Desideri, Serena

Abstract Background High-grade gliomas (HGG) have a poor prognosis despite aggressive treatment. Severe, persistent lymphopenia occurring in HGG patients after concurrent chemoradiation is associated with worse survival. NT-I7, a long-acting interleukin-7 analog, has been shown to increase CD4 and CD8 counts in healthy, septic, and HIV-positive adults. This multi-institutional, NCI-funded dose-escalation trial is the first to evaluate NT-I7 safety and activity in HGG patients with severe treatment-related lymphopenia (TRL) and the effect of co-administered glucocorticoids. Methods Eligible HGG patients had CD4 counts <300 cells/mm3 after 5 weeks of standard chemoradiation and were receiving either ≤0.75 or ≥4 mg/day of dexamethasone. Patients received a single intramuscular dose of NT-I7 (60 or 360 µg/kg) post-chemoradiation, followed by safety evaluation and multi-parameter, longitudinal monitoring of lymphocyte populations and immunologic function. Results NT-I7 was well tolerated in all 12 patients (median age 64; median CD4 count 161 cells/mm³) before the study closed prematurely. Absolute lymphocyte counts doubled in 83% (10/12; 95% CI: 51.6%-97.9%) of patients, and CD4 counts doubled in 42% (5/12; 95% CI: 15.2%-72.3%) of patients. Glucocorticoid use did not significantly affect CD4 or lymphocyte increases. Correlative immune profiling revealed increased Ki67 expression in CD4 (P < .005) and CD8 (P < .05) after one week, along with the expansion of CD4 and CD8 T-cell subsets and CD56 + natural killer cells. Conclusions NT-I7 is well tolerated and effectively increases lymphocyte and CD4 counts in severe TRL patients, regardless of glucocorticoid use, suggesting its potential to mitigate TRL and improve outcomes in HGG.

Abstract BACKGROUND Preclinical studies have demonstrated that IDH1-mutant (IDHmt) gliomas harbor a BRCAness phenotype with a defect in homologous recombination that confers PARP inhibitor sensitivity. METHODS The phase II component of ABTC 1801 examined the efficacy of the combination of pamiparib (BeiGene BGB-290) with low dose metronomic temozolomide in recurrent IDHmt grade 2 and 3 gliomas. In this two-stage design, Arm A enrolled patients who had failed two lines and Arm B a single line of alkylator therapy. Pamiparib and temozolomide doses based on phase I results was 60 mg BID and 20 mg daily. Primary endpoint was objective response rate (ORR). RESULTS 39 patients (Arm A 15, Arm B 24) enrolled in the phase II. Median age was 45 (range: 25-69), 56% male, and median KPS 90. 72% of tumors were MGMT methylated. There were no confirmed responses in Arm A and one in Arm B; neither arm met the threshold for additional accrual. One-third of subjects discontinued treatment for reasons other than progressive disease. Estimated median PFS was 5.8 months in Arm A and 11.3 months in Arm B. Seven subjects (Arm A 3, Arm B 4) developed DLT during treatment. Grade 3+ toxicity was principally hematologic; 9 patients had grade 3 anemia, 7 grade 3 and 3 grade 4 neutropenia, and 3 grade 3 thrombocytopenia. In enhancing and non-enhancing tumors from 8 surgical arm patients, median unbound drug tumor/plasma ratios were 0.98 and 0.92, respectively; and median unbound pamiparib tumor concentrations were 209 and 188 nmol/L (or nmol/kg), respectively, which were >20-fold the in vitro IC50 for PARP inhibition. CONCLUSIONS While pamiparib appeared to achieve sufficient pharmacologically active concentrations in both enhancing and non-enhancing tumors, combination with temozolomide did not produce a meaningful ORR in IDHmt recurrent gliomas. Cumulative hematologic toxicity was substantial.

Abstract Purpose: A phase I, dose-finding study of vorinostat in combination with temozolomide (TMZ) was conducted to determine the maximum tolerated dose (MTD), safety, and pharmacokinetics in patients with high-grade glioma (HGG). Experimental Design: This phase I, dose-finding, investigational study was conducted in two parts. Part 1 was a dose-escalation study of vorinostat in combination with TMZ 150 mg/m2/day for 5 days every 28 days. Part 2 was a dose-escalation study of vorinostat in combination with TMZ 150 mg/m2/day for 5 days of the first cycle and 200 mg/m2/day for 5 days of the subsequent 28-day cycles. Results: In part 1, the MTD of vorinostat administered on days 1 to 7 and 15 to 21 of every 28-day cycle, in combination with TMZ, was 500 mg daily. Dose-limiting toxicities (DLT) included grade 3 anorexia, grade 3 ALT, and grade 5 hemorrhage in the setting of grade 4 thrombocytopenia. In part 2, the MTD of vorinostat on days 1 to 7 and 15 to 21 of every 28-day cycle, combined with TMZ, was 400 mg daily. No DLTs were encountered, but vorinostat dosing could not be escalated further due to thrombocytopenia. The most common serious adverse events were fatigue, lymphopenia, thrombocytopenia, and thromboembolic events. There were no apparent pharmacokinetic interactions between vorinostat and TMZ. Vorinostat treatment resulted in hyperacetylation of histones H3 and H4 in peripheral mononuclear cells. Conclusion: Vorinostat in combination with temozolomide is well tolerated in patients with HGG. A phase I/II trial of vorinostat with radiotherapy and concomitant TMZ in newly diagnosed glioblastoma is underway. Clin Cancer Res; 18(21); 6032–9. ©2012 AACR.