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Outpatient program appears safe, effective in patients allergic to chemotherapy

BOSTON — The implementation of an outpatient chemotherapy desensitization program appeared safe and significantly reduced the mean time from arrival to desensitization in patients with hypersensitive reactions to chemotherapy, according to study results presented at the ACAAI Annual Scientific Meeting.

“Hypersensitive reactions to [various] platinum-based chemotherapies are increasing as cancer rates are rising,” Sara Barmettler, MD, a research fellow at Massachusetts General Hospital, said during her presentation.

Desensitization protocols – a process of inducing temporary tolerance by administering incremental doses of medication – allow patients to receive first-line chemotherapy agents despite allergic and hypersensitive reactions.

Historically desensitization protocols have often been performed in an inpatient setting to allow for close monitoring by trained professionals to mitigate risks, Barmettler said.

However, the problem with inpatient desensitization protocols is that they are time intensive and require a significant amount of personnel to conduct, she added.

Barmettler cited recent research from Marek L. Kowalski, MD, PhD, head of the department of immunology, rheumatology and allergy at the Medical University of Lodz in Poland, and colleagues that indicated positive results for the use of outpatient chemotherapy desensitization protocols. In fact, the study published in the World Allergy Organization Journal recommended that outpatient procedures be conducted after an initial successful inpatient chemotherapy desensitization protocol.

Massachusetts General Hospital placed two dedicated chairs to conduct outpatient chemotherapy desensitization protocols at the institution in January 2017 to evaluate if the protocol was a safe and effective strategy for performing desensitizations. The goal was to decrease delays in the administration of medication, as well as overall treatment time, Barmettler said.

The researchers compared time from patient arrival to the start-time of desensitization in a pre-intervention (August to September 2016) and post-intervention (January to June 2017) period.

The hospital performed 140 desensitizations during the pre-intervention period; patients with hypersensitive reactions to oxaliplatin were the most common (41%).

As a result, the hospital focused on oxaliplatin desensitizations during its post-intervention period.

Patients had to be an adult and be able to provide informed consent, have previously tolerated at least one infusion as an inpatient, and be physically able to sit-up in a chair for 12 hours to complete infusions.

Researchers reviewed electronic health records for patient characteristics, as well as severity of initial reaction and developed a patient experience survey to assess overall experience and any problems patients had with the outpatient program.

The study results demonstrated that the use of outpatient fusion chairs was associated with an 86% decrease in the mean-time to desensitization start compared with patients in the pre-intervention period (37 min. vs. 261 min; P < .0001).

Additionally, surveys administered to the patients demonstrated an improvement in perceived patient experience. Seventy-five percent of patients in the outpatient program stated that the wait time to begin chemotherapy was reasonable, compared with 67% in the inpatient program. Patients in the outpatient program also reported experiencing less disruptions to their daily routine (P < .03).

Barmettler acknowledged that there were several limitations to the study, including the “stringent” patient selection criteria.

“[Patients] had to have at least one inpatient desensitization, it was a small sample size and it was a single center study,” she said.

However, Barmettler said that although there were some limitations to the study, the outpatient program did improve timeliness and efficiency and that there are still things the institution plans on doing.

“We [have already] started to expand our outpatient infusions to non-oxaliplatin, and hope to do this for non-chemotherapeutics as well, such as antibiotics,” she said. “We [also] hope to implement this protocol at outside clinics and partner hospitals to increase first-line chemotherapies to make sure these with hypersensitive reactions to chemotherapy are able to get the best treatment for their needs.”

When questioned about the program’s cost-effectiveness, Barmettler said the exact information was complicated in terms of conducting a cost analysis, but that there is a likely benefit.

“One thing we feel, [at least] on the inpatient side, is because there are often so many delays in administration, [patients] end up staying overnight in the hospital,” she said. “Just by eliminating that overnight stay, we can say we are likely saving a lot of money.”

Additionally, Barmettler was questioned about the feasibility of doing away with inpatient desensitization programs and focusing solely on outpatient programs.

“I think one of the issues we have right now is the risk stratification of patients, and sometimes [not] knowing [what] their initial reaction to the chemotherapy [will be],” she said. “So, I think currently we're working on this model where we have at least one inpatient [session], so we have a general feel of how they might react. I think in the future, if we can get better predictors in terms of who might have more severe reactions, it would be certainly a more cost-effective, and more patient-centered way to go, but I don't think we're quite there yet.” – by Ryan McDonald

Reference:

Barmettler S, et al. OR004. Presented at: the ACAAI Annual Scientific Meeting; Oct. 26-30, 2017; Boston, MA.

Disclosure: Barmettler reports no relevant financial disclosures.