Joyce O'Shaughnessy M.D.

Johnston, S., O’Shaughnessy, J., Martin, M., Huober, J., Toi, M., Sohn, J., André, V.A.M., Martin, H.R., Hardebeck, M.C. and Goetz, M.P. (2021). “Abemaciclib as initial therapy for advanced breast cancer: MONARCH 3 updated results in prognostic subgroups.” NPJ Breast Cancer 7(1): 80.

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In MONARCH 3, continuous dosing of abemaciclib with an aromatase inhibitor (AI) conferred significant clinical benefit to postmenopausal women with HR+, HER2- advanced breast cancer. We report data for clinically prognostic subgroups: liver metastases, progesterone receptor status, tumor grade, bone-only disease, ECOG performance status, and treatment-free interval (TFI) from an additional 12-month follow-up (after final progression-free survival [PFS] readout). In the intent-to-treat population, after median follow-up of approximately 39 months, the updated PFS was 28.2 versus 14.8 months (hazard ratio [HR], 0.525; 95% confidence interval, 0.415-0.665) in abemaciclib versus placebo arms, respectively. Time to chemotherapy (HR, 0.513), time to second disease progression (HR, 0.637), and duration of response (HR, 0.466) were also statistically significantly prolonged with the addition of abemaciclib to AI. Treatment benefit was observed across all subgroups, as evidenced by objective response rate change from the addition of abemaciclib to AI, with the largest effects observed in patients with liver metastases, progesterone receptor-negative tumors, high-grade tumors, or TFI < 36 months. Extended follow-up in the MONARCH 3 trial further confirmed that the addition of abemaciclib to AI conferred significant treatment benefit to all subgroups, including those with poorer prognosis.

Ghergurovich, J.M., Lang, J.D., Levin, M.K., Briones, N., Facista, S.J., Mueller, C., Cowan, A.J., McBride, M.J., Rodriguez, E.S.R., Killian, A., Dao, T., Lamont, J., Barron, A., Su, X., Hendricks, W.P.D., Espina, V., Von Hoff, D.D., O’Shaughnessy, J. and Rabinowitz, J.D. (2021). “Local production of lactate, ribose phosphate, and amino acids within human triple-negative breast cancer.” Med (N Y) 2(6): 736-754.

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BACKGROUND: Upregulated glucose metabolism is a common feature of tumors. Glucose can be broken down by either glycolysis or the oxidative pentose phosphate pathway (oxPPP). The relative usage within tumors of these catabolic pathways remains unclear. Similarly, the extent to which tumors make biomass precursors from glucose, versus take them up from the circulation, is incompletely defined. METHODS: We explore human triple negative breast cancer (TNBC) metabolism by isotope tracing with [1,2-(13)C]glucose, a tracer that differentiates glycolytic versus oxPPP catabolism and reveals glucose-driven anabolism. Patients enrolled in clinical trial NCT03457779 and received IV infusion of [1,2-(13)C]glucose during core biopsy of their primary TNBC. Tumor samples were analyzed for metabolite labeling by liquid chromatography-mass spectrometry (LC-MS). Genomic and proteomic analyses were performed and related to observed metabolic fluxes. FINDINGS: TNBC ferments glucose to lactate, with glycolysis dominant over the oxPPP. Most ribose phosphate is nevertheless produced by oxPPP. Glucose also feeds amino acid synthesis, including of serine, glycine, aspartate, glutamate, proline and glutamine (but not asparagine). Downstream in glycolysis, tumor pyruvate and lactate labeling exceeds that found in serum, indicating that lactate exchange via monocarboxylic transporters is less prevalent in human TNBC compared with most normal tissues or non-small cell lung cancer. CONCLUSIONS: Glucose directly feeds ribose phosphate, amino acid synthesis, lactate, and the TCA cycle locally within human breast tumors.

Miles, D., Gligorov, J., André, F., Cameron, D., Schneeweiss, A., Barrios, C., Xu, B., Wardley, A., Kaen, D., Andrade, L., Semiglazov, V., Reinisch, M., Patel, S., Patre, M., Morales, L., Patel, S.L., Kaul, M., Barata, T. and O’Shaughnessy, J. (2021). “Primary results from IMpassion131, a double-blind, placebo-controlled, randomised phase III trial of first-line paclitaxel with or without atezolizumab for unresectable locally advanced/metastatic triple-negative breast cancer.” Ann Oncol Jul 1;S0923-7534(21)02026-3. [Epub ahead of print].

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BACKGROUND: In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-bound-paclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumab-paclitaxel in aTNBC. PATIENTS AND METHODS: Eligible patients [no prior systemic therapy or ≥12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m(2) (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression ≥1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint. RESULTS: Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P = 0.20; median PFS 6.0 months with atezolizumab-paclitaxel versus 5.7 months with placebo-paclitaxel]. In the PD-L1-positive population, atezolizumab-paclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placebo-paclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumab-paclitaxel versus 28.3 months with placebo-paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug. CONCLUSION: Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. CLINICALTRIALS.GOV: NCT03125902.

O’Shaughnessy, J., Sousa, S., Cruz, J., Fallowfield, L., Auvinen, P., Pulido, C., Cvetanovic, A., Wilks, S., Ribeiro, L., Burotto, M., Klingbiel, D., Messeri, D., Alexandrou, A., Trask, P., Fredriksson, J., Machackova, Z. and Stamatovic, L. (2021). “Preference for the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection in patients with HER2-positive early breast cancer (PHranceSCa): A randomised, open-label phase II study.” Eur J Cancer 152: 223-232.

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AIM: The aim of the study was to assess patient preference for the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection (PH FDC SC) in patients with HER2-positive early breast cancer in PHranceSCa (NCT03674112). MATERIALS AND METHODS: Patients who completed neoadjuvant P + H + chemotherapy + surgery were randomised 1:1 to three intravenous (IV) P + H cycles followed by three cycles of PH FDC SC or vice versa (crossover) and then chose subcutaneous (SC) injection or IV infusion to continue up to 18 cycles (continuation). Assessments were via patient and healthcare professional (HCP) questionnaires. RESULTS: One hundred and sixty patients were randomised (cut-off: 24 February 2020); 136 (85.0%, 95% confidence interval: 78.5-90.2%) preferred SC; 22 (13.8%) preferred IV; 2 (1.3%) had no preference. The main reasons for SC preference were reduced clinic time (n = 119) and comfort during administration (n = 73). One hundred and forty-one patients (88.1%) were very satisfied/satisfied with SC injection versus 108 (67.5%) with IV infusion; 86.9% chose PH FDC SC continuation. HCP perceptions of median patient treatment room time ranged from 33.0-50.0 min with SC and 130.0-300.0 min with IV. Most adverse events (AEs) were grade 1/2 (no 4/5s); serious AE rates were low. AE rates before and after switching were similar (cycles 1-3 IV → cycles 4-6 SC: 77.5% → 72.5%; cycles 1-3 SC → cycles 4-6 IV: 77.5% → 63.8%). CONCLUSION: Most patients strongly preferred PH FDC SC over P + H IV. PH FDC SC was generally well tolerated, with no new safety signals (even when switching), and offers a quicker alternative to IV infusion.

Bardia, A., Tolaney, S.M., Punie, K., Loirat, D., Oliveira, M., Kalinsky, K., Zelnak, A., Aftimos, P., Dalenc, F., Sardesai, S., Hamilton, E., Sharma, P., Recalde, S., Gil, E.C., Traina, T., O’Shaughnessy, J., Cortes, J., Tsai, M., Vahdat, L., Diéras, V., Carey, L.A., Rugo, H.S., Goldenberg, D.M., Hong, Q., Olivo, M., Itri, L.M. and Hurvitz, S.A. (2021). “Biomarker analyses in the phase III ASCENT study of sacituzumab govitecan versus chemotherapy in patients with metastatic triple-negative breast cancer.” Ann Oncol Jun 8;S0923-7534(21)02047-0. [Epub ahead of print].

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BACKGROUND: The pivotal phase III ASCENT trial demonstrated improved survival outcomes associated with sacituzumab govitecan (SG), an anti-trophoblast cell-surface antigen 2 (anti-Trop-2) antibody-drug conjugate linked with the topoisomerase-inhibitor SN-38, over single-agent chemotherapy treatment of physician’s choice (TPC) in previously treated metastatic triple-negative breast cancer (mTNBC). This prespecified, exploratory biomarker analysis from the ASCENT trial evaluates the association between tumor Trop-2 expression and germline BRCA1/2 mutation status with clinical outcomes. PATIENTS AND METHODS: Patients with mTNBC refractory to or progressing after two or more prior chemotherapies, with one or more in the metastatic setting, were randomized to receive SG (10 mg/kg intravenously days 1 and 8, every 21 days) or TPC (capecitabine, eribulin, vinorelbine, or gemcitabine) until disease progression/unacceptable toxicity. Biopsy or surgical specimens were collected at study entry to determine Trop-2 expression level using a validated immunohistochemistry assay and histochemical scoring. Germline BRCA1/2 mutation status was collected at baseline. RESULTS: Of 468 assessable patients, 290 had Trop-2 expression data [64% (n = 151 SG) versus 60% (n = 139 TPC)] and 292 had known BRCA1/2 mutation status [63% (n = 149 SG) versus 61% (n = 143 TPC)]. Median progression-free survival in SG- versus TPC-treated patients was 6.9, 5.6, and 2.7 months versus 2.5, 2.2, and 1.6 months for high, medium, and low Trop-2 expression, respectively. Median overall survival (14.2, 14.9, and 9.3 months versus 6.9, 6.9, and 7.6 months) and objective response rates (44%, 38%, and 22% versus 1%, 11%, and 6%) were numerically higher with SG versus TPC in patients with high, medium, and low Trop-2 expression, respectively. Efficacy outcomes were numerically higher with SG versus TPC in patients with and without germline BRCA1/2 mutations. CONCLUSIONS: SG benefits patients with previously treated mTNBC expressing high/medium Trop-2 compared with standard-of-care chemotherapy and regardless of germline BRCA1/2 mutation status. The small number of patients with low Trop-2 expression precludes definitive conclusions on the benefit of SG in this subgroup.