In a nutshell
This study investigated whether retreatment with cetuximab (Erbitux) was effective in patients whose cancer had progressed after treatment with cetuximab or panitumumab (Vectibix). The results showed that retreatment was effective in patients who had responded to previous treatment.
Some background
Colorectal cancer progresses in some patients despite treatment. This is because the cancer has developed mutations which make it resistant to treatment. It is suggested that there be a pause after initial treatment. It is thought that this break in treatment may allow cancer cells without resistance mutations a chance to grow in number. These cells would be responsive to treatment, and retreatment would be beneficial. This has been successful in studies examining other cancers. It has yet to be studied in colorectal cancer patients.
Methods & findings
This study investigated whether retreatment with cetuximab was effective in patients who had previously been treated with cetuximab or panitumumab and experienced disease progression. 89 patients took part. The patients’ previous response rates were analyzed. Patients who responded to prior treatment were termed 'prior responders'. Patients who had not responded to prior treatment were termed 'prior non-responders'.
All patients were treated with cetuximab. 73% received additional chemotherapy. 41.6% were prior responders.
The average time between prior and retreatment regimens was 4.57 months. The benefit of retreatment was greater in patients who had a longer interval between treatments. In total, 58% of patients responded to retreatment. Prior responders were 3.38 times more likely to respond than prior non-responders. Average survival without disease progression was 4.9 months in prior responders, in comparison to 2.5 months in prior non-responders.
The bottom line
The authors concluded that retreatment with cetuximab shows potential as a method to increase survival in patients whose cancer progressed despite previous treatment. They also suggested that prior responders were more likely to respond to retreatment.
The fine print
The authors note that further studies are required to identify which patients would benefit from retreatment.
What’s next?
Discuss whether retreatment would be beneficial with your doctor.
Published By :
BMC cancer
Date :
Oct 19, 2015
