Practice Pearl 1: Educating Staff on SQ Dosing
Experts provide perspective on how they prepare their staff for the transition to subcutaneous dosing.
Adam M. Brufsky, MD, PhD: The question is, are the nurses educated about how to administer it? Was there a resistance initially? We have pharmacists and physicians here, we shouldn't really diss the nurses. But nurses tend to like their things the way they are, and suddenly you're changing it. You're telling them now to give a slow subcutaneous injection of about 3 to 5 minutes.
Tim Peterson, PharmD, BCOP: Sure. And there's always a small fear of the unknown, right? Regardless if it's pharmacy, nursing or physicians. It doesn't really matter.
Adam M. Brufsky, MD, PhD: Right.
Tim Peterson, PharmD, BCOP: When we rolled out rituximab subcutaneous administration, as soon as the medical oncologist requested it to be added to the formulary, we had in place an education process for the nurses who would be in the lymphomas suites, treating these sorts of malignancies. And that was actually a contingency for our formulary rollout date. If the education wasn't completed with these presentations happening at their meetings and the materials being disbursed to them, then the date would have to be pushed back. And that was actually the contingency upon our formulary addition review.
Adam M. Brufsky, MD, PhD: Really?
Tim Peterson, PharmD, BCOP: Yes.
Adam M. Brufsky, MD, PhD: It's not so much the breast cancer business and maybe to a degree not the lymphoma business, but usually, people are used to giving subcutaneous IL-2 [interleukin-2], were they not? Is this similar to subcutaneous IL-2 or not? A little bit longer injection? We'll get to that in a few more minutes, but I'm just curious.
Tim Peterson, PharmD, BCOP: I think with the volume of administration that's required for these monoclonal antibodies we're looking at for our lymphoma doses, for rituximab, it's either 11 or 13 mL, and that's a fair amount of fluid to be giving subcutaneously, and that's where we get the hyaluronidase benefit out of it.
Adam M. Brufsky, MD, PhD: Got it. The question is in giving so much fluid, are there specific adverse events that patients and nurses have to be worried about, specifically different from the IV [intravenous] formulations?
Matthew J. Matasar, MD: The volume is really very well tolerated, and you look at the syringe and you look at the tissue that you're injecting it into, and you wonder, how is this going to fit there? The hyaluronidase really makes a tremendous impact in terms of the ease of administration. The reactions that you get from the subcutaneous administration really aren't volume related. You don't even get a major bump, per se. You can get local site reactions and they're actually quite common, but they're typically grade 1 to 2 in severity, usually easily managed with educating the patient ahead of time about what to watch for, what to expect, and using basic interventions like topical treatments to try to address local site reactions.
Adam M. Brufsky, MD, PhD: A patient won't come and call like that night and say, "I've got this giant like lemon-size thing under my thigh," or wherever you inject it?
Matthew J. Matasar, MD: Never once. It goes into the belly and it goes in easy.
Adam M. Brufsky, MD, PhD: Because that's what people are afraid of. You've given it, at least the rituximab, into the belly. OK, so do you do the same thing with trastuzumab or not?
Tim Peterson, PharmD, BCOP: Actually, interestingly enough for trastuzumab, there was an additional study. The HannaH study is the one that we looked at initially for the serum trough concentrations, just to see that the PK [pharmacokinetics] was similar. But there was a study called GAIN-2 where they looked at basically the Cmax [peak drug concentration] and overall AUC [area under the curve] when we were administering subcutaneously in the thigh versus in the abdomen. And they found that administration of trastuzumab subcutaneously in the thigh had upward of a 30% higher AUC and Cmax versus the abdomen. Very interesting.
Adam M. Brufsky, MD, PhD: What was the rationale? Did they know why?
Tim Peterson, PharmD, BCOP: I honestly am not familiar with what the rationale would be. And oddly enough, that's not something that I've seen reported with rituximab. Rituximab is recommended to be administered in the abdomen, and trastuzumab is specifically recommended to be given in the thigh, right or left alternating, and not in the abdomen. It's something that maybe with ongoing studies and more PK experience and clinical experience going forward, that will change. But as of right now, that's where we stand with that.