Phase II trial of sunitinib malate and lomustine in patients with temozolomide refractory recurrent low-grade and anaplastic gliomas.

Background: Recurrent low-grade and anaplastic gliomas eventually transform to a higher grade that is characterized by neo-angiogenesis. Sunitinib inhibits multiple tyrosine kinase receptors (including VEGFR, PDGFR and c-Kit) but has no meaningful activity as a mono-therapy for recurrent glioblastoma when given at a daily dose of 37,5 mg (Neyns et al. J Neurooncol. 2011). We investigated sunitinib in combination with lomustine (CCNU) for the treatment of patients (pts) with temozolomide (TMZ) refractory recurrent low-grade or anaplastic glioma. Methods: Pts received a daily dose of 25 mg sunitinib for 28 consecutive days followed by a 14 days treatment-free interval. CCNU was administered as a single dose (80 mg/m²) on day 14 of a 6w cycle. T1 ± Gd and T2/FLAIR weighted MRI images were obtained q6 wks. 18FET-PET was performed at baseline and reassessed in responding pts. Results: 13 pts were enrolled (mean age 40 [range 33-49]; M/F 8/5; KPS 80-90/70-60: 8/5 pts). All pts had PD following surgery, RT and TMZ. In 7 pts, treatment was initiated at 2nd recurrence, in 4 pts at 3rd recurrence and in 2 pts at the 4th recurrence. Most frequent AEs where fatigue (gr 2: n= 3; gr 3: n= 1), thrombopenia (gr 2: n= 1 gr 3: n= 3 gr4: n= 1), neutropenia (gr 2: n= 2; gr3: n= 2; gr4: n= 2) and lymphopenia (gr 2: n=1; gr 3: n=2; gr 4: n=1). In 5/13 pts CCNU had to be discontinued because of AEs. Treatment with sunitinib was continued in these cases without reoccurrence of AEs. BOR according to RANO criteria: 1 CR, 1 PR (not-confirmed) and 2 SD (DCR: 4/13= 31%). In the patient with CR, FET-PET indicated a complete metabolic response. After a mean FU of 7 mths (range 2 -19), 5 pts are alive. The 6-month PFS is 23% (3/13 pts); median PFS is 1,8 mths (95%CI 1.0 - 2,7). A durable disease control was obtained in 3 pts (TTP respectively 14.8, 11.8+ and 19.2+ mths). Conclusions: in this heavily pretreated population with recurrent low-grade and anaplastic glioma the combination of sunitinib and CCNU is associated with acceptable toxicity and offers a durable progression-free survival in a subgroup of pts. Molecular predictive factors identifying the sensitive population would be needed to justify further clinical investigation of this combination.