Peptide receptor radionuclide therapy (PRRT) can delay progression in patients with well-differentiated enteropancreatic neuroendocrine tumors, according to research published in JAMA Network Open.

When compared with chemotherapy or targeted therapy, PRRT significantly prolonged progression-free survival (PFS) in patients who had initially experienced disease progression after treatment with somatostatin analogues (SSAs).

The retrospective study included 508 patients with unresectable, locally advanced or metastatic, well-differentiated, grades 1 to 3 enteropancreatic neuroendocrine tumors.


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After progression on SSAs, 329 patients received PRRT, and 179 received chemotherapy or targeted therapy. The researchers conducted survival analyses in this unmatched population as well as a matched population of 222 patients (111 in each treatment arm).

PRRT was associated with improved PFS in the matched and unmatched populations.

In the unmatched population, the median PFS was 2.5 years with PRRT and 0.7 years with chemotherapy/targeted therapy (hazard ratio [HR], 0.35; 95% CI, 0.28-0.44; P <.001). In the matched population, the median PFS was 2.2 years and 0.6 years, respectively (HR, 0.37; 95% CI, 0.27-0.51; P <.001).

In a multivariate analysis, PRRT was independently associated with longer PFS (HR, 0.37; 95% CI, 0.26-0.51; P <.001).

On the other hand, PRRT was not associated with a significant improvement in overall survival (OS).

In the unmatched population, the median OS was 12.0 years in the PRRT arm and 11.6 years in the chemotherapy/targeted therapy arm (HR, 0.81; 95% CI, 0.62-1.06; P =.11). In the matched population, the median OS was 12.2 years and 11.5 years, respectively (HR, 0.83; 95% CI, 0.56-1.24; P =.36).

The researchers noted that using OS as a primary or secondary endpoint is challenging “in a retrospective study with a long observation period on a relatively indolent disease” because of extended survival and the use of salvage therapies after progression.

Still, the researchers concluded that PRRT “was associated with significantly improved survival outcomes” compared with chemotherapy or targeted therapy, and more research is needed “to investigate the correct strategy, timing, and optimal specific sequence of these therapeutic options.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Pusceddu S, Prinzi N, Tafuto S, et al. Association of upfront peptide receptor radionuclide therapy with progression-free survival among patients with enteropancreatic neuroendocrine tumors. JAMA Netw Open. Published online February 24, 2022. doi:10.1001/jamanetworkopen.2022.0290