Molecular responses with Tasigna and Sprycel

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Hi Everyone,

This abstract deals with molecular responses seen in Tasigna and

Sprycel patients.

http://ash.confex.com/ash/2008/webprogram/Paper15592.html

-87% of Tasigna patients saw a reduction in their PCR.

-92% of Sprycel patients saw a reduction in their PCR.

-12% of Tasigna patients had a Complete molecular response (PCRU).

-7% of Sprycel patients had a Complete molecular response (PCRU).

-39% of Tasigna patients had a Major molecular responses (3 log

reduction or better), although that number rises to 50% for patients

who started Tasigna as front line treatment.

-38% of Sprycel patients had a Major Molecular Response (3 log

reduction or better), although that number rises to 58% for patients

who started Sprycel as front line treatment.

These results are a bit tricky to interpret because there are several

factors to consider. Some of the patients were started on the drugs

as front line treatment and others were started after Gleevec failure

and some patients had known mutations while others didn't.

Keep in mind also that there is a clinical difference between Gleevec

failure and Gleevec intolerance. Gleevec failure is when the patient

fails to respond to the drug (or loses their response). Gleevec

intolerance is when the patient has had a response but cannot

tolerate the drug due to side effects.

It would appear from these numbers that Sprycel gave slightly more

responses while Tasigna gave slightly better responses but the

numbers seem rather close to me so I'm not sure how significant they

are.

We know from Gleevec that the longer a patient is on the drug, the

better the response is so I can only assume that the same will hold

true for these newer drugs. While the PCRU rates are rather low,

there hasn't been as much time to evaluate them, certainly not as

long as there has been with Gleevec so we can be hopeful that with

time, those numbers will increase.

Tracey