Phase II trial of docetaxel (Taxotere) in metastatic colorectal carcinoma

Recent clinical trials and optical control as a potential strategy to develop microtubule-targeting drugs in colorectal cancer management

Colorectal cancer (CRC) has remained the second and the third leading cause of cancer-related death worldwide and in the United States, respectively. Although significant improvement in overall survival has been achieved, death in adult populations under the age of 55 appears to have increased in the past decades. Although new classes of therapeutic strategies such as immunotherapy have emerged, their application is very limited in CRC so far. Microtubule (MT) inhibitors such as taxanes, are not generally successful in CRC. There may be some way to make MT inhibitors work effectively in CRC. One potential advantage that we can take to treat CRC may be the combination of optical techniques coupled to an endoscope or other fiber optics-based devices. A combination of optical devices and photo-activatable drugs may allow us to locally target advanced CRC cells with highly potent MT-targeting drugs. In this Editorial review, we would like to discuss the potential of optogenetic approaches in CRC management.

Repositioning VU-0365114 as a novel microtubule-destabilizing agent for treating cancer and overcoming drug resistance

Microtubule-targeting agents represent one of the most successful classes of anticancer agents. However, the development of drug resistance and the appearance of adverse effects hamper their clinical implementation. Novel microtubule-targeting agents without such limitations are urgently needed. By employing a gene expression-based drug repositioning strategy, this study identifies VU-0365114, originally synthesized as a positive allosteric modulator of human muscarinic acetylcholine receptor M5 (M5 mAChR), as a novel type of tubulin inhibitor by destabilizing microtubules. VU-0365114 exhibits a broad-spectrum in vitro anticancer activity, especially in colorectal cancer cells. A tumor xenograft study in nude mice shows that VU-0365114 slowed the in vivo colorectal tumor growth. The anticancer activity of VU-0365114 is not related to its original target, M5 mAChR. In addition, VU-0365114 does not serve as a substrate of multidrug resistance (MDR) proteins, and thus, it can overcome MDR. Furthermore, a kinome analysis shows that VU-0365114 did not exhibit other significant off-target effects. Taken together, our study suggests that VU-0365114 primarily targets microtubules, offering potential for repurposing in cancer treatment, although more studies are needed before further drug development.

Implementing patient derived organoids in functional precision medicine for patients with advanced colorectal cancer

BACKGROUND

Patient Derived Organoids (PDOs) emerged as the best technology to develop ex vivo tumor avatars. Whether drug testing on PDOs to identify efficient therapies will bring clinical utility by improving patient survival remains unclear. To test this hypothesis in the frame of clinical trials, PDO technology faces three main challenges to be implemented in routine clinical practices: i) generating PDOs with a limited amount of tumor material; ii) testing a wide panel of anti-cancer drugs; and iii) obtaining results within a time frame compatible with patient disease management. We aimed to address these challenges in a prospective study in patients with colorectal cancer (CRC).

METHODS

Fresh surgical or core needle biopsies were obtained from patients with CRC. PDOs were established and challenged with a panel of 25 FDA-approved anti-cancer drugs (chemotherapies and targeted therapies) to establish a scoring method ('chemogram') identifying in vitro responders. The results were analyzed at the scale of the cohort and individual patients when the follow-up data were available.

RESULTS

A total of 25 PDOs were successfully established, harboring 94% concordance with the genomic profile of the tumor they were derived from. The take-on rate for PDOs derived from core needle biopsies was 61.5%. A chemogram was obtained with a 6-week median turnaround time (range, 4-10 weeks). At least one hit (mean 6.16) was identified for 92% of the PDOs. The number of hits was inversely correlated to disease metastatic dissemination and the number of lines of treatment the patient received. The chemograms were compared to clinical data obtained from 8 patients and proved to be predictive of their response with 75% sensitivity and specificity.

CONCLUSIONS

We show that PDO-based drug tests can be achieved in the frame of routine clinical practice. The chemogram could provide clinicians with a decision-making tool to tailor patient treatment. Thus, PDO-based functional precision oncology should now be tested in interventional trials assessing its clinical utility for patients who do not harbor activable genomic alterations or have developed resistance to standard of care treatments.

Allergy in Cancer Care: Antineoplastic Therapy-Induced Hypersensitivity Reactions

As the backbone of oncological treatments, systemic chemotherapy is still one of the main pawns in cancer care, alone or in combination with newer targeted agents. All chemotherapy agents can be associated with a type of adverse event called an infusion reaction, which can be characterized as unpredictable, non-dose related, and unexplained by the cytotoxic profile of the drug. For some of these events, a certain immunological mechanism can be identified by blood or skin testing. In this case, we can speak of true hypersensitivity reactions that occur as a response to an antigen/allergen. The current work summarizes the main antineoplastic therapy agents and their susceptibility to induce hypersensitivity reactions and also includes a review of clinical presentation, diagnostic methods in hypersensitivity reactions, and perspectives to overcome these negative events in the treatment of patients suffering from various types of cancer.

A folate-targeted PEGylated cyclodextrin-based nanoformulation achieves co-delivery of docetaxel and siRNA for colorectal cancer

Docetaxel (DTX) is a chemotherapeutic agent used for a range of cancers, but it has little activity against colorectal cancer (CRC). However, combination therapy with other therapeutic agents is a potential strategy to enhance the efficacy of DTX in CRC treatment. The nuclear factor-κB (NF-κB) signaling pathway is implicated in a variety of malignancies (e.g., CRC), and the blockade of NF-κB may increase the sensitivity of cancer cells to chemotherapy. The application of small interference RNA (siRNA) to inhibit the translation of complementary mRNA has demonstrated the potential for cancer gene therapy. In this study, an amphiphilic cationic cyclodextrin (CD) nanoparticle modified with PEGylated folate (FA; a ligand to target folate receptor on CRC) has been developed for co-delivery of DTX and siRNA (against the RelA, a subunit of NF-κB) in the treatment of CRC. The resultant co-formulation (CD.DTX.siRelA.PEG-FA) achieved cell-specific uptake indicating the function of the folate targeting ligand. The CD.DTX.siRelA.PEG-FA nanoparticle enhanced the apoptotic effect of DTX with the downregulation of RelA expression, which significantly retarded the growth of CRC in mice, without causing significant toxicity. These results suggest that the FA-targeted PEGylated CD-based co-formulation provides a promising strategy for combining DTX and siRNA in treating CRC.

Mitotic checkpoint regulator RAE1 promotes tumor growth in colorectal cancer

Microtubules are among the most successful targets for anticancer therapy because they play important roles in cell proliferation as they constitute the mitotic spindle, which is critical for chromosome segregation during mitosis. Hence, identifying new therapeutic targets encoding proteins that regulate microtubule assembly and function specifically in cancer cells is critical. In the present study, we identified a candidate gene that promotes tumor progression, ribonucleic acid export 1 (RAE1), a mitotic checkpoint regulator, on chromosome 20q through a bioinformatics approach using datasets of colorectal cancer (CRC), including The Cancer Genome Atlas (TCGA). RAE1 was ubiquitously amplified and overexpressed in tumor cells. High expression of RAE1 in tumor tissues was positively associated with distant metastasis and was an independent poor prognostic factor in CRC. In vitro and in vivo analysis showed that RAE1 promoted tumor growth, inhibited apoptosis, and promoted cell cycle progression, possibly with a decreased proportion of multipolar spindle cells in CRC. Furthermore, RAE1 induced chemoresistance through its anti-apoptotic effect. In addition, overexpression of RAE1 and significant effects on survival were observed in various types of cancer, including CRC. In conclusion, we identified RAE1 as a novel gene that facilitates tumor growth in part by inhibiting apoptosis and promoting cell cycle progression through stabilizing spindle bipolarity and facilitating tumor growth. We suggest that it is a potential therapeutic target to overcome therapeutic resistance of CRC.

A phase 2 trial of gemcitabine and docetaxel in patients with metastatic colorectal adenocarcinoma with methylated checkpoint with forkhead and ring finger domain promoter and/or microsatellite instability phenotype

Abstract

We previously reported CHFR methylation in a subset of colorectal cancer (CRC; ∼30%) with high concordance with microsatellite instability (MSI). We also showed that CHFR methylation predicted for sensitivity to docetaxel, whereas the MSI‐high phenotypes were sensitive to gemcitabine. We hypothesized that this subset of patients with CRC would be selectively sensitive to gemcitabine and docetaxel. We enrolled a Phase 2 trial of gemcitabine and docetaxel in patients with MSI‐high and/or CHFR methylated CRC. The primary objective was Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 response rate. Enrolled patients were treated with gemcitabine 800 mg/m² on days 1 and 8 and docetaxel 70 mg/m² on day 8 of each 21‐day cycle. A total of 6 patients with CHFR‐methylated, MSI‐high CRC were enrolled from September 2012 to August 2016. The study was closed in September of 2017 due to poor accrual prior to reaching the first interim assessment of response rate, which would have occurred at 10 patients. No RECIST criteria tumor responses were observed, with 3 patients (50%) having stable disease as best response, 1 lasting more than 9 months. Median progression‐free survival (PFS) was 1.79 months (95% confidence interval [CI] = 1.28, not available [NA]) and median overall survival (OS) was 15.67 months (95% CI = 4.24, NA). Common grade 3 toxicities were lymphopenia (67%), leukopenia (33%), and anemia (33%). Although negative, this study establishes a proof‐of‐concept for the implementation of epigenetic biomarkers (CHFR methylation/MSI) as inclusion criteria in a prospective clinical trial to optimize combinatorial strategies in the era of personalized medicine.

Utidelone inhibits growth of colorectal cancer cells through ROS/JNK signaling pathway

Utidelone (UTD1), a novel microtubule stabilizing agent, is an epothilone B analogue which was produced by genetic engineering. UTD1 has exhibited broad antitumor activity in multiple solid tumors. However, its activity and mechanism in colorectal cancer (CRC) remain to be studied. In this study, UTD1 dramatically inhibited CRC cell proliferation (with 0.38 µg/ml, 0.77 µg/ml IC50 in RKO and HCT116, respectively) in vitro. Immunofluorescence staining showed that UTD1 induced the formation of microtubule bundling and asters in RKO cells. Flow cytometry analysis demonstrated that UTD1 induced cell cycle to arrest in G2/M phase, subsequent apoptosis. Significantly, UTD1 exhibited stronger effect on inducing apoptosis than paclitaxel and 5-FU, especially in HCT15 cells which is ABCB1 high-expression. UTD1 exposure cleaved caspase-3 and poly ADP-ribose polymerase (PARP), decreased mitochondrial membrane potential, released cytochrome c, increased the production of active oxygen and activated c-Jun N-terminal kinase (JNK), suggesting ROS/JNK pathway was involved in this process. Moreover, UTD1 inhibited tumor growth and was more effective and safer compared with paclitaxel and 5-FU in RKO xenograft in nude mice. Taken together, our findings first indicate that UDT1 inhibits tumor growth in CRC xenograft model and may be a promising agent for CRC treatment.

Pertuzumab and trastuzumab emtansine in patients with HER2-amplified metastatic colorectal cancer: the phase II HERACLES-B trial

BACKGROUND

HER2 is a therapeutic target for metastatic colorectal cancer (mCRC), as demonstrated in the pivotal HERACLES-A (HER2 Amplification for Colo-rectaL cancer Enhanced Stratification) trial with trastuzumab and lapatinib. The aim of HERACLES-B trial is to assess the efficacy of the combination of pertuzumab and trastuzumab-emtansine (T-DM1) in this setting.

METHODS

HERACLES-B was a single-arm, phase II trial, in patients with histologically confirmed RAS/BRAF wild-type and HER2+ mCRC refractory to standard treatments. HER2 positivity was assessed by immunohistochemistry and in situ hybridisation according to HERACLES criteria. Patients were treated with pertuzumab (840 mg intravenous load followed by 420 mg intravenous every 3 weeks) and T-DM1 (3.6 mg/kg every 3 weeks) until disease progression or toxicity. Primary and secondary end points were objective response rate (ORR) and progression-free survival (PFS). With a Fleming/Hern design (H0=ORR 10%; α=0.05; power=0.85), 7/30 responses were required to demonstrate an ORR ≥30% (H1).

RESULTS

Thirty-one patients, 48% with ≥4 lines of previous therapies, were treated and evaluable. ORR was 9.7% (95% CI: 0 to 28) and stable disease (SD) 67.7% (95% CI: 50 to 85). OR/SD ≥4 months was associated with higher HER2 immunohistochemistry score (3+ vs 2+) (p = 0.03). Median PFS was 4.1 months (95% CI: 3.6 to 5.9). Drug-related grade (G) 3 adverse events were observed in two patients (thrombocytopaenia); G≤2 AE in 84% of cycles (n = 296), mainly nausea and fatigue.

CONCLUSIONS

HERACLES-B trial did not reach its primary end point of ORR; however, based on high disease control, PFS similar to other anti-HER2 regimens, and low toxicity, pertuzumab in combination with T-DM1 can be considered for HER2+mCRC as a potential therapeutic resource.

TRIAL REGISTRATION NUMBER

2012-002128-33 and NCT03225937.

A Multicenter Retrospective Study to Evaluate Safety and Efficacy of Tocopheryl Polyethylene Glycol Succinate Docetaxel in Various Cancers

In order to overcome the polysorbate induced hypersensitivity reactions with chemotherapy drugs, novel drug-delivery mechanisms have been developed in the last decade. D-alpha-tocopheryl polyethylene glycol succinate (TPGS) is formed by esterification of alpha-tocopheryl succinate and polyethylene glycol 1000.

This was a real-world retrospective analysis designed to evaluate safety and efficacy of TPGS-docetaxel in various cancers. Patients hospitalized between June 2018 and May 2019 were included in the data set. While the efficacy was assessed by the Response Evaluation Criteria in Solid Tumors criteria, safety was assessed by the National Cancer Institute Common Terminology Criteria-adverse event (AE) criteria.

A total of 61 patients who received at least one dose of TPGS-docetaxel were incorporated into the analysis set. The dose of TPGS docetaxel ranged from 20 mg/m2 to 120 mg/m2, commonly prescribed dose being 75 mg/m2. While 25 (40.98%) patients had a partial response, 17 (27.86%) patients had stable disease. Five (8.19%) patients progressed and 4 (6.55%) patients died during the chemotherapy, which was adjudicated to be unrelated to the drug as opined by the treating clinician. AE were reported in 42 patients in the safety data set. There were no AEs pertaining to hypersensitivity reported during the study. One AE of Grade 3 hand foot syndrome was encountered.

The preliminary evidence suggests that the novel TPGS-based docetaxel formulation is efficacious in various cancers, and importantly, it has an enhanced safety profile, as it is devoid of polysorbate 80 induced hypersensitivity reactions.

Novel octapeptide-DTX prodrugs targeting MMP-7 as effective agents for the treatment of colorectal cancer with lower systemic toxicity

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer death around the world. The current treatments of CRC exhibited high occurrence rate of side effects. Docetaxel (DTX), an important drug widely used in cancer chemotherapy, showed serious toxicity in CRC. Reducing toxicity of DTX could be a feasible and promising way to achieve the new indication of DTX for CRC. In this study, a series of MMP-7 activated octapeptide-DTX/4FDT prodrugs (6a-10a and 6b-10b) were designed and synthesized based on the features of MMP-7 which is highly expressed in CRC and could specially recognize octapeptides with specific sequences. Among them, 9a and 9b, both possessing an octapeptide Gly-Pro-Gln-Gly-Ile-Ala-Met-Gln moiety, were the most potent prodrugs. Compounds 9a and 9b were also tested their release rate in HCT116 cell culture fluids and tumor homogenate along with in vivo anti-CRC activity and systemic toxicity. Since 9a showed better anti-CRC activity and lower systemic toxicity than 9b in CRC tumor bearing mice, it was further evaluated for its acute toxicity, pharmacokinetics and tissue distribution in comparison with its parent drug DTX. These results revealed that 9a possessed good systemic stability, rapid release rate in CRC and reduced systemic toxicity, while retaining similar anti-CRC activity to its parent drug DTX. Thus, 9a, an MMP-7 polypeptide prodrug of DTX, has been identified as a promising candidate for the treatment of CRC.

Intraperitoneal chemotherapy against peritoneal carcinomatosis: current status and future perspective

Peritoneal carcinomatosis (PC), caused by advanced abdominal malignancies, such as those of the ovarian and gastrointestinal tracts, has an extremely poor prognosis. Intraperitoneal (IP) chemotherapy has been clinically applied for several decades, but its clinical efficacy has not been fully determined. An accumulating body of evidence suggests that cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the optimal treatment for selected patients with ovarian and colorectal cancers with PC. Recent studies suggest that IP administration of taxane with systemic chemotherapy in a neoadjuvant setting improves patient survival in gastric cancer with PC. The pharmacokinetics of IP-administered drugs should be primarily considered in order to optimize IP chemotherapy. Therefore, the development of specific IP drugs using newly emerging molecular targeted reagents or new drug delivery systems, such as nanomedicine or controlled absorption/release methods, is essential to improve the efficacy of IP chemotherapy.

Drug development for intraperitoneal chemotherapy against peritoneal carcinomatosis from gastrointestinal cancer

Intraperitoneal (IP) chemotherapy for peritoneal carcinomatosis (PC) from gastrointestinal cancer has been investigated and applied clinically for several decades. Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy have been considered to be the optimal treatment options for selected patients with colorectal and gastric cancers with PC. Accumulating evidence suggests that the administration of IP paclitaxel for patients with PC from gastric cancer may improve the patient survival. The pharmacokinetics of such treatment should be considered to optimize IP chemotherapy. In addition, newly emerging molecular-targeted therapies and research into new drug delivery systems, such as nanomedicine or controlled absorption/release methods, are essential to improve the effects of IP chemotherapy. This review summarizes the current status and future prospects of IP chemotherapy for the treatment of gastrointestinal cancer.

CHFR silencing or microsatellite instability is associated with increased antitumor activity of docetaxel or gemcitabine in colorectal cancer

Phenotypic differences among cancers with the same origin may be associated with chemotherapy response. CHFR silencing associated with DNA methylation has been suggested to be predictive of taxane sensitivity in diverse tumor types. However, the use of microsatellite instability (MSI:unstable-MSS:stable) as a predictive marker for therapeutic effect has had conflicting results. We examined these molecular alterations as predictors of chemotherapy sensitivity in colorectal cancer (CRC). Differential sensitivity to docetaxel and gemcitabine was compared to potential predictive biomarkers CHFR methylation and MSI status. Cell lines that were MSI-H/CHFR-methylated, MSS/CHFR-methylated and MSS/CHFR-unmethylated were assessed for in vivo sensitivity of CRC cell line xenografts to docetaxel and/or gemcitabine. We observed increased sensitivity in vitro to gemcitabine in cell lines with MSI and docetaxel in cell lines with CHFR inactivation via DNA methylation. In vivo treatment of human xenografts confirmed differential sensitivity, with the MSI-H/CHFR-methylated line RKO having tumor growth inhibition to each agent, and at least additive tumor growth inhibition with combination therapy. The MSS-CHFR-unmethylated line, CACO2 , was resistant to single and combination therapy, while COLO205, the MSS/CHFR-methylated line, showed tumor growth inhibition with docetaxel, but not gemcitabine, therapy. CHFR methylation in CRC cell lines predicted for sensitivity in vitro and in vivo to docetaxel, while MSI-H cell lines were more sensitive to gemcitabine. These data suggest that a subset of CRC patients would be selectively sensitive to a novel combination of gemcitabine and docetaxel, and are the basis for an ongoing clinical trial of this combination in a biomarker-selected patient population.

The role of taxanes in the management of gastroesphageal cancer

Upper gastrointestinal cancers commonly referred to as gastroesophageal carcinomas encompass cancers of the esophagus, stomach and gastroesophageal junction. Although the number of newly diagnosed cases of gastric cancer has decreased in the United States, the whole burden of upper gastrointestinal carcinomas on society remains significantly high, with only a small improvement in overall survival achieved over the past two decades. Traditionally, therapeutic agents used to treat gastroesophageal cancers have been platinums and fluoropyrimidines. Taxanes are di-terpenes produced by the plants of the genus Taxus (yews). As their name suggests, taxanes were first derived from natural sources, but now they are all synthesized artificially. Interfering with cellular microtubular function during cell division is the main mechanism of action for currently available taxanes. Since their introduction into therapeutic oncology, many different other taxane-derivatives have been manufactured and are being developed. Changing the formulation of the drug to improve delivery such as liposomal encapsulation, and target deliver with antibody-drug conjugation, as well as introducing new class of cytotoxic agents that can overcome taxane-resistance. The two most commonly used taxanes are paclitaxel and docetaxel. Taxane is a class of cytotoxic agents more commonly administered in patients with breast and lung cancers. However, the regulatory approval of docetaxel to treat patients with metastatic or advanced gastroesophageal cancers in 2006 established the role of taxanes in the management of upper gastroesophageal cancers. This paper will review the current data of taxanes in the management of patients with upper gastrointestinal cancers.

Pharmacoethnicity of docetaxel-induced severe neutropenia: integrated analysis of published phase II and III trials

BACKGROUND

Ethnic differences in drug susceptibility and toxicity are a major concern, not only in drug development but also in the clinical setting. We review the toxicity profiles of docetaxel according to dose and ethnicity.

METHODS

We analyzed phase II and III clinical trials that included a once-every-3-weeks single-agent docetaxel arm. Logistic regression analysis was applied to identify the significant variables affecting the reported incidence of docetaxel-induced severe neutropenia.

RESULTS

Multivariate logistic regression analysis identified studies conducted in Asia [odds ratio (OR) 19.0; 95% confidence interval (95% CI) 3.64-99.0] and docetaxel dose (OR 1.08; 95% CI 1.03-1.13) as independent variables for the incidence of grade 3/4 neutropenia.

CONCLUSIONS

There is a significant difference in the incidence of docetaxel-induced severe neutropenia between Asian and non-Asian clinical studies. Physicians and pharmacists should consider ethnic diversity in docetaxel toxicity when interpreting the results of clinical trials.

Transcatheter arterial chemoembolization with docetaxel-loaded microspheres controls heavily pretreated unresectable liver metastases from colorectal cancer: a case study

This is the first case report describing transcatheter arterial chemoembolization (TACE) with docetaxel-loaded microspheres which was successful in controlling liver metastases. We report on a 50-year-old woman with unresectable liver metastases from colorectal cancer. Since November 2007, the patient had received 12 courses of mFOLFOX6 (LV/5-FU/L-OHP) as the 1st line therapy, 18 courses of LV/5-FU as the 2nd line therapy, 16 courses of FOLFIRI (LV/5-FU/CPT-11) + bevacizumab as the 3rd line therapy, and 32 courses of cetuximab as the 4th line therapy. All treatments had been conducted after confirmation of the disease progression. The patient experienced hepatic dysfunction, upper abdominal pain and malaise due to the growth of metastatic liver tumors. Since December 2009, the patient received 3 courses of TACE with docetaxel-loaded microspheres in combination with hepatic arterial infusion of 20 mg cisplatin (CDDP) in a palliative setting for the treatment of liver metastases, which resulted in a reduction or necrosis of liver metastases and improvement in hepatic function and symptoms. TACE with docetaxel-loaded microspheres may be a palliative therapy for patients with colorectal cancer who are refractory to the current standard systemic chemotherapy and have predominant liver metastases.

Gamma-secretase inhibitors enhance taxane-induced mitotic arrest and apoptosis in colon cancer cells

BACKGROUND & AIMS

Colorectal cancers are resistant to conventional chemotherapeutic treatments, including taxanes. gamma-Secretase is a multimeric membrane protein complex responsible for the intramembrane proteolysis of various type I transmembrane proteins, including amyloid beta-precursor protein and Notch. gamma-Secretase inhibitors have attracted increasing interest as anticancer drugs because of their ability to inhibit Notch signaling. However, the therapeutic usefulness of gamma-secretase inhibitors against colorectal cancers remains unclear.

METHODS

The effects of gamma-secretase inhibitors on growth and apoptosis induced by various chemotherapeutic agents in colon cancer cells were evaluated using Hoechst 33342 staining, colony formation assay, and cell cycle analysis. The effect of gamma-secretase inhibitors on taxane-induced mitotic arrest was evaluated using the cyclin B1-associated histone H1 kinase assay and MPM-2 reactivity. The involvement of Notch signaling was evaluated by the silencing of Notch/CBF1 signaling by RNA interference.

RESULTS

gamma-Secretase inhibitors enhanced taxane-induced mitotic arrest and apoptosis of colon cancer cells both in vitro and in vivo, although gamma-secretase inhibitors alone did not affect growth and apoptosis of colon cancer cells. We also showed that this effect by gamma-secretase inhibitors was restricted to taxanes and colon cancer cells. Silencing of Notch/CBF1 signaling failed to affect paclitaxel-induced mitotic arrest and apoptosis.

CONCLUSIONS

These data suggest that gamma-secretase inhibitors could be a new therapeutic modality for overcoming resistance to taxanes in colorectal cancers.

Pharmacobiologically based scheduling of capecitabine and docetaxel results in antitumor activity in resistant human malignancies

PURPOSE

Capecitabine and docetaxel have demonstrated preclinical antitumor synergy. This synergy is thought to occur from docetaxel-mediated upregulation of thymidine phosphorylase (dThdPase), an enzyme responsible for the relative tumor selectivity of capecitabine. On the basis of the time-dependency and transiency for this upregulation, we performed a phase I study of capecitabine in combination with weekly docetaxel. We hypothesized that weekly docetaxel would result in sustained dThdPase expression and that capecitabine administration at times of maximum dThdPase upregulation would increase the therapeutic index for this combination.

PATIENTS AND METHODS

Patients with advanced solid malignancies received docetaxel on days 1, 8, and 15, and capecitabine bid on days 5 to 18, every 4 weeks. Docetaxel was fixed at 36 mg/m(2)/wk, whereas capecitabine was escalated in successive patients cohorts.

RESULTS

Sixteen patients received 77 courses at capecitabine doses from 950 to 1,500 mg/m(2)/d. The most common toxicities were hand-foot syndrome, diarrhea, nausea/vomiting, and asthenia. Grades 3 to 4 hematologic toxicities were infrequent and no treatment-related hospitalizations occurred. Three of three patients treated at 1,500/36 mg/m(2) capecitabine/docetaxel developed grade 3 hand-foot syndrome or diarrhea during either their first or second course, whereas only two of 13 patients at 1,250/36 mg/m(2) doses developed significant toxicity. Antitumor responses (n = 7) occurred in patients with hepatocellular, non-small-cell lung, and chemotherapy-refractory breast, bladder, and colorectal carcinomas. Prolonged stabilizations occurred in patients with metastatic mesothelioma (n = 2), chemorefractory non-small-cell lung carcinoma, and bronchioloalveolar carcinoma.

CONCLUSION

Capecitabine in combination with weekly docetaxel is well tolerated. Recommended doses are capecitabine 1,250 mg/m(2)/d (625 mg/m(2) bid) with docetaxel 36 mg/m(2)/wk. The acceptable toxicity profile in this dose schedule, and the antitumor activity observed, warrant further evaluation of this regimen.

Prevention and management of antineoplastic-induced hypersensitivity reactions

Acute hypersensitivity reactions (HSRs) are an unpredictable and potentially catastrophic complication of treatment with chemotherapeutic agents. Reactions may affect any organ system in the body and range widely in severity from mild pruritus to systemic anaphylaxis. Certain classes of chemotherapeutic agents, such as the taxanes, platinum compounds, asparaginases, and epipodophyllotoxins are commonly associated with HSRs. The clinical characteristics of these high risk agents with respect to HSRs are discussed in this review. Protocols to prevent or reduce the severity of these reactions have been developed, but despite these attempts, HSRs will still happen. Should a reaction occur, it is imperative that it be recognised quickly in order to minimise exposure to the inciting agent and implement appropriate therapeutic and supportive measures. When a patient becomes sensitised to a chemotherapeutic agent, avoidance of re-exposure is the mainstay of future prevention. For sensitised patients who have derived clinically meaningful benefit from a particular agent, however, continuation of treatment with the agent is desirable. Options may include attempting a trial of desensitisation or treatment with a related compound. Virtually all patients demonstrating HSRs to paclitaxel and docetaxel are able to successfully tolerate re-treatment following discontinuation and administration of diphenhydramine and hydrocortisone. Re-treatment has generally been less successful with platinum compounds. with recurrent HSRs occurring in up to 50% of patients following desensitisation protocols. Patients sensitised to asparaginase are often able to tolerate the alternative preparations, Erwinia carotovora asparaginase or polyethylene glycol-modified Escherichia coli asparaginase. There is very little experience with re-treatment following sensitisation to the epipodophyllotoxins. As re-treatment may have serious consequences, careful consideration of the risks and benefits of these strategies is imperative when deciding among these options.

Phase II trial of docetaxel for cholangiocarcinoma

The authors evaluated the activity and toxicity of docetaxel given as a 1-hour infusion every 21 days in patients with unresectable cholangiocarcinoma. Seventeen patients with cytologically or histologically confirmed cholangiocarcinoma received intravenous docetaxel over 1 hour, repeated every 21 days. The initial dose of docetaxel was 100 mg/m2, with a subsequent 25% dose reduction for patients experiencing grade 3 or 4 toxicities. Treatment was continued until disease progression or occurrence of intolerable side effects. All patients received premedication with dexamethasone 8 mg by mouth twice daily for 5 days, starting 1 day before docetaxel infusion. Sixteen of the 17 patients were assessable for response and toxicity; one patient was removed from the trial for intercurrent illness. Thirty-eight cycles of docetaxel were delivered (median, two cycles). No complete or partial responses were noted. Fourteen patients had progressive disease, one patient had stable disease, and one patient died of septic shock shortly after starting treatment. Granulocytopenia was the dose-limiting toxicity. Thirteen patients had grade 4 granulocytopenia, 11 of whom required antibiotics for neutropenic fever. Granulocytopenia was the only grade 4 toxicity observed. Grade 3 toxicities included stomatitis, anemia, fatigue, vomiting, and hypotension. Grade 1 or 2 toxicities included alopecia, diarrhea, peripheral edema, myalgias, and anorexia. Administered on this dose and schedule, docetaxel lacked activity in patients with cholangiocarcinoma. The toxicity profile, including dose-limiting granulocytopenia, has been previously described in patients receiving docetaxel.

Phase II study of prolonged infusion of Taxol in patients with metastatic colorectal carcinoma

PURPOSE

Taxol represents a new class of anticancer agents with activity against a wide variety of solid tumors. In preclinical systems, its cytotoxicity is schedule dependent with prolonged exposure being more effective. We studied a 120-hour infusion schedule of Taxol in patients with metastatic measurable colorectal carcinoma who had had one prior 5-FU-based chemotherapy.

METHODS

Patients with measurable metastatic colorectal carcinoma were eligible. Patients had to have normal liver, renal, and bone marrow functions. Written informed consent was obtained from all patients. The starting dose of Taxol was 150 mg/m2 infused over 120-hours in the outpatient setting. Taxol was repeated every 21 days.

RESULTS

Fifteen patients were registered. Among 14 evaluable patients, we did not observe any complete or partial response. Major toxicity included myelosuppression and mucositis. There was no treatment-related death.

CONCLUSION

Taxol administered by this schedule was found ineffective in patients with metastatic colorectal carcinoma who had previously received one 5-FU-based chemotherapy.

New drugs in the treatment of colorectal carcinoma

BACKGROUND

Treatment with 5-fluorouracil (5-FU) plus leucovorin has been the unofficial standard therapy for patients with colorectal carcinoma (CRC) for more than a decade; however, the optimal dose and schedule remain a matter of debate. Recently several new drugs have shown activity in this disease. These include irinotecan (CPT-11); oxaliplatin; the thymidylate synthase inhibitors raltitrexed, uracil/tegafur (UFT), capecitabine, and S-1; the biochemical modulators trimetrexate and 5-ethynyluracil; and the monoclonal antibody 17-1A.

METHODS

The results of clinical trials with these and other new agents, as well as their current status and main characteristics, were reviewed.

RESULTS

Several of these agents, some with a novel mechanism of action, show promising activity in CRC. In combination with 5-FU and leucovorin, trimetrexate showed encouraging response rates in Phase II studies. Other interesting agents include capecitabine, UFT, and S-1. The biochemical modulator 5-ethynyluracil may allow the oral administration of 5-FU; however, results of Phase II clinical trials are not yet available. CPT-11 is in the most advanced stage of development and, based on consistent data generated in extensive Phase II studies, currently appears to be a reasonable choice for 5-FU-resistant or refractory disease. Another promising agent is oxaliplatin, which showed activity as first-line and second-line treatment.

CONCLUSIONS

Several new agents have shown promise in the treatment of CRC, and changes in the standard treatment of advanced or high risk CRC appear likely in the near future.

Phase II trial of docetaxel (Taxotere) for untreated advanced colorectal carcinoma

The antimicrotubule agent docetaxel (Taxotere), a semisynthetic taxoid, has demonstrated antitumor activity against colorectal cancer cell lines in vitro, and in murine tumor models. We sought to characterize its activity in a group of previously untreated patients with colorectal carcinoma. Eighteen previously untreated patients with advanced, measurable colorectal carcinoma were treated with a 60-min intravenous infusion of docetaxel with a dose of 100 mg/m2 administered every 21 days. Routine premedication with diphenhydramine was given. Patients were required to have normal organ function and a Karnofsky performance status (KPS) > or = 60%. No complete response (CR) or partial responses (PR) were observed. Median survival was 13 months, despite a median time to progression of only 1.3 months. Neutropenia was the most common dose-limiting toxicity, resulting in 5 episodes of febrile neutropenia requiring hospitalization and intravenous antibiotics. One patient experienced a grade 4 hypersensitivity reaction (HSR) requiring treatment termination. No toxic deaths occurred. Despite encouraging preclinical data, docetaxel is an inactive drug in advanced colorectal cancer when given in the dose and on the schedule examined in the present study, and has significant, although reversible, toxicities.

[Docetaxel in treatment of other solid tumors]

PHASE-II-STUDIES: Docetaxel (Taxotere; Rhône-Poulenc Rorer) was evaluated in the treatment of a wide range of tumors in the early nineties. This overview relates mainly to the results of 32 phase-II-studies from Europe, North America and Japan including the following malignancies: head and neck cancer, cancer of the ovary and cervix uterus, soft tissue sarcomas, gastrointestinal cancers, renal and transitional cell cancer as well as melanoma and glioma. Results of recent studies also revealed a high activity of combination chemotherapy with cisplatinum in untreated head and neck cancer as well as ovarian cancer.

RESULTS

A remarkable single agent activity was observed in the palliative treatment after recurrence of head and neck tumors (ORR 27 to 42%) and as salvage chemotherapy after failure of platinum compounds in ovarian cancer, where Docetaxel appeared to be similarly active as Paclitaxel and Topotecan. Remarkable activity was also observed in the treatment of gastric, pancreatic and urothelial cancer as well as melanoma.

CONCLUSION

Docetaxel ist a new cytotoxic drug with a broad range of activity in various solid tumors. The place of this compound in relation to established regimens and its value its value in combination chemotherapy warrants further investigation.

Phase II data on paclitaxel and docetaxel in gastrointestinal malignancies

From the contributions in this volume, it is apparent that in spite of promising chemotherapy combinations and new multidisciplinary approaches, the treatment of advanced gastrointestinal malignancies remains a difficult task. New agents have recently been developed with either a better therapeutic ratio (fluoropyrimidine analogs or modulators of the metabolic pathway of those agents) or a better activity due to a different mechanism of action. Among the latter agents, the topoisomerase I inhibitors (especially irinotecan, also known as CPT-11) and new antimetabolities (difluorodeoxycytidine, also known as gemcitabine) are of interest for difficult tumors, such as colon and pancreatic cancer. This short review describes the phase II studies on the activity of taxoids, agents that promote tubulin assembly in microtubules and inhibit their depolymerization.

Docetaxel (Taxotere): single agent activity, development of combination treatment and reducing side-effects

Docetaxel is a new semi-synthetic taxoid, which acts as an antimicrotubule agent and is now clinically available. Clinical studies of docetaxel as a single agent and in combination with other cytotoxic drugs reveals favourable response rates in a number of solid tumor types. Docetaxel appears to have great potential in advanced breast cancer as first or secondline chemotherapy. The dose-limiting toxicity is an early and short-lasting neutropenia. Fluid retention is a cumbersome, sometimes disabling, side-effect. Other side-effects are usually mild and include alopecia, myalgia, mucostitis, neuropathy, hypersensitivity reaction, nail changes and cutaneous reactions.