Durvalumab Plus Gemcitabine/Cisplatin Approved by the FDA for Advanced or Metastatic Biliary Tract Cancers

Data from the phase 3 TOPAZ-1 trial (NCT03875235) has supported the FDA approval of durvalumab (Imfinzi) in combination with gemcitabine and cisplatin for adult patients with locally advanced or metastatic biliary tract cancer (BTC).¹

Findings demonstrated that among 685 patients with BTC the median overall survival (OS) was 12.8 months (95% CI, 11.1-14) with the immunotherapy/chemotherapy regimen vs 11.5 months (95% CI, 10.1-12.5) for those receiving a placebo in addition to chemotherapy.

Moreover, the median progression-free survival was 7.2 months (95% CI, 6.7-7.4) vs 5.7 months (95% CI, 5.6-6.7), respectively. Investigator assessments of response showed that patients receiving durvalumab had an overall response rate of 27% (95% CI, 22% -32%) compared with 19% (95% CI, 15%-23%) with placebo, respectively.

Durvalumab should be administered as an intravenous infusion for a duration of 60 minutes. It should be administered via an intravenous line containing a sterile, low-protein binding 0.2 or 0.22 micron inline filter. It should not be coadministered through the same infusion line with other drugs.²

When preparing to administer durvalumab, nurses should transfer it into an intravenous bag containing a 0.9% sodium chloride injection, USP, or 5% dextrose injection, USP. The solution should be mixed by gentle inversion; it should not be shaken. The final diluted solution should be at a concentration between 1 mg/mL and 15 mg/mL.

Durvalumab should be administered prior to the chemotherapy, on the same day as the chemotherapy. The recommended dose for durvalumab is as follows:

• For those who weigh 30 kg or more, the dose should be 1500 mg every 3 weeks in combination with chemotherapy, followed by 1500 mg every 4 weeks as a single agent.
• For those who weigh less than 30 kg, the dose should be 20 mg/kg every 3 weeks in combination with chemotherapy, followed by 20 mg/kg every 4 weeks as a single agent.

Notably, the agent comes with warnings for immune-mediated adverse events (irAEs) and infusion-related reactions. The drug also comes with warnings for embryo-fetal toxicities.

Patients receiving durvalumab should be monitored for immune-mediated AEs including pneumonitis, colitis, hepatitis, endocrinopathies, dermatologic adverse reactions, and nephritis. Additional adverse events to monitor for include renal dysfunction and solid organ transplant rejection. At baseline, liver enzymes, creatinine, and thyroid function should be assessed. Assessments should continue periodically throughout treatment. If an irAE occurs, treatment may need to be withheld or permanently discontinued.

If an infusion-related reaction occurs with durvalumab a slower rate of infusion, infusion interruption, or infusion discontinuation may be appropriate.

Patients who received allogenic hematopoietic stem cell transplantation (HSCT) prior to receiving the PD-1/PD-L1 blocking antibodies may be at a higher risk of complications. Nurses caring for these patients should be aware of the patients HSCT history and monitor accordingly.

Overall, the most common any-grade toxicities included fatigue, nausea, constipation, decreased appetite, abdominal pain, rash, and pyrexia.

The prescribing information does not offer a recommended dose reduction with durvalumab. However, in general, severe (grade 3) irAEs indicate that treatment should be withheld, and life-threatening (grade 4) reactions indicate that treatment should be permanently discontinued. If irAEs do not response to corticosteroids, are recurrent, or if the patients cannot reduce their corticosteroid dose to 10 mg or less of prednisone within 12 weeks of initiation corticosteroids treatment, then durvalumab should be discontinued.

Following administration, it durvalumab needs to be stored, it should not be refrigerated for more than 28 days, nor left in room temperature for more than 8 hours. It should not be frozen.

References

1. FDA approves durvalumab for locally advanced or metastatic biliary tract cancer. FDA. News release. September 2, 2022. Accessed September 2, 2022. https://bit.ly/3wRdTXJ
2. Imfinzi. Prescribing information. AstraZeneca Pharmaceuticals LP; 2022. Accessed September 2, 2022. https://bit.ly/3RtupoA