Phase I and pharmacokinetic study of mitomycin C and celecoxib as potential modulators of tumor resistance to irinotecan in patients with solid malignancies

Individualization of Irinotecan Treatment: A Review of Pharmacokinetics, Pharmacodynamics, and Pharmacogenetics

Since its clinical introduction in 1998, the topoisomerase I inhibitor irinotecan has been widely used in the treatment of solid tumors, including colorectal, pancreatic, and lung cancer. Irinotecan therapy is characterized by several dose-limiting toxicities and large interindividual pharmacokinetic variability. Irinotecan has a highly complex metabolism, including hydrolyzation by carboxylesterases to its active metabolite SN-38, which is 100- to 1000-fold more active compared with irinotecan itself. Several phase I and II enzymes, including cytochrome P450 (CYP) 3A4 and uridine diphosphate glucuronosyltransferase (UGT) 1A, are involved in the formation of inactive metabolites, making its metabolism prone to environmental and genetic influences. Genetic variants in the DNA of these enzymes and transporters could predict a part of the drug-related toxicity and efficacy of treatment, which has been shown in retrospective and prospective trials and meta-analyses. Patient characteristics, lifestyle and comedication also influence irinotecan pharmacokinetics. Other factors, including dietary restriction, are currently being studied. Meanwhile, a more tailored approach to prevent excessive toxicity and optimize efficacy is warranted. This review provides an updated overview on today’s literature on irinotecan pharmacokinetics, pharmacodynamics, and pharmacogenetics.

Is there still a role for mitomycin-based combination chemotherapy in treating patients with nonsmall cell lung cancer? A single institution experience

Background:

Mitomycin and irinotecan are widely used in the treatment of colorectal cancer, furthermore both of these drugs are active agents against nonsmall cell lung cancer and their combination has shown synergism in preclinical studies. The aim of the study was to evaluate the efficacy and safety of mitomycin- and irinotecan-based chemotherapy combination in patients with advanced nonsmall cell lung cancer progressing after previous antineoplastic therapies.

Methods:

Thirty-one consecutive patients suffering from nonsmall cell lung cancer, who underwent mitomycin- plus irinotecan-based chemotherapy as salvage treatment after failure of at least two previous systemic treatments, were retrospectively identified in our database. Between September 2003 and March 2011, 31 patients with histologically proven stage IIIB or IV nonsmall cell lung cancer, received mitomycin 5 mg/m2 on day 1 followed by irinotecan 150 mg/m2 on day 2. Cycles were repeated at 2-week interval.

Results:

A total of 164 cycles of treatment were given with a median of five per patient (range 1–10). The objective responses included partial response in 6 patients (19.3%), stable disease in 4 (13%), and progressive disease in 21 (67.7%). Median time to disease progression was 4 months, and median survival was 9+ months. Twelve patients (38%) reached 1-year survival. Grade 3–4 toxicities occurred in seven patients (22.5%), mainly myelosuppression (neutropenia, anemia, and thrombocytopenia), mucositis, and diarrhea. No treatment-related death was recorded.

Conclusion:

The mitomycin- and irinotecan-based combination chemotherapy seems to be tolerated and active in this subset of heavily pretreated patients with advanced nonsmall cell lung cancer. However, evaluation or recruitment of a larger number of patients would be needed to provide more adequate data on safety and activity of the described combination.

A novel LMP1 antibody synergizes with mitomycin C to inhibit nasopharyngeal carcinoma growth in vivo through inducing apoptosis and downregulating vascular endothelial growth factor

Combined therapy emerges as an attractive strategy for cancer treatment. The aim of this study was to investigate the inhibitory effects of mitomycin C (MMC) combined with a novel antibody fragment (Fab) targeting latent membrane protein 1 (LMP1) on nasopharyngeal carcinoma (NPC) xenograft nude mice. The inhibitory rates of MMC (2 mg/kg), Fab (4 mg/kg), MMC (2 mg/kg) + Fab (4 mg/kg), and MMC (1 mg/kg) + Fab (4 mg/kg) were 20.1%, 7.3%, 42.5% and 40.5%, respectively. Flow cytometry analysis showed that the apoptotic rate of xenograft tumor cells in the MMC and Fab combination group was 28 ± 4.12%, significantly higher than the MMC (2 mg/kg) group (P < 0.01). Immunohistochemical staining showed that VEGF expression in NPC xenografts was significantly inhibited in the combination group compared to the Fab (4 mg/kg) group (P < 0.05). In conclusion, both MMC and Fab could inhibit NPC xenograft tumor growth in vivo and combination therapy showed apparent synergistic anti-tumor effects, which may be due to the induction of tumor cell apoptosis and the downregulation of VEGF expression. These results suggest that the novel combined therapy utilizing traditional chemotherapeutics and antibody-targeted therapy could be a promising strategy for the treatment of NPC.

Phase II randomized study of two regimens of sequentially administered mitomycin C and irinotecan in patients with unresectable esophageal and gastroesophageal adenocarcinoma

BACKGROUND

Based on the observation of topoisomerase-1, upregulation by mitomycin C (MMC), and the phase I antitumor activity of sequential MMC/irinotecan in esophageal cancer, we conducted a phase II evaluation of two schedules of this combination in previously untreated stage III/IV esophageal/gastroesophageal junction adenocarcinomas.

PATIENTS AND METHODS

Patients (n = 76) were randomized to either 6 mg/m MMC on day 1 and 125 mg/m irinotecan on days 2 and 9 (arm A) or 3 mg/m MMC on days 1 and 8 and 125 mg/m irinotecan on days 2 and 9 (arm B). Each cycle was repeated every 28 days. Restaging was planned after two cycles, and resections were performed whenever possible. A two-stage Simon minimax design was used for each arm, with a "pick-the-winner" approach based on efficacy.

RESULTS

The response rate (complete response + partial response) in 73 evaluable patients was 52% (21 of 40 patients) for arm A and 33% (11/33) for arm B. Moderate or severe toxicity was similar. Twenty-seven patients were resected (20:7, arm A:B). There was one complete pathologic response; five others were node negative.

CONCLUSION

Irinotecan/MMC is feasible in esophageal/gastroesophageal junction adenocarcinoma. MMC (6 mg/m) every 28 days for up to six cycles is the recommended modulatory dose for irinotecan in future trials.

A phase I dose escalation study of a pharmacobiologically based scheduling of capecitabine and mitomycin C in patients with gastrointestinal malignancies

BACKGROUND

Mitomycin C (MMC) produces significant upregulation of thymidine phosphorylase, a principal determinant of the therapeutic index of capecitabine-based treatment, starting 4-6 days after treatment. On the basis of the time-dependency of this upregulation, we performed a phase I dose escalation study of capecitabine and MMC in patients with gastrointestinal malignancies.

METHODS

A total of 29 patients with advanced gastrointestinal malignancies received MMC at 6 mg/m2 on day 1 and capecitabine escalated in four successive patient cohorts of doses 500-1,000 mg/m2/day twice daily on days 8-21, every 28 days. MMC was capped at 36 mg/m2.

RESULTS

A total of 29 patients were enrolled and 90% had at least one prior treatment in the metastatic setting. There was one DLT, grade 3 hand and foot syndrome, at dose level four. The most common toxicity was fatigue (61%). No patients experienced grade 4 toxicities. Nine patients experienced prolonged stability of disease.

CONCLUSION

Capecitabine in combination with MMC in the proposed schedule is well-tolerated with evidence of preliminary activity. The recommended dose for phase II studies are MMC at 6 mg/m2 on day 1 of a 28-day cycle with the dose capped at 36 mg/m2, in combination with capecitabine at 1,000 mg/m2 twice daily on days 8-21.