At the recent EHA meeting at Copenhagen, Michael Hallek reported on current therapeutic options for CLL. He emphasised that most patients entering clinical trials are younger than 65, and therefore the treatments recommended following these trials may not be valid for older patients. Of particular interest was the German CLL5 trial which is unpublished, but which he reported in preliminary form. It compared fludarabine and chlorambucil. As expected there were more complete remissions with fludarabine and longer remissions, though this was not statistically significant, but when it came to overall survival the chlorambucil arm seemed to do better. However, there were 7 chances in a hundred that this result could have occurred by chance and normally we do not consider this to be statistically significant, requiring there to be fewer than 5 chances in 100. Nevertheless, this was sufficiently counter-intuitive to make the Germans look at the question more carefully. I would be interested in a meta-analysis on this point because the the British CLL4 trial was rather similar, and the Polish trial comparing chlorambucil and Cladribine apparently gives the same answer.
There were some other interesting observations from the German trials. Although fludarabine/cyclophosphamide generally seems to be better than fludarabine alone, especially for patients with del 11q and del 13q, this does not hold for patients with trisomy 12, where the reverse is true.
The other regimen that the Germans are interested in is FC+Campath for patients with del 17p or p53 abnormalities.
Finally just to make the point, in the recent American epidemiological study 72% of CLL patients were over-65.