Biochemical modulation therapy for pancreatic cancer

A phase II study of LFP therapy (5-FU (5-fluorourasil) continuous infusion (CVI) and Low-dose consecutive (Cisplatin) CDDP) in advanced biliary tract carcinoma

Background

Unresectable biliary tract carcinoma is known to demonstrate a poor prognosis. We conducted a single arm phase II study of LFP therapy (5-FU (5-fluorourasil) continuous infusion (CVI) and Low-dose consecutive (Cisplatin) CDDP) for advanced biliary tract malignancies basically on an outpatient basis.

Methods

Between February 1996 and September 2003, 42 patients were enrolled in this trial.

LFP therapy

By using a total implanted CV-catheter system, 5-FU (160 mg/m²/day) was continuously infused over 24 hours for 7 consecutive days and CDDP (6 mg/m²/day) was infused for 30 minutes twice a week as one cycle. The administration schedule consisted of 4 cycles as one course. RESIST criteria (Response evaluation criteria for solid tumors) and NCI-CTC (National Cancer Institute-Common Toxicity Criteria) (ver.3.0) were used for evaluation of this therapy. The median survival time (MST) and median time to treatment failure (TTF) were calculated by the Kaplan-Meier method.

Results

Patients characteristics were: mean age 66.5(47–79): male 24 (54%): BDca (bile duct carcinoma) 27 GBca (Gallbladder carcinoma) 15: locally advanced 26, postoperative recurrence 16. The most common toxicity was anemia (26.2%). Neither any treatment related death nor grade 4 toxicity occurred. The median number of courses of LFP Therapy which patients could receive was two (1–14). All the patients are evaluable for effects with an over all response rates of 42.9% (95% confidence interval C.I.: 27.7–59.0) (0 CR, 18 PR, 13 NC, 11 PD). There was no significant difference regarding the anti tumor effects against both malignant neoplasms. Figure 2 Shows the BDca a longer MST and TTF than did GBca (234 vs 150, 117 vs 85, respectively), but neither difference was statistically significant.

The estimated MST and median TTF were 225 and 107 days, respectively. The BDca had a longer MST and TTF than GBca (234 vs 150, 117 vs 85, respectively), but neither difference was statistically significant.

Conclusion

LFP therapy appears to be useful modality for the clinical management of advanced biliary tract malignancy.

Gene therapy for intraperitoneally disseminated pancreatic cancers by Escherichia coli uracil phosphoribosiltransferase (UPRT) gene mediated by restricted replication-competent adenoviral vectors

Although patients with unresectable pancreatic tumors have been treated with 5-fluorouracil (5FU)-based combination chemotherapy, the drug resistance of cancer cells presents a crucial therapeutic problem. It was reported that UPRT overcomes 5FU resistance. UPRT catalyzes the synthesis of 5-fluorouridine monophosphate (FUMP) from Uracil and phosphoribosylpyrophosphate (PRPP). The antitumor effect of 5FU is enhanced by augmenting 5-fluorodeoxyuridine monophosphate (FdUMP) converted from FUMP, which inhibits thymidylate synthetase (TS). We first demonstrated that injecting an E1-deficient adenoviral vector (Adv) expressing UPRT (AxCAUPRT) followed by 5-FU treatment resulted in a volume reduction of xenotransplanted human tumors. In examining the therapeutic effect of AxCAUPRT/5-FU against peritoneal dissemination, we found that non-selective gene transduction of AxCAUPRT caused severe adverse effects arising from the increase of F-dUMP in normal intestine. Because the therapeutic gene delivered by a restricted replication-competent Adv lacking 55 kDa E1B protein (AxE1AdB) is speculated to be expressed selectively in tumors, mice with established tumors were injected with AxE1AdB and E1-deleted Adv expressing the lacZ reporter gene (AxCAlacZ). The expression of the reporter gene (lacZ) was selectively enhanced in disseminated tumors. The therapeutic advantage of restricted replication competent Adv that expresses UPRT (AxE1AdB-UPRT) was evaluated in an intraperitoneal disseminated tumor model. To study the anti-tumor effect of AxE1AdB-UPRT/5FU, mice with disseminated AsPC-1 tumors were administered the Adv, followed by the 5FU treatment. It was shown that the treatment with AxE1AdB-UPRT/5FU caused a dramatic reduction of the disseminated tumor burden without toxicity in normal tissues. Our results showed that the AxE1AdB-UPRT/5FU system is a promising tool for intraperitoneal disseminated pancreatic cancer.