Leonie Voorwerk, a PhD student at the Netherlands Cancer Institute, discusses the rationale for examining the combination of atezolizumab (Tecentriq) plus carboplatin in patients with metastatic lobular breast cancer.

This combination was examined in the phase 2 GELATO trial (NCT03147040) as an immune induction treatment for patients with metastatic lobular breast cancer, according to Voorwerk. Invasive lobular breast cancer is the most common histological subtype; it acts as a different disease entity vs other breast cancers without the subtype in terms of metastases patterns and a higher level of estrogen receptor expression in most patients, Voorwerk explains.

Translational data have indicated that a subset of patients with invasive lobular carcinoma (ILC) are categorized as immune-related, with a high expression of immune-related genes, immune checkpoints, and a higher abundance of tumor-infiltrating lymphocytes. Moreover, in vitro research has indicated that immune-related ILCs may be more sensitive to platinum agents, Voorwerk says. Mouse models for metastatic ILC have also identified synergy between immune checkpoint blockades and platinum agents. 

These previous findings helped to build the rationale for the exploration of the combination in the GELATO trial, Voorwerk concludes.

Videos

Leonie Voorwerk, discusses the rationale for examining the combination of atezolizumab plus carboplatin in patients with metastatic lobular breast cancer.

Dr. Voorwerk on Rationale for Atezolizumab/Carboplatin in Metastatic Lobular Breast Cancer

Leonie Voorwerk, a PhD student at the Netherlands Cancer Institute, discusses outcomes with the combination of atezolizumab (Tecentriq) plus carboplatin in metastatic lobular breast cancer, which was evaluated as part of the phase 2 GELATO trial (NCT03147040).

In total, 22 patients received at least 1 cycle of atezolizumab and were available for further analysis, 5 of whom had triple-negative breast cancer (TNBC), according to Voorwerk. Among the 21 patients who were eligible for response evaluation, 4 patients experienced a partial response (PR), while 2 patients achieved stable disease for at least 6 months. This translated to an objective response rate of 19%, and a clinical benefit rate of 29%.

Additionally, investigators identified a median duration of response of 12 weeks, with 1 patient experiencing an ongoing response, Voorwerk says. At least 3 patients remained progression free at 6 months, meeting the primary end point of the trial. Among the 6 patients who experienced clinical benefit, defined as either PR or stable disease, 4 had TNBC.

Baseline stromal tumor-infiltrating lymphocytes and stromal CD8 counts were also investigated, Voorwerk adds. Although these factors were not associated with clinical benefit, a trend toward a higher PD-L1 expression was observed in patients who experienced clinical benefit with the regimen, Voorwerk concludes.

Leonie Voorwerk, discusses outcomes with the combination of atezolizumab plus carboplatin in metastatic lobular breast cancer, which was evaluated as part of the phase 2 GELATO trial.


Leonie Voorwerk

Articles

Dr. Voorwerk on Rationale for Atezolizumab/Carboplatin in Metastatic Lobular Breast Cancer

Dr. Voorwerk on Outcomes with Atezolizumab Plus Carboplatin in Metastatic Lobular Breast Cancer