A Phase Ib multicenter, dose-escalation study of the polyamine analogue PG-11047 in combination with gemcitabine, docetaxel, bevacizumab, erlotinib, cisplatin, 5-fluorouracil, or sunitinib in patients with advanced solid tumors or lymphoma.

PURPOSE: Polyamines are absolutely essential for maintaining tumor cell proliferation. PG-11047, a polyamine analogue, is a nonfunctional competitor of the natural polyamine spermine that has demonstrated anticancer activity in cells and animal models of multiple cancer types. Preclinical investigations into the effects of common chemotherapeutic agents have revealed overlap with components of the polyamine metabolic pathway also affected by PG-11047. This report describes a Phase Ib clinical trial investigating PG-11047 in combination with cytotoxic and anti-angiogenic chemotherapeutic agents in patients with advanced refractory metastatic solid tumors or lymphoma. METHODS: A total of 172 patients were assigned to treatment arms based on cancer type to receive the appropriate standard-of-care therapy (gemcitabine, docetaxel, bevacizumab, erlotinib, cisplatin, 5-fluorouracil (5-FU), or sunitinib as directed) along with once weekly intravenous infusions of PG-11047. PG-11047 dose escalation ranged from 50 to 590 mg. RESULTS: The maximum tolerated dose (MTD) of PG-11047 in combination with bevacizumab, erlotinib, cisplatin, and 5-FU was 590 mg. Dose-limiting toxicities (DLTs) in these groups were rare (5 of 148 patients). Overall partial responses (PR) were observed in 12% of patients treated with PG-11047 and bevacizumab, with stable disease documented in an additional 40%. Stable disease occurred in 71.4% of patients in the 5-FU arm, 54.1% in the cisplatin arm, and 33.3% in the erlotinib arm. Four of the patients receiving cisplatin + PG-11047 (20%) had unconfirmed PRs. MTDs for gemcitabine, docetaxel, and sunitinib could not be determined due to DLTs at low doses of PG-11047 and small sample size. CONCLUSIONS: Results of this Phase Ib trial indicate that PG-11047 can be safely administered to patients in combination with bevacizumab, erlotinib, cisplatin, and 5-FU on the once weekly dosing schedule described and may provide therapeutic benefit. The manageable toxicity profile and high MTD determination provide a safety profile for further clinical studies.

Azacitidine favorably modulates PSA kinetics correlating with plasma DNA LINE-1 hypomethylation in men with chemonaïve castration-resistant prostate cancer.

BACKGROUND: Azacitidine is a hypomethylating agent that activates genes repressed by promoter methylation. Preclinically, demethylating agents reverse resistance of prostate cancer to androgen ablation. A phase II trial evaluated azacitidine for men with castration-resistant prostate cancer (CRPC) progressing on combined androgen blockade (CAB). METHODS: Chemonaïve patients with CRPC on CAB and PSA-doubling time (DT) < 3 months were eligible. The primary endpoint was prolongation of PSA-DT to ≥ 3 months. Correlation of biologic activity (fetal hemoglobin, plasma DNA LINE-1 methylation) with prolongation of PSA-DT was tested. CAB was continued and azacitidine 75 mg/m(2) was administered subcutaneously on days 1-5 of each 28-day cycle up to 12 cycles or until clinical progression/intolerable toxicities. RESULTS: Thirty-six patients were enrolled, 80.6% had metastatic disease, and 34 were evaluable. A PSA-DT ≥ 3 months was attained in 19 patients (55.8%). Overall median PSA-DT was significantly prolonged compared to baseline (2.8 vs. 1.5 months, P < 0.01). Fourteen patients had some PSA decline during therapy and 1 patient had a ≥ 30% decline compared with baseline. The median clinical progression-free survival was 12.4 weeks. Grade 3 toxicities included fatigue (12%), and neutropenia (6%), with 4 patients discontinuing due to toxicities. A trend in decreasing plasma DNA LINE-1 methylation was seen with longer treatment duration (P = 0.06), which significantly correlated with prolongation of PSA-DT (P = 0.02). CONCLUSIONS: Azacitidine favorably modulates PSA kinetics in chemonaïve CRPC that correlates with decreasing plasma DNA LINE-1 methylation. Given the excellent tolerability, further development of azacitidine for CRPC may be warranted, with exploration of combination regimens.

Results of a Phase II trial of gemcitabine, mitoxantrone, and rituximab in relapsed or refractory mantle cell lymphoma.

BACKGROUND: Gemcitabine (G) has shown activity in mantle cell lymphoma (MCL) as a single agent. The combination of mitoxantrone (M) and rituximab (R) is also active in MCL. The primary objective of this study was to determine the efficacy of G+M+R in relapsed or refractory MCL. PATIENTS AND METHODS: Sixteen patients were enrolled between April 2005 and January 2007, 88% had Stage IV MCL, Median patient age was 74 years. Patients received gemcitabine 900 mg/m(2) IV (30-60 min infusion) on Days 1 and 8, mitoxantrone 10 mg/m(2) IV (5-10 min infusion) on day 1, and rituximab 375 mg/m(2) IV on Day 1 (max 400 mg/hour) of the 21-day cycle. Patients received a median of 6 cycles (range, 1-8). RESULTS: Best responses were CR 20% (95%CI, 0, 40.2), PR 27% (95%CI, 4.3, 49.1), SD 40% (95%CI, 15.2, 64.8), and PD 13% (95%CI, 0, 30.5). Median survival and PFS have not been reached with a median follow-up of 10.7 months. The most common Grade 3-4 toxicities were neutropenia (100%), thrombocytopenia (67%), leukopenia (53%), and anemia (33%). The study was closed early due to slow accrual owing to an alternative treatment which became available at the time. CONCLUSION: The combination of G+M+R in MCL was well-tolerated with manageable toxicity using growth factors to minimize neutropenia; further studies are warranted.