Clin Cancer Res: Efficacy of nivolumab in combination with temozolomide in the treatment of neuroendocrine tumors

Neuroendocrine tumors (NEN) are a heterogeneous group of tumors that include low-grade gastrointestinal and pancreatic neuroendocrine tumors (GEP-NET), thymic and pulmonary neuroendocrine tumors, and aggressive, rapidly growing neuroendocrine carcinoma
.
Treatment options are limited
for patients with metastatic neuroendocrine tumors.

Results from phase II trials of the combination of nivolumab and temozolomide in patients with advanced NEN and immune changes in peripheral blood are reported here
.

This is a non-randomized Phase 2 clinical trial for combination therapy with nivolumab and telmozolomide in patients with NN
.
The primary endpoint was response rate
.
Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety
.

Progression-free survival

A total of 28 patients with NEN were enrolled, with a clear response rate of 32.
1% (9/28).

In 11 patients with pulmonary NN, the response rate was 64% (7/11); Remission rates varied significantly between patients with different primary tumor sites (lung vs other; p=0.
020）
。 The median PFS was 8.
8 months and the median OS was 32.
3 months
.

Overall survival rate

Exploratory blood immune cell analysis showed that after 2 weeks of treatment, circulating CD8+ T cell levels were elevated (27.
9% ± 13.
4% vs 31.
7% ±14.
6%, p=0.
03) and CD4+ T cell levels decreased (59.
6% ±13.
1% vs 56.
5% ±13.
0%, p=0.
001).

Total LAG-3-expressing T cell levels were reduced in patients who achieved partial response (0.
18%±0.
24% vs 0.
83%±0.
55%, p=0.
028).

Levels of bone marrow-derived suppressor cells were elevated during the study period, but were not
associated with response.

In summary, nivolumab in combination with temozolomide has shown good activity in patients with neuroendocrine tumors, especially in patients with
pulmonary neuroendocrine tumors.

Original source:

Dwight H.
Owen, Brooke Benner, Lai Wei, et al.
A Phase II Clinical Trial of Nivolumab and Temozolomide for Neuroendocrine Neoplasms.
Clin Cancer Res 2022; https://doi.
org/10.
1158/1078-0432.
CCR-22-1552