Erick Gamelin

Prevention of Oxaliplatin-Related Neurotoxicity by Calcium and Magnesium Infusions: A Retrospective Study of 161 Patients Receiving Oxaliplatin Combined with 5-Fluorouracil and Leucovorin for Advanced Colorectal Cancer

Purpose: Oxaliplatin is active in colorectal cancer. Sensory neurotoxicity is its dose-limiting toxicity. It may come from an effect on neuronal voltage-gated Na channels, via the liberation one its metabolite, oxalate. We decided to use Ca and Mg as oxalate chelators. Experimental Design: A retrospective cohort of 161 patients treated with oxaliplatin + 5-fluorouracil and leucovorin for advanced colorectal cancer, with three regimens of oxaliplatin (85 mg/m2/2w, 100/2w, 130/3w) was identified. Ninety-six patients received infusions of Ca gluconate and Mg sulfate (1 g) before and after oxaliplatin (Ca/Mg group) and 65 did not. Results: Only 4% of patients withdrew for neurotoxicity in the Ca/Mg group versus 31% in the control group (P = 0.000003). The tumor response rate was similar in both groups. The percentage of patients with grade 3 distal paresthesia was lower in Ca/Mg group (7 versus 26%, P = 0.001). Acute symptoms such as distal and lingual paresthesia were much less frequent and severe (P = 10-7), and pseudolaryngospasm was never reported in Ca/Mg group. At the end of the treatment, 20% of patients in Ca/Mg group had neuropathy versus 45% (P = 0.003). Patients with grade 2 and 3 at the end of the treatment in the 85 mg/m2 oxaliplatin group recovered significantly more rapidly from neuropathy than patients without Ca/Mg. Conclusions: Ca/Mg infusions seem to reduce incidence and intensity of acute oxaliplatin-induced symptoms and might delay cumulative neuropathy, especially in 85 mg/m2 oxaliplatin dosage.

Clinical aspects and molecular basis of oxaliplatin neurotoxicity: Current management and development of preventive measures

Neurotoxicity is the most frequent dose-limiting toxicity of oxaliplatin. Acute neurotoxicity is characterized by the rapid onset of cold-induced distal dysesthesia and/or paresthesia. Sensory symptoms may also be accompanied by cold-dependent muscular contractions of the extremities or the jaw. The symptoms, often occurring during or shortly after infusion, are usually transient and mild. A persistent sensory peripheral neuropathy may also develop with prolonged treatment, eventually causing superficial and deep sensory loss, sensory ataxia, and functional impairment. Studies have shown patients with acute sensory symptoms to display little or no axonal degeneration, suggesting a specific effect of oxaliplatin on sensory neurons and/or motor neurons or muscle cells that is not observed with other platinum agents. The similarity of the acute symptoms induced by oxaliplatin with those caused by several drugs or toxins acting on neuronal or muscular ion channels suggests that these symptoms may result from a specific interaction of oxaliplatin with ion channels located in the cellular membrane. Recent data indicate that oxaliplatin may act on specific isoforms of the voltage gated sodium (Na(+)) channel to increase the excitability of sensory neurons, an action inhibited by the Na(+) channel blocker carbamazepine. This contention is supported by recent clinical findings indicating that pharmacologic blockade of Na(+) channels may prevent and/or repress the acute neurotoxicity of oxaliplatin. Although there is no indication at the moment that a common cellular mechanism induces both the acute and the cumulative neurotoxicity of oxaliplatin, controlled clinical trials are currently underway to establish the value of Na(+) channel blockade against both acute and cumulative oxaliplatin neurotoxicities.

Relevance of Different UGT1A1 Polymorphisms in Irinotecan-Induced Toxicity: A Molecular and Clinical Study of 75 Patients

Purpose: We wanted to assess polymorphisms in the uridine diphosphoglucuronosyl transferase 1A1 (UGT 1A1) gene: the TATA box polymorphism and UGT 1A1 G71R and Y486D mutations in the coding sequence, the main mutations characterizing Gilbert’s syndrome, as predictors of severe toxic event occurrence after irinotecan (CPT-11) administration. Therefore, we set up a rapid, sensitive, and reliable technique in routine practice to detect before CPT-11 treatment, the at-risk patients. Experimental Design: Seventy-five patients with advanced colorectal cancer and treated with CPT-11 and 5-fluorouracil, entered the study. We used the Pyrosequencing technology a real-time sequencing method, to detect the UGT 1A1 TATA box polymorphisms and mutations in the coding regions. Patients were also assessed for both biochemical and clinical evaluation and tolerance to treatment. Results: No G71R and Y486D mutations were found in our population. Frequencies for UGT 1A1 TATA box polymorphisms were 41, 47, and 9% for wild-type 6/6, heterozygous 6/7, and Gilbert’s syndrome 7/7, respectively. Tolerance to treatment decreased with increased number of TA repeat with 71% of the patients in 7/7 group who experienced grade 3/4 toxicity. Conclusions: The method we set up is suitable for the detection of UGT 1A1 polymorphism in routine practice before irinotecan treatment. It could help to detect the patients homozygous or heterozygous for Gilbert’s syndrome, at-risk of CPT 11-induced toxicity, and thus could help to individualize the dose to optimize efficacy and limit toxicity.

Individual Fluorouracil Dose Adjustment Based on Pharmacokinetic Follow-Up Compared With Conventional Dosage: Results of a Multicenter Randomized Trial of Patients With Metastatic Colorectal Cancer

PURPOSE A phase III, multicenter, randomized study compared conventional dosing of fluorouracil (FU) plus folinic acid with pharmacokinetically guided FU dose adjustment in terms of response, tolerability, and survival. PATIENTS AND METHODS Two hundred eight patients with measurable metastatic colorectal cancer were randomly assigned to one of two arms: arm A (104 patients; 96 assessable), in which the FU dose was calculated based on body-surface area; and arm B (104 patients; 90 assessable), in which the FU dose was individually determined using pharmacokinetically guided adjustments. The initial regimen was 1,500 mg/m(2) FU plus 200 mg/m(2) folinic acid infusion during a continuous 8-hour period administered once weekly. FU doses were adjusted weekly in arm B based on a single-point measurement of FU plasma concentrations at steady state until the therapeutic range (targeted area under the curve 20-25 mg x h x L(-1)) previously established in other studies was reached. RESULTS An intent-to-treat analysis of the 208 patients showed the objective response rate was 18.3% in arm A and 33.7% in arm B (P = .004). Median overall survival was 16 months in arm A and 22 months in arm B (P = .08). The mean FU dose throughout treatment was 1,500 mg/m(2)/wk in arm A and 1,790 +/- 386 mg/m(2)/wk (range, 900 to 3,300 mg/m(2)/wk) in arm B. Toxic adverse effects were significantly more frequent and severe in arm A compared with arm B (P = .003). CONCLUSION Individual FU dose adjustment based on pharmacokinetic monitoring resulted in significantly improved objective response rate, a trend to higher survival rate, and fewer grade 3/4 toxicities. These results support the value of pharmacokinetically guided management of FU dose in the treatment of metastatic colorectal patients.

Hepatic Arterial Oxaliplatin Infusion Plus Intravenous Chemotherapy in Colorectal Cancer With Inoperable Hepatic Metastases: A Trial of the Gastrointestinal Group of the Fédération Nationale des Centres de Lutte Contre le Cancer

PURPOSE Isolated hepatic metastases of colorectal cancer constitute a frequent and serious therapeutic problem that has led to the evaluation of hepatic arterial infusion (HAI) of different drugs. Oxaliplatin combined with fluorouracil (FU) and leucovorin is effective in the treatment of colorectal cancer. In this context, a phase II study was conducted to evaluate concomitant administration of oxaliplatin by HAI and intravenous (IV) FU plus leucovorin according to the LV5FU2 protocol (leucovorin 200 mg/m(2), FU 400 mg/m(2) IV bolus, FU 600 mg/m(2) 22-hour continuous infusion on days 1 and 2 every 2 weeks). PATIENTS AND METHODS Patients had metastatic colorectal cancer that was restricted to the liver and inoperable. The patients were not to have previously received oxaliplatin. After surgical insertion of a catheter in the hepatic artery, patients were treated with oxaliplatin 100 mg/m(2) HAI combined with FU + leucovorin IV according to the LV5FU2 protocol. Treatment was continued until disease progression or toxicity. Response was evaluated every 2 months. RESULTS Twenty-eight patients were included, and 26 patients were treated. Two hundred courses of therapy were administered, and the median number of courses received was eight courses (range, zero to 20 courses). The most frequent toxicity consisted of neutropenia. The main toxicity related to HAI was pain. The intent-to-treat objective response rate was 64% (95% CI, 44% to 81%; 18 of 28 patients). With a median follow-up of 23 months, the median overall and disease-free survival times were 27 and 27 months, respectively. CONCLUSION The combination of oxaliplatin HAI and FU + leucovorin according to the LV5FU2 protocol is feasible and effective in patients presenting with isolated hepatic metastases of colorectal cancer.

Clinical relevance of different dihydropyrimidine dehydrogenase gene single nucleotide polymorphisms on 5-fluorouracil tolerance

Purpose: Although single nucleotide polymorphisms (SNP) of the dihydropyrimidine dehydrogenase gene (DPYD) have been reported, which affect enzyme activity and the severity of 5-fluorouracil (5-FU) toxicity, no pretherapeutic detection has thus far been developed. We investigated 22 DPYD gene SNPs, their respective incidence, their link with grade 3 to 4 toxic side effects, and their management in practice: 9 were looked for in 487 patients, whereas 13 others were investigated in 171 patients. Patients and Methods: SNPs were detected before 5-FU-based treatment in WBC using a Pyrosequencing method. Close clinical and biological follow-up was done. Results: Five different SNPs were found in 187 patients (IVS14 + 1G>A, 2846A>T, 1679T>G, 85T>C, −1590T>C). Three hundred patients had no SNP. Forty-four patients had grade 3 to 4 toxic side effects in either the first or second cycle. Sixty percent of patients with either IVS14 + 1G>A or 2846A>T SNPs and the only patient with 1679T>G SNP experienced early grade 3 to 4 toxicity, compared with 0%, 5.5%, and 15% of those with either −1590T>C, 85T>C SNP, or no SNP, respectively. In cases with grade 3 to 4 toxicity, treatment either had to be quickly stopped, or could be safely continued with an individual dose adjustment. Sensitivity, specificity, and positive and negative predictive values of the detection of these three major SNPs as toxicity predictive factors were 0.31, 0.98, and 0.62 and 0.94, respectively. Conclusion: Pretreatment detection of three DPYD SNPs could help to avoid severe toxic side effects. This approach is suitable for clinical practice and should be compared or combined with pharmacologic approaches. In the case of dihydropyrimidine dehydrogenase deficiency, 5-FU administration often can be safely continued with an individual dose adjustment. [Mol Cancer Ther 2006;5(11):2895–904]

Correlation Between Uracil and Dihydrouracil Plasma Ratio, Fluorouracil (5-FU) Pharmacokinetic Parameters, and Tolerance in Patients With Advanced Colorectal Cancer: A Potential Interest for Predicting 5-FU Toxicity and Determining Optimal 5-FU Dosage

PURPOSE Patients with genetic fluorouracil (5-FU) catabolic deficiencies are at high risk for severe toxicity. To predict 5-FU catabolic deficiencies and toxic side effects, we conducted a prospective study of patients treated for advanced colorectal cancer by high-dose 5-FU. PATIENTS AND METHODS Eighty-one patients were treated with weekly infusions of 5-FU and folinic acid. The initial 5-FU dose of 1,300 mg/m(2) was individually adjusted according to a dose-adjustment chart. Plasma concentrations of uracil (U) and its dihydrogenated metabolite, dihydrouracil (UH(2)), were measured before treatment, and the ratio of UH(2) to U was calculated. Pharmacokinetic and pharmacodynamic studies were conducted to look for a relationship between the ratio of UH(2) to U and 5-FU metabolic outcome and tolerance. RESULTS The UH(2)-U ratios were normally distributed (mean value, 2.82; range, 0.35 to 7.13) and were highly correlated to (1) 5-FU plasma levels after the first course of treatment (r =.58), (2) 5-FU plasma clearance (r =.639), and (3) individual optimal therapeutic 5-FU dose (r =.65). Toxic side effects were observed only in patients with initial UH(2)-U ratios of less than 1.8. No adverse effects were noted in patients with UH(2)-U ratios of greater than 2.25. CONCLUSION The UH(2)-U ratio, easily determined before treatment, could help to identify patients with metabolic deficiency and, therefore, a risk of toxicity.

Interferon-γ reverses the immunosuppressive and protumoral properties and prevents the generation of human tumor-associated macrophages

Tumor‐associated macrophages (TAM) are M2d‐polarized cells (IL‐10high, IL‐12low, ILT3high, CD86low) that accumulate in tumor microenvironment. TAM inhibit antitumor T lymphocyte generation and function, contribute to tumor tolerance and are trophic for tumors. In this study, we investigated whether some immunological factors may reverse TAM immunosuppressive properties. Among 32 cytokines, we have identified IFNγ on its ability to switch immunosuppressive TAM into immunostimulatory cells. Upon IFNγ exposure, TAM purified from ovarian cancer ascites recover a M1 phenotype (IL‐10low, IL‐12high), express high levels of CD86 and low levels of ILT3, enhance the proliferation of CD4+ T lymphocytes and potentiate the cytotoxic properties of a MelanA‐specific CD8+ T cell clone. IFNγ‐treated TAM also secreted reduced levels of mediators promoting suppressive T cell accumulation (CCL18) and trophic for tumors (VEGF and MMP9). As TAM derive from the local differentiation of peripheral blood monocytes, we investigated whether IFNγ may also affect TAM generation. In the presence of ovarian ascites, IFNγ skewed monocyte differentiation from TAM‐like cells to M1‐polarized immunostimulatory macrophages. Together, these data show that IFNγ overcomes TAM‐induced immunosuppression by preventing TAM generation and functions. These data highlight that IFNγ used locally at the tumor site could potentiate the efficacy of antitumor immunotherapies based on the generation of effector T cells.

Predictive Factors of Oxaliplatin Neurotoxicity: The Involvement of the Oxalate Outcome Pathway

Purpose: Oxaliplatin displays a frequent dose-limiting neurotoxicity due to its interference with neuron voltage-gated sodium channels through one of its metabolites, oxalate, a calcium chelator. Different clinical approaches failed in neurotoxicity prevention, except calcium-magnesium infusions. We characterized oxalate outcome following oxaliplatin administration and its interference with cations and amino acids. We then looked for genetic predictive factors of oxaliplatin-induced neurotoxicity. Experimental Design: We first tested patients for cations and oxalate levels and did amino acid chromatograms in urine following oxaliplatin infusion. In the second stage, before treatment with FOLFOX regimen, we prospectively looked for variants in genes coding for the enzymes involved (a) in the oxalate metabolism, especially glyoxylate aminotransferase (AGXT), and (b) in the detoxification glutathione cycle, glutathione S-transferase π, and for genes coding for membrane efflux proteins (ABCC2). Results: In the first 10 patients, urinary excretions of oxalate and cations increased significantly within hours following oxaliplatin infusion, accompanied by increased excretions of four amino acids (glycine, alanine, serine, and taurine) linked to oxalate metabolism. In a further 135 patients, a minor haplotype of AGXT was found significantly predictive of both acute and chronic neurotoxicity. Neither glutathione S-transferase π nor ABCC2 single nucleotide polymorphisms we looked for were linked to neurotoxicity. Conclusion: These data confirm the involvement of oxalate in oxaliplatin neurotoxicity and support the future use of AGXT genotyping as a pretherapeutic screening test to predict individual susceptibility to neurotoxicity.

Oxaliplatin-Related Neurotoxicity: Interest of Calcium-Magnesium Infusion and No Impact on Its Efficacy

TO THE EDITOR: We read with special attention the letter from Hochster, Grothey, and Childs about preliminary results of the Combined Oxaliplatin Neuropathy Prevention Trial. The aims of this study were to explore two approaches in first-line chemotherapy with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) bevacizumab for metastatic colorectal cancer— the Stop-and-Go strategy from the French Oncology Research Group (GERCOR) group developed in the Stop-and-Go strategy study and the prevention of neurotoxicity with calcium and magnesium (Ca Mg ) infusion. According to these authors, preliminary results have led to suspect a lesser response rate in the two arms of patients treated with FOLFOX-bevacizumab plus Ca -Mg , and the authors decided to stop the administration of Ca Mg . We would like to step back to the concept of Ca -Mg infusions for preventing oxaliplatin-induced neurotoxicity. Obviously, oxaliplatin-induced neurotoxicity is the drug-limiting toxic adverse effect. It alters patients’ quality of life and can lead to postponed or even interrupted treatments with oxaliplatin. Considering the unique profile of acute oxaliplpatin-induced neurotoxicity, we suspected that certain ionic channels could be involved as it has been described in channellopathies, or Na channels inhibitors poisoning, such as tetrodotoxin. We showed in electrophysiological studies with patch-clamp technique that oxaliplatin, and more precisely one of its two direct metabolites, the oxalate, which is a potent Ca chelator, interferes with certain ionic channels expressed on the peripheral neurones (Ca dependent voltage-gated Na channels). On the other hand, diamminocyclohexane platin, the active cytotoxic metabolite, had no effect on the Na channels. The hypothesis was that when oxaliplatin enters the neurones, it splits into diamminocyclohexane platin and oxalate, and the latter one chelates Ca and interferes with Na channel activity, leading to a neurone ehyperexcitability, and secondarily, to a chronic neuropathy. We tested Ca and Mg infusion as chelators of oxalate to inhibit its action on Na channels and could show in a retrospective study a dramatic decrease of acute and chronic neurotoxicity, with no impact on oxaliplatin efficacy. In the French multicentric “Neuroxa” study, patients were randomly assigned in a double blind randomized study designed to prove the interest of Ca and Mg infusions for preventing oxaliplatin neurotoxicity. One hundred forty-four patients have been treated with the FOLFOX 4 regimen, with 85 mg/m oxaliplatin every 2 weeks. They either received or did not receive calcium gluconate 1g and magnesium sulfate 1.5 g, administered in 250-mL glucose serum just before and just after oxaliplatin infusion. In the first 52 patients treated for metastatic colorectal cancer in first-line therapy, we reviewed the data in term of patients’ characteristics, efficacy, and neurotoxicity. These 52 patients are split into two groups, with and without Ca and Mg infusion, respectively. Since all the data are not collected and treated yet, we did not take off the blind. These preliminary results were presented at the 2007 International Society of Gastrointestinal Oncology meeting in Philadelphia, PA, and will be published in its newsletter. The two groups are well balanced in term of age, Eastern Cooperative Oncology Group (ECOG) performance status, primary tumor, number of metastases, and number of metastatic sites. There is neither difference in term of objective response rate (50% v 53%, P .45), nor in progression-free (12 0.6 SE v 12 0.5 SE, P .79) and overall survivals (25.1 4 SE v 25.5 4.1 SE, P .45). On the other hand, we report a significantly lower frequency and grade of oxaliplatin neurotoxicity in one group (5% v 24% grade 3 National Cancer Institute Common Toxicity Criteria, P .001). According to these preliminary results, we confirmed that there is no impact of Ca and Mg infusions on oxaliplatin efficacy, and there is a significant effect on its neurotolerance. These results seem to be in contradiction with those presented by Hochster et al. Some major points must be highlighted; we reported results on FOLFOX combination, and we have no background about a potential interference between Ca and Mg infusions and bevacizumab. However, de Gramont reports a high objective response rate, 62.5%, in a phase II study with patients treated with FOLFOX bevacizumab with Ca -Mg (personal communication from A. de Gramont, December 2007). According to these results, coordinators of the Combined Oxaliplatin Neuropathy Prevention Trial should make sure that other parameters have been taken in account, such as being certain that the compounds have not been mixed altogether. We always emphasize the importance of not coadministering oxaliplatin, flourouracil, folinic acid, and Ca -Mg infusions, and we recommended to infuse Ca -Mg just before and after oxaliplatin administration. One hypothesis is that the wish to reduce the time of infusions for outpatients could have lead to the administration of some compounds at the same time and in the same tubulure. This could have led to a diminished drug stability and, thus, a reduced activity. According to our results, we continue to propose Ca -Mg infusions to reduce oxaliplatin neurotoxicity, in FOLFOX regimens, provided that the compounds are delivered sequentially and not in the same time.