Abstract 1469
Background
Pem, an immune checkpoint inhibitor, has been demonstrated to be active in various neoplasms with MMRd. No data exist about its efficacy in MMRd glioma patients.
Methods
MMRd HGG patients relapsed after receiving RT and CT were treated with Pem. MMR status was analyzed by immunohistochemistry, including the MLH1, MSH2, MSH6, and PMS2 markers. MMR deficiency was defined as presence of a weak (wMMRd) or absent (aMMRd) signal on immunohistochemistry for at least one MMR protein. Other inclusion criteria were: ECOG PS 0-2, histologically confirmed gliomas, dexamethasone ≤4 mg. Pem was administered at 200 mg every 3 weeks until disease progression or unacceptable toxicity. Tumor response was evaluated by brain MRI every 10 weeks according to the RANO criteria. OS and PFS were evaluated by Kaplan-Meier curves. CTCAE v4.0 was used for toxicity assessment.
Results
Among 167 glioma patients, we found 22 MMRd gliomas. 12 PTS were treated with Pem: 8 wMMRd and 4 aMMRd. According to Bethesda criteria, all PTS had microsatellite stability. Tumor histologies included 5 anaplastic astrocytoma, 1 anaplastic oligodendroglioma, 6 glioblastoma (GBM). MSH2 deficiency was found in 6 cases, MSH6 deficiency in 9 cases, PMS2 and MLH1 deficiency in 2 cases. Median number of prior lines of chemotherapy was 1 (range 1-5). Stable disease (SD) was reported in 4 PTS (33%); 8 PTS showed progressive disease (PD). PTS with anaplastic gliomas showed a statistically significant association with SD (p = 0.03, OR = 3); all GBM PTS reported PD; status of MMRd (weak/absent), IDH (mutated/wild-type), MSH2 and MLH6 (deficient/proficient) were not associated with SD. Median follow up was 14.7 ms. OS was 5.6 ms (95% CI 0.1-13.8), PFS 2.4 ms (95% CI 1.8-2.9). OS was 2.8 ms and 5.6 ms (p = 0.9), PFS was 1.8 ms and 3.1 ms (p = 0.5) in PTS with wMMRd and aMMRd. PTS reporting SD and PD had PFS of 7.4 ms (95% CI 4.6-10.2) and 1.8 ms (95% CI 0.2-3.4), p = 0.002; OS was “not reached” and 2.8 ms in PTS having SD vs PD (p = 0.04). Grade ≥3 adverse events were reported in 8% of PTS.
Conclusions
A subgroup of recurrent MMRd HGG patients might benefit from Pem, especially those with anaplastic gliomas. There was a trend for a longer PFS and OS in PTS with aMMRd. Analyses for identifying additional molecular predictive factors is ongoing.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2728 - MicroRNA expression and DNA methylation profiles do not distinguish between primary and recurrent well-differentiated liposarcoma
Presenter: Melissa Vos
Session: Poster Display session 1
Resources:
Abstract
3197 - Genomic Alterations, Tumor Mutation Burden and Prognosis of Chinese Cardiac Sarcoma Patients
Presenter: Na Zhu
Session: Poster Display session 1
Resources:
Abstract
4214 - Evaluation of a peptide-conjugated alkylator melflufen in osteosarcoma preclinical models
Presenter: Konstantin Byrgazov
Session: Poster Display session 1
Resources:
Abstract
2654 - Expression analysis of NHEJ and HR genes in Ewing sarcomas: indications of DSB repair dysfunction
Presenter: Anastasios Kyriazoglou
Session: Poster Display session 1
Resources:
Abstract
4383 - Epidemiology of Synovial Sarcoma in EU28 countries
Presenter: Nedra Joseph
Session: Poster Display session 1
Resources:
Abstract
1937 - Resection Of High-Grade Large Soft Tissue Sarcoma With Adequate Wide Margin Can Lead To Good Local Control Without Adjuvant Radiotherapy
Presenter: Toshiyuki Kunisada
Session: Poster Display session 1
Resources:
Abstract
3757 - Influence of eribulin on proliferation, migration and invasion properties of leiomyosarcoma cell line models
Presenter: Marta Mendiola
Session: Poster Display session 1
Resources:
Abstract
1040 - EREMISS: Efficacy of regorafenib (REG) as maintenance therapy in non-adipocytic soft tissue sarcomas (STS) having received 1st-line doxorubicin-based chemotherapy (Doxo-CT)
Presenter: Nicolas Penel
Session: Poster Display session 1
Resources:
Abstract
1048 - A Phase 2 biomarker-driven study evaluating the clinical efficacy of an MDM2 inhibitor, milademetan, in patients with intimal sarcoma, a disease with a high unmet need
Presenter: Kan Yonemori
Session: Poster Display session 1
Resources:
Abstract
1511 - A pilot study of oral paclitaxel (ORAXOL) in subjects with cutaneous angiosarcomas (KX-ORAX-010)
Presenter: Herbert Loong
Session: Poster Display session 1
Resources:
Abstract