# GeparSixto

Source: https://onco.cc/trials/geparsixto/  
OnCo record `geparsixto` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

GeparSixto showed that adding carboplatin to chemotherapy given before surgery made triple-negative breast tumours disappear completely far more often, and in longer follow-up cut relapses, which put platinum into the standard neoadjuvant regimen for this type.

## Summary

GeparSixto randomised 595 women with early triple-negative or HER2-positive breast cancer to 18 weeks of weekly paclitaxel and non-pegylated liposomal doxorubicin, with bevacizumab for triple-negative and trastuzumab plus lapatinib for HER2-positive disease, with or without weekly carboplatin. The primary endpoint was pathological complete response.

Carboplatin increased the pathological complete response rate in triple-negative disease, and in longer follow-up improved disease-free survival in that group, but did not help HER2-positive disease and added haematological toxicity. Together with CALGB 40603 and later BrighTNess it established carboplatin as part of neoadjuvant chemotherapy for triple-negative breast cancer, the backbone that KEYNOTE-522 then added pembrolizumab to.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-17
- Also known as: GBG 66
- Tags: subtype-trials
- Registry id: NCT01426880
- Phase: 2/3
- Setting: Early triple-negative and HER2-positive breast cancer: neoadjuvant paclitaxel and non-pegylated liposomal doxorubicin (with bevacizumab in triple-negative and trastuzumab plus lapatinib in HER2-positive disease) with or without carboplatin
- Sponsor: German Breast Group (GBG Forschungs GmbH)
- Enrolled: 595
- Result: Carboplatin increased pathological complete response and improved disease-free survival in triple-negative breast cancer, without benefit in HER2-positive disease.
- Outcomes: Pathological complete response (ypT0 ypN0), all patients: Carboplatin added to neoadjuvant therapy 43.7% vs No carboplatin 36.9%; Pathological complete response, triple-negative breast cancer: Carboplatin added to neoadjuvant therapy 53.2% vs No carboplatin 36.9%; Pathological complete response, HER2-positive breast cancer: Carboplatin added to neoadjuvant therapy 32.8% vs No carboplatin 36.8%; Grade 3-4 neutropenia: Carboplatin added to neoadjuvant therapy 65% vs No carboplatin 27%

## Notes

- Survival analysis (Annals of Oncology 2018, median follow-up 47.3 months): disease-free survival hazard ratio 0.56 (0.34 to 0.93, p 0.022) with carboplatin in triple-negative disease, overall survival not significantly improved, no benefit in HER2-positive disease. Homologous recombination deficiency was found in 70.5 percent of 193 triple-negative tumours and predicted pathological complete response (odds ratio 2.60) but not carboplatin benefit; pathological complete response rose from 33.9 to 63.5 percent with carboplatin in HR-deficient tumours and from 20.0 to 29.6 percent in HR-proficient ones.

## Sources

- ClinicalTrials.gov NCT01426880: https://clinicaltrials.gov/study/NCT01426880
- GeparSixto survival and HRD analysis (Annals of Oncology 2018): https://doi.org/10.1093/annonc/mdy460

## Connected records

- cancers: [Basal-like 1 triple-negative breast cancer (BL1)](https://onco.cc/cancers/tnbc-basal-like-1/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Early triple-negative breast cancer](https://onco.cc/cancers/tnbc-early/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/), [Platinum agents](https://onco.cc/technologies/platinum/)
- drugs: [Bevacizumab](https://onco.cc/drugs/bevacizumab/), [Carboplatin](https://onco.cc/drugs/carboplatin/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Lapatinib](https://onco.cc/drugs/lapatinib/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Trastuzumab](https://onco.cc/drugs/trastuzumab/)
- companies: [German Breast Group (GBG)](https://onco.cc/companies/gbg/)
- trials: [BrighTNess](https://onco.cc/trials/brightness/), [CALGB 40603 (Alliance)](https://onco.cc/trials/calgb-40603/), [KEYNOTE-522](https://onco.cc/trials/keynote-522/)
- people: [Gunter von Minckwitz](https://onco.cc/people/gunter-von-minckwitz/)
- key papers: [Germline mutation status, pathological complete response, and disease-free survival in triple-negative breast cancer: secondary analysis of the GeparSixto randomized clinical trial](https://onco.cc/key-papers/paper-hahnen-geparsixto-germline-brca-jama-oncol-2017/), [Impact of the addition of carboplatin and/or bevacizumab to neoadjuvant once-per-week paclitaxel followed by dose-dense doxorubicin and cyclophosphamide on pathologic complete response rates in stage II to III triple-negative breast cancer: CALGB 40603 (Alliance)](https://onco.cc/key-papers/paper-sikov-calgb-40603-carboplatin-bevacizumab-jco-2015/), [Neoadjuvant carboplatin in patients with triple-negative and HER2-positive early breast cancer (GeparSixto; GBG 66): a randomised phase 2 trial](https://onco.cc/key-papers/paper-geparsixto-lancet-oncol-2014/), [Survival analysis of carboplatin added to an anthracycline/taxane-based neoadjuvant chemotherapy and HRD score as predictor of response-final results from GeparSixto](https://onco.cc/key-papers/paper-loibl-geparsixto-survival-hrd-ann-oncol-2018/)
- terms: [Homologous recombination deficiency (HRD) in breast cancer](https://onco.cc/terms/hrd-in-breast-cancer/)
- roadmaps: [Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem](https://onco.cc/roadmaps/tnbc-roadmap/)

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