Electra trial results-- adding herceptin 2 letrozole safe, effective 1st line trtmnt

[Lani]

for metastatic ER+her2+ bc

This is only the third trial of antihormonal treatments+/- herceptin

The first, Tandem was reported over 4 years ago if I recall correctly

ABSTRACT: Higher efficacy of letrozole in combination with trastuzumab compared to letrozole monotherapy as first-line treatment in patients with HER2-positive, hormone-receptor-positive metastatic breast cancer - Results of the eLEcTRA trial
[The Breast]

The eLEcTRA trial compared efficacy and safety of letrozole combined with trastuzumab to letrozole alone in patients with HER2 and hormone receptor (HR) positive metastatic breast cancer (MBC). Patients were randomized to either letrozole alone (arm A, n = 31) or letrozole plus trastuzumab (arm B, n = 26) as first-line treatment. Additional 35 patients with HER2 negative and HR positive tumors received letrozole alone (arm C).

Median time to progression in arm A was 3.3 months compared to 14.1 months in arm B (hazard ratio 0.67; p = 0.23) and 15.2 months in arm C (hazard ratio 0.71; p = 0.03). Clinical benefit rate was 39% for arm A compared to 65% in arm B (odds ratio 2.99, 95% CI 1.01-8.84) and 77% in arm C (odds ratio 5.34, 95% CI 1.83-15.58).

The eLEcTRA trial showed that the combination of letrozole and trastuzumab is a safe and effective treatment option for patients with HER2 positive and HR positive MBC.

[Rich66]

This is only the third trial of antihormonal treatments+/- herceptin

Only? They are completely different mechanisms..though arguably on a sliding scale. You have two identifiable receptors..block them.

[Debbie L.]

I agree with the "only"!? And although they are completely different mechanisms, aren't there clues that the anti-HER2 agents increase endocrine sensitivity?

This seems such an important area to explore on two fronts. For stage IV disease, tweaking of anti-HER2 therapy and endocrine therapy could give women YEARS of chemo-free life. We do have info about Lapatinib and Letrazole, right?

What kind of experience have those on this list had, with an anti-HER2 and an endocrine agent only? What did you do when progression happened? Did you switch endocrine tx and continue the anti-HER2, or did you move to chemo?

And then there's the concept that not all ERPR-negative cancer is devoid of ER but perhaps it's just silenced and could be turned back on, which muddies it up further but also opens new possibilities for less-toxic treatments.

And especially now that we're more worried about ultra-small primary tumors when they are HER2+, it seems such a logical choice, when they are also ERPR+, to treat without chemo (using anti-HER2 and and endocrine tx).

But what about after that year of adjuvant Herceptin (or other anti-HER2)? So much we don't know. Is the endocrine tx still effective for the whole five years, after the Herceptin (or whatever) is stopped? Or maybe for triple-positive disease (tends to recur earlier?), a year of the combo is enough and then both could be stopped? Or maybe both should be continued for five (or more) year$$. So much we don't know. So much we don't know. Etc.