Recurrent WHO Grade Research Articles

Inhibition of TGF-β2 with AP 12009 in Recurrent Malignant Gliomas: From Preclinical to Phase I/II Studies

Transforming growth factor-beta2 (TGF-beta2) is known to suppress the immune response to cancer cells and plays a pivotal role in tumor progression by regulating key mechanisms including proliferation, metastasis, and angiogenesis. For targeted protein suppression the TGF-beta2-specific antisense oligodeoxynucleotide AP 12009 was developed. In vitro experiments have been performed to prove specificity and efficacy of the TGF-beta2 inhibitor AP 12009 employing patient-derived malignant glioma cells as well as peripheral blood mononuclear cells (PBMCs) from patients. Clinically, the antisense compound AP 12009 was assessed in three Phase I/II-studies for the treatment of patients with recurrent or refractory malignant (high-grade) glioma WHO grade III or IV. Although the study was not primarily designed as an efficacy evaluation, prolonged survival compared to literature data and response data were observed, which are very rarely seen in this tumor indication. Two patients experienced long-lasting complete tumor remissions. These results implicate targeted TGF-beta2-suppression using AP 12009 as a promising novel approach for malignant gliomas and other highly aggressive, TGF-beta-2-overexpressing tumors.

Phase II study of imatinib mesylate and hydroxyurea for recurrent grade III malignant gliomas

Recent reports demonstrate the activity of imatinib mesylate, an ATP-mimetic, tyrosine kinase inhibitor, plus hydroxyurea, a ribonucleotide reductase inhibitor, in patients with recurrent glioblastoma multiforme. We performed the current phase 2 study to evaluate this regimen among patients with recurrent WHO grade III malignant glioma (MG). Patients with grade III MG at any recurrence, received imatinib mesylate plus hydroxyurea (500 mg twice a day) orally on a continuous, daily schedule. The imatinib mesylate dose was 500 mg twice a day for patients on enzyme inducing anti-epileptic drugs (EIAEDs) and 400 mg once a day for those not on EIAEDs. Clinical assessments were performed monthly and radiographic assessments were obtained at least every 2 months. The primary endpoint was 6-month progression-free survival (PFS) rate. Thirty-nine patients were enrolled. All patients had progressive disease after prior radiotherapy and at least temozolomide-based chemotherapy. The median number of episodes of prior progression was 2 (range, 1-7) and the median number of prior treatment regimens was 3 (range, 1-8). With a median follow-up of 82.9 weeks, 24% of patients were progression-free at 6 months. The radiographic response rate was 10%, while 33% achieved stable disease. Among patients who achieved at least stable disease at first evaluation, the 6-month and 12-month PFS rates were 53% and 29%, respectively. The most common grade 3 or greater toxicities were hematologic and complicated less than 4% of administered courses. Imatinib mesylate plus hydroxyurea, is well tolerated and associated with anti-tumor activity in some patients with recurrent grade 3 MG.

Hydroxyurea Treatment of Meningiomas: A Pilot Study

To present a pilot study of hydroxyurea chemotherapy in the management of surgically difficult meningiomas. Prospective case series. Tertiary referral center. Six patients were enrolled: five had symptomatic recurrent or residual WHO Grade I meningiomas and one had an unoperated anterior clinoidal meningioma. MRI volumetry before and after treatment, hematological state, progression to surgery. Hydroxyurea was administered for 1 year, starting at a dose of 15 mg/kg/day. No tumors reduced in size on treatment and one continued to grow rapidly. Three remained stable. Full volumetry was unavailable on two patients. One patient was withdrawn from the study because of myelosuppression and underwent further surgery. Three experienced significant drug-related side effects. Two patients underwent further surgery. From this small pilot study we conclude that although hydroxyurea may be associated with disease stabilization in some patients, it did not reduce tumor mass and it caused significant side effects in some of our subjects.

Reirradiation of Recurrent WHO Grade III Astrocytomas Using Fractionated Stereotactic Radiotherapy (FSRT)

To assess the effect of reirradiation in recurrent WHO grade III astrocytomas. From January 1995 to July 2003, 40 patients with grade III gliomas were treated with fractionated stereotactic reirradiation at the time point of recurrence. Median size of planning target volume for reirradiation was 56.2 ml (range 25.1-296.2 ml). A median target total dose of 36 Gy (range 20-57.6 Gy) was applied using a median fractionation of 5 x 2 Gy/week with a 6-MeV linear accelerator. Radiotherapy was well tolerated by all patients. No toxicities > CTC grade 2 developed. Median overall survival calculated from the time point of primary diagnosis was 48 months (range 7-180 months). The 5- and 10-year overall survival rates were 49.5% and 24.7%, respectively. From the time point of reirradiation, median survival was 16 months (range 1-98 months). Median progression-free survival from the time point of reirradiation was 8 months (range 1-72 months). No prognosticators for survival or progression-free survival after reirradiation could be identified. Fractionated stereotactic radiotherapy is well tolerated and effective in patients with recurrent grade III astrocytomas.