Breast Cancer Highlights in ASCO 2021

DelveInsight has already covered the significant abstracts that were presented on DAY 1 of the  ASCO 21 virtual event, and now is the time for some of the most notable ones presented on Day 2 in Breast Cancer.   

Abstract #1002: Dalpiciclib plus fulvestrant as a new treatment option in Patients with HR+/HER2- ABC (DAWNA-1) Study 

Dalpiciclib (SHR6390) is a novel CDK4/6 inhibitor, as monotherapy has demonstrated tolerability and preliminary antitumor activity in pretreated HR+/HER2− advanced breast cancer (ABC). Jiangsu Hengrui Medicine has presented the primary results from the DAWNA-1 study. DAWNA-1 trial was a multicenter, randomized, phase 3 study assessing Dalpiciclib versus placebo plus fulvestrant in HR+/HER2- advanced breast cancer that relapsed or progressed on previous endocrine therapy.

In the phase III DAWNA-1 study, 361 patients with HR+/HER2− locally advanced or metastatic breast cancer were randomized 2:1 to receive fulvestrant plus either dalpiciclib, or placebo. The results demonstrated that the dalpiciclib plus fulvestrant significantly improved the progression-free survival versus placebo plus fulvestrant (15.7 vs 7.2 months). The PFS results based on independent review committee assessment were consistent with the primary analysis showing a reduction in the risk of progression or death by 55% in the dalpiciclib group versus the placebo group. PFS in all prespecified subgroups favored the dalpiciclib group and showed a hazard ratio (HR) of less than 1 regardless of menopausal status. Per investigator, the assessment showed the ORR in the dalpiciclib group versus the placebo group was 27% vs 20%.

The results also showed that the risk of initiating the first subsequent chemotherapy was reduced by 53% in the dalpiciclib group as compared with the placebo group. The occurrence of grade 3 or 4 adverse events was more frequent in the dalpiciclib group than the placebo group, with the most common being neutropenia (84.2%; vs 0% with PBO-fulv) and leukopenia (62.1%; vs 0%).

The interim analysis showed that phase 3 DAWNA-1 met its primary endpoint with PFS significantly improved with dalpiciclib plus fulvestrant vs placebo plus fulvestrant. The side effects were generally tolerable and manageable and consistent with the known class effects of CDK4/6 inhibitors. 

Considering the data of DAWNA-1 study, these findings support dalpiciclib plus fulvestrant as a new treatment option in patients with HR+/HER2- advanced breast cancer who relapsed or progressed on prior endocrine therapy. 

Abstract # 1007: Combination of famitinib with camrelizumab plus nab-paclitaxel as first-line treatment for patients with immunomodulatory advanced triple-negative breast cancer/FUTURE-C-PLUS Study

First antiangiogenic, immune checkpoint inhibitors, and chemotherapy combination study for advanced TNBC

Molecular subtyping and precise treatment help in improving patient survival of TNBC. It has been reported that anti-VEGF antibodies increased CD8 infiltration and PD-L1 expression in multiple tumor tissues, and the effect of anti-angiogenesis combined with immunotherapy―which is called chemo-free—was observed without increasing adverse events. This FUTURE-C-PLUS Study aimed to evaluate the efficacy and safety of a novel triplet combination of famitinib, camrelizumab and nab-paclitaxel in the first-line treatment for patients with immunomodulatory advanced TNBC patient population. The primary endpoint of the study includes overall response rate, and secondary endpoints included progression-free survival (PFS), overall survival (OS), disease DOR, and safety. 

The results showed that the ORR was 81.3%, which is the highest for first-line treatment of mTNBC at present. The PFS data which was shown in the results was not mature. After the follow up of 11.5 months, the PFS rate at 9 month was 60.2%, and at 10 month it was 53.5%. The median time to treatment response (TTR) was observed to be 1.8 months. Considering the safety data points, there were no unexpected AEs, and the triplet combination was well tolerated in the study. 

Summarizing the evaluated data, it can be concluded that it is the first prospective study to combine antiangiogenic, immune checkpoint inhibitors, and chemotherapy in advanced TNBC. The PFS improvement is quite promising, and the safety profile was manageable. 

Catch up with the major highlights from Day 1 ASCO 2021 in the Breast Cancer space here