A phase Ib study of GSK3052230, an FGF ligand trap in combination with pemetrexed and cisplatin in patients with malignant pleural mesothelioma.

Background Fibroblast growth factors (FGFs) have a fundamental role in cancer. Sequestering FGFs with GSK3052230 (FP-1039) blocks their ability to activate FGFRs while avoiding toxicities associated with small molecule inhibitors of FGFR, including hyperphosphatemia and retinal, nail, and skin toxicities. Methods A multicenter, open-label, phase Ib study evaluated weekly GSK3052230 added to pemetrexed/cisplatin in patients with treatment-naive, unresectable malignant pleural mesothelioma. Doses were escalated according to a 3 + 3 design, followed by cohort expansion at the maximum tolerated dose (MTD). Endpoints included safety, overall response rate, progression-free survival, and pharmacokinetics. Results 36 patients were dosed at 10, 15, and 20 mg/kg doses of GSK3052230. Three dose-limiting toxicities were observed at 20 mg/kg and one at 15 mg/kg. The MTD was defined as 15 mg/kg and used for cohort expansion. The most common treatment-related adverse events (AEs) were nausea (56%), decreased appetite (36%), infusion reactions (36%), decreased neutrophil counts (36%), and fatigue (33%). The confirmed ORR was 39% (95% CI: 23.1-56.5) (14/36 PRs) and 47% had stable disease (17/36), giving a disease control rate of 86%. At 15 mg/kg GSK3052230 (n = 25), the ORR was 44% (95% CI: 24.4-65.1), and the median PFS was 7.4 months (95% CI: 6.7-13.4). Four patients had disease control for over 1 year, and three were still ongoing. Conclusion At 15 mg/kg weekly, GSK3052230 was well tolerated in combination with pemetrexed/cisplatin and durable responses were observed. Importantly, AEs associated with small molecule inhibitors of FGFR were not observed, as predicted by the unique mechanism of action of this drug.

An open-label phase IB study to evaluate GSK3052230 in combination with paclitaxel and carboplatin, or docetaxel, in FGFR1-amplified non-small cell lung cancer.

OBJECTIVES: GSK3052230 (FP-1039) is a soluble fusion protein that acts as ligand trap sequestering fibroblast growth factors (FGFs) involved in tumor growth and angiogenesis, while sparing the hormonal FGFs. Because of this selectivity, the molecule is predicted to avoid toxicities associated with small molecule inhibitors of FGFR, including hyperphosphatemia and retinal, nail, and skin toxicities. Herein we report the results of a phase 1b study where GSK3052330 was administered with standard of care chemotherapy in FGFR1-amplified squamous non-small cell lung cancer (sqNSCLC) patients. METHODS AND METHODS: Eligible patients with stage IV or recurrent metastatic sqNSCLC harboring FGFR1 gene amplification received escalating doses of GSK3052230 in combination with paclitaxel and carboplatin at the starting doses 200 mg/m2 and AUC of 6, respectively, in the first line setting (Arm A) or docetaxel 75 mg/m2 in second line (Arm B). The primary endpoints of the study were safety and tolerability, to identify a maximum tolerated dose (MTD), and to assess overall response rate (ORR) based on investigator assessment. RESULTS: Twenty-nine patients were enrolled into the study, including 20 patients on Arm A and 9 patients on Arm B. There were no dose limiting toxicities in either Arm and the MTD was not reached. The most common adverse events (AEs) were compatible with the chemotherapy backbone used in each Arm, including neutropenia, alopecia, nausea, arthralgia, asthenia, diarrhea and peripheral neuropathy. The overall response rate and median progression-free survival were 47% and 5.5 months, respectively, for Arm A and 0% and 4.6 months, respectively, for Arm B. CONCLUSION: GSK3052230 is a novel FGFR pathway inhibitor, which is well tolerated in combination with chemotherapy. Importantly, AEs associated with small molecule inhibitors of FGFR were not observed, as predicted by the unique mechanism of action of this drug.

Pazopanib Maintenance Therapy in East Asian Women With Advanced Epithelial Ovarian Cancer: Results From AGO-OVAR16 and an East Asian Study.

OBJECTIVE: The recent phase 3 trial AGO-OVAR16 demonstrated that pazopanib maintenance improved median progression-free survival in patients with ovarian cancer whose disease did not progress during first-line treatment. However, this improvement was not seen in the subset of East Asian patients. The current analysis evaluated the efficacy and safety of pazopanib maintenance in East Asian patients from AGO-OVAR16 and a separate East Asian study. MATERIALS AND METHODS: East Asian patients from AGO-OVAR16 (n = 209) and the East Asian study (N = 145) were randomized 1:1 to receive pazopanib 800 mg/d or placebo for up to 24 months. The primary end point for each study was progression-free survival by RECIST (Response Evaluation Criteria in Solid Tumors) based on investigator assessment. Clinical and genetics data were analyzed separately by study or pooled according to separate predetermined statistical plans. RESULTS: Pazopanib maintenance had a detrimental effect on median progression-free survival versus placebo in East Asian patients from the combined studies (n = 354; 17.9 vs 21.5 months; hazard ratio, 1.114; 95% confidence interval, 0.818-1.518; P = 0.4928). Pazopanib maintenance showed a disadvantage in overall survival in East Asian patients from AGO-OVAR16 versus placebo (hazard ratio, 1.706; 95% confidence interval, 1.010-2.883; P = 0.0465); overall survival analysis was not performed in the East Asian study because of insufficient event numbers. Pazopanib-treated patients had a significantly higher incidence of grade 3 or higher hypertension (27%) and neutropenia (13%) versus placebo. CONCLUSIONS: The treatment effect of maintenance pazopanib in East Asian patients seemed to differ from that in non-Asian patients. In study-specific and pooled analyses, none of the potential factors analyzed could satisfactorily explain the different efficacy results of pazopanib in East Asian patients.

HLA-B*57:01 Confers Susceptibility to Pazopanib-Associated Liver Injury in Patients with Cancer.

PURPOSE: Pazopanib is an effective treatment for advanced renal cell carcinoma and soft-tissue sarcoma. Transaminase elevations have been commonly observed in pazopanib-treated patients. We conducted pharmacogenetic analyses to explore mechanistic insight into pazopanib-induced liver injury. EXPERIMENTAL DESIGN: The discovery analysis tested association between four-digit HLA alleles and alanine aminotransferase (ALT) elevation in pazopanib-treated patients with cancer from eight clinical trials (N = 1,188). We conducted confirmatory analysis using an independent dataset of pazopanib-treated patients from 23 additional trials (N = 1,002). Genome-wide association study (GWAS) for transaminase elevations was also conducted. RESULTS: The discovery study identified an association between HLA-B*57:01 carriage and ALT elevation [P = 5.0 × 10(-5) for maximum on-treatment ALT (MaxALT); P = 4.8 × 10(-4) for time to ALT > 3× upper limit of normal (ULN) event; P = 4.1 × 10(-5) for time to ALT > 5× ULN event] that is significant after adjustment for number of HLA alleles tested. We confirmed these associations with time to ALT elevation event (P = 8.1 × 10(-4) for ALT > 3× ULN, P = 9.8 × 10(-3) for ALT > 5× ULN) in an independent dataset. In the combined data, HLA-B*57:01 carriage was associated with ALT elevation (P = 4.3 × 10(-5) for MaxALT, P = 5.1 × 10(-6) for time to ALT > 3×ULN event, P = 5.8 × 10(-6) for time to ALT > 5× ULN event). In HLA-B*57:01 carriers and noncarriers, frequency of ALT > 3× ULN was 31% and 19%, respectively, and frequency of ALT > 5× ULN was 18% and 10%, respectively. GWAS revealed a possible borderline association, which requires further evaluation. CONCLUSIONS: These data indicate that HLA-B*57:01 carriage confers higher risk of ALT elevation in patients receiving pazopanib and provide novel insight implicating an immune-mediated mechanism for pazopanib-associated hepatotoxicity in some patients.

Progression-free survival by local investigator versus independent central review: comparative analysis of the AGO-OVAR16 Trial.

BACKGROUND: Analysis of progression-free survival (PFS) as the primary endpoint in advanced epithelial ovarian, fallopian tube, and primary peritoneal cancer (AEOC) trials may be confounded by the difficulty of radiologic evaluation of disease progression and the potential for discrepancy between investigator and blinded independent central assessments. PFS as assessed by local investigator (INV) was the primary endpoint of AGO-OVAR16, a randomized, double-blind trial of pazopanib maintenance therapy in AEOC. To confirm the robustness of the primary analysis, PFS was also evaluated by blinded independent central review (BICR). METHODS: Patients with histologically confirmed AEOC (N = 940) were randomized 1:1 to receive pazopanib 800 mg/day or placebo for up to 24 months. Tumor response in the intent-to-treat population was evaluated by CT/MRI every 6 months and analyzed per RECIST 1.0. RESULTS: Pazopanib prolonged PFS versus placebo by INV (median 17.9 vs 12.3 months; hazard ratio [HR] = 0.766, 95% confidence interval [CI]: 0.643-0.911; P = 0.0021). Results for PFS by BICR were similar (median 15.4 vs 11.8 months; HR = 0.802, 95% CI: 0.678-0.949; P = 0.0084). Progression events were recorded later by INV in 23% of pazopanib-treated patients and 17% of placebo-treated patients. The overall concordance between INV and BICR assessments was 84% and 86% in the pazopanib and placebo arms, respectively. CONCLUSIONS: By INV and BICR assessments, maintenance therapy with pazopanib in AEOC provided a significantly longer PFS than placebo. The good overall concordance between INV and BICR assessments, as well as HR and P value consistency, supports the reliability of investigator-assessed PFS as the primary endpoint in AGO-OVAR16.

Incorporation of pazopanib in maintenance therapy of ovarian cancer.

PURPOSE: Pazopanib is an oral, multikinase inhibitor of vascular endothelial growth factor receptor (VEGFR) -1/-2/-3, platelet-derived growth factor receptor (PDGFR) -α/-ß, and c-Kit. Preclinical and clinical studies support VEGFR and PDGFR as targets for advanced ovarian cancer treatment. This study evaluated the role of pazopanib maintenance therapy in patients with ovarian cancer whose disease did not progress during first-line chemotherapy. PATIENTS AND METHODS: Nine hundred forty patients with histologically confirmed cancer of the ovary, fallopian tube, or peritoneum, International Federation Gynecology Obstetrics (FIGO) stages II-IV, no evidence of progression after primary therapy consisting of surgery and at least five cycles of platinum-taxane chemotherapy were randomized 1:1 to receive pazopanib 800 mg once per day or placebo for up to 24 months. The primary end point was progression-free survival by RECIST 1.0 assessed by the investigators. RESULTS: Maintenance pazopanib prolonged progression-free survival compared with placebo (hazard ratio [HR], 0.77; 95% CI, 0.64 to 0.91; P = .0021; median, 17.9 v 12.3 months, respectively). Interim survival analysis based on events in 35.6% of the population did not show any significant difference. Grade 3 or 4 adverse events of hypertension (30.8%), neutropenia (9.9%), liver-related toxicity (9.4%), diarrhea (8.2%), fatigue (2.7%), thrombocytopenia (2.5%), and palmar-plantar erythrodysesthesia (1.9%) were significantly higher in the pazopanib arm. Treatment discontinuation related to adverse events was higher among patients treated with pazopanib (33.3%) compared with placebo (5.6%). CONCLUSION: Pazopanib maintenance therapy provided a median improvement of 5.6 months (HR, 0.77) in progression-free survival in patients with advanced ovarian cancer who have not progressed after first-line chemotherapy. Overall survival data to this point did not suggest any benefit. Additional analysis should help to identify subgroups of patients in whom improved efficacy may balance toxicity (NCT00866697).