The Guardian has published today at article entitled ‘Unpublished data shows breast cancer drug ‘third less effective’’
guardian.co.uk/science/2008/may/16/cancer.medicalresearch
Thanks to JaneRA for pointing this out to me. She has asked me to comment on it because she knows that I have followed this closely.
I think that the article title is misleading, since it is not so much that herceptin isn’t good. Herceptin may just not add that much used after taxanes.
This is a very complicated matter and I don’t think that the article has quite gotten it right. There were a number of different trials that reported out in 2005 and they weren’t exactly comparable. HERA used herceptin after any chemo standard combo and showed a reduction of recurrence of 50% by May 2005. The US trial (NCCTG, which also was published in 2005, had three arms: 1) herceptin after the US standard chemo (anthracycline adriamycin followed by taxol) compared with 2) no herceptin and 3) compared herceptin started during the taxane chemo. In NCCTG the herceptin started with taxol halved recurrence (a cut that has over time been reduced to a one-third) but the difference for herceptin started after the taxane was not significant.
The combination of these results suggested to me at the time that herceptin with a taxane chemo was definitely better than herceptin after a taxane chemo. In fact, the HERA results presented indicated that there was only a statistically significant difference in recurrence for patients who had not received a taxane. I brought this aspect of the HERA results with my oncologist and he cautioned that the HERA trial had not really been set up to answer the question regarding whether her2 positive patients needed taxanes. I think the whole ‘hidden unpublished data’ angle is a bit of a con because the presentations were there on the web for anyone to see, no medical journal subscription access required.
In the end the UK moved at first towards herceptin after chemo, but this may have been the only alternative under the circumstances. Perhaps the results would have been better if the UK had adopted something like NCCTG but there were several barriers to this. Firstly, the chemo used in NCCTG was the US standard which included a taxane, but taxanes have not been part of the standard treatment in the UK. Overall the lack of taxanes has probably benefitted patients since they are quite harsh and data that has come out over the last year makes it clear that only a small subset of patients benefits from them (including her2-positive patients). To complicate matters further, Britain usually doesn’t use US trial results because the US has generally used AC chemo, while Britain has used FEC. Canadian data that has come out since 2005 indicates that FEC is probably much better than the combo used in the NCCTG trial. Most importantly, the rate of heart problems was much higher in NCCTG than in HERA.
Pharmac does seem to be seeking praise for using herceptin with taxanes, but it should be mentioned that in New Zealand the combination recommended is not NCCTG or HERA, but FinHer, under which herceptin is only given with a taxane. While I believe Finher-type regimes are the way forward, FinHer was never subject to really large-scale testing. It has the potential to be not more cost effective but also safer than NCCTG because the herceptin is used before the potentially heart-damaging drugs which can make patients ineligible for herceptin. Personally, I would prefer it if Pharmac had championed the need for international trials of this cost-effective form of treatment.