Re: Enlarged Speen - any danger?

[Guest guest]

I had the full first round dose of 350mg/mm2 of rituxan,

split evenly over two days. The CLL expert that I consulted

with thinks that it is a mistake that oncologists make to

eliminate or reduce the rituxan on the first round. That

could be why your results were not as good as mine. I also

lost weight, but I'm putting it back on. My oncologist was

planning to give me 110mg of rituxan, and I insisted that he

raise the dose to 350mm. My feeling about it was that I

didn't want to " waste " a round of chemotherapy, or go

through the difficulties of treatment, and not get all the

benefits. Tumor lysis is managed by the allopurinol that I

started taking 3 days before treatment and continued for 11

more days. Plus I drank more water than usual.

My blood tests showed continued improvement each week.

Since Rituxan stays in the body for six months, I guess it

is still working in my body.

As far as reaction goes, I didn't feel like myself for

about 5 days. I was a bit hoarse in the throat and my

intestines felt strange. Since then I've been feeling

better and gaining a little weight back. I go in tomorrow

for round 2.

Ron

Ron, What reaction to the BR routine? I had 1 treatment

with just Bendamustine and get Rituxan added the first of

Nov. In a week the WBC went from 117K to 107K which doesn't

seem like much. I've been worried about my weight loss.

Maybe my enlarged spleen is shrinking also.

[Guest guest]

It is important to remember how arbitrary the dose of

rituximab is. Rituximab's dose was determined by the amount

of rituximab available divided by the number of patients

needed to gain approval given the difficulties with

manufacturing it back then.

We typically do phase I studies to determine the maximum

tolerated dose. One has never " officially " been done for

rituximab. Rituximab monotherapy has always been less

effective compared with other low-grade lymhpomas, likely

due to the dim CD20 expression and the larger tumor burden.

There is also soluble CD20 that might act as a " sink " for

the rituximab.

O'Brien did a dose escalation study and was able to

escalate the dose of rituximab to 2250 mg/m2 (as compared

with 350 mg/m2). While more rituximab is likely better, and

Dr. O'Brien achieved higher response rates with the higher

doses of rituximab, seeing a difference in effect due to

several hundred mgs of rituximab is unlikely.

Rick Furman, MD

Ron wrote:

/message/16200

[Guest guest]

Maybe I'm the only one who needs further clarification of

what I'm hearing as two contradictory statements in Dr.

Furman's post,, i.e. if more Rituximab is " likely better "

and " Dr. O'Brien achieved higher response rates, " how is it

unlikely then that several hundred mgs more of rituximab

will not produce a difference in effect? Is he saying that

while there may be a better response rate, it's still not

enough to make a real difference in a CLL patient's

condition?

" While more rituximab is likely better, and Dr. O'Brien

achieved higher response rates with the higher doses of

rituximab, seeing a difference in effect due to several

hundred mgs of rituximab is unlikely. "

[Guest guest]

The difference is in quantity. In Dr. O'Brien's work, a

typical adult might be receiving 3,750 mg more each week,

not 300 mg. The ten fold difference is enough to have an

impact.

Rick Furman, MD

Frances Friedman wrote:

/message/16210

[Guest guest]

Dr. Furman,

My original point about the rituxan dose was that we only

get 6 rounds of treatment, and to eliminate or reduce

rituxan on the 1st round is sort of like losing the benefit

of that round. My doctor was planning to give me 110m2 on

the first round instead of the standard 375m2, and was

planning to give 350m2 in rounds 2 - 6 instead of the

standard 500m2.

If I had not advocated on my behalf, I would have received

1860m2 of rituxan over 6 rounds instead of 2875m2. So I'm

getting over 50% more rituxan than my oncologist was going

to use. Isn't that a significant difference?

Ron

Dr. Furman wrote:

> The difference is in quantity. In Dr. O'Brien's work, a

> typical adult might be receiving 3,750 mg more each week,

> not 300 mg. The ten fold difference is enough to have an

> impact.

[Guest guest]

We don't know. The FCR regimen and the FDA approval is

based upon rituximab dosing of 375 mg/m2 cycle 1, followed

by 500 mg/m2 cycles 2-6. It is hard to believe the

difference in antibody quantity of this amount could impact

outcome, but we do not know.

Rick Furman, MD

Ron wrote:

/message/16217