There's been a great ASCO 2021 conference for the breast cancer field. Unfortunately, it was again a virtual conference only, but it's very nice to see that the research has progressed, despite all these difficult times. And many important news have become available for improving the care of our cancer patients despite all the difficulties that we had to face over the last year.
If I have to select my main takes from the ASCO 2021 conference, I will start, of course, from the OlympiA trial results-- the use of adjuvant olaparib following adjuvant or neoadjuvant chemotherapy in BRCA carriers with HER2-negative, triple-negative, or hormone receptor-positive, high-risk tumors. In this trial, patients were randomized to receive olaparib versus placebo for a year. And the use of olaparib significantly improved patient outcomes almost 8.8% INAUDIBLE difference in three-year invasive disease-free survival, similar findings in distant disease-free survival, with a trend that was not statistically significant in overall survival.
These are very important data, practice changing also in terms of how to test for BRCA in the early breast cancer setting because, based on these data, we are kind of moving towards the universal testing for BRCA or at least all patients in the early disease, high risk of recurrence, and HER2-negative disease.
On the top of the OlympiA trial results, another very awaited trial, the ECOG-ACRIN 1131 study testing the use of platinum-based chemotherapy as post-neoadjuvant treatment in triple-negative breast cancer patients. So those patients without pCR were randomized to receive capecitabine, which is our current standard of care in this setting, or single-agent, platinum-based chemotherapy, cisplatin or carboplatin.
The trial closed early because of one of the interim analyses, showing that the trial would have been very unlikely to show any difference. And what is quite alarming, besides the lack of difference between capecitabine and platinum-based chemotherapy or, better, the non-inferiority that could not be proven of platinum-based chemotherapy as compared to capecitabine, but, beside that, what I think is quite important to note and worrisome are the outcomes of these patients with a disease-free survival at three years of less than 50% in both treatment arms. So this is indeed a patient population where we need more research efforts and that we really need to improve their outcomes.
On this aspect, some important data in the neoadjuvant setting has been presented, survival outcomes from two important studies, one for triple-negative patients, the other for patients with the HER2-positive disease. On the first study, the GeparNUEVO trial tested the addition of durvalumab on the top of taxane, anthracycline, and cyclophosphamide-based neoadjuvant chemotherapy. This trial did not show any difference in pCR rate, the primary endpoint, but, at long-term follow-up, the survival outcomes were significantly better for the durvalumab arm as compared to the placebo arm, suggesting that immune therapy in the neoadjuvant setting may improve the outcomes of our patients besides and beyond a potential improvement in pCR.
So we are really now awaiting the results from the other neoadjuvant trials that already reported the pCR rates and improved pCR rates like the KEYNOTE-522 or the IMpassion031 trial. The 522 has already a press release suggesting positive survival outcomes. So I think that the immunotherapy field in the early setting of breast cancer has just started, and we are starting to see really very important results.
The other study, the ADAPT trial, has also reported the important survival outcomes, showing, at five years, very good survival rates for patients that received almost 98% invasive disease-free survival, distant disease-free survival, and overall survival for patients that received a neoadjuvant treatment with taxane alone, chemotherapy, and dual anti-HER2 blockade, trastuzumab and pertuzumab. Most of these patients achieving pCR did not receive additional chemotherapy. And the whole population of patients included in this study had very good survival outcomes, supporting the ongoing phase III trial to deescalate chemotherapy for patients responding to deescalating neoadjuvant treatment.
Many important trial also in the advanced setting, just to highlight the three presentations on CDK4/6 inhibitor, updated data from PALOMA-3 and MONALEESA-2 suggest an improved overall survival with the addition of a CDK4/6 inhibitor in the endocrine resistant and-- both endocrine resistant and sensitive population. And then the first data of the DAWNA-1 trial with the use of dalpiciclib in addition to fulvestrant in the endocrine-resistant population, showing a doubling in the PFS, Progression-Free Survival, results with the addition of a CDK4/6 inhibitor, suggesting that there is a potential fourth option that we could choose in the future. However, in this trial, no overall survival data have been presented so far.
The final take from the advanced setting is the very interesting trial conducted in China, the sysucc-002 trial, that randomized patients with the triple-positive disease, hormone receptor positive, HER2 positive, to first-line treatment with trastuzumab as anti-HER2 treatment with endocrine therapy in one arm or chemotherapy in the other arm, testing the non-inferiority of endocrine therapy over chemotherapy. The trial was positive, so showed that endocrine therapy is non-inferior to chemotherapy, opening the door to deescalate chemotherapy in some specific groups of patients.
However, we have to keep in mind that our current standard of care in these settings is the combination of taxane-based chemotherapy and dual anti-HER2 blockade. And the outcomes observed in this trial are not really comparable and are much worse than what we have observed in the CLEOPATRA study.
Overall, this has been a great ASCO conference. And many of these data are really applicable in our daily clinical practice or hopefully will be applicable in our daily clinical practice very soon.