Hypersensitivity Reactions to Taxanes: A Multicenter Study for Outcomes and Safety of Rapid Drug Desensitization

PURPOSE

Taxanes can cause hypersensitivity reactions (HSRs), which pose a significant challenge in the treatment of malignancies. Patients who are eligible for rapid drug desensitization (RDD) can continue treatment; however, some patients experience breakthrough reactions (BTRs). Data about risk factors for BTRs during RDDs in patients with HSRs to taxanes are limited.

METHODS

This was a multicenter, retrospective study of patients with immediate-HSRs to taxanes. Initial HSRs were classified as grade 1, 2, or 3 based on severity. Prick/intradermal skin tests were performed with implicated taxanes. A 12-step protocol was used during RDD.

RESULTS

The study comprised 75 patients (F/M: 63/12, mean age 49.92 ± 11.72 years, 43 HSRs to paclitaxel, 32 HSRs to docetaxel). The majority of reactions (86.7%) occurred during the first or second exposure. The prevalence of drug allergy history was higher in patients with paclitaxel HSR than in those with docetaxel HSR, although it was not statistically significant (23.3% vs. 6.3%). The initial HSRs were mostly grade 2 (n = 50, 66.7%) or grade 3 (n = 22, 29.3%). Skin tests with implicated taxanes were done on 48 patients, and the rate of positive response in patients with grade 1, 2, and 3 initial HSRs were 50%, 17.6%, and 16.7%, respectively. . A total of 255 RDDs were completely performed, although BTRs occurred in 27 (grade 1, 55.6%; grade 2, 40.7%; grade 3, 3.7%). There were no statistically significant correlations between the risk of BTR and age, drug cycle, gender, positivity of skin test or atopy. The step reduction was successfully done on 9 eligible patients with mild or moderate HSRs during the 12-step RDDs.

CONCLUSIONS

Our experience demonstrates a 100% success rate in completing the 255 RDDs for taxanes, affirming the safety and efficacy of the RDD within the study population.

Quality evaluation of compounds in leaves of six Taxus species based on UPLC-MS/MS and chemometrics

Introduction: Taxus species are used as medicinal plants all over the world. The leaves of Taxus species are sustainable medicinal resources that are rich in taxoids and flavonoids. However, traditional identification methods cannot effectively identify Taxus species on the basis of leaces used as raw medicinal materials, because their appearance and morphological characteristics are almost the same, and the probability of error identification increases in accordance with the subjective consciousness of the experimenter. Moreover, although the leaves of different Taxus species have been widely used, their chemical components are similar and lack systematic comparative research. Such a situation is challenging for quality assessment. Materials and methods: In this study, ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry combined with chemometrics was applied for the simultaneous determination of eight taxoids, four flavanols, five flavonols, two dihydroflavones, and five biflavones in the leaves of six Taxus species, namely, T. mairei, T. chinensis, T. yunnanensis, T. wallichiana, T. cuspidata, and T. media. Chemometric methods, including hierarchical cluster analysis, principal component analysis, orthogonal partial least squares-discriminate analysis, random forest iterative modeling, and fisher linear discriminant analysis, were utilized to differentiate and evaluate the six Taxus species. Results: This proposed method exhibited good linearity (R ² = 0.9999-0.9972) with a lower quantification limits of 0.94-3.05 ng/mL for all analytes. The intra- and inter-day precisions were within 6.83%. Six compounds, namely, 7-xylosyl-10-deacetyltaxol, ginkgetin, rutin, aromadendrin, 10-deacetyl baccatin III, and epigallocatechin, were identified through chemometrics for the first time. These compounds can be used as important chemical markers to distinguish the above six Taxus species rapidly. Conclusion: This study established a method for determination of the leaves of six Taxus species, and revealing the differences in the chemical components of these six Taxus species.

Profiling of Taxoid Compounds in Plant Cell Cultures of Different Species of Yew (Taxus spp.)

Plant cell cultures of various yew species are a profitable source of taxoids (taxane diterpenoids) with antitumor activity. So far, despite intensive studies, the principles of the formation of different groups of taxoids in cultured in vitro plant cells have not been fully revealed. In this study, the qualitative composition of taxoids of different structural groups was assessed in callus and suspension cell cultures of three yew species (Taxus baccata, T. canadensis, and T. wallichiana) and two T. × media hybrids. For the first time, 14-hydroxylated taxoids were isolated from the biomass of the suspension culture of T. baccata cells, and their structures were identified by high-resolution mass spectrometry and NMR spectroscopy as 7β-hydroxy-taxuyunnanin C, sinenxane C, taxuyunnanine C, 2α,5α,9α,10β,14β-pentaacetoxy-4(20), 11-taxadiene, and yunnanxane. UPLC-ESI-MS screening of taxoids was performed in more than 20 callus and suspension cell lines originating from different explants and grown in over 20 formulations of nutrient media. Regardless of the species, cell line origin, and conditions, most of the investigated cell cultures retained the ability to form taxane diterpenoids. Nonpolar 14-hydroxylated taxoids (in the form of polyesters) were predominant under in vitro culture conditions in all cell lines. These results, together with the literature data, suggest that dedifferentiated cell cultures of various yew species retain the ability to synthesize taxoids, but predominantly of the 14-OH taxoid group compared to the 13-OH taxoids found in plants.

Synthesis and Cytotoxicity of 7,9-O-Linked Macrocyclic C-Seco Taxoids

A series of novel 7,9-O-linked macrocyclic taxoids together with modification at the C2 position were synthesized, and their cytotoxicities against drug-sensitive and P-glycoprotein and βIII-tubulin overexpressed drug-resistant cancer cell lines were evaluated. It is demonstrated that C-seco taxoids conformationally constrained via carbonate containing-linked macrocyclization display increased cytotoxicity on drug-resistant tumors overexpressing both βIII and P-gp, among which compound 22b, bearing a 2-m-methoxybenzoyl group together with a five-atom linker, was identified as the most potent. Molecular modeling suggested the improved cytotoxicity of 22b results from enhanced favorable interactions with the T7 loop region of βIII.

Prognostic and predictive factors of eribulin efficacy in heavily pretreated patients affected by metastatic breast cancer: correlation with tumor biology and previous therapies

Background

Eribulin mesylate is currently approved in the United States and Europe for the treatment of metastatic breast cancer (MBC).

Scope

The objective of this retrospective study is to find specific predictive criteria related to patient or tumor characteristics in order to select patients that might benefit the most from eribulin and define the correct treatment sequence.

Findings

Forty-four patients with MBC who received eribulin in third or subsequent lines of therapy in a single Italian center were considered eligible. Patients were stratified by body mass index, hormonal/HER2 status, and previous therapies. Primary endpoint was progression free survival (PFS), whereas secondary endpoint was disease control rate (DCR).

A longer PFS was found in patients with hormone-positive tumors (p=0.0051), in HER2-negative cases (p=0.037), and in overweight patients (p=0.0015). No difference in efficacy was observed when eribulin was administered in third or subsequent lines of therapy. Significantly longer PFS (p<0.0001) and higher DCR (p=0.035) were achieved by patients previously treated with paclitaxel-bevacizumab in comparison to those pretreated with other drug combinations or with anthracyclines. Prior treatment with nab-paclitaxel seems to have a detrimental effect on PFS (p=0.0008).

Conclusion

Hormone and HER2 status seems a good predictive and prognostic indicator of response to eribulin. Efficacy seems independent from the number of prior therapies, and it is not influenced by prior endocrine treatments and anthracyclines-containing regimens. On the other hand, sensitivity to a prior treatment with paclitaxel-bevacizumab might be predictive of response to eribulin.

Dose modifications in Asian cancer patients with hepatic dysfunction receiving weekly docetaxel: A prospective pharmacokinetic and safety study

Hepatic dysfunction may modify the safety profile and pharmacokinetics of docetaxel in cancer patients, but no validated guideline exists to guide dose modification necessitated by this uncommon comorbidity. We carried out the first prospective study of a personalized dosage regimen for cancer patients with liver dysfunction treated with docetaxel. Weekly dosages were stratified by hepatic dysfunction classification as such: Category 1, normal; Category 2, mild – alkaline phosphatase, aspartate aminotransferase, and/or alanine aminotransferase ≤5× upper limit of normal (ULN), and total bilirubin within normal range; and Category 3, moderate – any alkaline phosphatase, and aspartate aminotransferase or alanine aminotransferase ≤5–10× ULN, and/or total bilirubin ≤1–1.5× ULN. Category 1, 2 and 3 patients received starting dosages of 40, 30, and 20 mg/m² docetaxel, respectively. Pharmacokinetics were evaluated on day 1 and 8 of the first treatment cycle, and entered into a multilevel model to delineate interindividual and interoccasion variability. Adverse event evaluation was carried out weekly for two treatment cycles. We found that docetaxel clearance was significantly different between patient categories (P < 0.001). Median clearance was 22.8, 16.4, and 11.3 L/h/m² in Categories 1, 2, and 3, respectively, representing 28% and 50% reduced clearance in mild and moderate liver dysfunction patients, respectively. However, docetaxel exposure (area under the concentration–time curve) and docetaxel‐induced neutropenia (nadir and the maximum percentage decrease in neutrophil count) were not significantly different between categories. Median area under the concentration–time curve was 1.74, 1.83, and 1.77 mg·h/L in Categories 1, 2, and 3, respectively. The most common Grade 3/4 toxicity was neutropenia (30.0%). An unplanned comparison with the Child–Pugh and National Cancer Institute Organ Dysfunction Working Group grouping systems suggests that the proposed classification system appears to more effectively discriminate patients by docetaxel clearance and dose requirements. (ClinicalTrials.gov registration no. NCT00703378).

SNPs and taxane toxicity in breast cancer patients

AIM

In order to identify genetic variants associated with taxanes toxicity, a panel with 47 SNPs in 20 genes involved in taxane pathways was designed.

PATIENTS & METHODS

Genomic DNA of 113 breast cancer patients was analyzed (70 taking docetaxel, 43 taking paclitaxel).

RESULTS

Two SNPs associated with docetaxel toxicity were identified: CYP3A4*1B with infusion-related reactions; and ERCC1 Gln504Lys with mucositis (p≤0.01). Regarding paclitaxel toxicity: CYP2C8 HapC and CYP2C8 rs1934951 were associated with anemia; and ERCC1 Gln504Lys with neuropathy (p≤0.01).

CONCLUSION

Genes involved in DNA repair mechanisms and reactive oxygen species levels influence taxane toxicity in cancer patients treated with chemotherapy schemes not containing platinum. These findings could lead to better treatment selection for breast cancer patients.

Taxol biosynthesis and molecular genetics

Biosynthesis of the anticancer drug Taxol in Taxus (yew) species involves 19 steps from the universal diterpenoid progenitor geranylgeranyl diphosphate derived by the plastidial methyl erythritol phosphate pathway for isoprenoid precursor supply. Following the committed cyclization to the taxane skeleton, eight cytochrome P450-mediated oxygenations, three CoA-dependent acyl/aroyl transfers, an oxidation at C9, and oxetane (D-ring) formation yield the intermediate baccatin III, to which the functionally important C13-side chain is appended in five additional steps. To gain further insight about Taxol biosynthesis relevant to the improved production of this drug, and to draw inferences about the organization, regulation, and origins of this complex natural product pathway, Taxus suspension cells (induced for taxoid biosynthesis by methyl jasmonate) were used for feeding studies, as the foundation for cell-free enzymology and as the source of transcripts for cDNA library construction and a variety of cloning strategies. This approach has led to the elucidation of early and late pathway segments, the isolation and characterization of over half of the pathway enzymes and their corresponding genes, and the identification of candidate cDNAs for the remaining pathway steps, and it has provided many promising targets for genetically engineering more efficient biosynthetic production of Taxol and its precursors.

Oral fluoropyrimidines among the new drugs for patients with metastatic breast cancer

Although drugs such as the taxoids and vinorelbine have increased the options available for anthracycline-resistant metastatic breast cancer, new therapeutic options are needed, particularly for taxoid-refractory tumours. Increasing emphasis is being placed on the development of oral agents, which many patients prefer provided efficacy is not compromised, particularly if the oral agents are less toxic than current intravenous agents. Capecitabine, a new, oral fluoropyrimidine, mimics continuous infusion 5-FU and is activated preferentially at the tumour site. Phase II studies of capecitabine have demonstrated encouraging response rates in patients with few further treatment options (20% response with an additional 43% achieving stable disease in paclitaxel-refractory patients; 36% response with a further 23% achieving stable disease in anthracycline-refractory patients). In addition, a randomized, phase II trial demonstrated a response rate of 30% (95% Cl: 19-43%) with capecitabine as first-line treatment for metastatic breast cancer, compared with 16% (95% Cl: 5-33%) in patients receiving low-dose CMF. These trials also showed that capecitabine has a favourable safety profile typical of infused fluoropyrimidines. Both alopecia and myelosuppression were rare. Capecitabine may therefore provide an effective, well-tolerated and convenient alternative to intravenous cytotoxic agents, not only in taxoid-resistant patients, but also in anthracycline-resistant metastatic breast cancer or as first-line therapy. Furthermore, the low incidence of myelosuppression makes capecitabine an attractive agent for incorporation into combination regimens with agents such as epirubicin/doxorubicin, the taxoids and vinorelbine.

Multidrug resistance reversal activity of taxoids from Taxus cuspidata in KB-C2 and 2780AD cells

Some non-taxol-type taxoids having neither an oxetane ring at C-4 and C-5 nor an N-acylphenyl-isoserine group at C-13, such as taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J, which were isolated from the Japanese yew Taxus cuspidata, increased cellular accu-mulation of vincristine (VCR) in multidrug-resistant 2780AD cells as potently as verapamil, and efficiently inhibited [(3)H]azidopine photolabeling of P-glycoprotein (P-gp). Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J at 10 microM completely reversed the resistance to colchicine, VCR, and taxol in KB-C2 cells, which overexpress P-gp, while taxinine and taxinine M showed no effect. Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J may be candidate pharmaceuticals for reversing multidrug resistance (MDR) and also may be good modifiers of MDR in cancer chemotherapy.

Differentiation of human colon cancer cells changes the expression of beta-tubulin isotypes and MAPs

The human colon adenocarcinoma HT29-D4 cell line is an interesting model for studies on epithelial cell differentiation. Undifferentiated cells are malignant proliferating cells, whereas differentiated cells act like epithelial polarized cells. In the present study, we first characterized the action of taxoids on the microtubular network of HT29-D4 cells according to the state of differentiation. Microtubular bundles were found in undifferentiated cells but not in differentiated cells, even with 500-fold higher taxoid concentrations for 96 h. This finding led us to study changes in microtubules according to the polarity status of the cell. E-MAP-115 was expressed only in differentiated cells; expression of beta-tubulin isotypes was altered in them relative to undifferentiated cells. Classes I, II, III, IVa and IVb isotypes were expressed in both phenotypes; however, differentiated epithelial cells displayed a specific increase in class III beta-tubulin. Thus, the increase in expression of this beta-tubulin isotype in differentiated cells is not restricted to neuronal cells. Moreover, these expression changes may reflect a higher stability of microtubular network in differentiated cells, which may explain the lower activity of anti-microtubule agents, independently of the mitotic process. These results indicate that the composition of microtubules should be considered as one of the criteria involved in the response of tumour cells to chemotherapy with anti-microtubule agents.