NCT04281355: INDAX

Individualized Locoregional Treatment of Initially Biopsy-proven Node-positive Breast Cancer After Primary Systemic Therapy

Withdrawn Phase 3 Last updated 25 February 2021

What this trial tests

Phase 3 trial testing Omission of axillary lymph node dissection in Breast Cancer. Withdrawn.

Timeline

1 January 2021

Primary endpoint
31 December 2025

31 December 2029

Quick facts

Lead sponsor	Karolinska Institutet
Phase	Phase 3
Status	Withdrawn
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	none
Primary purpose	treatment
Start date	1 January 2021
Primary completion	31 December 2025
Estimated completion	31 December 2029

Drugs / interventions tested

• Omission of axillary lymph node dissection
• Omission of regional irradiation

Conditions studied

• Breast Cancer — all drugs for Breast Cancer →

Sponsor

Karolinska Institutet

Who can join

18 and older, any sex, with Breast Cancer. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

In clinically node-positive (cN+) breast cancer, preoperative systemic therapy (PST) is common. With increasing rates of complete tumour eradication, there is a need for de-escalation of locoregional treatment in the interest of decreased morbidity.

In order to individually adapt postoperative therapies, axillary staging is crucial. Axillary lymph node dissection (ALND) comes at a high risk of arm morbidity. There is extreme divergence in the use of less extensive staging methods, i.e. targeted lymph node biopsy (TLNB), sentinel node biopsy (SNB) or both (TAD), and in the use of subsequent locoregional treatment, since prospective data are largely lacking.

The main purpose of the European INDAX trial is to implement de-escalated staging and evaluate which regional treatment, individually adapted to the response after PST, is oncologically safe but least harmful.

Population: cN+ breast cancer patients receiving PST, recruited 2021-2025. Staging by TLNB, TAD or SNB.

Intervention: Negative staging (ypN0, Randomisation A, N=1433): no regional treatment. Positive staging (ypN+, Randomisation B, N=1513): no ALND but regional radiotherapy (rRT).

Control: Randomisation A: rRT only. Randomisation B: ALND plus rRT.

Outcome: Invasive disease-free survival (non-inferiority), arm morbidity and quality of life.

Drug tests in whole-tumour organoid cultures, algorithm-based digital image analysis and gene expression analysis are performed to improve response prediction, facilitate tailoring of PST and increase eradication rates.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Patient-Derived Ex Vivo Cultures and Endpoint Assays with Surrogate Biomarkers in Functional Testing for Prediction of Therapeutic Response.
   Tsukamoto Y, Hirashita Y, Shibata T, Fumoto S, et al · · 2023 · cited 3× · PMID 37627132 · DOI 10.3390/cancers15164104