Real World Analysis of G6PD Testing Prior to the Use of Rasburicase in Hematologic Malignancies; A Single Center Experience

Introduction: The use of Rasburicase is contraindicated in patients with (Glucose -6-Phosphate Dehydrogenase) G6PD deficiency. The FDA recommends screening for G6PD deficiency prior to the use of Rasburicase, especially in those of African or Mediterranean ancestry. This recommendation, however, is not implemented uniformly.

Methods:

This was an IRB approved study. A retrospective chart analysis of adult patients with hematological malignancies treated in both the inpatient and outpatient setting between 2019 and 2022 was conducted. Data was reviewed and collected by investigators and compiled in a confidential platform.

Results:

A total of 437 patients were reviewed. The median age was 67 years. 54.9% were male and 45.1% were female. 65.6% of the patients were White, 23.5% were Black. Other ethnicities included Hispanics 3.8%, Asians 3.7%, Native American or Alaskan Natives 0.4% and unknown ethnicity in 4.3%.

37.3% of the patients had a diagnosis of Diffuse Large B Cell Lymphoma/High Grade B Cell Lymphoma, 34.1% had AML, 29.1% had CLL, 6.2 % had B or T-ALL, 2% had Burkitt lymphoma, and 1.6% had anaplastic T cell lymphoma.

Rasburicase was utilized in 85/437 (19.5%) patients for the treatment of hyperuricemia of malignancy 50/85 (59%) and in 35/85 (41%) patients for the treatment of tumor lysis syndrome.

G6PD was tested in 197 patients (45%) of which 39.5% were White, 21.8% were Black, 3.5% were Hispanic, 1% were Asian and 2.5% of unknown ethnicity. G6PD status was unknown in 55% patients.

7 cases of G6PD deficiency were identified, and 2 cases were highly suspicious for it due to the development of hemolysis after Rasburicase administration. 8/9 of these patients were African-American.

In those patients who received Rasburicase, 70/85 (82.3%) received the medication prior to the G6PD results being available; 6 patients developed hemolysis and 1 patient developed methemoglobinemia. Of these 7 patients, 4 had unknown G6PD status, 2 had G6PD levels which were elevated but sent after signs of hemolysis were present and 1 was G6PD deficient. Of these patients, 3 were Black, 3 were Hispanic and 1 was White.

Conclusions:

G6PD testing was requested in 45% of patients being evaluated for hematologic malignancies. Of these, only 17.7% had results available before the administration of Rasburicase. 2% of this sample were found to either be G6PD deficient or had clinical suspicion for the same. 89% of them were Black. 8.2% of patients receiving Rasburicase developed complications related to oxidant injury caused by G6PD of which 43% were Black and 43% were Hispanic, though they constituted only 27.3% of the population.

This study goes on to highlight the ethnic prevalence of G6PD deficiency, especially in the Black population. Strategies to increase testing for G6PD for all new diagnoses of hematological malignancies known to have a risk of TLS and reducing the time to resulting of G6PD levels can mitigate known adverse events from Rasburicase. The incorporation of G6PD testing as part of chemotherapy order set labs or use of hard stops prior to signing the treatment plan can be potential options to increase testing and screening.