Comparison of an aprepitant regimen with a multiple-day ondansetron regimen, both with dexamethasone, for antiemetic efficacy in high-dose cisplatin treatment

BACKGROUND

We compared an aprepitant regimen with a control regimen of ondansetron + dexamethasone given for 4 days.

PATIENTS AND METHODS

Patients scheduled to receive cisplatin > or =70 mg/m(2) were randomized to either the aprepitant regimen (aprepitant, ondansetron and dexamethasone on day 1; aprepitant and dexamethasone on days 2-3; dexamethasone on day 4) or control regimen (ondansetron + dexamethasone on days 1-4). Patients recorded vomiting, nausea and rescue therapy use. The primary end point was complete response (no vomiting and no use of rescue therapy) in the overall phase (days 1-5 post-cisplatin).

RESULTS

Complete response rates were higher in the aprepitant than control group in the overall (72% versus 61%; P = 0.003), acute (day 1; 88% versus 79%; P = 0.005) and delayed phases (days 2-5; 74% versus 63%; P = 0.004), as were rates of no vomiting (overall 77% versus 62%, P < or = 0.001; acute 89% versus 81%, P = 0.004; delayed 79% versus 64%, P < or = 0.001). Rates of no rescue therapy were similar between groups.

CONCLUSIONS

Compared with an antiemetic regimen in which ondansetron + dexamethasone were given for 4 days, the aprepitant regimen was superior in the acute, delayed and overall phases of chemotherapy-induced nausea and vomiting. The aprepitant regimen should be considered a new standard of antiemetic therapy for cisplatin-treated patients. www.ClinicalTrials.gov Identifier: NTC00090207.

Loss of Oct-3/4 Expression in Embryonal Carcinoma Cells Is Associated with Induction of Cisplatin Resistance

Although the majority of testicular germ cell tumors (TGCTs) are curable by cisplatin-based chemotherapy, in a few cases, the occurrence of cisplatin resistance results in a poor outcome. The biological basis of this differential cisplatin sensitivity in TGCTs remains largely unexplained. Embryonal carcinoma (EC) cells represent the presumptive tumor stem cells in nonseminomatous TGCTs and are known to express the embryonal transcription factor Oct-3/4 and to be hypersensitive to cisplatin. In the present study, we analyzed TGCT cell lines and nude mouse xenografts showing differential cisplatin sensitivity. Here we demonstrate that a lack of expression of Oct-3/4 in TGCT cells is associated with a higher apoptotic threshold and cisplatin resistance which is accompanied by an impaired caspase-9 activation, reduced caspase-3 activity and altered p53 accumulation. We were able to induce loss of Oct-3/4 in a cisplatin-sensitive EC cell line resulting in a secondary cisplatin-resistant cell type with retained EC cell characteristics and changes in apoptotic signaling identical to those in primary resistant cells. Furthermore, we show that EC cells are retained in their undifferentiated state by Oct-3/4 and that a complete and ultimate loss of Oct-3/4 followed by an early differentiation step is necessary to establish the cisplatin-resistant state. Our data suggest that loss of Oct-3/4 expression leads to induction of a higher apoptotic threshold and to cisplatin resistance in EC cells of nonseminomatous TGCTs. We hypothesize that in refractory TGCTs the original tumor stem cell population of Oct-3/4-positive, cisplatin-sensitive EC cells could be replaced by an Oct-3/4-negative, resistant population in a selection process. In contrast, the presence of the Oct-3/4-positive, highly sensitive EC cells as the tumor stem cell component in most TGCTs could explain the general high chemosensitivity and curability of these tumors.

The future development of bevacizumab in colorectal cancer

Bevacizumab (Avastin), the first approved therapy designed to inhibit tumor angiogenesis, has significant clinical benefits in the management of colorectal cancer (CRC). When bevacizumab is added to IFL (5-fluorouracil [5-FU]/leucovorin [LV]/irinotecan [Camptosar)]) as first-line therapy for metastatic CRC, significant overall and progression-free survival benefits are obtained. Similar survival benefits may be achieved when bevacizumab is added to 5-FU/LV alone. In addition, additive and synergistic effects with a range of chemotherapeutic agents illustrate that bevacizumab has considerable potential in combination with existing therapeutic options. Clinical data indicate that bevacizumab is the only agent in addition to chemotherapy that has demonstrated survival benefit in the first- and second-line settings. In addition, bevacizumab is expected to produce clinical benefit in the adjuvant setting: inhibition of vascular endothelial growth factor should prevent the angiogenic switch in micrometastases, which is a key factor in malignancy. The clinical program is examining the activity of bevacizumab in combination with the likely future standard of care in both the metastatic and adjuvant treatment settings. Phase III trials (NO16966C, CONcePT and TREE-2) are studying the benefit of combining bevacizumab with oxaliplatin (Eloxatin)-based regimens. Similarly, in the adjuvant setting, phase III trials are assessing the efficacy and tolerability of bevacizumab in combination with oxaliplatin-based chemotherapy (AVANT, NSABP C-08).

Phase I/II Dose-Escalation Study of Pemetrexed plus Irinotecan in Patients with Advanced Colorectal Cancer

BACKGROUND

Pemetrexed and irinotecan have demonstrated antitumor activity as single agents in lung, pancreatic, breast, and colorectal cancer (CRC). The distinct mechanisms of action and patterns of resistance displayed by pemetrexed and irinotecan make them attractive agents for combination therapy.

PATIENTS AND METHODS

This phase I/II, nonrandomized, open-labeled, single-arm study was composed of 3 segments. The initial phase II portion of the study enrolled 23 patients with advanced CRC who had received 1 previous dose of 5-fluorouracil (5-FU)-based chemotherapy for advanced disease. Because of poorer than anticipated efficacy, a phase I dose-escalation study using vitamin supplementation (n = 12) was added to the original protocol. The phase II dose-escalation portion of the study enrolled 36 patients (64% with previous oxaliplatin-based therapy) who received pemetrexed 500 mg/m2 followed by irinotecan 300 mg/m2 on day 1, every 21 days.

RESULTS

For the 35 evaluable patients in the phase II dose-escalation study, the objective response rate was 11.4% (95% confidence interval, 3.2%-26.7%); there was 1 patient with a complete response, 3 with partial responses, and 17 with stable disease. Three of four responders had received previous oxaliplatin-based combination therapy. Grade 3/4 hematologic toxicities included leukopenia (5.6%), anemia (2.8%), and thrombocytopenia (2.8%). Grade 3/4 nonhematologic toxicities included diarrhea (11.1%), increased aminotransferase levels (8.3%), nausea (8.3%), febrile neutropenia (5.6%), vomiting (5.6%), and reduced creatinine clearance (2.8%).

CONCLUSION

Pemetrexed plus irinotecan appears to be at least as active as FOLFIRI (leucovorin/5-FU/irinotecan) for second-line therapy of CRC following 5-FU-based combination chemotherapy. Further studies are warranted.

Potential activity of paclitaxel, vinorelbine and gemcitabine in anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) has a rapidly fatal course in the mostly elderly patients with a median survival after diagnosis of 4-12 months. Activity of commonly used chemotherapy (doxorubicin) is low, thus more active compounds need to be introduced into the therapeutic concept of ATC. Recently, based on preclinical data Ain et al. conducted a clinical phase II study with paclitaxel 96 h infusion in ATC achieving a promising response rate of 53%. To further improve therapeutic options in ATC, we evaluated the activity of topotecan, oxaliplatin, vinorelbine, gemcitabine and paclitaxel in comparision to cisplatin and doxorubicin (1 and 96 h drug exposure) alone or in combination in the ATC cell lines SW1736 and 8505C. IC50 values were determined by the sulforhodamine B assay, potential clinical activity was estimated by relative antitumor activity (RAA) and drug interaction was analyzed using a parametric response surface approach (Greco model) of the Loewe additivity. Duration of drug effect was estimated by regrowth kinetics. We found paclitaxel, vinorelbine and gemcitabine active in ATC with RAA (1 h drug exposure) ranging from 86 to 454, 15 to 17 and 31 to 140, respectively. The activity of doxorubicin and cisplatin was moderate with RAA ranging from 1.4 to 2.2 and 0.2 to 0.3, respectively. Combined drug exposure of gemcitabine/paclitaxel and gemcitabine/vinorelbine was synergistic with a Loewe index > 0. However, these results did not reach statistical significance with p > 0.05. At clinically relevant drug concentrations paclitaxel, gemcitabine and vinorelbine but not oxaliplatin exerted a sustained growth inhibition after cessation of drug exposure for the complete assay time of 15 days. In conclusion, paclitaxel, gemcitabine and vinorelbine but not topotecan or oxaliplatin appeared to be active in anaplastic thyroid carcinoma based on RAA or growth delay at clinically relevant drug concentrations. Combinations of vinorelbine/gemcitabine and paclitaxel/gemcitabine exerted a trend to synergy. Thus, further evaluation of paclitaxel, vinorelbine and gemcitabine alone or in combination with ATC seems warranted.

Resistance mechanisms following cisplatin and oxaliplatin treatment of the human teratocarcinoma cell line 2102EP

BACKGROUND

Oxaliplatin and cisplatin are widely used in cancer chemotherapy, however, their clinical efficiency is often limited by the development of resistance.

MATERIALS AND METHODS

We examined different mechanisms of resistance in the human teratocarcinoma cell line 2102EP following exposure to cisplatin or oxaliplatin. Cells were exposed ten times with IC90-doses of 30 microM cisplatin and 50 microM oxaliplatin, respectively. Different cell clones were tested for expression of resistance using the SRB-assay. Moreover, resistance mechanisms in terms of drug uptake, platinum-adduct formation, GSH metabolism, DNA mismatch repair and p53 protein function were investigated.

RESULTS

Three cisplatin cell clones with significant resistance factors of 2.0 to 2.6 were found. Two oxaliplatin cell clones showed only weak resistance, with resistance factors of 1.6 and 1.7, respectively. In all three cisplatin-exposed cell clones a decreased cellular uptake of cisplatin was found. Furthermore, mechanisms of DNA damage tolerance may also play a role in the development of cisplatin-resistance in these cells. However, only two cell clones showed a decreased level of platinum-DNA-adducts. An increased DNA-repair of platinum-DNA adducts was not seen. In addition, no differences in expression of mismatch-repair proteins MSH2 and MLH1, tumor suppressor protein p53, or glutathione metabolism were found. However, significant resistance mechanisms for the observed oxaliplatin resistance could not be identified, although in one oxaliplatin-exposed cell clone, there was some evidence that a decreased cellular uptake of oxaliplatin may contribute to the observed low level resistance.

CONCLUSIONS

The data add weight to the hypothesis that resistance mechanisms following oxaliplatin exposure may be similar to cisplatin. The precise mechanisms of resistance in the oxaliplatin-resistant cell clones are still not fully understood and current studies are underway to further eluciate this finding.

Successful treatment of mediastinal lymphomatoid granulomatosis with rituximab monotherapy

Lymphomatoid granulomatosis is a rare Epstein-Barr virus (EBV)-positive-B-cell lymphoproliferative disorder. Treatment options include corticosteroids, antiviral therapy, interferon-alpha and chemotherapy. However, long-term prognosis is poor and no therapeutic standard has been established yet. In a 21-year-old woman, a biopsy of mediastinal mass revealed lymphomatoid granulomatosis. Combined therapy with valganciclovir and interferon-alpha proved ineffective. In view of the CD20 expression of the tumor cells, monotherapy with rituximab was intiated. After 3 months a complete remission was achieved. Rituximab was continued for another 6 months with subsequent consolidation radiotherapy. This is the first report of an enduring complete remission (20 months) of a non-CNS lymphomatoid granulomatosis treated with rituximab.

Chemotherapy-induced nausea and vomiting: current and new standards in the antiemetic prophylaxis and treatment

Nausea and vomiting are considered as two of the most distressing side-effects of chemotherapy. Chemotherapy-induced nausea and vomiting have been classified into acute, delayed and anticipatory based on the time of onset. The frequency of nausea and vomiting depends primarily on the emetogenic potential of the chemotherapeutic agents used. With the introduction of the 5-HT3 receptor-antagonists in combination with dexamethasone in the early 1990s approximately 70% of patients receiving highly emetogenic chemotherapy were protected from acute emesis. However, 40% of patients have symptoms in the delayed phase. Another group of antiemetics, the neurokinin-1-receptor-antagonists, have recently been introduced. The addition of neurokinin receptor (NK1 receptor)-antagonists to standard therapy significantly improves emesis protection in the acute and in particular in the delayed phase by approximately 20%. Due to these new developments, revised antiemetic guidelines have been set. Here, the most recent developments in antiemetic therapy, including these guidelines, are reviewed.

European consensus on diagnosis and treatment of germ cell cancer: a report of the European Germ Cell Cancer Consensus Group (EGCCCG)

Germ cell tumour is the most frequent malignant tumour type in young men with a 100% rise in the incidence every 20 years. Despite this, the high sensitivity of germ cell tumours to platinum-based chemotherapy, together with radiation and surgical measures, leads to the high cure rate of > or = 99% in early stages and 90%, 75-80% and 50% in advanced disease with 'good', 'intermediate' and 'poor' prognostic criteria (IGCCCG classification), respectively. The high cure rate in patients with limited metastatic disease allows the reduction of overall treatment load, and therefore less acute and long-term toxicity, e.g. organ sparing surgery for specific cases, reduced dose and treatment volume of irradiation or substitution of node dissection by surveillance or adjuvant chemotherapy according to the presence or absence of vascular invasion. Thus, different treatment options according to prognostic factors including histology, stage and patient factors and possibilities of the treating centre as well may be used to define the treatment strategy which is definitively chosen for an individual patient. However, this strategy of reduction of treatment load as well as the treatment itself require very high expertise of the treating physician with careful management and follow-up and thorough cooperation by the patient as well to maintain the high rate for cure. Treatment decisions must be based on the available evidence which has been the basis for this consensus guideline delivering a clear proposal for diagnostic and treatment measures in each stage of gonadal and extragonadal germ cell tumour and individual clinical situations. Since this guideline is based on the highest evidence level available today, a deviation from these proposals should be a rare and justified exception.

Saccharic acid 1.4-lactone protects against CPT-11-induced mucosa damage in rats

PURPOSE

To evaluate the ability of D-saccharic acid 1.4-lactone (SAL), a beta-glucuronidase inhibitor, to prevent irinotecan hydrochloride (CPT-11) from inducing mucosal damage as a cause of diarrhea in rats.

METHODS

Wistar rats were divided into six groups of three animals each, administered 1.0 ml isotonic solution intraperitoneally once daily for up to three consecutive days, respectively for up to six days. The series were as follows: (1) On days 1-3: saline; (2) On days 1-3: 200 mg CPT-11/m2; (3) On days -3 to -1 relative to the first administration of CPT-11: 10 mg/ml SAL; on days 1-3: 200 mg CPT-11/m2; (4) On days -3 to +3 relative to the first administration of CPT-11: 10 mg/ml SAL, and on days 1-3: additional 200 mg CPT-11/m2; (5) On days 1-3: 200 mg CPT-11/m2 (0.5 ml) + 10 mg/0.5 ml SAL; (6) On days -3 to -1 relative to the first administration of CPT-11: 3 mg/ml SAL, and on days 1-3: 200 mg CPT-11/m2. Luminal mucosa damage of the small intestine was detected by histology 24 h after the last intraperitoneal application. Peptidase activities of the proximal jejunum were measured by using an in situ perfusion model.

RESULTS

Following intraperitoneal CPT-11 treatment, using conventional histology of paraffin sections, we observed severe mucosal damage. This was reflected by a decrease of the villi/crypt ratio, an increase of apoptotic cells, as well as an increase of mitotic figures in the crypt region. There was a concomitant increased lymphatic infiltration in mucosa of CPT-11 treated rats. This damage pattern could be clearly reduced by co-treatment with the beta-glucuronidase inhibitor, SAL, independent of the treatment schedule. In contrast to our expectations based on previous reports, the intraperitoneal application of CPT-11 alone or in combination with SAL did not cause significant differences in luminal enzyme liberation in comparison with controls in the in situ perfusion assay.

CONCLUSIONS

The beta-glucuronidase inhibitor SAL is able to significantly reduce CPT-11-induced mucosal damage in the small intestine of rats. This observation might soon have a clinical impact for the treatment of patients with CPT-11.

Intensive chemotherapy with idarubicin, cytarabine, etoposide, and G-CSF priming in patients with advanced myelodysplastic syndrome and high-risk acute myeloid leukemia

In an attempt to improve the complete remission (CR) rates and to prolong the remission duration especially in elderly patients > 50 years of age, we have used a combination chemotherapy of idarubicin (10 mg/m2 IV x 3 days), cytarabine (AraC, 100 mg/m2 CIVI x 7d), and etoposide (100 mg/m2 x 5 days) in combination with granulocyte colony-stimulating factor (G-CSF) priming [5 mg/kg SQ day 1 until absolute neutrophil count (ANC) recovery] for remission induction. Responding patients received two consolidation courses of idarubicin, AraC, and etoposide, followed by a late consolidation course of intermediate-dose AraC (600 mg/m2 IV every 12 h x 5 days) and amsacrine (60 mg/m2 IV x 5 days). A total of 112 patients (57 male/55 female) with a median age of 58 years (range: 22-75) have been entered and are evaluable for response: 19 refractory anemia with excess of blast cells in transformation (RAEB-T), 84 acute myeloid leukemia (AML) evolving from myelodysplastic syndrome (MDS), and 9 secondary AML after chemotherapy/radiotherapy. The overall CR rate was 62%, partial remission (PR) rate 10%, treatment failure 16%, and early death rate 12%. The CR rate was higher in patients < or = 60 years (68 vs 55%), mainly due to a lower early death rate (5 vs 21%, p<0.001). After a median follow-up of 58 months, the median overall survival is 14.5% and median duration of relapse-free survival 8 months. After 60 months, the probability of CR patients to still be in CR and alive is 16% (20% in patients < or = 60 years and 13% in patients >60 years), while the probability of overall survival is 12% (15% in patients < or = 60 years and 9% in patients > 60 years). Compared to our previous trial (AML-MDS Study 01-92) which was done with identical chemotherapy but no G-CSF priming in 110 patients with RAEB-T, AML after MDS, or secondary AML (identical median age, age range, and distribution of subtypes), the CR rate in all patients, as well as CR rate, overall survival, and relapse-free survival in patients > 60 years have significantly been improved. Thus, intensive chemotherapy with G-CSF priming is both well tolerated and highly effective for remission induction in these high-risk patients.

Survival of patients with advanced colorectal cancer improves with the availability of fluorouracil-leucovorin, irinotecan, and oxaliplatin in the course of treatment

PURPOSE

Fluorouracil (FU)-leucovorin (LV), irinotecan, and oxaliplatin administered alone or in combination have proven effective in the treatment of advanced colorectal cancer (CRC). Combination protocols using FU-LV with either irinotecan or oxaliplatin are currently regarded as standard first-line therapies in this disease. However, the importance of the availability of all three active cytotoxic agents, FU-LV, irinotecan, and oxaliplatin, on overall survival (OS) has not yet been evaluated.

MATERIALS AND METHODS

We analyzed data from seven recently published phase III trials in advanced CRC to correlate the percentage of patients receiving second-line therapy and the percentage of patients receiving all three agents with the reported median OS, using a weighted analysis.

RESULTS

The reported median OS is significantly correlated with the percentage of patients who received all three drugs in the course of their disease (P =.0008) but not with the percentage of patients who received any second-line therapy (P =.19). In addition, the use of combination protocols as first-line therapy was associated with a significant improvement in median survival of 3.5 months (95% CI, 1.27 to 5.73 months; P =.0083).

CONCLUSION

Our results support the strategy of making these three active drugs available to all patients with advanced CRC who are candidates for such therapy to maximize OS. In addition, our findings suggest that, with the availability of effective salvage options, OS should no longer be regarded as the most appropriate end point by which to assess the efficacy of a palliative first-line treatment in CRC.

The evolving role of oxaliplatin in the management of colorectal cancer

The introduction of oxaliplatin into the chemotherapy of advanced colorectal cancer has substantially increased the frequency and magnitude of clinical response compared with that achieved using 5-FU/leucovorin, and has extended progression-free and overall survival. Research is now in progress on several fronts to determine how oxaliplatin-based therapy can be optimized. A phase III multicentre trial recently compared the efficacy and safety of the FUFOX regimen, based on high dose infusional 5-FU/leucovorin and 50 mg/m2 oxaliplatin given weekly for 4 weeks in a 5-week cycle (n = 123) with the Mayo clinic 5-FU/leucovorin regimen (n = 129) in the first-line therapy of metastatic disease. The response rate with the FUFOX regimen was 48.3%, more than twice that in the Mayo regimen (22.6%; P < 0.0001) and median survival was 20.4 months, despite the fact that the FUFOX regimen had lower toxicity. The value of high dose oxaliplatin and 5-FU/leucovorin has also been demonstrated in the FOLFOX series of studies, where patients who received more than 85 mg/m2 oxaliplatin per 2-week cycle had double the response rate of patients receiving less than 85 mg/m2. In the FOLFOX7 regimen based on a simplified high dose bolus/infusional regimen of 5-FU/leucovorin (sLV5FU2) plus 130 mg/m2 oxaliplatin, a response rate of over 40% has been achieved in second line therapy. Studies have also compared first-line therapy based on oxaliplatin with irinotecan-based first-line therapy. A large trial coordinated by the North Central Cancer Treatment Group (NCCTG) recently compared the IFL regimen, which is currently the standard irinotecan-based first-line treatment for advanced colorectal cancer in the United States, with oxaliplatin-based treatment using the FOLFOX4 regimen. Compared with irinotecan-based chemotherapy, oxaliplatin was associated with a 30% increase in overall survival (19.5 months vs. 15.0 months; P = 0.0001), a higher response rate (45% vs. 31%, P = 0.002) and lower toxicity. Further studies are investigating how therapy can be optimized over multiple lines. In a phase III two-line study comparing first-line therapy with FOLFOX6 and second line therapy with irinotecan-based therapy (FOLFIRI) (n = 109) with the reverse sequence (n = 111), progression-free and overall survival were comparable whichever regimen was used first, although patient numbers were smaller than in the NCCTG study and less able to detect treatment differences. FOLFOX6 was also more effective than FOLFIRI in second-line therapy. Currently, studies based on FOLFOX7, novel FOLFIRI regimens and sLV5FU2 are in progress to determine how disease control can be sustained in the long-term, and the development of drug resistance delayed, in multiline therapeutic management. In parallel with these studies, two large phase III trials are now investigating the role of oxaliplatin in the adjuvant treatment of nonmetastatic colorectal cancer. The first of these studies, MOSAIC, has already shown a very encouraging 23% decrease in the risk of relapse at 3 years (P = 0.002) with FOLFOX4 compared to LV5FU2.

Randomized phase III study of high-dose fluorouracil given as a weekly 24-hour infusion with or without leucovorin versus bolus fluorouracil plus leucovorin in advanced colorectal cancer: European organization of Research and Treatment of Cancer Gastrointestinal Group Study 40952

PURPOSE

This trial was conducted to determine whether high-dose fluorouracil (FU) given as a weekly 24-hour infusion is more active than bolus FU + leucovorin (LV), and whether high-dose infusional FU can be modulated by LV.

PATIENTS AND METHODS

A total of 497 patients with previously untreated metastatic colorectal cancer were randomly assigned to receive bolus FU 425 mg/m2 intravenously + LV 20 mg/m2 on days 1 to 5 and repeated on day 28 (FU + LV), or FU 2600 mg/m2 as a 24-hour infusion alone (FU24h) or in combination with 500 mg/m2 LV (FU24h + LV)-all given weekly x6 followed by a 2-week rest period. Survival was the major study end point.

RESULTS

With a median follow-up of more than 3 years, survival did not differ among the treatment groups (median FU + LV, 11.1 months [95% CI, 10.2 to 15.0 months]; FU24h, 13.0 months [95% CI, 10.4 to 15.4 months]; FU24h + LV, 13.7 months [95% CI, 12.0 to 16.4 months]; P =.724). Progression-free survival (PFS) was significantly longer for FU24h + LV (median FU + LV, 4.0 months [95% CI, 3.4 to 4.9]; FU24h, 4.1 months [95% CI, 3.4 to 5.0]; FU24h + LV 5.6 months [95% CI, 4.4 to 6.7]; P =.029). The response rates in the subgroup of patients with measurable disease were 12%, 10%, and 17% for FU + LV, FU24h, and FU24h + LV, respectively (not significant). Occurrence of grade 3 and 4 diarrhea was higher in the FU24h + LV arm (22%) compared with the FU24h (6%) or FU + LV (9%) arms; however, stomatitis (11% in FU + LV v 3% in FU24h v 5% in FU24h + LV arms) and hematologic toxicity were higher in the bolus FU + LV arm. Global quality of life did not differ within the three arms.

CONCLUSION

Neither FU24h + LV nor FU24h prolong survival, relative to bolus FU + LV. Leucovorin increases PFS if added to FU24h, but increases toxicity.

Biomolecules linked to transition metal complexes--new chances for chemotherapy

From the synthetic point of view the fast developing fields of medicine and biology offer new opportunities for the design of very effective drugs with high selectivity. Especially in the field of anticancer therapy many efforts have been made to deliver drugs to specific tissues. Sugar substituted porphyrin compounds, bile acid conjugates, and pH-sensitive immunoliposomes are only some examples. Although there are many different approaches to exploit biomolecules as shuttles only a start has been made. Since the targeting of a drug is a very complex process, a successful design of a new compound has to consider chemical as well as biological aspects and requires a multidisciplinary cooperation with physicians and biologists. Three interesting concepts are evaluated exemplarily: antibodies, molecules with binding affinity to hormone receptors, and bile acids. The main issues are: selection of the drug and the carrier, ways of linking the pharmacological active compound to the biomolecule, the optimal way of linking the drug to the spacer, and cytotoxicity, apoptosis, and drug resistance.

Dihydropyrimidine dehydrogenase inhibition as a strategy for the oral administration of 5-fluorouracil: utility in the treatment of advanced colorectal cancer

Dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme in 5-fluorouracil (5-FU) catabolism, has been a key target for the development of novel oral fluoropyrimidines. DPD-inhibiting oral fluoropyrimidines showing promise in early clinical studies included UFT (the 5-FU prodrug, tegafur, plus the DPD substrate, uracil), eniluracil (an irreversible DPD inhibitor that improves the oral bioavailability of 5-FU) and S-1 (tegafur plus a reversible DPD inhibitor, 5-chloro-2,4-dihydroxypyridine, and oxonic acid). However, results from phase II/III trials evaluating these agents as first-line therapy for metastatic colorectal cancer have been disappointing. Although DPD-inhibiting oral fluoropyrimidines have some activity in colorectal cancer and oral administration provides significant convenience advantages, the inferior efficacy of UFT/leucovorin and eniluracil/5-FU versus 5-FU/leucovorin in phase III trials does not support the use of these compounds. A feasible regimen for the phase III development of S-1 outside Japan has not been defined. Thus the DPD-inhibiting oral fluoropyrimidines have failed to fulfill their early promise: clinical data indicate that none of these compounds is likely to improve outcomes for patients with metastatic colorectal cancer.