EPEN-06. CHEMOTHERAPY OF RECURRENT EPENDYMOMA: LONG-TERM RESPONSE ONLY IN FEW CASES

INTRODUCTION The efficacy of chemotherapy in recurrent ependymoma is unclear. We present results from the German HIT-REZ-studies. METHODS 137 patients were analyzed regarding the treatment with chemotherapy at first recurrence, the time from first relapse to progression (PFS) and to either time-point of death or last follow-up (OS). Tumor response evaluation was based on MRI and clinically; molecular data was available in 80. RESULTS In our cohort, 96 patients (20 supratentorial, 73 infratentorial, 3 spinal) received chemotherapy during first recurrence: 49 (51.0%) temozolomide (TMZ) monotherapy, 12 (12.5%) HIT-SKK regime, 9 (9.4%) carboplatin/etoposide (CE) and 26 (27.1%) other combinations. In 19.8% (26.5% in TMZ), chemotherapy was administered prior to surgery (neoadjuvant), which resulted in tumor progression in 78% (85% in TMZ). Gross-total resection was achieved in 86% without neoadjuvant chemotherapy and in 74% (69% in TMZ) with neoadjuvant treatment. Switching to trofosfamide/etoposide (TE) after surgery and unresponsiveness to TMZ showed further progression in all cases of tumor-residuum after surgery. Regarding 1-year-PFS, treatment with HIT-SKK (50.0%±14.4%) or CE (55.6%±16.6%) was advantageous over TMZ (30.2%±6.7%). However, 5-y-OS was lower in CE (19.0% ±16.8%) than in TMZ (39.8%±7.7%) and HIT-SKK (42.9%±8.7%). Long-term control was seen in individual cases of TMZ, HIT-SKK and CE, with TMZ providing longest response of 72 months. CONCLUSION Neoadjuvant TMZ has no significant advantage regarding PFS. However, in few cases chemotherapy prevented progression after incomplete resection. Difficulties in response evaluation and variability in therapies hinder conclusions. Supported by the German Children’s Cancer Foundation

Sintilimab for relapsed/refractory (r/r) extranodal NK/T cell lymphoma (ENKTL): Extended follow-up on the multicenter, single-arm phase II trail (ORIENT-4).

8050 Background: Patients with r/r ENKTL have a poor prognosis after failing an asparaginase-based regimen. The overexpression of PD-L1 induced by EBV infection is a potential mechanism for ENKTL to avert immune surveillance. Sintilimab, a fully human anti-PD-1 monoclonal antibody, has demonstrated efficacy in r/r ENKTL after the primary analysis of the ORIENT-4 study. Here, we report the updated efficacy and safety results with extended follow-up. Methods: Patients with pathologically confirmed r/r ENKTL were enrolled. Sintilimab was given 200 mg IV Q3W, until PD, death, unacceptable toxicity, or withdrawal from the study. Treatment beyond PD is allowed. Tumor response evaluation was performed by both PET-CT and CT/MRI with contrast. The primary endpoint was objective response rate per Lugano 2014. Data cut-off date for this analysis was Jan 17, 2020. Results: A total of 28 patient were enrolled and treated. With a median follow-up of 26.9 months (range, 23.3 to 28.6), the median treatment duration was 24.15 months (range, 1.4 to 28.7). Of 20 patients with progressive disease (PD) by investigator per Lugano 2014 criteria, 19/20 (95%) patients received treatment beyond PD. The median OS has not been reached and 24-month OS rate was 78.6% (95% CI, 58.4% to 89.8%). ORR was 67.9% (95% CI, 47.6% to 84.1%), including 4 pts who experienced PD prior to having a response. DCR was 85.7%, including 5 pts who experienced PD before SD or response. Median duration of response was 4.1 months (range, 1.9 to 15.2+). After treatment, the mean EQ-5D-5L VAS Score (from 79.3 to 90.8), EQ-5D-5L Index Value (from 0.8 to 0.9) and EORTC QLQ-C30 (from 70.5 to 87.3) were all increased. The Treatment-related adverse events (TRAEs) of any grade occurred in 28 (100%) pts; grade 3 occurred in 11 (39.4%) pts, most commonly, decreased lymphocyte count (2 [7.1%]) and diabetes (2 [7.1%]); no grade 4-5 TRAE. Conclusions: In addition to an encourage response, sintilimab also demonstrated long-term clinical benefit, with 78.6% of 24-month OS rate, and favorable long-term safety profile after extended follow-up. Considering the high rate (95%) of treatment beyond PD, Lugano 2014 may not be a suitable criteria for evaluating the efficacy of anti-PD-1 antibody in r/r ENKTL. Clinical trial information: NCT03228836 .

Apatinib combined with SOX neoadjuvant therapy for locally advanced gastric cancer: A multicenter, single-armed, prospective study.

367 Background: Molecular targeted therapy has made great progress in the treatment of gastric cancer. In some previous studies, apatinib, an oral small molecular of VEGFR-2 TKI, had been confirmed can improve OS and PFS with an acceptable safety profile in patients with advanced gastric cancer refractory to two or more lines of prior chemotherapy. However, there is limited evidence about the safety and feasibility of apatinib combined with SOX regimen as neoadjuvant therapy for locally advanced gastric cancer (AGC). Methods: This is a multicenter, single-armed, prospective study. Patients with AGC (cT2-4N+M0) without prior anti-cancer strategies were included. Patients were received 2 to 5 cycles (21 days a cycle) of neoadjuvant therapy using S-1 (po, 40-60 mg bid, day1-day14), oxaliplatin (iv, 130 mg/m2, day1), and apatinib (po, 500 mg qd). Apatinib was prohibited in the last cycle. The operation should be performed 2 to 4 weeks later of the neoadjuvant therapy. The primary endpoint was R0 resection rate. The secondary endpoint included safety, ORR, and DCR. Results: A total of 56 patients from 10 centers in China were recruited. There were 43 males and 13 females. The median age was 63.04 years (range 41-75 years). There were 43 patients with tumor response evaluation, 29 patients (67.4%) had partial response (PR), 12 patients (27.9%) had stable disease (SD), and 2 patient (4.6%) had progressive disease (PD). The ORR and DCR were 67.4% (29/43) and 95.3% (41/43), respectively. 36 patients received gastric surgery, the R0 resection rate was 97.2%, 3 patients had postoperative complication: one had intestinal obstruction and 2 had pneumonia (all Clavien-Dindo classification less than grade II). 46 patients were included for safety analysis. The incidence of adverse events (AEs) and grade 3/4 AEs were 84.8% (39/46) and 17.4% (8/46), respectively. The most common AEs were neutropenia (40%), low platelet count (40%), leucopenia (32.6%), vomit (13%). Conclusions: This prospective study shows that neoadjuvant therapy using apatinib plus SOX brings clinical benefit to AGC with a high disease control rate and tolerable adverse reactions. Clinical trial information: NCT 03192735.

Sintilimab for relapsed/refractory (r/r) extranodal NK/T-cell lymphoma (ENKTL): A multicenter, single-arm, phase 2 trial (ORIENT-4).

7504 Background: ENKTL account for more than 20% of the peripheral T-cell lymphoma in Asia. Patients with r/r ENKTL have a poor prognosis after failing an L-asparaginase based regimen, and the median overall survival is less than 6 months. The overexpression of PD-L1 induced by EBV infection is a potential mechanism for ENKTL to avert immune surveillance, and recent studies of PD-1 antibodies in pts with r/r ENKTL have demonstrated potential efficacy. Sintilimab, a fully human anti-PD-1 monoclonal antibody, has a safety profile consistent with other approved PD-1 antibodies and was approved for r/r classical Hodgkin lymphoma in China in 2018. This multicenter, single-arm, phase 2 study aims to validate the efficacy and safety of sintilimab monotherapy in patients with r/r ENKTL in China. Methods: Patients with pathologically confirmed r/r ENKTL were enrolled. Sintilimab was given 200 mg IV Q3W, until PD, death, unacceptable toxicity, or withdrawal from the study. Treatment beyond PD is allowed. Tumor response evaluation was performed by both PET-CT and CT/MRI with contrast. The primary endpoint was objective response rate based on LUGANO 2014 criteria. Data cut-off date for this analysis was Feb 2, 2019. Results: From Aug 31, 2017 to Feb 7, 2018, a total of 28 patients were enrolled: 60.7% male and the median age was 37 (range: 19–65) yr. Sixty-eight percent of patients were stage IV and 89.3% were ECOG PS ≥ 1. All patients had failed an L-asparaginase based regimen, the median lines of previous therapy were 3 (range: 1–13), 78.6% patients received prior radiotherapy and 7.1% had failed HSCT. Median duration of therapy was 14.04 (range: 1.4–17.3) months and 19 patients are still receiving sintilimab. Sixty-eight percent (19/28, 95%CI: 47.6%–84.1%) of patients achieved response (CR+PR), including 4 pts who experienced PD prior to having a response. DCR was 85.7%, including 5 pts who experienced PD before SD or response. The 1-year OS rate was 82.1% and the median OS has not been reached. Most TRAEs were G1–2 (67.9%) and no patients discontinued treatment due to AEs. The most common TRAE was decreased lymphocyte count (46.4%) and 84.6% were grade 1–2. SAEs occurred in 21.4% of patients and none were related to sintilimab. No patients died from AEs. Conclusions: Sintilimab is effective and well tolerated in r/r ENKTL and could be a promising treatment option for these patients. Early disease progression observed by PET scan in this study could be pseudoprogression as it did not correlate with poor outcome, which warrants further investigation. Clinical trial information: NCT03228836.

Comparative Effectiveness of Tumor Response Assessment Methods: Standard of Care Versus Computer-Assisted Response Evaluation

Purpose To compare the effectiveness of metastatic tumor response evaluation with computed tomography using computer-assisted versus manual methods. Materials and Methods In this institutional review board–approved, Health Insurance Portability and Accountability Act–compliant retrospective study, 11 readers from 10 different institutions independently categorized tumor response according to three different therapeutic response criteria by using paired baseline and initial post-therapy computed tomography studies from 20 randomly selected patients with metastatic renal cell carcinoma who were treated with sunitinib as part of a completed phase III multi-institutional study. Images were evaluated with a manual tumor response evaluation method (standard of care) and with computer-assisted response evaluation (CARE) that included stepwise guidance, interactive error identification and correction methods, automated tumor metric extraction, calculations, response categorization, and data and image archiving. A crossover design, patient randomization, and 2-week washout period were used to reduce recall bias. Comparative effectiveness metrics included error rate and mean patient evaluation time. Results The standard-of-care method, on average, was associated with one or more errors in 30.5% (6.1 of 20) of patients, whereas CARE had a 0.0% (0.0 of 20) error rate ( P < .001). The most common errors were related to data transfer and arithmetic calculation. In patients with errors, the median number of error types was 1 (range, 1 to 3). Mean patient evaluation time with CARE was twice as fast as the standard-of-care method (6.4 minutes v 13.1 minutes; P < .001). Conclusion CARE reduced errors and time of evaluation, which indicated better overall effectiveness than manual tumor response evaluation methods that are the current standard of care.