Top ASCO Abstracts 2017

The American Society of Clinical Oncology’s annual meeting is an excellent opportunity to learn about and assess new developments in cancer treatment. The staff of Cleveland Clinic Cancer Center’s Department of Hematology and Medical Oncology has compiled the following list of the top abstracts from ASCO 2017 that our physicians consider to be the most intriguing, the most clinically relevant, or that have the greatest potential to change the practice of clinical oncology in the near future.

Abstract No. LBA9008

Alectinib Versus Crizotinib in Treatment-Naive Advanced ALK-Positive Non-Small Cell Lung Cancer (NSCLC): Primary Results of the Global Phase III ALEX Study

Comment: Daily crizotinib has been the standard of care for advanced, ALK-gene-fusion-positive non-small cell lung cancer (ALK+ NSCLC) since its approval in 2011, with the second-generation ALK inhibitor alectinib approved for patients who develop resistance to crizotinib. In this randomized phase III trial in first-line treatment of ALK+ NSCLC, alectinib showed superiority over crizotinib, with a progression-free survival (PFS) hazard ratio of 0.47 (median PFS 25 months versus 10 months for crizotinib), with increased control of brain metastases and significantly less toxicity. Alectinib should now be considered the new standard of care for first-line ALK+ NSCLC.

Abstract No. LBA5003

Adding Abiraterone for Men with High-Risk Prostate Cancer (PCa) Starting Long-Term Androgen Deprivation Therapy (ADT): Survival Results From STAMPEDE (NCT00268476)

Comment: Abiraterone offers a survival advantage for patients with castration-refractory prostate cancer. This randomized controlled trial assessed whether patients with PCa would also benefit. The adjusted HR was 0.63 (95% CI 0.52-0.76; P = 0.115×10-7) for ADT + AA/P versus ADT alone. Three-year overall survival (OS) improved from 76 to 83 percent. Results demonstrate a clinically and statistically significant effect on overall and failure-free survival, and a manageable increase in toxicity, in patients who begin abiraterone along with standard-of-care ADT. Abiraterone and ADT should now be considered standard of care for patients with PCa.

Abstract No: LBA3

LATITUDE: A Phase III, Double-Blind, Randomized Trial of Androgen Deprivation Therapy with Abiraterone Acetate plus Prednisone or Placebos in Newly Diagnosed High- Risk Metastatic Hormone-Naive Prostate Cancer

Comment: The current standard of care for high-risk metastatic hormone-naive prostate cancer is based on volume of metastatic disease (low vs. high) and includes androgen deprivation therapy (ADT) alone (low-volume) or in combination with upfront docetaxel-based chemotherapy (high-volume). LATITUDE evaluated the addition of the novel oral CYP-17 inhibitor abiraterone acetate/prednisone (AA/P) to standard ADT. The adjusted HR was 0.62 (95% CI 0.51-0.76; P < 0.0001) for ADT + AA/P versus ADT/placebo. Median OS was 34.6 months for ADT/placebo. At the time of presentation, the median OS for the ADT + AA/P arm was not reached.

Abstract No. LBA1

Prospective Pooled Analysis of Six Phase III Trials Investigating Duration of Adjuvant (Adjuv) Oxaliplatin-Based Therapy (3 vs 6 Months) for Patients (Pts) with Stage III Colon Cancer (CC): The IDEA (International Duration Evaluation of Adjuvant Chemotherapy) Collaboration

Comment: This study investigated whether shortening the duration of adjuvant therapy with oxaliplatin-based regimens from the standard six to three months was feasible. The findings of this complex study design indicate improved toxicity with the shorter regimen but with a relative loss of efficacy, particularly for high-risk subgroups.

Abstract No. 4006

Adjuvant Capecitabine for Biliary Tract Cancer: The BILCAP Randomized Study

Comment: This study demonstrated a statistically significant improvement in OS compared to observation following radical surgery. The results show an impressive improvement in median survival with six months of adjuvant capecitabine, and this study creates a new treatment paradigm in this disease.

Abstract No. 9503

REGN2810: A Fully Human Anti-PD-1 Monoclonal Antibody, for Patients with Unresectable Locally Advanced or Metastatic Cutaneous Squamous Cell Carcinoma (CSCC) — Initial Safety and Efficacy from Expansion Cohorts (ECs) of Phase I Study

Comment: Although this is a very early report, it is the first evidence that PD-1 inhibitors may have a role in the management of advanced CSCC. The overall response (52 percent) and disease control rates (70 percent) observed in this small study are excellent, and it is possible that the responses achieved are durable. Further study is underway, but if the results are confirmatory, this drug and this class of agents will prove important in the management of this disease.

Abstract No. LBA4

OlympiAD: Phase III Trial of Olaparib Monotherapy Versus Chemotherapy for Patients (Pts) with HER2-Negative Metastatic Breast Cancer (mBC) and a Germline BRCA Mutation (gBRCAm)

Comment: This randomized, open-label study assessed the efficacy and safety of olaparib in comparison with a single-agent chemotherapy chosen by the treating physician. This study is the first in which PARP inhibitors show an improvement in PFS for metastatic breast cancer patients with gBRCAm. The results of this trial could potentially change the treatment paradigm for patients with BRCA-mutated breast cancer.

Abstract No. LBA500

APHINITY Trial (BIG 4-11): A Randomized Comparison of Chemotherapy (C) plus Trastuzumab (T) plus Placebo (Pla) Versus Chemotherapy plus Trastuzumab (T) plus Pertuzumab (P) as Adjuvant Therapy in Patients (Pts) with HER2-Positive Early Breast Cancer (EBC).

Comment: This trial assessed whether the addition of pertuzumab to adjuvant trastuzumab plus chemotherapy improved patient outcomes. Dual HER2 blockade in adjuvant setting with trastuzumab and pertuzumab showed only marginal benefit. Adjuvant pertuzumab should not be recommended to every HER2-positive breast cancer patient. In the adjuvant setting, it should be offered only to high-risk patients such as ER/PR negative and node positive, or to patients with multiple lymph nodes positive. Even in the neoadjuvant setting, we should limit the use of pertuzumab to high-risk patients. Low risk, ER-positive patients, especially early stage, should not receive pertuzumab.