Jan Buter

Purpose: Myelotoxicity is a well-known adverse effect of alkylating chemotherapy for glioblastoma. While risk factors during first-line therapy are established, little is known about myelotoxicity recurrence in second-line treatment. This study investigates whether first-line myelotoxicity therapy predisposes patients to recurrence in the second-line setting. Patients and Methods: We conducted a retrospective cohort study of 589 patients with glioblastoma treated at the Brain Tumor Centre Amsterdam (2005-2022). Of these, 178 received second-line lomustine or rechallenge temozolomide. Myelotoxicity severity was predominantly assessed using nadir hematological values and its duration. A log-link generalized linear model evaluated associations between first-line and second-line myelotoxicity severity, adjusting for covariates. Cox proportional hazards models assessed time to myelotoxicity onset. Results: We included 151 patients (mean age 57.1 ± 11.8 years; 66.9% male). Lomustine was given to 66.9%. Myelotoxicity occurred in 73.5% of patients, with 19.9% developing severe toxicity. First-line myelotoxicity severity was significantly associated with second-line severity (β = 1.3, P < .001). Lomustine correlated with higher myelotoxicity severity than temozolomide (β = 1.4, P = .002). Higher first-line myelotoxicity scores predicted earlier onset of any-grade (HR = 1.4, P < .001) and severe (HR =2.1, P < .001) myelotoxicity in second-line therapy. Conclusion: First-line myelotoxicity for glioblastoma predicts its recurrence and earlier onset in second-line therapy. Patients with toxicity in first-line have an increased risk of severe hematological toxicity upon re-exposure. Lomustine carries a higher risk for myelotoxicity than temozolomide. These findings suggest an inherent predisposition to alkylating chemotherapy-induced myelotoxicity for a subgroup of patients. Integrating prior myelotoxicity history into second-line treatment decisions may improve risk stratification and guide monitoring.

The prognosis of malignant primary high-grade brain tumors, predominantly glioblastomas, is poor despite intensive multimodality treatment options. In more than 50% of patients with glioblastomas, potentially targetable mutations are present, including rearrangements, altered splicing, and/or focal amplifications of epidermal growth factor receptor (EGFR) by signaling through the RAF/RAS pathway. We studied whether treatment with the clinically available anti-EGFR monoclonal antibody panitumumab provides clinical benefit for patients with RAF/RAS-wild-type (wt) glioblastomas in the Drug Rediscovery Protocol (DRUP). Patients with progression of treatment refractory RAF/RASwt glioblastoma were included for treatment with panitumumab in DRUP when measurable according to RANO criteria. The primary endpoints of this study are clinical benefit (CB: defined as confirmed objective response [OR] or stable disease [SD] ≥ 16 weeks) and safety. Patients were enrolled using a Simon-like 2-stage model, with 8 patients in stage 1 and up to 24 patients in stage 2 if at least 1 in 8 patients had CB in stage 1. Between 03-2018 and 02-2022, 24 evaluable patients were treated. CB was observed in 5 patients (21%), including 2 patients with partial response (8.3%) and 3 patients with SD ≥ 16 weeks (12.5%). After median follow-up of 15 months, median progression-free survival and overall survival were 1.7 months (95% CI 1.6-2.1 months) and 4.5 months (95% CI 2.9-8.6 months), respectively. No unexpected toxicities were observed. Panitumumab treatment provides limited CB in patients with recurrent RAF/RASwt glioblastoma precluding further development of this therapeutic strategy.

The optimal volumetric threshold for determining progressive disease (PD) in recurrent glioblastoma is yet to be determined. We investigated a range of thresholds in association with overall survival (OS). First recurrent glioblastoma patients treated with bevacizumab and/or lomustine were included from the phase II BELOB and phase III EORTC26101 trials. Enhancing and nonenhancing tumor volumes were measured at baseline, first (6 weeks), and second (12 weeks) follow-up. Hazard ratios (HRs) for the appearance of new lesions and several thresholds for tumor volume increase were calculated using cox regression analysis. Results were corrected in a multivariate analysis for well-established prognostic factors. At first and second follow-up, 138 and 94 patients respectively, were deemed eligible for analysis of enhancing volumes, while 89 patients were included in the analysis of nonenhancing volumes at first follow-up. New lesions were associated with a significantly worse OS (3.2 versus 11.2 months, HR = 7.03, P < .001). At first follow-up a threshold of enhancing volume increase of ≥20% provided the highest HR (5.55, p = .001. At second follow-up, any increase in enhancing volume (≥0%) provided the highest HR (9.00, p < .001). When measuring nonenhancing volume at first follow-up, only 6 additional patients were scored as PD with the highest HR of ≥25% increase in volume (HR=3.25, p = .008). Early appearing new lesions were associated with poor OS. Lowering the volumetric threshold for PD at both first and second follow-up improved survival prediction. However, the additional number of patients categorized as PD by lowering the threshold was very low. The per-RANO added change in nonenhancing volumes to the analyses was of limited value.

The S100B protein is associated with brain damage and a breached blood–brain barrier. A previous pilot study showed that high serum levels of S100B are associated with shorter survival in glioma patients. The aim of our study was to assess the prognostic value in terms of survival and longitudinal dynamics of serum S100B for patients with newly diagnosed and recurrent glioma. We obtained blood samples from patients with newly diagnosed and recurrent glioma before the start (baseline) and at fixed time-points during temozolomide chemotherapy. S100B-data were dichotomized according to the upper limit of the reference value of 0.1 μg/L. Overall survival (OS) was estimated with Kaplan–Meier curves and groups were compared with the log rank analysis. To correct for potential confounders a Cox regression analysis was used. We included 86 patients with newly-diagnosed and 27 patients with recurrent glioma. Most patients in both groups had baseline serum levels within normal limits. In the newly diagnosed patients we found no significant difference in OS between the group of patients with S100B levels >0.1 μg/L at baseline compared to those with <0.1 μg/L. In the patients with recurrent glioma we found a significantly shorter OS for patients with raised levels. In both groups, S100B values did not change significantly throughout the course of the disease. Serum S100B levels do not seem to have prognostic value in newly diagnosed glioma patients. In recurrent glioma patients S100B might be of value in terms of prognostication of survival.

INTRODUCTION: Treatment options for recurrent glioblastoma remain limited, with only modest activity of second line chemotherapy. Despite the absence of well controlled trials, bevacizumab is widely used for recurrent glioblastoma. Nonetheless, it remains unclear if the high response rates observed after treatment with bevacizumab translate into an overall survival (OS) benefit. We report the first randomized phase II trial on bevacizumab in recurrent glioblastoma with a control arm without bevacizumab. METHODS: This was multicenter phase II study conducted in 14 Dutch sites. Patients with a first recurrence of a glioblastoma after chemo-irradiation with temozolomide were randomized between treatment with oral lomustine 110 mg/m2 once every 6 weeks, with bevacizumab 10 mg/kg once every 2 weeks intravenously or with the combination lomustine 110 mg/m2 every 6 weeks and bevacizumab 10 mg/kg every 2 weeks. Response was assessed using the RANO criteria. Primary endpoint was OS at 9 months. A safety analysis was planned after the first ten patients completed two cycles of 6 weeks in the combination arm. RESULTS: 153 patients were randomized, of which 148 were eligible. After the safety analysis the lomustine dosage in the combination arm was reduced to 90 mg/m2 because of thrombocytopenia, resulting in bevacizumab dose delays. After reduction the treatment in the combination arm was well tolerated. The percentage 9 month OS (95% confidence interval) was 43% (29, 57) in the lomustine arm, 38% (25, 51) in the bevacizumab arm, and 59% (43, 72) in the bevacizumab/lomustine 90 arm. Response rates were 35-40% for bevacizumab treated patients, and 5% in the lomustine single agent arm. CONCLUSION: This study does not show a meaningful OS at 9 months after treatment with bevacizumab alone. However, the results of combination therapy of bevacizumab with lomustine met the prespecified criterion for further phase III studies. AKNOWLEDGMENTS: This study was supported by an unrestricted grant from Roche Nederland bv. The study was also supported by grant nr DDHK 2010-4678 from the ‘KWF Kankerbestrijding’ (Dutch Cancer Society).

Local treatment with surgery and radiotherapy gives unsatisfactory results in patients with locally advanced cancer. In many cases distant metastases appear shortly after the removal of the primary tumor. Selecting breast cancer as a model for locally advanced disease, we are extrapolating our findings to other solid tumors. Neoadjuvant chemotherapy has improved survival of these patients by downstaging the primary tumors allowing local treatment and early elimination of distant micrometastases.We recently reported in this journal on a study of 42 patients with locally advanced breast cancer (LABC) who received prolonged neoadjuvant chemotherapy of doxorubicin, cyclophosphamide, and GM-CSF prior to surgery and postoperative radiotherapy. These results were promising and prompted us to initiate an international randomized phase III study in which either six neoadjuvant cycles or three neoadjuvant cycles plus three adjuvant cycles are being compared. In LABC patients treated with six neoadjuvant chemoimmunotherapy cycles, we observed a significant rise in the dendritic cell content of the axillary tumor-draining lymph nodes after therapy, associated with an encouraging disease free survival and overall survival. We hypothesize that the prolonged presence of draining lymph nodes in combination with the repeated tumor antigen release, dendritic cell recruitment, and activation may account for the observed increased survival of LABC patients. Based on our findings and the results of preclinical studies, we hypothesize that it is more effective to administer chemotherapy in an extended neoadjuvant regimen, taking advantage of the concurrent biological and immunological processes in the primary tumor and its draining lymph nodes.