4% (12 SD, 1 PR); CBR24 was 25% (5 SD, 2 PR). Median PFS was 20 wks (95% CI 11-48, and median PFS for pts with CBR12 was 24 wks. 7 pts had PFS > 6 months (24, 32, 36, 36, 48, 184 and 274 wks); 2 pts had PFS > 3 years (184 and 274 weeks). The most common grade 1/2 AE were nausea (48.2%), fatigue (33.3%), diarrhea (29.6%), back pain (22.2%), and arthralgias (22.2%). Grade 3/4 AEs included HTN (3/28; 11.1), transaminitis (3/28; 11.1%), headache (2/28; 7.4), heart failure, vertigo, nausea, oral pain, vomiting, fever, fatigue, and hypokalemia (one patient each: 3.7%). Conclusions: The addition of PZ to NSAIs resulted in a CBR12 of 46.4%, and a CBR24 of 25% in pts with heavily pre-treated ABC resistant to NSAIs. These results support clinical efficacy of antiangiogenic TKI in HR+ ABC, and suggest benefit in hormone resistant disease. Expected toxicities resulted in early discontinuation in 28.6%, which limited drug exposure. Clinical trial information: NCT 01466972 .

CD31 Expression Determines Redox Status and Chemoresistance in Human Angiosarcomas.

Purpose: Angiosarcomas are soft tissue sarcomas with endothelial differentiation and vasoformative capacity. Most angiosarcomas show strong constitutive expression of the endothelial adhesion receptor CD31/PECAM-1 pointing to an important role of this molecule. However, the biological function of CD31 in angiosarcomas is unknown.Experimental Design: The expression levels of CD31 in angiosarcoma cells and its effects on cell viability, colony formation, and chemoresistance were evaluated in human angiosarcoma clinical samples and in cell lines through isolation of CD31high and CD31low cell subsets. The redox-regulatory CD31 function linked to YAP signaling was determined using a CD31-blocking antibody and siRNA approach and was further validated in CD31-knockout endothelial cells.Results: We found that most angiosarcomas contain a small CD31low cell population. CD31low cells had lost part of their endothelial properties and were more tumorigenic and chemoresistant than CD31high cells due to more efficient reactive oxygen species (ROS) detoxification. Active downregulation of CD31 resulted in loss of endothelial tube formation, nuclear accumulation of YAP, and YAP-dependent induction of antioxidative enzymes. Addition of pazopanib, a known enhancer of proteasomal YAP degradation resensitized CD31low cells for doxorubicin resulting in growth suppression and induction of apoptosis.Conclusions: Human angiosarcomas contain a small aggressive CD31low population that have lost part of their endothelial differentiation programs and are more resistant against oxidative stress and DNA damage due to intensified YAP signaling. Our finding that the addition of YAP inhibitors can resensitize CD31low cells toward doxorubicin may aid in the rational development of novel combination therapies to treat angiosarcomas. Clin Cancer Res; 24(2); 460-73. ©2017 AACR.

Addition of pazopanib (PZ) to endocrine therapy in hormone resistant advanced breast cancer (ABC).

560Background: A major limitation of endocrine therapy is development of resistance in hormone receptor positive (HR+) ABC. Preclinical data suggests that higher levels of vascular endothelial grow...

Inhibition of OCT2, MATE1 and MATE2-K as a possible mechanism of drug interaction between pazopanib and cisplatin

We hypothesized that pazopanib is an inhibitor of cisplatin renal transporters OCT2, MATE1 and MATE2-K based on previous studies demonstrating an interaction between tyrosine kinase inhibitors and these transporters. Because several combinations of targeted therapies and cytotoxics are currently in development for cancer treatment, such an interaction is worth investigating. Experiments on HEK293 cells stably transfected to express OCT2, MATE1, MATE2-K or an empty vector (EV) were conducted. The inhibitory effect of pazopanib on these transporters was measured using the uptake of fluorescent substrate ASP+ and cisplatin in the different cell lines. The effect of pazopanib on cisplatin-induced cytotoxicity was also evaluated. A decrease of ASP+ uptake was observed in OCT2-HEK, MATE1-HEK and MATE2K-HEK cell lines after addition of pazopanib at increasing concentrations. Pazopanib inhibited cisplatin specific uptake in OCT2-HEK, MATE1-HEK and MATE2K-HEK lines. Cytotoxicity experiments showed that co-incubation of cisplatin with pazopanib multiplied up to 2.7, 2.4 and 1.6 times the EC50 values of cisplatin in OCT2-HEK, MATE1-HEK and MATE2K-HEK cell lines respectively, reaching about the same values as in EV-HEK cells. To conclude, pazopanib inhibits OCT2, MATE1 and MATE2-K, which are involved in cisplatin secretion into urine. The combination of these two drugs may lead to an interaction and increase the cisplatin-induced systemic toxicity. Given the wide variability of plasma pazopanib concentrations observed in vivo, the interaction may occur in a clinical setting, particularly in overexposed patients. The existence of a drug–drug interaction should be investigated when pazopanib is associated with a substrate of these transporters.