Best Practices for Transitioning From IV to SQ Dosing

Directions in Pharmacy, December 2019, Volume 3, Issue 2

According to the experts, having well thought-out administration procedures is imperative to providing a smooth transition process for the health care team.

With new subcutaneous (SQ) formulations launching for commonly used intravenous (IV) medications, an understanding of both the advantages and disadvantages of switching to SQ treatments is crucial.

In a Pharmacy Times® Practice Pearls video series, experts discussed the clinical and patient-facing implications of transitioning from IV to SQ formulations. The panel included Adam M. Brufsky, MD, PhD, FACP, professor of medicine at the University of Pittsburgh School of Medicine in Pennsylvania, associate division chief for the Division of Hematology/ Oncology in the Department of Medicine, and medical director of the Magee-Women’s Cancer Program, part of the University of Pittsburgh Medical Center’s Hillman Cancer Center; Matthew J. Matasar, MD, regional care medical site director at Memorial Sloan Kettering (MSK) Cancer Center Bergen in New Jersey; and Tim Peterson, PharmD, BCOP, clinical pharmacy specialist at MSK Cancer Center.

According to the experts, having well thought-out administration procedures is imperative to providing a smooth transition process for the health care team. The discussion centered on 4 key pearls of information for providers to consider.

Pearl 1: Financial Implications

SQ dosing affords various levels of financial benefit, according to the experts.

Regarding patient co-pays, the panel noted that they do not see any differences in how much patients are paying out of pocket for SQ versus IV dosing. “For out of pocket, my perspective is that it’s a push for my patients, and certainly I haven’t had anybody come back to me saying that there have been cost implications from that change,” Matasar said.

Peterson explained that regarding average wholesale price costs, acquisition costs for SQ formulations are similar overall to those of IV. This is where many of the benefits are apparent, according to the experts. They used waste prevention as an example, pointing to how the difference in preparation for SQ versus IV medications can prevent financial loss from waste.

IV trastuzumab (Kanjinti), for instance, requires reconstitution and dilution for preparation.

“If we’ve premixed it and the patient doesn’t come in, or you as the oncologist decides this is not a good day for trastuzumab or rituximab, we have that bag that’s been prepared of 6 mg/kg of trastuzumab,” Peterson said. This can translate into waste if the medication is not used.

He explained that this also applies to rituximab (Rituxan) 375 mg/m2 and 500 mg/m2. “Versus a 1400-mg or 1600-mg syringe that’s drawn up, you’re much more likely to be able to use that and not have as much waste,” Peterson said.

Pearl 2: Formulary Considerations

Adding SQ formulations to the formulary can require a collaboration among the oncologist, the clinical pharmacy team, the chemotherapy guidelines committee, and the pharmacy and therapeutics (P&T) committee, according to Peterson.

At MSK, the request begins with a specialist medical oncologist, who then works with clinical pharmacists to develop a formulary that incorporates clinical efficacy and safety data, which is then presented to the P&T committee. Importantly, regarding the criteria used, the decision to add an agent to the formulary rests on whether it will add value to patient treatment.

“It doesn’t necessarily have to be better per se, but the context in which it’s used needs to add something to the patient’s options,” Peterson said. This value can be in pricing, quality of life, outcomes, toxicity, or alternative options.

In addition, the panel indicated that clinicians may need to have conversations with payers to obtain approval. Payers may not want to approve an SQ formulation if the clinician prescribes one but the clinical situation falls outside the predefined parameters for use. In this case, Matasar explained, practitioners need to explain the clinical rationale, which may or may not lead to approval.

Pearl 3: Impact on Patient Care

Providers should also consider the effects of SQ formulations on patient care.

According to the panelists, results of early-outcome studies have shown no difference in the pharmacokinetic properties and efficacy between SQ and IV formulations. Regarding contraindications to SQ dosing, they noted that only in limited cases have they not recommended SQ dosing for clinical reasons, even in patients with low platelet counts.

“It’s really not been a problem,” Matasar said of such patients. “We don’t get a lot of bruising, and we get no bleeding.”

Generally, adverse effects associated with SQ formulations are common injection site reactions, such as erythema and itchiness. Additionally, in quality-of-life studies (PrefMab for rituximab, PrefHer for trastuzumab), patients reported less emotional distress over receiving SQ formulations compared with extended IV infusions, which can be invasive and more painful. Patients who preferred SQ over IV cannulations also cited less bruising, Peterson noted.

Matasar said that MSK clinicians examined different practice level metrics specifically for the use of SQ rituximab, for which the biggest benefit was reduced time in clinic. “The most obvious change is [in] the chair time for the patient, where they’re getting 5 to 7 minutes of injection instead of an intravenous approach that may take anywhere from 90 minutes to upward [of] 3 or 4 hours,” he explained.

This can ultimately translate into financial benefits for patients because long periods in the clinic can lead to increased indirect costs. In addition, less time in the clinic can help ease the overall burden of receiving treatment.

“Ultimately, we’re trying to make our patients’ lives better,” Matasar said. “Part of that is just being aware that their time sitting around waiting for us—waiting for labs, waiting for room, waiting in the chair, waiting for their car—is hard.”

Pearl 4: Current Challenges

Reluctance to use SQ agents can be a challenge when transitioning from IV dosing, the experts explained.

formulations is apparent particularly with rituximab, which is administered in several different settings for a variety of reasons. He noted a greater reluctance to switch to SQ formulations when treating patients with a curative intent, especially because IV rituximab has already been proved to improve overall survival (OS).

For SQ rituximab, Matasar said that “without a rigorous assessment looking at well-powered OS benefit end points, I think there is still a natural reluctance among some of the lymphoma community to substitute when [rituximab] is being given with curative intent.”

However, results of current studies have shown that response rates are similar between IV and SQ formulations, with no statistically significant difference, according to the panel.

In addition to reassuring staff about the efficacy of SQ agents, clinicians should also educate them on the differences between dosing for SQ and IV formulations. For example, neither of the currently available SQ agents has a loading dose or weight-adjusted dosing, unlike IV formulations.

The experts also noted the distinction between rituximab and trastuzumab SQ dosing. With rituximab, clinicians must administer the first dose intravenously because of the risk of adverse effects, whereas they can give trastuzumab subcutaneously from the start.

“You have to be confident enough that they have Rituxan on board and they’re well saturated so you can give it subcutaneously without worries about generating some sort of severe reactions,” Matasar said.

In terms of choosing between SQ and IV formulations, the experts explained that because of the similarities, cost should not be a primary factor. However, the entrance of biosimilars into the market will likely make pricing more competitive and increase the need for decision making.

“We have the emergence of biosimilars that have different value propositions in that we as a discipline, pharmacists and oncologists together, have a lot of work to do to unravel the various pros and cons of these different formulations in the guiding of our patients,” Matasar concluded.