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KATHERINE

Switching to an ADC after surgery when pre-surgery treatment left cancer behind halved the risk of recurrence and improved survival.

3-year iDFS 88.3% vs 77.0% (HR 0.50); 7-year iDFS 80.8% vs 67.1%; OS HR 0.66 (7-year OS 89.1% vs 84.4%). Established the 'response-adapted' post-neoadjuvant paradigm now being upgraded by T-DXd (DESTINY-Breast05).

Setting
HER2+ early breast cancer with residual invasive disease after neoadjuvant therapy: T-DM1 vs trastuzumab for 14 cycles
Phase
Phase 3
Sponsor
Roche / Genentech
Registry
Headline result
iDFS HR 0.50; OS HR 0.66.
Reported
2018
Enrolled
1486
Replication
Superseded rather than replicated: DESTINY-Breast05 showed T-DXd beats T-DM1 in the same population.

Outcomes

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In plain words
What these results mean for people, not percentages
1,486 people took part
3-year invasive disease-free survivalprimarysurrogate endpoint
  • 88.3 vs 77 out of 100 alive without the cancer coming back at 3 years with T-DM1 compared with Trastuzumab; 11.3 more per 100.
  • Roughly one extra person helped for every 9 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
  • Put another way, the treated group had about 50 percent lower chance of the event at any given time (hazard ratio 0.5, likely range 0.39 to 0.64).
  • This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
Overall survival (7-year)survival endpoint
  • 89.1 vs 84.4 out of 100 alive at 7 years with T-DM1 compared with Trastuzumab; 4.7 more per 100.
  • Roughly one extra person helped for every 21 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
  • Put another way, the treated group had about 34 percent lower chance of the event at any given time (hazard ratio 0.66, likely range 0.51 to 0.87).
  • Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
Be careful
  • These results apply to the people the trial enrolled: HER2+ early breast cancer with residual invasive disease after neoadjuvant therapy: T-DM1 vs trastuzumab for 14 cycles. People in a different situation may not see the same effect.
  • The trial selected people by a biomarker (HER2); the result should not be assumed for people whose cancer does not have it.

Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.

1,486 participants enrolled.

3-year invasive disease-free survivalprimary
HR 0.5 (0.39–0.64) · p <0.001
T-DM188.3 of 100
n = 743
Trastuzumab77 of 100
n = 743
Source
Overall survival (7-year)
HR 0.66 (0.51–0.87)
T-DM189.1 of 100
Trastuzumab84.4 of 100
Source
EndpointArmnValueHR (95% CI)pSource
3-year invasive disease-free survivalprimaryT-DM174388.3%0.5 (0.39–0.64)<0.001link
Trastuzumab74377%
Overall survival (7-year)T-DM189.1%0.66 (0.51–0.87)link
Trastuzumab84.4%
Replication
Superseded rather than replicated: DESTINY-Breast05 showed T-DXd beats T-DM1 in the same population.

Connected

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