Joyce O'Shaughnessy M.D.

Schmid, P., J. Cortes, L. Pusztai, H. McArthur, S. Kummel, J. Bergh, C. Denkert, Y. H. Park, R. Hui, N. Harbeck, M. Takahashi, T. Foukakis, P. A. Fasching, F. Cardoso, M. Untch, L. Jia, V. Karantza, J. Zhao, G. Aktan, R. Dent and J. O’Shaughnessy (2020). “Pembrolizumab for Early Triple-Negative Breast Cancer.” New England Journal of Medicine 382(9): 810-821.

Full text of this article.

BACKGROUND: Previous trials showed promising antitumor activity and an acceptable safety profile associated with pembrolizumab in patients with early triple-negative breast cancer. Whether the addition of pembrolizumab to neoadjuvant chemotherapy would significantly increase the percentage of patients with early triple-negative breast cancer who have a pathological complete response (defined as no invasive cancer in the breast and negative nodes) at definitive surgery is unclear. METHODS: In this phase 3 trial, we randomly assigned (in a 2:1 ratio) patients with previously untreated stage II or stage III triple-negative breast cancer to receive neoadjuvant therapy with four cycles of pembrolizumab (at a dose of 200 mg) every 3 weeks plus paclitaxel and carboplatin (784 patients; the pembrolizumab-chemotherapy group) or placebo every 3 weeks plus paclitaxel and carboplatin (390 patients; the placebo-chemotherapy group); the two groups then received an additional four cycles of pembrolizumab or placebo, and both groups received doxorubicin-cyclophosphamide or epirubicin-cyclophosphamide. After definitive surgery, the patients received adjuvant pembrolizumab or placebo every 3 weeks for up to nine cycles. The primary end points were a pathological complete response at the time of definitive surgery and event-free survival in the intention-to-treat population. RESULTS: At the first interim analysis, among the first 602 patients who underwent randomization, the percentage of patients with a pathological complete response was 64.8% (95% confidence interval [CI], 59.9 to 69.5) in the pembrolizumab-chemotherapy group and 51.2% (95% CI, 44.1 to 58.3) in the placebo-chemotherapy group (estimated treatment difference, 13.6 percentage points; 95% CI, 5.4 to 21.8; P<0.001). After a median follow-up of 15.5 months (range, 2.7 to 25.0), 58 of 784 patients (7.4%) in the pembrolizumab-chemotherapy group and 46 of 390 patients (11.8%) in the placebo-chemotherapy group had disease progression that precluded definitive surgery, had local or distant recurrence or a second primary tumor, or died from any cause (hazard ratio, 0.63; 95% CI, 0.43 to 0.93). Across all treatment phases, the incidence of treatment-related adverse events of grade 3 or higher was 78.0% in the pembrolizumab-chemotherapy group and 73.0% in the placebo-chemotherapy group, including death in 0.4% (3 patients) and 0.3% (1 patient), respectively. CONCLUSIONS: Among patients with early triple-negative breast cancer, the percentage with a pathological complete response was significantly higher among those who received pembrolizumab plus neoadjuvant chemotherapy than among those who received placebo plus neoadjuvant chemotherapy. (Funded by Merck Sharp & Dohme [a subsidiary of Merck]; KEYNOTE-522 ClinicalTrials.gov number, NCT03036488.).

Cobleigh, M., D. A. Yardley, A. M. Brufsky, H. S. Rugo, S. M. Swain, P. A. Kaufman, D. Tripathy, S. A. Hurvitz, J. O’Shaughnessy, G. Mason, V. Antao, H. Li, L. Chu and M. Jahanzeb (2020). “Baseline Characteristics, Treatment Patterns, and Outcomes in Patients with HER2-Positive Metastatic Breast Cancer by Hormone Receptor Status from SystHERs.” Clin Cancer Res 26(5): 1105-1113.

Full text of this article.

PURPOSE: We report treatments and outcomes in a contemporary patient population with HER2-positive metastatic breast cancer (MBC) by hormone receptor (HR) status from the Systemic Therapies for HER2-positive Metastatic Breast Cancer Study (SystHERs). EXPERIMENTAL DESIGN: SystHERs (NCT01615068) was an observational, prospective registry study of U.S.-based patients with newly diagnosed HER2-positive MBC. Endpoints included treatment patterns and clinical outcomes. RESULTS: Of 977 eligible patients (enrolled from 2012 to 2016), 70.1% (n = 685) had HR-positive and 29.9% (n = 292) had HR-negative disease. Overall, 59.1% (405/685) of patients with HR-positive disease received any first-line endocrine therapy (with or without HER2-targeted therapy or chemotherapy); 34.9% (239/685) received HER2-targeted therapy + chemotherapy + sequential endocrine therapy. Patients with HR-positive versus HR-negative disease had longer median overall survival (OS; 53.0 vs 43.4 months; hazard ratio, 0.70; 95% confidence interval, 0.56-0.87). Compared with patients with high HR-positive staining (10%-100%, n = 550), those with low HR-positive staining (1%-9%, n = 60) received endocrine therapy less commonly (64.2% vs 33.3%) and had shorter median OS (53.8 vs 40.1 months). Similar median OS (43.4 vs 40.1 months) was observed in patients with HR-negative versus low HR-positive tumors (1%-9%). CONCLUSIONS: Despite evidence that first-line HER2-targeted therapy, chemotherapy, and sequential endocrine therapy improves survival in patients with HR-positive, HER2-positive disease, only 34.9% of patients in this real-world setting received such treatment. Patients with low tumor HR positivity (1%-9%) had lower endocrine therapy use and worse survival than those with high tumor HR positivity (10%-100%).

Golshan, M., S. Loibl, S. M. Wong, J. B. Houber, J. O’Shaughnessy, H. S. Rugo, N. Wolmark, M. D. McKee, D. Maag, D. M. Sullivan, O. Metzger-Filho, G. Von Minckwitz, C. E. Geyer, Jr., W. M. Sikov and M. Untch (2020). “Breast Conservation After Neoadjuvant Chemotherapy for Triple-Negative Breast Cancer: Surgical Results From the BrighTNess Randomized Clinical Trial.” JAMA Surg Jan 8. [Epub ahead of print].

Full text of this article.

Importance: Neoadjuvant systemic therapy (NST) is often administered to enable breast-conserving therapy (BCT) in stages II to III breast cancer. Objectives: To prospectively evaluate the role of NST in conversion from BCT ineligibility to BCT eligibility and to assess the association of response to NST, germline BRCA (gBRCA) status, and region of treatment with surgical choice in women with triple-negative breast cancer (TNBC). Design, Setting, and Participants: This prespecified secondary analysis of a multicentered, phase 3, double-blind, randomized clinical trial (BrighTNess) enrolled 634 eligible women across 145 centers in 15 countries in North America, Europe, and Asia. Women with operable, clinical stages II to III TNBC who underwent gBRCA mutation testing before initiating NST were eligible to participate. Data were collected from April 1, 2014, to December 8, 2016. This preplanned analysis was performed from January 5, 2018, to October 28, 2019. Interventions: Study participants were randomized to receive 12 weeks of weekly paclitaxel alone or with the addition of carboplatin and/or veliparib, followed by 4 cycles of doxorubicin hydrochloride and cyclophosphamide. Main Outcomes and Measures: Surgeons assessed BCT candidacy by clinical and radiographic criteria before and after NST. Surgical choices and whether BCT eligibility was associated with the likelihood of pathologic complete response were then analyzed. Results: Among the 634 randomized patients (median age, 51 [range, 22-78] years), pre- and post-NST assessments were available for 604 patients. Of 141 patients deemed BCT ineligible at baseline, 75 (53.2%) converted to BCT eligible. Overall, 342 (68.1%) of 502 patients deemed BCT eligible after NST underwent BCT, including 42 (56.0%) of the 75 who converted to BCT eligible. Patients treated in Europe and Asia were more likely to undergo BCT (odds ratio, 2.66; 95% CI, 1.84-3.84) compared with those treated in North America. Among patients without gBRCA mutation undergoing mastectomy, those treated in North America were more likely to undergo contralateral prophylactic mastectomy (57 of 81 [70.4%] vs 6 of 30 [20.0%]; P < .001). Rates of pathologic complete response were similar between patients deemed BCT eligible at baseline and those who were BCT ineligible but converted to BCT eligibility after NST (55.3 [235 of 425] vs 49.3% [37 of 75]; P = .38). Conclusions and Relevance: This prospective analysis of NST and BCT eligibility in TNBC demonstrates a conversion from BCT ineligibility to BCT eligibility of 53.2%. Lower BCT rates among eligible patients and higher bilateral mastectomy rates among patients without gBRCA mutation in North America merit investigation. Trial Registration: ClinicalTrials.gov identifier: NCT02032277.

Golshan, M., S. M. Wong, S. Loibl, J. B. Huober, J. O’Shaughnessy, H. S. Rugo, N. Wolmark, P. Ansell, D. Maag, D. M. Sullivan, O. Metzger-Filho, G. Von Minckwitz, C. E. Geyer, Jr., W. M. Sikov and M. Untch (2020). “Early assessment with magnetic resonance imaging for prediction of pathologic response to neoadjuvant chemotherapy in triple-negative breast cancer: Results from the phase III BrighTNess trial.” Eur J Surg Oncol 46(2): 223-228.

Full text of this article.

INTRODUCTION: The ability of breast magnetic resonance imaging (MRI) to predict pathologic complete response (pCR) to neoadjuvant systemic therapy (NST) varies across biological subtypes. We sought to determine how well breast MRI findings following initial treatment on the phase III BrighTNess trial correlated with pCR in patients with triple negative breast cancer (TNBC). METHODS: Baseline and mid-treatment imaging and pathologic response data were available in 519 patients with stage II-III TNBC who underwent NST as per protocol. MRI complete response (mCR) was defined as disappearance of all target lesion(s) and MRI partial response (mPR) as a >/=50% reduction in the largest tumor diameter. RESULTS: Overall, mCR was demonstrated in 116 patients (22%), whereas 166 (32%) had mPR and 237 (46%) had stable/progressive disease (SD/PD). The positive predictive value (PPV), negative predictive value, and overall accuracy of the mid-treatment MRI for pCR were 78%, 56%, and 61%, respectively; accuracy did not differ significantly between gBRCA mutation carriers and non-carriers (52% vs. 63%, p=0.10). When compared to patients with SD/PD, those with mPR or mCR were 3.35-fold (95% CI 2.07-5.41) more likely to have pCR at surgery. MRI response during NST was significantly associated with eligibility for breast-conserving surgery following completion of treatment (93.1% for mCR vs. 81.6% for SD/PD, p<0.001). CONCLUSIONS: Complete response on mid-treatment MRI in the BrighTNess trial had a PPV of 78% for demonstration of pCR after completion of NST in TNBC. However, a substantial proportion of patients with mPR or SD/PD also achieved a pCR. CLINICAL TRIAL REGISTRATION: NCT02032277.

Tew, B. Y., C. Legendre, M. A. Schroeder, T. Triche, G. C. Gooden, Y. Huang, L. Butry, D. J. Ma, K. Johnson, R. A. Martinez, M. Pierobon, E. F. Petricoin, J. O’Shaughnessy, C. Osborne, C. Tapia, D. N. Buckley, J. Glen, M. Bernstein, J. N. Sarkaria, S. A. Toms and B. Salhia (2020). “Patient-derived xenografts of central nervous system metastasis reveal expansion of aggressive minor clones.” Neuro Oncol 22(1): 70-83.

Full text of this article.

BACKGROUND: The dearth of relevant tumor models reflecting the heterogeneity of human central nervous system metastasis (CM) has hindered development of novel therapies. METHODS: We established 39 CM patient-derived xenograft (PDX) models representing the histological spectrum, and performed phenotypic and multi-omic characterization of PDXs and their original patient tumors. PDX clonal evolution was also reconstructed using allele-specific copy number and somatic variants. RESULTS: PDXs retained their metastatic potential, with flank-implanted PDXs forming spontaneous metastases in multiple organs, including brain, and CM subsequent to intracardiac injection. PDXs also retained the histological and molecular profiles of the original patient tumors, including retention of genomic aberrations and signaling pathways. Novel modes of clonal evolution involving rapid expansion by a minor clone were identified in 2 PDXs, including CM13, which was highly aggressive in vivo forming multiple spontaneous metastases, including to brain. These PDXs had little molecular resemblance to the patient donor tumor, including reversion to a copy number neutral genome, no shared nonsynonymous mutations, and no correlation by gene expression. CONCLUSIONS: We generated a diverse and novel repertoire of PDXs that provides a new set of tools to enhance our knowledge of CM biology and improve preclinical testing. Furthermore, our study suggests that minor clone succession may confer tumor aggressiveness and potentiate brain metastasis.