Low-dose capecitabine plus docetaxel as first-line therapy for metastatic breast cancer: phase II results

Capecitabine in Combination with Docetaxel in First Line in HER2-Negative Metastatic Breast Cancer: an Observational Study

Due to the limited experience with capecitabine plus docetaxel (XT) combination in the first-line treatment of metastatic breast cancer in Hungary, the main objective of the study was to analyze the effectiveness and tolerability of XT therapy. A prospective, open-label, non-randomized, single-arm, multicenter, observational study was designed. All female patients were eligible whose metastatic breast cancer could be treated with the XT protocol according to the summary of product characteristics of the drugs. The median progression free survival was 9.9 ± 3.0 months. Time to treatment failure was 4.6 ± 5.1 months on average. The overall response rate was 28.9 %, the clinical benefit rate was 73.3 %. The treatment was discontinued in 35.6 % of patients due to disease progression and in 20.0 % due to adverse events (AE). 33 patients with a total of 73 AEs have been reported, and 13 of them had serious adverse events (SAE). The efficacy and the safety profile of XT chemotherapy proven in the study are consistent with the results demonstrated in randomized trials. First-line XT chemotherapy effectively improves the PFS in metastatic breast cancer.

Acceptable but limited efficacy of capecitabine-based doublets in the first-line treatment of metastatic triple-negative breast cancer: a pilot study

BACKGROUND

This open-label, nonrandomized phase II clinical trial investigated the efficacy of capecitabine-based doublets in the first-line treatment of metastatic triple-negative breast cancer (mTNBC).

METHODS

Eligible mTNBC women with measurable diseases were recruited to receive either TX regimen (docetaxel 75 mg/m(2) i.v. on day 1 plus capecitabine 1,000 mg/m(2) b.i.d. on days 1-14 every 3 weeks) or NX regimen (vinorelbine 25 mg/m(2) i.v. on days 1 and 8 plus capecitabine 1,000 mg/m(2) b.i.d. on days 1-14 every 3 weeks) for up to 6 cycles until disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR) and secondary end points included progression-free survival (PFS), overall survival (OS) and clinical benefit rate (CBR).

RESULTS

Forty-five mTNBC patients, 27 in TX and 18 in NX were recruited. The total ORR was 20.0% and CBR was 40%. After a median follow-up of 28 months, PFS was 5.2 months (95% CI, 4.1-6.3 months) and OS was 18.2 months (95% CI, 8.7-27.7 months). The response rate was numerically but not statistically lower in the TX group than in the NX group (27.8 vs. 14.8%, p = 0.449). No difference was found in either PFS (4.9 vs. 5.2 months, p = 0.483) or OS (21.5 vs. 18.3 months, p = 0.964) between the two regimens.

CONCLUSIONS

Although the OS seems to be reasonable, the efficacy of capecitabine-containing TX or NX regimen was limited in terms of response and PFS in mTNBC patients, suggesting capecitabine-based doublet may be acceptable but has limited potency in this subtype.

Managing ixabepilone adverse events with dose reduction

Ixabepilone is a synthetic analogue of epothilone B approved for the treatment of patients with metastatic or locally advanced breast cancer in combination with capecitabine for cancer resistant to an anthracycline and a taxane, and as monotherapy for cancer resistant or refractory to anthracyclines, taxanes, and capecitabine. The principal dose-limiting adverse events (AEs) of ixabepilone's standard dose (40 mg/m(2) administered by 3-hour infusion once every 3 weeks) are peripheral neuropathy, neutropenia, and fatigue. An effective strategy to manage ixabepilone-related AEs is dose reduction by 20% (from 40 to 32 to 25 mg/m(2)); this does not appear to affect treatment efficacy and enables continuation of treatment after recovery (grade 1 or resolved). When appropriate, treatment can be restarted with a 20% dose reduction (to 32 mg/m(2)). For heavily pretreated patients, especially those with a low performance status, 32 mg/m(2) is an appropriate initial dose; the dose of capecitabine should also be lowered by 20%. Weekly ixabepilone (15-20 mg/m(2) on days 1, 8, and 15 every 28 days) may have an improved tolerability profile, but prospective studies with a large number of patients are required to determine whether it has therapeutic benefit comparable with the current approved regimen. More information is required on dosage and scheduling of ixabepilone in combination with other agents, including novel targeted therapies.

Evaluations of biomarkers associated with sensitivity to 5-fluorouracil and taxanes for recurrent/advanced breast cancer patients treated with capecitabine-based first-line chemotherapy

The aim of the present study was to investigate the gene expression of biomarkers associated with the sensitivity to fluoropyrimidine and taxanes in recurrent/advanced breast cancer patients treated with first-line capecitabine chemotherapy. We evaluated the clinicopathological/prognostic significance of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), class III β-tubulin (βIII-tubulin), and stathmin-1 or oncoprotein-18 (STMN1). Formalin-fixed, paraffin-embedded tumor specimens from 42 patients were used for analysis of TS, DPD, TP, βIII-tubulin, and STMN1 expression with a real-time reverse transcription-PCR technique. Patients were classified into the high-expression and low-expression groups according to the median value of the expression level of each biomarker. There was a significantly longer time to progression (TTP) in the high-TP group (P=0.018). The multivariate analysis revealed that the TP expression (hazard ratio for the low-TP group vs. the high-TP group, 2.873; 95% confidence interval, 1.143-7.223; P=0.025) is independent of prognostic factors for TTP. In the subgroup of patients treated with capecitabine plus taxanes as first-line chemotherapy, TTP was significantly longer in the low-βIII-tubulin group (P=0.047). The gene expression of TS, DPD, and STMN1 failed to have any significant impact on the outcome. These results provide further evidence that the TP expression may be a prognostic factor in breast cancer patients treated with capecitabine-based first-line chemotherapy, and βIII-tubulin can be used to predict the outcome of capecitabine in combination with taxanes as first-line chemotherapy. Therefore, these potential biomarkers should be further evaluated.

A multicenter phase II trial of docetaxel and capecitabine as salvage treatment in anthracycline- and taxane-pretreated patients with metastatic breast cancer

OBJECTIVE

To evaluate the efficacy and safety of docetaxel plus capecitabine (DC) combination as salvage treatment in anthracycline- and taxane-pretreated patients with metastatic breast cancer (MBC).

PATIENTS AND TREATMENT

Patients with MBC who had disease progression after initial chemotherapy with anthracyclines (n = 29; 100 %) and taxanes (n = 11; 37.9 %) were treated with oral capecitabine 950 mg/m(2) twice daily on days 1-14 and docetaxel 75 mg/m(2) on day 1 every 3 weeks. Nineteen (65.5 %) patients received this regimen as second line and 10 (34.5 %) as ≥3rd line of therapy. All patients were evaluable for response and toxicity.

RESULTS

Complete response occurred in two (6.9 %) patients and partial response in eleven (37.9 %) for an overall response rate of 44.8 % (95 % CI 26.7-62.9 %). Eleven women (37.9 %) had stable disease and five (17.2 %) progressive disease. Of the eleven patients previously treated with anthracyclines and taxanes, five (45.5 %) responded to DC combination. The median duration of response was 5.7 months (range 3.4-64.2), the median time to disease progression 9.3 months (range 1.2-58), and the median overall survival 25.5 months. No toxic death occurred. Neutropenia grade 4 occurred in 58.6 % of patients and three of them (10.3 %) developed neutropenic fever. Non-hematological toxicities were manageable with grade 3 hand-foot syndrome occurring in 6.9 % of the patients, fatigue in 3.4 %, and neurotoxicity in 3.4 %.

CONCLUSION

The DC combination is a valuable regimen as salvage treatment in anthracycline- or anthracycline and taxane-pretreated patients with MBC.

Randomized phase II non-inferiority study (NO16853) of two different doses of capecitabine in combination with docetaxel for locally advanced/metastatic breast cancer

BACKGROUND

This phase II study investigated whether a lower-than-approved dose of capecitabine, plus docetaxel (XT), would improve tolerability versus standard-dose XT without compromising efficacy.

PATIENTS AND METHODS

Women aged ≥18 years with locally advanced/metastatic breast cancer resistant to anthracycline-based chemotherapy in the (neo)adjuvant, first- or second-line metastatic setting were eligible. Patients were randomly assigned to receive standard-dose XT (capecitabine 1250 mg/m(2) twice daily, days 1-14; docetaxel 75 mg/m(2), day 1 every 3 weeks) or low-dose XT (capecitabine 825 mg/m(2) twice daily, days 1-14; docetaxel as above). The primary objective was to demonstrate non-inferiority of low-dose to standard-dose XT in terms of progression-free survival (PFS).

RESULTS

470 patients were randomly allocated in a 1 : 1 ratio to standard-dose or low-dose XT. Median PFS was 7.9 versus 5.8 months [hazard ratio 1.16, 95% confidence interval (CI) 0.95-1.43] in the standard-dose and low-dose arms, respectively. The upper limit of the 95% CI was above the predefined non-inferiority margin (1.35, P = 0.078). Secondary efficacy end points were consistent with PFS. The frequency and severity of adverse events was similar in both treatment arms.

CONCLUSIONS

Non-inferiority of low-dose to standard-dose XT in terms of PFS was not demonstrated; this may be due to regional subgroup effects.