Phase II randomised discontinuation trial of brivanib in patients with advanced solid tumours

BACKGROUND

Brivanib is a selective inhibitor of vascular endothelial growth factor and fibroblast growth factor (FGF) signalling. We performed a phase II randomised discontinuation trial of brivanib in 7 tumour types (soft-tissue sarcomas [STS], ovarian cancer, breast cancer, pancreatic cancer, non-small-cell lung cancer [NSCLC], gastric/esophageal cancer and transitional cell carcinoma [TCC]).

PATIENTS AND METHODS

During a 12-week open-label lead-in period, patients received brivanib 800 mg daily and were evaluated for FGF2 status by immunohistochemistry. Patients with stable disease at week 12 were randomised to brivanib or placebo. A study steering committee evaluated week 12 response to determine if enrolment in a tumour type would continue. The primary objective was progression-free survival (PFS) for brivanib versus placebo in patients with FGF2-positive tumours.

RESULTS

A total of 595 patients were treated, and stable disease was observed at the week 12 randomisation point in all tumour types. Closure decisions were made for breast cancer, pancreatic cancer, NSCLC, gastric cancer and TCC. Criteria for expansion were met for STS and ovarian cancer. In 53 randomised patients with STS and FGF2-positive tumours, the median PFS was 2.8 months for brivanib and 1.4 months for placebo (hazard ratio [HR]: 0.58, p = 0.08). For all randomised patients with sarcomas, the median PFS was 2.8 months (95% confidence interval [CI]: 1.4-4.0) for those treated with brivanib compared with 1.4 months (95% CI: 1.3-1.6) for placebo (HR = 0.64, 95% CI: 0.38-1.07; p = 0.09). In the 36 randomised patients with ovarian cancer and FGF2-positive tumours, the median PFS was 4.0 (95% CI: 2.6-4.2) months for brivanib and 2.0 months (95% CI: 1.2-2.7) for placebo (HR: 0.56, 95% CI: 0.26-1.22). For all randomised patients with ovarian cancer, the median PFS in those randomised to brivanib was 4.0 months (95% CI: 2.6-4.2) and was 2.0 months (95% CI: 1.2-2.7) in those randomised to placebo (HR = 0.54, 95% CI: 0.25-1.17; p = 0.11).

CONCLUSION

Brivanib demonstrated activity in STS and ovarian cancer with an acceptable safety profile. FGF2 expression, as defined in the protocol, is not a predictive biomarker of the efficacy of brivanib.

Results of a prospective phase 2 study of pazopanib in patients with surgically unresectable or metastatic chondrosarcoma

BACKGROUND

This single-arm, multicenter, phase 2 study evaluated the safety and antitumor activity of pazopanib in patients with unresectable or metastatic conventional chondrosarcoma.

METHODS

Eligible patients had conventional chondrosarcoma of any grade with measurable tumors that were unresectable or metastatic. Patients with mesenchymal, dedifferentiated, and extraskeletal myxoid chondrosarcoma subtypes and patients who received prior tyrosine kinase inhibitor therapy were excluded. Pazopanib at 800 mg once daily was administered for 28-day cycles. Tumor responses were evaluated by local radiology assessments every 2 cycles. The primary endpoint was the disease control rate (DCR) at week 16 (4 cycles).

RESULTS

Forty-seven patients were enrolled. The DCR at 16 weeks was 43% (95% confidence interval [CI], 28%-58%), which was superior to the null hypothesis rate of 30%, but the 2-sided P value (exact test) was .09 (1-sided P = .045). One patient had a partial response. The median overall survival was 17.6 months (95% CI, 11.3-35.0 months), and the median progression-free survival was 7.9 months (95% CI, 3.7-12.6 months). Grade 3 or higher adverse events were infrequent; hypertension (26%) and elevated alanine aminotransferase (9%) were most common.

CONCLUSIONS

This study provides evidence of positive drug activity for pazopanib in conventional chondrosarcoma.

A phase II study of ixabepilone (BMS-247550) in metastatic renal-cell carcinoma

INTRODUCTION

Ixabepilone (BMS-247550) is a semi-synthetic analog of epothilone B that has been characterized as a microtubule stabilizing agent with a mechanism of action distinct from taxanes. Suggestion of activity in renal cell carcinoma (RCC) has been seen in early clinical studies.

METHODS

Eligible patients had metastatic RCC as well as ECOG performance status 0-2 and normal organ function. Patients received ixabepilone at a dose of 40 mg/m2 intravenously over three hours every 21 days. There was no restriction on RCC histology or prior treatment type, but prior treatment with tubule inhibitors was not allowed. The primary endpoint was RECIST defined response and radiographic evaluations were performed every three cycles. Toxicity evaluations utilized CTCAE v3.0 and were performed every cycle. Using a Simon two-stage optimal design with alpha = 0.1, beta = 0.1, a null hypothesized response rate of 0.05 and an alternative response rate of 0.2, an initial 12 patients were to be accrued with full accrual of 37 patients if at least one response were observed.

RESULTS

A median of five cycles were administered. No objective responses were observed in the first 12 evaluable patients, and six patients showed stable disease for more than 18 weeks on therapy. Median time to progression among those with objective progression was nine weeks. One patient experienced grade 4 anemia and lymphopenia. Grade 3 adverse events included lymphopenia, neutropenia, leukopenia, diarrhea, and infection. Common grade 2 toxicities included alopecia, fatigue and anemia.

CONCLUSION

Ixabepilone administered at a dose of 40 mg/m2 every 21 days should not be advanced for further study in metastatic RCC. Given previous results, however, other dosing schedules may be worthy of further investigation.

Dose-finding and pharmacokinetic study to optimize the dosing of irinotecan according to the UGT1A1 genotype of patients with cancer

PURPOSE

The risk of severe neutropenia from treatment with irinotecan is related in part to UGT1A1*28, a variant that reduces the elimination of SN-38, the active metabolite of irinotecan. We aimed to identify the maximum-tolerated dose (MTD) and dose-limiting toxicity (DLT) of irinotecan in patients with advanced solid tumors stratified by the *1/*1, *1/*28, and *28/*28 genotypes.

PATIENTS AND METHODS

Sixty-eight patients received an intravenous flat dose of irinotecan every 3 weeks. Forty-six percent of the patients had the *1/*1 genotype, 41% had the *1/*28 genotype, and 13% had the *28/*28 genotype. The starting dose of irinotecan was 700 mg in patients with the *1/*1 and *1/*28 genotypes and 500 mg in patients with the *28/*28 genotype. Pharmacokinetic evaluation was performed at cycle 1.

RESULTS

In patients with the *1/*1 genotype, the MTD was 850 mg (four DLTs per 16 patients), and 1,000 mg was not tolerated (two DLTs per six patients). In patients with the *1/*28 genotype, the MTD was 700 mg (five DLTs per 22 patients), and 850 mg was not tolerated (four DLTs per six patients). In patients with the *28/*28 genotype, the MTD was 400 mg (one DLT per six patients), and 500 mg was not tolerated (three DLTs per three patients). The DLTs were mainly myelosuppression and diarrhea. Irinotecan clearance followed linear kinetics. At the MTD for each genotype, dosing by genotype resulted in similar SN-38 areas under the curve (AUCs; r(2) = 0.0003; P = .97), but the irinotecan AUC was correlated with the actual dose (r(2) = 0.39; P < .001). Four of 48 patients with disease known to be responsive to irinotecan achieved partial response.

CONCLUSION

The UGT1A1*28 genotype can be used to individualize dosing of irinotecan. Additional studies should evaluate the effect of genotype-guided dosing on efficacy in patients receiving irinotecan.

Clinical results of a phase II study of sorafenib in patients (pts) with non-GIST sarcomas (CTEP study #7060)

10001

Background: Sorafenib, an oral multi-targeted tyrosine kinase inhibitor, approved for the treatment of renal carcinoma, inhibits tumor cell proliferation and angiogenesis. We performed a multi-institutional phase II trial of sorafenib in sarcoma. Methods: Six different histological categories were examined, each as a separate Simon two-stage trial. The starting dose of sorafenib was 400 mg PO BID. If ≥1 RECIST partial response (PR) was observed in the first 12 pts, 25 more were accrued to that arm. Results: 120 pts (40 M, 80 F) received 553 28-day cycles of therapy as of 1/07. Two RECIST PR were observed in 37 (6%) leiomyosarcoma (LMS) pts and at least 3 PR in 23 (13%) angiosarcomas (AS) pts. No PR were seen in pts with MFH, synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST) or other sarcomas. Median time to progression (mTTP) is 10 ( ± 2), 15 ( ± 3), and 23 ( ± 4) weeks for non-AS, LMS and AS pts, respectively (Kaplan-Meier estimate,  ± SE). mTTP for AS is >2 fold longer than for other histologies (p=0.039, log rank), and compares favorably with single institution mTTP data for angiosarcoma (paclitaxel 17.3 wk, doxorubicin 16 wk, Fury et al. Cancer J. 2005; 11:241). 64/120 (53%) pts required dose reductions, mostly for dermatological toxicity (see abstract by Keohan, this meeting). Other grade 3, 4 and 5 toxicities included asthenia, hypertension, cardiomyopathy and hemorrhage. Two fatalities, from hemorrhage and intestinal perforation, were deemed possibly related to treatment. Correlative sorafenib pharmacokinetics, MAPK pathway activation and soluble markers of angiogenesis will be presented. Conclusions: Sorafenib has significant activity against angiosarcoma, although the RECIST response rate is low. Sorafenib is associated with disease control in other sarcoma subtypes (e.g. LMS). Accrual continues in AS and MPNST. Further study of sorafenib in sarcomas appears warranted, either in combination with cytotoxic chemotherapy or in a randomized setting. Supported in part by P01-CA47179 Sarcoma Program Project grant and N01 phase II grant.

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A phase II study of ixabepilone (BMS 247550) in metastatic renal cell carcinoma

14646

Introduction Ixabepilone (BMS) is a semi-synthetic analog of Epothilone B that functions as a microtubule stabilizer and has anti-cancer effects in several cancers including renal cell carcinoma (RCC) (Zhuang, ASCO 2004). The initial phase II study in RCC utilized a difficult and unconventional dosing schedule (6 mg/m2 IV days 1–5 every 21 days). Hence, this phase II study in RCC was designed to verify previous observations and to test the safety, feasibility, and activity of administering BMS once every 3 weeks- a schedule used in other malignancies. Methods Treatment consists of BMS 40 mg/m2 IV on day 1 every 3 weeks. Eligibility included metastatic RCC with clear or non-clear cell histology, no limits on the number of previous treatments, performance status 0–2, and normal organ function. The primary endpoint is the overall response rate by RECIST criteria on radiologic evaluation conducted every 9 weeks. Accrual to the full planned 41 patients (pts) will proceed provided that 2 or more responses are observed in the first 21 pts. Results Ten pts have enrolled (4 clear cell) with 1 declining participation prior to receiving any treatment. Eight pts have completed at least 3 cycles. Grade 3–4 toxicities include lymphopenia-2, diarrhea-2, alopecia-1, and infection-1. Grade 1–2 toxicities seen in more than 50% of pts include alopecia, neuropathy, nausea, fatigue, anemia, and lymphopenia. We have observed 1 unconfirmed partial response of short duration and 1 pt exhibited stable disease with a minor response but discontinued treatment due to excessive neurotoxicity. Three pts continue on treatment. Conclusions Toxicity at 40 mg/m2 IV on day 1 every 3 weeks is higher than previously reported with the daily x 5 schedule. While lymphopenia, diarrhea, neuropathy, and fatigue are all expected adverse events, the rates of toxicity across all grades is higher than previous reports. VHL mutation analysis is planned and will be correlated with response to therapy. Accrual and pt follow up continue.

No significant financial relationships to disclose.

Correction of the galactocerebrosidase deficiency in globoid cell leukodystrophy-cultured cells by SL3-3 retroviral-mediated gene transfer

Globoid cell leukodystrophy (GCL) or Krabbe disease is an autosomal recessive inherited disease caused by the deficiency of galactocerebrosidase, the lysosomal enzyme responsible for the degradation of galactocerebroside, a major component of myelin. An animal model homologue of GCL is the twitcher mouse. In the present work, using novel recombinant retroviruses harboring the SL3-3 LTR, we have been able to stably correct the galactocerebrosidase deficiency in twitcher mouse TM-2 cells and in primary human fibroblasts from a patient with globoid cell leukodystrophy. These results show the possibility of retroviral-mediated gene therapy for the treatment of GCL.