- Immune checkpoint inhibition (ICI) combined with stereotactic body radiation therapy (SBRT) was safe and well-tolerated in advanced pancreatic adenocarcinoma (aPDAC).
Why this matters
- Chemotherapy only modestly improves aPDAC outcome.
- Single-agent ICI has limited effectiveness in PDAC, possibly due to an immunosuppressive tumor microenvironment.
- Since SBRT boosts antitumor immunity, it may enhance ICI activity, suggesting that combining the 2 therapies may offer more clinical benefit for aPDAC than either alone.
- 51 patients who had received prior chemotherapy for aPDAC underwent 1 of 4 treatment regimens until unacceptable toxicity or disease progression:
- Durvalumab 1500 mg every 4 weeks + SBRT 1 fraction x 8 Gy on day 1.
- SBRT 5 fractions x 5 Gy, followed by durvalumab.
- Durvalumab + Tremelimumab 75 mg every 4 weeks + SBRT 1 fraction x 8 Gy on day 1.
- SBRT 5 fractions x 5 Gy, followed by durvalumab + tremelimumab.
- Primary objectives were safety and feasibility.
- 31 patients were evaluable.
- Median PFS was 2.2 months.
- Median OS was 4.9 months.
- 2 patients who received 5 Gy x 5 + durvalumab +tremelimumab had partial responses with a duration longer than 12 months.
- Small pilot study.