QD 75 - Dosing RTX And REM Save
QD 75 - Dosing RTX And REM by Dr. Cush
Transcription
Hi. This is QD clinic brought to you by RheumNow live coming up 03/13/1415. I'm doctor Jack Cush, RheumNow, and I'm gonna talk about dosing rituximab versus infliximab. Now these drugs are fabulous drugs. They are mainstays in our therapy.
There probably are declining numbers of people taking these drugs in current times or current years because we have so many options. I think at last count, I think in rheumatology, for the management of RA, I think we have 23, new drugs since 1999, and that's not counting the old, conventional DMARDs. That includes, I think 11 or 13 biosimilars. There's two rituximab biosimilars, one neither of them are actually approved for use in rheumatoid arthritis. One is approved for GPA, other one is not.
And then there's FDA approved Rituxan. And we're going to talk about how to dose that drug. I think many rheumatologists don't use a lot of Rituxan when they probably should. It's a fabulous drug, it's easy to give. It's got long lasting responses.
It's the best drug to give your patients who are non compliant. They can get two doses per year and have fabulous control. It works about 10% better or more in patients who are strongly seropositive for RF or CCP. And my regimen in dosing rituximab is the drug dosing that was used in the clinical trials. Thousand milligrams done twice or two weeks apart and then repeated every twelve months.
There seems to be some concern about when you give the next round, a round being two infusions two weeks apart. I do it every twelve months because I have found that when patients respond great to rituximab, they drop their B cell counts, their CD19 B cell counts, and they go to zero for six months, and then they creep up between month six 12, and then they're gonna need it again at month twelve as far as clinical efficacy. They don't change their immunoglobulin levels in general, until you've done many repeated infusions. The question is what do you give next year or the second go around? There are some rheumatologists that do this every six months.
I think if you've to give rituximab every six months, you shouldn't be given rituximab. It's a drug that's designed to work longer than six months. If you're giving it less than every six months, you definitely need to use another drug because there are better drugs with better responses. I had a patient yesterday who was on rituximab who felt fabulous after she got her rituximab infusions. Well, that's because she got a hundred or two hundred milligrams of IV hydrocortisone.
Rituximab doesn't work that fast. Rituximab really starts to work about four to six to eight weeks after they've got their their first or second infusion. So my second go around, I'm either gonna do five hundred milligrams two weeks apart or one thousand milligrams and leave it at that because the dosing studies show that five hundred done twice is equal to a thousand done twice. My extrapolation of that is a thousand once every year is good enough. Should you use or be monitoring CD19 cell counts in these patients?
I don't, unless I'm into like the third or fourth year. I don't do serum immunoglobulin levels prior to infusions. I know they're gonna go to zero after the infusions. If you ask a number of rheumatologists and leading rheumatologists and those who've done the studies, the vast majority don't. You know who does recommend it?
The allergists. Our friends who are board certified in allergy, Arti Kavanaugh, Bing Bingham, Anna Postalova, who gave a great lecture on this at RWCS last week. They all measure it, be figuring that it's gonna help them make some decisions about whether they need to worry about those immunoglobulin levels as far as infectious risk going forward. Turns out that's a low frequency event. It's only seen with many, infusions.
It's not it's not a bad thing to measure them. I just don't think I do them all the time. Have my friends changed my mind? Not quite yet. What about Remicade?
My starting dose on Remicade, whether it's infliximab or a biosimilar, I believe they both work fabulously well, is three to five milligrams per kilogram. I might amp it up a little bit if I think they're more aggressive disease, But my starting dose is three to five, and I often do three, but I'm not afraid to use five. Turns out the more you use, the less immunogenic the drug is. Right? But nonetheless, three to five milligrams.
If patient hasn't responded sufficiently well, I'll increase from three to five after the zero to and then six weeks later at eight weeks, I'll increase after that infusion, at my next infusion to five to six milligrams, and do it two more times. If they don't respond, I'm not going to ten milligrams. I'm sorry. If you need to use more than six milligrams per kilogram to use Remicade to treat rheumatoid arthritis, you need to be moving on. Because there's one thing clear to me as someone who monitors safety data and all the safety reports, turns out all the biologics are similar as far as their efficacy and as far as their safety, especially with regard to serious infectious events, TB events, opportunistic events.
You know what stands out? Remicade. All the time, Remicade stands out as the bad player with the worst event rates, and that's because of people who are escalating the dose. It's not people on three milligrams per kilogram who are getting in trouble with Remicade. It's the ten milligrams per kilogram who get in trouble.
So I don't need to go there. Now, again, occasional refractory patients who failed everything else and are only controlled by ten milligrams, yes. But they're the exception and not the rule. You've got another enough choices running around that you don't necessarily have to use a ten milligram dose. That's it for this week, for this day.
Tune in tomorrow for another great QD video. Let me tell you about our step or TED talks that we're going to have. We have this fabulous session on Saturday morning, Masters of the EU, our international experts. The future of rheumatology by Gerd Burmester. Ten, fifteen minutes crisp.
Lord knows what he's gonna say. Are we doing this right? Robert Landaway, a real thought leader in The EU on RA and the master of T2T, treat the target, Joseph Smolin's gonna say, after ten years of t two t, is this still a good idea, and are we getting it right? You really need to tune in and be there for this. Tune in tomorrow for QD clinic.
There probably are declining numbers of people taking these drugs in current times or current years because we have so many options. I think at last count, I think in rheumatology, for the management of RA, I think we have 23, new drugs since 1999, and that's not counting the old, conventional DMARDs. That includes, I think 11 or 13 biosimilars. There's two rituximab biosimilars, one neither of them are actually approved for use in rheumatoid arthritis. One is approved for GPA, other one is not.
And then there's FDA approved Rituxan. And we're going to talk about how to dose that drug. I think many rheumatologists don't use a lot of Rituxan when they probably should. It's a fabulous drug, it's easy to give. It's got long lasting responses.
It's the best drug to give your patients who are non compliant. They can get two doses per year and have fabulous control. It works about 10% better or more in patients who are strongly seropositive for RF or CCP. And my regimen in dosing rituximab is the drug dosing that was used in the clinical trials. Thousand milligrams done twice or two weeks apart and then repeated every twelve months.
There seems to be some concern about when you give the next round, a round being two infusions two weeks apart. I do it every twelve months because I have found that when patients respond great to rituximab, they drop their B cell counts, their CD19 B cell counts, and they go to zero for six months, and then they creep up between month six 12, and then they're gonna need it again at month twelve as far as clinical efficacy. They don't change their immunoglobulin levels in general, until you've done many repeated infusions. The question is what do you give next year or the second go around? There are some rheumatologists that do this every six months.
I think if you've to give rituximab every six months, you shouldn't be given rituximab. It's a drug that's designed to work longer than six months. If you're giving it less than every six months, you definitely need to use another drug because there are better drugs with better responses. I had a patient yesterday who was on rituximab who felt fabulous after she got her rituximab infusions. Well, that's because she got a hundred or two hundred milligrams of IV hydrocortisone.
Rituximab doesn't work that fast. Rituximab really starts to work about four to six to eight weeks after they've got their their first or second infusion. So my second go around, I'm either gonna do five hundred milligrams two weeks apart or one thousand milligrams and leave it at that because the dosing studies show that five hundred done twice is equal to a thousand done twice. My extrapolation of that is a thousand once every year is good enough. Should you use or be monitoring CD19 cell counts in these patients?
I don't, unless I'm into like the third or fourth year. I don't do serum immunoglobulin levels prior to infusions. I know they're gonna go to zero after the infusions. If you ask a number of rheumatologists and leading rheumatologists and those who've done the studies, the vast majority don't. You know who does recommend it?
The allergists. Our friends who are board certified in allergy, Arti Kavanaugh, Bing Bingham, Anna Postalova, who gave a great lecture on this at RWCS last week. They all measure it, be figuring that it's gonna help them make some decisions about whether they need to worry about those immunoglobulin levels as far as infectious risk going forward. Turns out that's a low frequency event. It's only seen with many, infusions.
It's not it's not a bad thing to measure them. I just don't think I do them all the time. Have my friends changed my mind? Not quite yet. What about Remicade?
My starting dose on Remicade, whether it's infliximab or a biosimilar, I believe they both work fabulously well, is three to five milligrams per kilogram. I might amp it up a little bit if I think they're more aggressive disease, But my starting dose is three to five, and I often do three, but I'm not afraid to use five. Turns out the more you use, the less immunogenic the drug is. Right? But nonetheless, three to five milligrams.
If patient hasn't responded sufficiently well, I'll increase from three to five after the zero to and then six weeks later at eight weeks, I'll increase after that infusion, at my next infusion to five to six milligrams, and do it two more times. If they don't respond, I'm not going to ten milligrams. I'm sorry. If you need to use more than six milligrams per kilogram to use Remicade to treat rheumatoid arthritis, you need to be moving on. Because there's one thing clear to me as someone who monitors safety data and all the safety reports, turns out all the biologics are similar as far as their efficacy and as far as their safety, especially with regard to serious infectious events, TB events, opportunistic events.
You know what stands out? Remicade. All the time, Remicade stands out as the bad player with the worst event rates, and that's because of people who are escalating the dose. It's not people on three milligrams per kilogram who are getting in trouble with Remicade. It's the ten milligrams per kilogram who get in trouble.
So I don't need to go there. Now, again, occasional refractory patients who failed everything else and are only controlled by ten milligrams, yes. But they're the exception and not the rule. You've got another enough choices running around that you don't necessarily have to use a ten milligram dose. That's it for this week, for this day.
Tune in tomorrow for another great QD video. Let me tell you about our step or TED talks that we're going to have. We have this fabulous session on Saturday morning, Masters of the EU, our international experts. The future of rheumatology by Gerd Burmester. Ten, fifteen minutes crisp.
Lord knows what he's gonna say. Are we doing this right? Robert Landaway, a real thought leader in The EU on RA and the master of T2T, treat the target, Joseph Smolin's gonna say, after ten years of t two t, is this still a good idea, and are we getting it right? You really need to tune in and be there for this. Tune in tomorrow for QD clinic.
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