An open-label, phase 2 study evaluating the efficacy and safety of the anti-IGF-1R antibody cixutumumab in patients with previously treated advanced or metastatic soft-tissue sarcoma or Ewing family of tumours

BACKGROUND

Cixutumumab (IMC-A12), a fully human immunoglobulin G1 (IgG1) monoclonal antibody, exerts preclinical activity in several sarcoma models and may be effective for the treatment of these tumours.

METHODS

In this open-label, multicentre, phase 2 study, patients with previously treated advanced or metastatic rhabdomyosarcoma, leiomyosarcoma, adipocytic sarcoma, synovial sarcoma or Ewing family of tumours received intravenous cixutumumab (10mg/kg) for 1h every other week until disease progression or discontinuation. The primary end-point was the progression-free survival rate (PFR), defined as stable disease or better at 12 weeks. In each tier of disease histology, Simon's optimum 2-stage design was applied (PFR at 12 weeks P0=20%, P1=40%, α=0.10, β=0.10). Stage 1 enrolled 17 patients in each disease group/tier, with at least four patients with stable disease or better required at 12 weeks to proceed to stage 2.

RESULTS

A total of 113 patients were enrolled; all tiers except adipocytic sarcoma were closed after stage 1 due to futility. The 12-week PFR was 12% for rhabdomyosarcoma (n=17), 14% for leiomyosarcoma (n=22), 32% for adipocytic sarcoma (n=37), 18% for synovial sarcoma (n=17) and 11% for Ewing family of tumours (n=18). Median progression-free survival (weeks) was 6.1 for rhabdomyosarcoma, 6.0 for leiomyosarcoma, 12.1 for adipocytic sarcoma, 6.4 for synovial sarcoma and 6.4 for Ewing family of tumours. Among all patients, the most frequent treatment-emergent adverse events (AEs) were nausea (26%), fatigue (23%), diarrhoea (23%) and hyperglycaemia (20%).

CONCLUSIONS

Patients with adipocytic sarcoma may benefit from treatment with cixutumumab. Cixutumumab treatment was well tolerated, with limited gastrointestinal AEs, fatigue and hyperglycaemia.

Randomized phase II study of docetaxel with or without ramucirumab (IMC-1121B) or icrucumab (IMC-18F1) in patients with urothelial transitional cell carcinoma (TCC) following progression on first-line platinum-based therapy

TPS4675^

Background: The vascular endothelial growth factor (VEGF) pathway may play an important role in the pathogenesis of bladder cancer. Two antibodies (ramucirumab or icrucumab) in combination with docetaxel are being tested in this clinical study. Ramucirumab is a fully human IgG1 monoclonal antibody (MAb) that specifically binds with high affinity to VEGF receptor-2 (VEGFR-2), thereby blocking the interaction of VEGF ligands. Ramucirumab inhibits VEGF-mediated proliferation of human endothelial cells and migration of human leukemia cells. Icrucumab is a fully human IgG1 MAb that specifically binds with high affinity to VEGFR-1 and blocks the binding of VEGF-A, VEGF-B, and placental growth factor (PlGF) to the receptor, thereby inhibiting subsequent signaling. Blockage of VEGFR-1 and VEGFR-2 by antibodies demonstrates antiangiogenic and antitumor activity and prevents dissemination and growth of lung metastases in several tumor xenograft models. Methods: This study includes patients (pts) with TCC with progressive disease after prior platinum-based therapy. Pts are randomized equally to 1 of 3 open-label treatments given on a 21-day cycle: docetaxel (75 mg/m2) on Day 1 (Arm A); docetaxel on Day 1 and ramucirumab (10 mg/kg) on Day 1 (Arm B); or docetaxel on Day 1 and icrucumab (12 mg/kg) on Days 1 and 8 (Arm C). Randomization is stratified by the absence/presence of visceral metastases and receipt of prior antiangiogenic therapy. The primary endpoint is progression-free survival (PFS). Secondary outcome measures include response rate and duration of response, overall survival, and pharmacodynamic markers, including circulating levels of PlGF, VEGF-A, VEGF-B, soluble VEGFR-1, and soluble VEGFR-2. Exploratory analyses of VEGF, VEGFR-1, and VEGFR-2 genetic polymorphisms will be performed. As of 12 January 2012, approximately 20% of 138 planned pts were randomized in the US and Canada. The sample size will allow differentiation of an expected increase in median PFS from 3.0 months to 4.5 months with a one-sided alpha of 0.1 and a power of 71%. ClinicalTrials.gov identifier: NCT01282463.