MIRACLE I demonstrates high tumour control rate for drug-eluting microspheres

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Goetz Richter

Goetz Richter, Clinic for Diagnostic and Interventional Radiology, Stuttgart, Germany, presented breaking data from the Miracle 1 multicentre hepatocellular carcinoma trial at The Symposium on Clinical Interventional Oncology (CIO, 4–5 February, Hollywood, Florida). He spoke to Interventional News on the role of drug-eluting particles in interventional oncology.

What are the key findings from the MIRACLE 1 trial?

MIRACLE I study results demonstrated a high tumour control rate and few serious adverse events among patients with locally or clinically unresectable hepatocellular carcinoma treated with Embozene Tandem (Boston Scientific) microspheres loaded with 150mg doxorubicin. Specifically, complete response was achieved in nearly half of the patients (48%) treated; 19% had a partial response; 29% had stable disease; and disease progression was observed in only one patient (5%). No specific safety concerns were associated with the small 75μm microsphere size used in the study, and systemic toxicities were minimal with no myelosuppression and only one patient developing mild alopecia.

Although the study was relatively small with 25 patients enrolled, it was fairly representative of a “real world” situation of hepatocellular carcinoma interventional treatment: around 40% of the patients had ascites and, furthermore, almost 40% had an advanced stage of liver disease besides the tumour burden (Child B and C stage).

These study results support the safety of transarterial chemoembolization (TACE) procedures using drug-eluting beads performed with small (75μm) calibrated microspheres.

Additionally, these small microspheres loaded with doxorubicin provided good local tumour control. We never encountered pulmonary complications indicating that choosing a size of 75μm for drug-eluting particle embolization does not entail systemic (shunt) risk as compared to Y-90 therapy.

What is the role of drug-eluting particles in interventional oncology?

The role of drug-eluting particles is growing. As the body of evidence demonstrating procedural safety, tumour response, and a lack of systemic effects grows, it builds support for drug-eluting embolic therapy as an option for patients with hepatocellular carcinoma and other cancers that have few or no other treatment alternatives.

What were some of the limitations of MIRACLE 1?

The study sample size was small with 25 patients and, as with many studies of hepatocellular carcinoma treatment, patient characteristics such as tumour burden and severity of liver disease varied widely. Furthermore and theoretically, it would be conceivable to use 40μm or 100μm sizes for drug-eluting bead embolization in hepatocellular carcinoma. This was not tested in this study.

In general, what are the trends you see with regard to embolic particles in interventional oncology?

Embolic particles are very versatile and the ability to load drugs further adds to their therapeutic potential. This potential will not be restricted to its use in hepatocellular carcinoma alone. Research is ongoing to test the safety and efficacy of particle embolization in liver metastastic disease. There is also interest in combining the use of embolic particles with thermal ablation in a variety of organs to enhance safety and efficacy.