Cancer drug: Are the high benefits worth the high risks?

Patients with previously-treated metastic colorectal cancer (mCRC) taking regorafenib (Stivarga) experienced progression-free survival of 2.7 months, according to new data presented at the recent ESMO 17th World Congress on Gastrointestinal Cancer 2015 in Barcelona.

The randomized phase 3 CORRECT trial previously showed that regorafenib significantly improves survival in patients with pre-treated mCRC and led to regulatory approval. Then, researchers from Belgium presented new data from the phase 3b CONSIGN study, which confirmed the benefit of regorafenib in mCRC patients.

CONSIGN included more than 2,800 patients at 188 sites in 25 countries, who received regorafenib for a median of 2.5 months. The estimated progression-free survival was 2.7 months. However, greater than Grade 3 adverse events occurred in 80% of patients.

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“This study in a real-world population of patients with pre-treated mCRC shows a similar safety profile and progression-free survival with regorafenib as shown in the randomized CORRECT trial. The findings add to our knowledge of how to select patients and how to manage toxicities,” said lead study author and professor Eric Van Cutsem with University Hospitals Leuven in Belgium. "We need to establish clear guidelines on the management of adverse events to make taking the drug more tolerable for patients."

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Still, the adverse events reported in CONSIGN were within the scope of expectation and comparable to the CORRECT trial, according to Dirk Arnold, ESMO spokesperson and director of the Department of Medical Oncology, Klinik für Tumorbiologie in Freiburg, Germany. "There were no surprising findings in terms of toxicity. All of the adverse events were quite class-specific and also likely manageable."

The merit of CONSIGN is that it translates phase 3 data into the clinical routine, “since patients had similar characteristics and pre-treatment to what we see in daily practice,” Arnold said. "CONSIGN depicts what we would expect from an observational trial in this setting. It shows that we have further treatment options for mCRC patients pre-treated with chemotherapy, and that this comes at the cost of a specific, but manageable toxicity profile."

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