Abstract OT3-05-01: A randomized double-blind phase III clinical trial of neoadjuvant chemotherapy (NAC) with atezolizumab or placebo in patients (pts) with triple negative breast cancer (TNBC) followed by adjuvant atezolizumab or placebo: NSABP B-59/GBG 96-GeparDouze

Background:

TNBC is associated with higher percentages of pathological complete response (pCR) to neoadjuvant chemotherapy (NAC), and women with a pCR have a favorable prognosis. However, Liedtke (2008) and Loibl (2017) found that women with residual disease have a substantially higher risk of recurrence than women with other subtypes of breast cancer. Additionally, Adams (2017) and Schmid (2017) found that therapeutic blockade of PD-L1 binding by atezolizumab has resulted in relevant anti-tumor efficacy.

Methods:

Design

This is a phase III, double blind, placebo-control trial evaluating neoadjuvant atezolizumab with NAC followed by adjuvant atezolizumab in TNBC. Pts are stratified by region (North America; Europe), tumor size (1.1-3.0cm; >3.0cm), AC/EC schedule (q2w; q3w), and nodal status (positive; negative), then randomized 1:1 to receive atezolizumab/placebo 1200 mg IV every 3 wks concurrently with both sequential regimens of weekly paclitaxel 80 mg/m2 IV for 12 doses with every 3-wk carboplatin AUC of 5 IV for 4 doses followed by AC/EC every 2-3 wks (per investigator discretion) for 4 cycles. Following surgery, pts resume atezolizumab/placebo 1200 mg IV every 3 wks as adjuvant therapy for 6 months. Radiotherapy based on local standards is co-administered with atezolizumab/placebo.

Eligibility criteria

Centrally-confirmed ER-neg, PR-neg, HER2-neg invasive breast cancer by ASCO/CAP guidelines. Primary tumor must be stage T2 or T3 if cN0 or cN1 with negative biopsy or T1c, T2, or T3 if cN1 with positive biopsy or cN2 or cN3. LVEF >55% and no significant cardiac history.

Statistical methods

Co-primary endpoints are event-free survival (EFS) and pCR breast/nodes. Secondary endpoints include pCR breast, overall survival, distant disease-free survival, safety and toxicity. Trial is an academic collaboration between NSABP and GBG with support from Genentech/Roche.

NCT03281954

Support: Genentech/Roche

Citation Format: Geyer, Jr. CE, Loibl S, Rastogi P, Seiler S, Costantino JP, Nekljudova VN, Cortazar P, Lucas PC, Denkert C, Mamounas EP, Jackisch C, Wolmark N. A randomized double-blind phase III clinical trial of neoadjuvant chemotherapy (NAC) with atezolizumab or placebo in patients (pts) with triple negative breast cancer (TNBC) followed by adjuvant atezolizumab or placebo: NSABP B-59/GBG 96-GeparDouze [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-05-01.

Abstract P6-13-02: Increased mortality risk among elderly patients with early stage triple negative breast cancer who did not receive adjuvant or neoadjuvant therapy

Background: Worldwide, breast cancer (BC) is the most frequently diagnosed cancer and the leading cause of cancer death in women. The triple negative (TN) subtype accounts for up to 20% of BC and has a poorer prognosis compared to other subtypes. We set out to evaluate treatment patterns and survival associated with receiving adjuvant or neo-adjuvant therapy in an older, demographically diverse population of patients with TNBC.

Methods: The analysis included 10,694 patients with first primary TNBC from the linked SEER-Medicare database. Patients were diagnosed with Stage I-III disease between January 1, 2001-December 31, 2011, ≥66 years, continuously enrolled in Medicare Parts A and B in the year prior to diagnosis, and underwent breast cancer surgery within 6 months after diagnosis. Unadjusted Kaplan Meier analyses and time-varying Cox proportional hazards regression adjusting for patient characteristics assessed overall survival. Date of last follow-up was December 31, 2013.

Results: There were 4,807 (45%) patients treated with adjuvant/neo-adjuvant chemotherapy and 5,887 (55%) untreated. Treatment rates increased over the study time-period from 45% in 2001 to 52% in 2011 (p<.0001). Compared to treated patients, untreated patients were older (78 vs. 73 years), had earlier stage disease (57% vs. 31% Stage I), lower tumor grade (34% vs. 23% grade 1/2), smaller tumors (57 vs.40% <2cm), poorer performance (13% vs. 6%), higher comorbidity burden (45% vs. 37% NCI Comorbidity Score ≥ 1) and were less likely to receive radiotherapy (47% vs. 65%; p<0.0001). The median unadjusted overall survival was 94.3 months for the overall population and was longer for treated patients (101.5 months) compared to untreated patients (88.4 months; log rank p <.0001). In the adjusted Cox model, there was a 28% higher risk of death in untreated compared to treated patients (HR=1.28; 95% CI=1.19-1.38). The model also showed that as age, stage, tumor size, tumor grade, and comorbidity score increased, mortality risk also significantly increased. Having poor performance indicators was also significantly associated with higher mortality risks, while prior radiotherapy was associated with lower risks.

Conclusions: Although therapy use has increased over time, this large observational study confirmed that 55% of elderly patients with Stage I-III TNBC are not receiving adjuvant/neo-adjuvant therapy following diagnosis. As a result, untreated patients exhibited a significantly elevated risk of death compared to those who received treatment. The results of this study highlight the unmet need in this patient population and provide an important context to optimize disease management in real-world settings.

Citation Format: Satram-Hoang S, Bajaj PS, Stein A, Hoang KQ, Momin F, Cortazar P, Reyes C. Increased mortality risk among elderly patients with early stage triple negative breast cancer who did not receive adjuvant or neoadjuvant therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-13-02.

Abstract P5-17-01: A definition of a high-risk early-breast cancer population based on data from the collaborative trials in neoadjuvant breast cancer (CTNeoBC) meta-analysis

Background: Pathological complete response (pCR) is a proposed surrogate endpoint for predicting long-term clinical benefit on endpoints such as event-free survival (EFS) or overall survival (OS). The CTNeoBC meta-analysis did not validate the surrogacy of pCR for EFS or OS, and there is no precedent for its use as a regulatory endpoint in oncology. Use of the accelerated approval pathway has been proposed for neoadjuvant therapies that substantially improve pCR as a means to expedite widespread access to highly effective therapies for high-risk, early breast cancer. Potential risks of this approach include approving an agent that ultimately does not demonstrate clinical benefit and, in the interim, exposing curable patients to the toxicity of therapy without certainty of benefit. To mitigate the risks of this pathway, enrollment to neoadjuvant trials intended to support accelerated approval should be restricted to patients presenting with high-risk early-stage breast cancer. The 5-year EFS rate by breast cancer subtype in the CTNeoBC meta-analysis population is presented. Methods: We identified 12 neoadjuvant randomized trials (N = 12,993) with pCR clearly defined and long-term follow-up available for EFS and OS. Trials included AGO 1 (n = 668), ECTO (n = 1355), EORTC 10994/BIG 1-00 (n = 1856), GeparDuo (n = 907), GeparQuattro (n = 1495), GeparTrio (n = 2072), GeparTrio-Pilot (n = 285), NOAH (n = 234), NSABP B18 (n = 760), NSABP B27 (n = 2411), PREPARE (n = 733), and TECHNO (n = 217). The key objective of this analysis was to establish a definition of “high-risk” based on the Kaplan-Meier estimates of the 5-year EFS rate in the different clinical breast cancer subtypes (hormone receptor-positive, HER2-positive and triple-negative) analyzed by tumor stage and tumor grade at presentation. Results: The 5-year EFS rate was less than 65% in all the breast cancer subtypes with stage III disease. For patients with stage II disease, the impact of tumor grade varied by hormone receptor status. Patients with hormone receptor-negative breast cancer, regardless of HER2 status had a poor prognosis that was independent of tumor grade. For patients with hormone receptor-positive tumors, regardless of HER2 status, high grade histology was associated with an increased risk of recurrence.

5-year Event-Free Survival Rate (EFS) 5-year EFS Rate Estimate (95% confidence interval)TNMStage IIStage III Grade IIGrade IIIGrade IIGrade IIIHormone Receptor + HER2-83% (80%, 85%)71% (65%, 77%)63% (58%, 69%)51% (42%, 59%)HER2+ HR+81% (75%, 86%)69% (60%, 76%)50% (41%, 59%)48% (37%, 59%)HER2+ HR-61% (51%, 70%)66% (57%, 73%)58% (46%, 69%)46% (36%, 55%)Triple Negative66% (58%, 72%)72% (67%, 76%)38% (27%, 48%)37% (29%, 45%)

Conclusions: This analysis estimated the 5-year EFS rate in the breast cancer subtypes from the CTNeoBC meta-analysis population. The HER2-positive population in the meta-analysis was at particularly high risk because most of the patients had locally advanced breast cancer and only 39% of these patients received trastuzumab therapy. We propose defining less than 75% 5-year EFS rate as “high-risk” for the purposes of designing neoadjuvant trials that intend to use pCR to support accelerated approval.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-17-01.

Trastuzumab cardiotoxicity: FDA review of four adjuvant breast cancer clinical trials leading to trastuzumab marketing approvals

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Background: Trastuzumab can result in sub-clinical and clinical cardiac failure manifesting as congestive heart failure (CHF), and decreased left ventricular ejection fraction (LVEF). Methods: Data was reviewed from 9837 patients in four randomized trials (NCCTG 9831, NSABP B-31, HERA, and BCIRG-06) that supported trastuzumab HER2 overexpressing adjuvant breast cancer approval. Results: Trastuzumab can cause left ventricular cardiac dysfunction, arrhythmias, hypertension, disabling cardiac failure, cardiomyopathy, and cardiac death. Herceptin can also cause asymptomatic decline in LVEF. There is a 4−6 fold increase in the incidence of symptomatic myocardial dysfunction among patients receiving trastuzumab as a single agent or in combination therapy compared with those not receiving trastuzumab. The highest absolute incidence occurs when trastuzumab is administered with an anthracycline. Clinical trials NCCTG 9831, NSABP B-31, and BCIRG-06 included arms with doxorubicin- cyclophosphamide (AC) followed by a taxane plus trastuzumab. Among 32 patients receiving adjuvant chemotherapy from studies NCCTG 9831 and NSABP B-31 who developed CHF, one patient died of cardiomyopathy and all other patients were receiving cardiac medication at last follow-up. Approximately half of the patients recovered to a normal LVEF (defined as ≥ 50%) on continuing medical management at the time of last follow-up. In BCIRG-06 the incidence of CHF was six (6) fold higher in the AC followed by docetaxel plus trastuzumab arm as compared to AC followed by docetaxel. There was a lower incidence of CHF in the non-anthracycline TCH (docetaxel, carboplatin and trastuzumab) arm in BCIRG-06 comparable to trastuzumab monotherapy. Conclusions: Cardiotoxicity manifesting as sub-clinical and clinical cardiac failure is a known side effect of trastuzumab. In an era where trastuzumab is given earlier in the treatment of breast cancer (adjuvant setting), the safety of continuation or resumption of trastuzumab in patients with trastuzumab-induced left ventricular cardiac dysfunction has not been studied.

No significant financial relationships to disclose.

Adjuvant breast cancer: FDA approval overview

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Background: Improved disease-free survival (DFS) in randomized controlled trials (RCT) is the primary basis for approval of adjuvant breast cancer (ABC) treatments. Methods: Review of clinical trials leading to new drug approvals for ABC. Results: DFS is a composite endpoint defined as the time from randomization to the earliest occurrence of invasive loco-regional recurrence, invasive contralateral breast cancer, DCIS, distant metastases, second primary tumors or death from any cause. Trials supporting marketing approval have used inconsistent DFS definitions that included different components of this endpoint. Basis of paclitaxel approval following AC was superior DFS (HR= 0.78; 95% CI 0.67–0.91, p=0.002) and overall survival (HR=0.74; 95% CI 0.60–0.92, p=0.0065). Trastuzumab approval as part of a treatment regimen was based on 4 clinical trials that showed improved DFS. Docetaxel approval was based on improved DFS of the docetaxel-containing combination regimen TAC compared to FAC (HR: 0.74; 2- sided 95% CI=0.60–0.92, p=0.0047). Doxorubicin approval was based on a meta-analysis of six ABC trials comparing doxorubicin- containing regimens to CMF. Analyses demonstrated that doxorubicin-containing regimens retained at least 75% of the historical CMF adjuvant effect on DFS (HR: 0.91; 95% CI 0.82–1.01) and OS (HR: 0.91; 95% CI 0.81–1.03). Epirubicin approval was based on a longer relapse free survival (RFS) of the epirubicin-containing combination therapy (CEF-120) compared to CMF (HR=0.76; 95% CI 0.60–0.96, p=0.013). Tamoxifen approval was based on an overview of tamoxifen adjuvant therapy. Ten-year survival was 61.4% for tamoxifen vs. 50.5% for control (p < 0.00001) and RFS was 59.7% for tamoxifen vs. 44.5% for control (p < 0.00001). Anastrozole approval was based on a longer DFS (HR: 0.87; 95% CI=0.78–0.97, p=0.0127). Letrozole was based on a superior DFS (HR= 0.62; 95% CI 0.49–0.78, p=0.00003). Exemestane approval was based on improved DFS (HR: 0.65; 95% CI=0.53–0.79, p=0.00001). Conclusions: Although DFS was the basis for approval in most of the ABC clinical trials, the endpoint definition varies between trials. DFS definition should be standardized in ABC clinical trials to permit consistent interpretation and analysis and to facilitate cross-trial comparisons.

No significant financial relationships to disclose.

Review of the efficacy of individualized chemotherapy selected by in vitro drug sensitivity testing for patients with cancer

PURPOSE

The purpose of this study is to review the potential efficacy of individualized chemotherapy selected by in vitro drug sensitivity testing (DST) compared with empiric regimens for patients with cancer.

METHODS

MEDLINE and CANCERLIT were searched for articles published (in English) about prospective clinical trials in which patients were treated with chemotherapy that was selected with the use of in vitro DST.

RESULTS

We identified 12 prospective studies that examined the benefit of chemotherapy selected by DST. Five hundred six patients (33%) were treated with chemotherapy that was selected with the use of in vitro DST. The mean response rate for patients treated with in vitro-selected therapy was 27% (range, 10% to 100%; n = 12 studies) compared with 18% (range, 0% to 100%; n = 7 studies) for patients treated with empiric therapy. Five studies (only one randomized) evaluated the impact of chemotherapy selected by in vitro DST on patient survival. Three studies showed that survival was 1 to 4 months longer for the 238 patients treated with empiric chemotherapy compared with that of the 65 patients treated with chemotherapy that was selected by in vitro testing. Two nonrandomized studies showed that survival was 4 or 19 months longer for 27 patients treated with chemotherapy selected by in vitro testing compared with that of 80 patients who were treated with empiric chemotherapy.

CONCLUSION

Only one third of patients entered in prospective trials of in vitro DST were actually treated with an in vitro best regimen. The response rates seem to be better with in vitro selected chemotherapy regimens than with empiric regimens, but the impact on survival has not been adequately addressed.

Second lung cancers in patients successfully treated for lung cancer

The rate of developing second lung cancers and other aerodigestive tumors in patients who have been treated for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) is approximately 10-fold higher than other adult smokers. The risk of second lung cancers in patients surviving resection of NSCLC is approximately 1% to 2% per year. The series reported show that the patients who develop second NSCLCs tend to have early-stage NSCLC (predominantly stage I and II). The survival of patients after the second resection of lung cancer is similar to that of patients presenting with initial NSCLC. The risk of second lung cancers in patients surviving SCLC is 2% to 14% per patient per year and increases two- to seven-fold with the passage of time from 2 to 10 years. The risk of second lung cancers in patients treated for SCLC appears to be higher than that found in patients with NSCLC who were treated only with surgical resection. In addition, the chances of successful resection of second primary NSCLCs in patients who were treated for SCLC is much less than that for patients with metachronous lung cancers after an initial NSCLC. Patients treated for SCLC who continue to smoke cigarettes increase their rate of developing second lung cancers. The contribution of chest radiation and chemotherapy administration to the risk of developing second lung tumors remain to be defined but may be responsible for some of the increased risk in patients treated for SCLC compared to patients undergoing a surgical resection for NSCLC.

Survival of patients with limited-stage small cell lung cancer treated with individualized chemotherapy selected by in vitro drug sensitivity testing

Our purpose was to study the feasibility of determining individualized chemotherapy regimens by in vitro drug sensitivity testing (DST) for patients with limited-stage small cell lung cancer (SCLC) and to evaluate patient response and survival. Fifty-four previously untreated patients with limited-stage small cell cancer were studied. Fresh tumor specimens for DST were collected, when possible, from patients' biopsies before the start of treatment. The differential staining cytotoxicity assay was used to determine the in vitro sensitivity of the tumor cells to different drugs. From these results, an in vitro best regimen (IVBR), a three-drug combination of previously proven efficacy of seven active drugs in SCLC, was selected. Patients were initially treated with four cycles of etoposide/cisplatin and concurrent radiotherapy. This was followed by four cycles of either individualized chemotherapy regimens based on the results of DST or, when DST results were not available, four cycles of vincristine, doxorubicin, and cyclophosphamide. Eighteen patients (33%) underwent biopsy procedures that provided tissue specimens for DST. The biopsy specimens contained tumor cells in 16 of 18 patients. The median duration from diagnosis to start of treatment was 22 days (range, 4-58 days) for the 18 patients who underwent elective thoracic biopsies compared to 21 days (range, 2-74 days) for members of the group that did not (P2 = 0.58). Time from thoracic biopsy to initiation of chemotherapy was a median of 4 days (range, 2-22 days). DST was done in 10 patients, and IVBR was administered to 8 patients. The median actuarial survival of 8 patients treated with their IVBR was 38.5 months compared to 19 months for the 46 patients treated with empiric chemotherapy. Selection of individualized chemotherapy regimens is labor intensive but feasible in limited-stage SCLC. Treatment with an individualized IVBR in our patients was associated with prolonged patient survival; however, because of the nature of our study design, other factors could have affected the results.