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

Current treatment landscape for patients with locally recurrent inoperable or metastatic triple-negative breast cancer: a systematic literature review

Background

Metastatic triple-negative breast cancer (mTNBC), an aggressive histological subtype, has poor prognosis. Chemotherapy remains standard of care for mTNBC, although no agent has been specifically approved for this breast cancer subtype. Instead, chemotherapies approved for metastatic breast cancer (MBC) are used for mTNBC (National Comprehensive Cancer Network Guidelines [NCCN] v1.2019). Atezolizumab in combination with nab-paclitaxel was recently approved for programmed death-ligand 1 (PD-L1)–positive locally advanced or metastatic TNBC. Published historical data were reviewed to characterize the efficacy of NCCN-recommended (v1.2016) agents as first-line (1L) and second-line or later (2L+) treatment for patients with locally recurrent inoperable or metastatic TNBC (collectively termed mTNBC herein).

Methods

A systematic literature review was performed, examining clinical efficacy of therapies for mTNBC based on NCCN v1.2016 guideline recommendations. Data from 13 studies, either published retrospective mTNBC subgroup analyses based on phase III trials in MBC or phase II trials in mTNBC, were included.

Results

A meta-analysis of mTNBC subgroups from three phase III trials in 1L MBC reported pooled objective response rate (ORR) of 23%, median overall survival (OS) of 17.5 months, and median progression-free survival (PFS) of 5.4 months with single-agent chemotherapy. In two subgroup analyses from a phase III study and a phase II trial (n = 40 each), median duration of response (DOR) to 1L chemotherapy for mTNBC was 4.4–6.6 months; therefore, responses were not durable. A meta-analysis of seven cohorts showed the pooled ORR for 2L+ chemotherapy was 11% (95% CI, 9–14%). Median DOR to 2L+ chemotherapy in mTNBC was also limited (4.2–5.9 months) per two subgroup analyses from a phase III study. No combination chemotherapy regimens recommended by NCCN v1.2016 for treatment of MBC showed superior OS to single agents.

Conclusions

Chemotherapies have limited effectiveness and are associated with unfavorable toxicity profiles, highlighting a considerable unmet medical need for improved therapeutic options in mTNBC. In addition to the recently approved combination of atezolizumab and nab-paclitaxel for PD-L1–positive mTNBC, new treatments resulting in durable clinical responses, prolonged survival, and manageable safety profile would greatly benefit patients with mTNBC.

Vinorelbine plus Capecitabine (Vinocap): a retrospective analysis in heavily pretreated HER2 negative metastatic breast cancer patients

PURPOSE

Metastatic breast cancer is regarded as an incurable entity. In heavily pretreated patients with increasingly limited options for palliative management, ensuring proper quality of life continues is to be an elusive issue. With this in mind, the authors evaluated the efficacy and safety of the Vinorelbine/Capecitabine doublet (VINOCAP).

PATIENTS AND METHODS

The investigators retrospectively analyzed a cohort of 67 women with HER2 negative MBC treated at a large breast cancer practice and a local cancer center with Vinorelbine 22.5 mg/m2 IV on days 1 and 8 combined with Capecitabine 1 g PO BID for 14 consecutive days of 21 day cycles. Patients had been treated with an average of 4 prior lines of chemotherapy. Patient characteristics and outcomes were evaluated.

RESULTS

A total of 67 patients received VINOCAP, and an additional 2 underwent repeat exposure yielding a cohort of 69. Clinical benefit rate, defined as complete response (CR), partial response (PR) or stable disease ≥ 6 months (SD), was 55.07%. Complete response was seen in 4.34%, PR in 18.8% and SD ≥ 6 months in 31.9%. Median progression-free survival was 6.2 months and overall survival 35.47 months after VINOCAP exposure. The most common grade 3-4 toxicity was neutropenia in 10% of cases. Dose had to be reduced in 18% of cases due to toxicity of any type. The regimen was well tolerated, and serious side effects were uncommon.

CONCLUSION

Vinorelbine/Capecitabine appears to be an active and well-tolerated regimen in women with MBC. In particular, encouraging was the efficacy of VINOCAP as fourth or greater line of chemotherapy.

Comparison of the Therapeutic Efficacy of the Early and the Delayed Use of Vinorelbine-Based Regimens for Patients with Advanced Breast Cancer

BACKGROUND

The aim of this study was to evaluate the efficacy of vinorelbine-based regimens as first-, second- and more-line therapies in advanced breast cancer (ABC) and to analyze the best timing of vinorelbine treatment.

METHODS

A total of 71 ABC patients were retrospectively reviewed. Of these, 35 patients were treated with vinorelbine-based regimens as first-line chemotherapy, and 36 patients were treated with vinorelbine-based regimens as second-line or more-line therapy. The primary end point of the study was progression-free survival (PFS).

RESULTS

No difference was found in baseline characteristics between the two groups (p > 0.1 for all comparisons). There was a significant difference in the objective response rate (ORR; p = 0.006) and clinical benefit rate (CBR; p = 0.013) between the first-line group and the second- or more-line groups. In the vinorelbine first-line group, the ORR was 68.6% (24 patients), and in the second-line or more-line groups the ORR was 36.1% (13 patients). A significant difference in PFS between the first-line group and the second-line or more-line groups was also observed (p = 0.030). The median PFS in the overall population was 6.3 ± 1.32 months (95% CI 3.69-8.90). The median PFS was 11.1 ± 3.76 months (95% CI 3.73-18.47) in the first-line group compared with 5.2 ± 1.35 months (95% CI 2.54-7.85) in the second-line or more-line groups. In patients treated with vinorelbine-trastuzumab combination as the first-line therapy, a complete response was observed in 1 patient (12.5%) and partial response in 5 patients (62.5%), giving an ORR of 75.0%. Progressive disease was observed in 1 patient (12.5%), and stable disease in 1 patient (12.5%), leading to a CBR of 87.5%. The median PFS was 13.8 ± 2.75 months (95% CI 8.42-19.18), and median OS was 37.0 ± 11.6 months (95% CI 14.18-59.82). No significant difference was found in overall survival (OS) between the groups (p = 0.612).

CONCLUSION

For ABC patients, no significant difference in median OS was found between the early use and delayed use of vinorelbine-based regimens, but the short-term efficacy and PFS of vinorelbine-based regimens were significantly better in the early use group than in the delayed use group.

Vinorelbine With Capecitabine, an Evergreen Doublet for Advanced Breast Cancer: A Systematic Literature Review and Pooled-Analysis of Phase II-III Studies

Metastatic breast cancer (MBC) is treated with cytotoxic drugs or endocrine agents according to the site and extent of the disease, biology, previous treatments, and the patient's condition, comorbidities, and wishes. In MBC, vinorelbine (VRB) and capecitabine (X; VRB + X) are chemotherapy drugs that hold activity as first or later lines of therapy. We conducted a systematic literature review and meta-analysis to quantify the efficacy of the VRB + X combination in HER2-negative (HER2^-) MBC. We searched PubMed, EMBASE, SCOPUS, Web of Science, the Cochrane Library, and CINAHL for phase II/III clinical trials that assessed VRB + X for patients with HER2^- MBC. Pooled estimates of the overall response rate (RR), median progression-free survival (PFS), and overall survival (OS) were computed using random or fixed effects models. Twenty-seven studies were included in the analysis, encompassing a total of 1356 MBC patients. All were phase II (n = 21) or prospective/pilot (n = 5) trials, except for 1 that was a phase III controlled trial. The pooled estimate for the RR in first-line therapy (n = 16 trials) was 52.9% (95% confidence interval [CI], 46.5%-59.2%). For second-line trials, data were available in n = 9 studies and the overall RR was 41% (95% CI, 31.2%-51.6%). The pooled estimates for median PFS and OS in first-line therapy were 7.3 (95% CI, 6.2-8.3) and 22.3 (95% CI, 20-24.5) months, respectively. Vinorelbine + X, with the dose and schedules currently used in clinical practice, appears to be an effective and feasible chemotherapy for MBC, for first- and also for second-line therapy.

Gemcitabine and Capecitabine Combination Chemotherapy in Patients with Metastatic Breast Cancer Pretreated with Anthracyclines and/or Taxanes

BACKGROUND

Owing to the need for effective and tolerable new regimens for the treatment of patients with metastatic breast cancer (MBC) previously treated with anthracyclines and/or taxanes, we aimed to assess the activity and safety of the gemcitabine plus capecitabine combination chemotherapy.

METHODS

Sixty-four patients were enrolled. Treatment consisted of gemcitabine 1,000 mg/m2 intravenously on days 1 and 8, plus oral capecitabine at 1,250 mg/m2 twice daily on days 1-14. The primary end point was the overall response rate (ORR). Secondary objectives included the disease control rate (DCR), overall survival (OS), progression-free survival (PFS), toxicity, and predictive factors.

RESULTS

In the 64 patients, the ORR and DCR was 28.1 and 67.2%. Median OS and PFS were 23.6 and 13.4 months, respectively. Toxicities were mild and curable.

CONCLUSION

The combination of gemcitabine and capecitabine is an effective and tolerable treatment for MBC previously treated with anthracyclines and/or taxanes.

Neoadjuvant chemotherapy for different molecular breast cancer subtypes: a retrospective study in Russian population

The aim of this retrospective study was to evaluate the objective clinical response (cOR), pathological complete response (pCR), and progression-free survival (PFS) in 231 Russian patients with four subtypes of breast cancer treated with neoadjuvant chemotherapy. About 130 (56.3 %) patients received anthracycline-based, 56 (24.2 %) capecitabine-containing (CAX), 28 (12.1 %) taxotere and 17 (7.4 %) non-anthracycline-containing chemotherapy regimens at the Tomsk Cancer Research Institute between 2000 and 2010. Tumors were subtyped according to the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) immunohistochemical data. The majority of tumors (48.9 %) were ER+/PR+ and HER2-negative (HR+/HER2-), 10.4 % were ER+ PR+ and HER2-positive (HR+/HER2+), 9.1 % were ER-/PR- and HER2-overexpressed (HER2-enriched) and 31.6 % were ER-/PR- and HER2-negative (triple negative). Both cOR and pCR were significantly higher in the triple-negative tumors compared to the other subtypes (P = 0.021 and P = 0.033, respectively). Among the four chemotherapy regimens, only CAX regimen had a predictive value for cOR (HR 2.30, 95 % CI 1.16-4.58, P = 0.009). Multivariate regression analysis showed that the triple-negative subtype (HR 2.54, 95 % CI 1.06-1.42, P = 0.011) and CAX regimen (HR 3.01, 95 % CI 1.01-1.46, P = 0.002) were significantly associated with cOR. No association between patient's PFS and a tumor subtype was observed. However, there was a trend for a prolonged PFS among patients with cOR (P = 0.056). Our data indicate a potentially better prognosis for triple-negative breast cancer patients if treated with the CAX neoadjuvant regimen.