Trials · for clinicians

DESTINY BREAST 11 TRIAL

11/16/2025 · 5 min read · updated 28 Oct 2026

Bottom line

Anthracycline-free T-DXd ×4 → THP ×4: pCR +11.2% (p=0.003), grade ≥3 AEs 37.5% vs 55.8%, less LV dysfunction. EFS immature. T-DXd alone (43% pCR) is not enough.

Design

Phase 3, open-label, 147 sites in 18 countries; randomised 1:1:1. High-risk HER2+ early breast cancer (≥T3, node-positive or inflammatory). Arms: T-DXd ×8 (closed early), T-DXd ×4 → THP ×4, ddAC ×4 → THP ×4. Primary endpoint: pCR (ypT0/is ypN0).

Results (data cut-off 12 Mar 2025)

Randomised: T-DXd 286, T-DXd → THP 321, ddAC → THP 320 (927 in total). Median follow-up 24.2 vs 23.6 months. [AstraZeneca 2025]
pCR: 67.3% vs 56.3% (Δ 11.2%, 95% CI 4.0–18.3; p=0.003). T-DXd alone 43.0%. [Ann Oncol 2026]
HR+: 61.4% (145/236) vs 52.3% (123/235), Δ 9.1% (95% CI 0.2–17.9). HR−: 83.1% (69/83) vs 67.1% (57/85), Δ 16.1% (95% CI 3.0–28.8). [Ann Oncol 2026]
RCB 0/I: 81.3% vs 69.1% (Δ 12.2%). [AstraZeneca 2025]
EFS: HR 0.56 (0.26–1.17), 4.5% maturity — not interpretable yet.
Grade ≥3 AEs 37.5% vs 55.8% (T-DXd alone 22.6%); serious AEs 10.6% vs 20.2%; all-grade LV dysfunction 1.3% vs 6.1%; adjudicated drug-related ILD 4.4% vs 5.1% (T-DXd alone 4.9%). Treatment-related deaths: 1 (0.3%) vs 2 (0.6%). [Ann Oncol 2026]

DESTINY-Breast11: pathological complete response

T-DXd → THP67.3%

ddAC → THP56.3%

T-DXd alone43.0%

HR−: T-DXd → THP83.1%

HR−: ddAC → THP67.1%

Interpretation

First anthracycline-free regimen to beat ddAC-THP for pCR in a phase 3 trial of high-risk disease.
Caveats: open label; pCR is a surrogate; EFS/OS awaited; ILD needs vigilance.
Adjuvant pathway has moved: pCR → complete HP; residual invasive disease → T-DM1 (KATHERINE) or, since May 2026 in the US, T-DXd (DESTINY-Breast05 — see the update below).

For high-risk patients with cardiac concerns, T-DXd → THP is attractive where affordable. I would wait for EFS before abandoning anthracycline regimens universally.

Who was enrolled

High-risk HER2-positive early breast cancer: T3 or larger, inflammatory, or node-positive disease (cT0–4, cN1–3). HER2 status was centrally confirmed. 927 patients were randomised across the three arms (286 / 321 / 320); enrolment to the T-DXd monotherapy arm was closed early on the recommendation of the Independent Data Monitoring Committee. [Ann Oncol 2025]

Regimens in detail

T-DXd → THP: trastuzumab deruxtecan 5.4 mg/kg every 3 weeks ×4 (the FDA-labelled neoadjuvant dose), then paclitaxel + trastuzumab + pertuzumab ×4.
ddAC → THP: dose-dense doxorubicin + cyclophosphamide every 2 weeks ×4, then THP ×4 (the standard high-risk control in many countries).
After surgery, patients received standard adjuvant HER2-directed therapy per investigator (HP, or T-DM1 for residual disease).

Why pCR matters (and its limits)

pCR after neoadjuvant therapy is strongly associated with better event-free survival at the patient level, but trial-level gains in pCR have not always translated into EFS gains. Residual disease also opens the door to post-neoadjuvant escalation: T-DM1 improved invasive disease-free survival over trastuzumab in KATHERINE (3-year IDFS 88.3% vs 77.0%; HR 0.50, 95% CI 0.39–0.64), [NEJM 2019] and T-DXd improved it further over T-DM1 in DESTINY-Breast05 (HR 0.47). [NEJM 2026] Long-term EFS from DESTINY-Breast11 is therefore essential.

Safety in practice

ILD/pneumonitis: baseline chest imaging, educate about cough and breathlessness, stop T-DXd for any grade ≥2 ILD.
Nausea: T-DXd is moderately-to-highly emetogenic — use a three-drug antiemetic regimen.
Cardiac: baseline and serial LVEF are still required because THP follows.
Alopecia and fatigue occur with both regimens.

Guideline context

Neoadjuvant anthracycline-free regimens such as TCHP were already acceptable alternatives: in TRAIN-2 (n=438), pCR was 67% with anthracyclines vs 68% without (p=0.95), with more grade ≥3 febrile neutropenia when anthracyclines were added (10% vs 1%). [Lancet Oncol 2018] DESTINY-Breast11 adds a new option for the highest-risk patients; NCCN/ESMO adoption should be checked against the current guideline version.

Regulatory and adjuvant update (verified 28 Oct 2026):

FDA, 15 May 2026: T-DXd followed by THP approved as neoadjuvant treatment for HER2-positive (IHC 3+ or ISH+) stage II or III breast cancer, at 5.4 mg/kg every 3 weeks ×4, then THP ×4. FDA noted that EFS and OS in DESTINY-Breast11 were not statistically controlled or powered, and that DESTINY-Breast05 provided supportive evidence. A post-marketing requirement asks for 3-year EFS and final OS (reports due 11/2027). [FDA 2026]
DESTINY-Breast05 (adjuvant, residual disease): n=1635, T-DXd vs T-DM1, up to 14 cycles. 3-year IDFS 92.4% vs 83.7% (HR 0.47, 95% CI 0.34–0.66; P<0.001). Adjudicated drug-related ILD 9.6% vs 1.6%; 2 ILD deaths with T-DXd. Nausea 71.3% with T-DXd. [NEJM 2026] FDA approved adjuvant T-DXd for residual invasive disease on the same day. [FDA 2026]
The T-DXd label carries a boxed warning for ILD/pneumonitis. ILD risk was about 4–5% with 4 neoadjuvant cycles (DESTINY-Breast11) but 9.6% with up to 14 adjuvant cycles (DESTINY-Breast05), so take exposure into account when planning a T-DXd-containing sequence.

Post-neoadjuvant escalation for residual HER2+ disease: 3-year invasive disease-free survival

KATHERINE: T-DM188.3%

KATHERINE: trastuzumab77.0%

DESTINY-Breast05: T-DXd92.4%

DESTINY-Breast05: T-DM183.7%

KATHERINE: NEJM 2019 (HR 0.50). DESTINY-Breast05: NEJM 2026 (HR 0.47); DB-05 enrolled a higher-risk population (node-positive residual disease or inoperable at diagnosis), so do not compare arms across trials.

The original oncosphere.in article was image-based and could not be recovered; this is a rewritten, referenced version under the same title.

Sources

Educational summary, not medical advice. Opinions are labelled as such and are the author's own. Approvals and availability in India (CDSCO) may differ from the US/EU.

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