At the 2012 American Society of Clinical Oncology (ASCO) annual meeting, data was presented by Dr Oliver Sartor (ASCO 2012 Abstract 4551) that showed radium-223 (Alpharadin) significantly delayed time to first skeletal-related event (SRE) in patients with castratation-resistant prostate cancer (CRPC) and bone metastases.
The SRE data for radium-223 from the ALSYMPCA phase III trial was first presented at ASCO GU earlier this year.
ASCO 2012 radium-223 data discrepancies
Algeta in a communication I received today, however, have advised that the data contained in the ASCO 2012 abstracts has “discrepancies.” In the absence of more precise information, the discrepancies may or may not be significant.
As with good practice, the sponsors have conducted further verification of the ALSYMPCA SRE data in preparation for the US FDA NDA regulatory submission. This has resulted in changes in the numbers previously reported for SRE data in the ASCO 2012 abstracts (Abstract #4551, LBA #4512). Though discrepancies were noted, the overall interpretation of the results has not changed. The SRE data will be disclosed once all additional data verification and analyses activities are completed.
Mike Booth, Algeta Communications & Corporate Affairs, June 15, 2012 email communication.
While the message that radium-223 significantly delays time to first SRE may not have changed, data accuracy is important and should not be taken lightly.
In his ASCO 2012 prostate cancer poster discussion, Evan Yu, Associate Professor at the University of Washington, made no mention of any “discrepancy.” Instead he used the data in Sartor’s poster that showed the time to first SRE with radium-223 to be 13.6 months versus 8.4 months with placebo, a delay of 5.1 months.
Dr Parker presented updated ALSYMPCA trial data at ASCO 2012 that showed a 5.5 month delay in time to first SRE with radium-223 (12.2 versus 6.7 months). Dr Sartor’s poster was based on 541 patients on radium-223, while Dr Parker’s data was for 614 patients. This suggests that the two presentations represent data at different time points.
Were Bayer and Algeta aware of the issues at the time of ASCO and chose not to say anything? Obviously, if the discrepancies are small or insignificant then it would not make much difference, but a large difference would be more of a concern.
What is the accurate SRE data for radium-223 from the ALSYMPCA trial?
I look forward to a future press release from Algeta/Bayer clarifying this, and hope that they will advise ASCO if corrections need to be made to the data previously presented and published.