Yondelis plus cisplatin opens new possibilities against cancer.

2003 JUL 3 - (NewsRx.com & NewsRx.net) -- New data announced on behalf of PharmaMar show that Yondelis (ET-743) has positive activity in advanced adult soft tissue sarcoma (STS).

Encouraging clinical data of Yondelis in combination with cisplatin and phase II results in small round cell sarcomas (tumors that occur predominantly in children) were also reported. The data were presented at the 2003 Annual Meeting of the American Association for Clinical Oncology (ASCO).

During the poster discussion session, J.A. Lopez-Martin, from PharmaMar, Madrid, Spain, reported the results of an exploratory analysis that assessed the efficacy of Yondelis and its influence on the tumor growth rate (TGR) in patients with advanced soft tissue sarcoma participating in three pivotal phase II trials.

At study entry, all patients had progressive disease, despite having received previous chemotherapy, and were administered 1.5 mg/m[superscript]2 Yondelis by 24-h infusion every 3 weeks. Of the 183 patients evaluated using conventional efficacy measurements, 7.7% (n =3D 14) achieved objective response (> 50% tumor shrinkage), a further 7.7% (n =3D 14) achieved minor response (25% to 50% tumor shrinkage), and 36.1% (n =3D 66) had stabilization of the disease with a median duration of 9 months. In total, 51.4% (n =3D 94) of patients showed clinical benefit in terms of tumor growth control from treatment with Yondelis.

The best ways to evaluate the efficacy of novel antitumor agents, particularly in soft tissue sarcoma, are the subject of much debate among oncology experts. The European Organisation for Research and Treatment of Cancer (EORTC) endorsed the use of progression free survival (PFS) rates, denoting the percentage of patients whose disease has not progressed by a defined time point, as a way to evaluate the efficacy of an anti-tumour agent, in this disease.

Applying the PFS endpoint for efficacy analysis of Yondelis, the 6-month PFS rate was found to be 19.8%. This compares favorably with results of an EORTC study which recommends that a 6-month PFS rate above 14% shows efficacy, and below 8% inactivity of antitumor agents in STS. Following Yondelis treatment 47.5% and 29.3% of patients were alive after 1 and 2 years, respectively. Median overall survival time was 10.3 months with 29% (55/189) of patients being alive at 2 years or beyond.

STS is an aggressive type of cancer that can metastasize to other parts of the body. In Western Europe 9000 people are diagnosed with STS every year. More than half of patients with grade 3 tumors die within 5 years of diagnosis and patients with inoperable metastatic disease on average live only 8 to 12 months following diagnosis. There is an urgent need for new agents to treat STS and no new treatment for this indication has been developed in the last 25 years.