Abstract A167: Targeting HER2 (ERBB2) amplification identified by next-generation sequencing (NGS) in patients with advanced or metastatic solid tumors

Introduction: Personalized cancer treatment is becoming more tumor agnostic by choosing a treatment based on the tumor genomics rather than the tumor type. HER2 is an effective therapeutic target with FDA-approved treatments in breast and gastric/gastroesophageal junction (GEJ) cancers; however, less is known about the efficacy of HER2-targeted treatment in other tumor types. Methods: Next-generation sequencing (NGS) was performed in 2221 patients (pts) with advanced solid tumors in CLIA-certified laboratories using multiple platforms for personalized cancer therapy. HER2 amplification (amp) was assessed by NGS platforms that report copy-number variations as per their respective algorithm. We assessed clinical characteristics and coalterations with HER2 amp. We evaluated the clinical benefit of HER2-targeted therapy, by measuring the progression-free survival (PFS) on HER2-matched targeted therapy (PFS2) compared to the PFS on prior therapy (PFS1). We also evaluated the response rate and overall survival (OS) of pts who received vs pts who did not receive HER2-targeted therapy. Results: A total of 122 pts (5.5%) were found to have HER2 amp. The most frequent tumor types were colorectal, biliary/gallbladder, gastric/gastroesophageal, esophageal, endometrial, head and neck squamous cell and salivary gland, non-small cell lung, and bladder cancers. Coalterations included mutations in TP53, APC, PIK3CA, LRP1B, NF1, KRAS, mutations and deletions in CDKN2A, and amp in MYC and CCNE1. Frequent amp in CDK12, RARA, and TOP2A amp (all within chromosome 17q) were also found in our pts. Concurrent mutations in HER2 were found in 16 pts (13%). Forty pts with HER2 amp on NGS also underwent HER2 IHC testing: 30 pts (75%) had overexpression (3+), 4 pts (10%) had equivocal expression (2+), 2 pts (5%) had low expression (1+), and 4 pts (10%) had no HER2 expression. FISH analysis was performed in 14 patients, out of which 12 patients were positive for amplification. Forty-four of 115 pts received at least 1 line of HER2-targeted therapy (range 1-4) with 42 pts receiving trastuzumab in combination with other drugs, including 11 (92%) of 12 pts with gastric, GEJ cancers with HER2 amp having received trastuzumab with chemotherapy (8 pts in the first line). Median OS of pts who received HER2-targeted therapy was 42 months vs 23 months for pts who did not receive HER2-targeted therapy (Hazard Ratio [HR] 0.6, 95% CI 0.38-0.97, p=0.0384). For 32 evaluable pts, PFS2/PFS1 ratio was ≥1.3 in 17 pts (53%) and ≥2 in 11 pts (34%) with median PFS2 of 23 weeks vs PFS1 of 11 weeks (p=0.0089). After exclusion of pts with gastric or GEJ cancers, pts receiving HER2-targeted therapy still had an improved OS (53 vs 23 months) (HR 0.56, 95% CI 0.33-0.93, p=0.0307) and the PFS2/PFS1 ratio was ≥1.3 in 15 (52%) of 29 pts with a median PFS2 of 23 weeks vs PFS1 of 12 weeks (p=0.0174). Conclusion: NGS reveals HER2 amp in a clinically relevant proportion of tumors and in a variety of tumor types. HER2-targeted therapy may confer clinical benefit in tumor types beyond those for which HER2 inhibitors are approved. The association of HER2 amp with genomic alterations in other oncogenic drivers provides rationale for novel therapeutic combinations.

Citation Format: Ecaterina Ileana Dumbrava, Kavitha Balaji, Kanwal Raghav, Milind Javle, Mariela Blum-Murphy, Blessy Sajan, Scott Kopetz, Russell Broaddus, Mark Routbort, Shubham Pant, Apostolia Tsimberidou, Vivek Subbiah, David S. Hong, Jordi Rodon Ahnert, Kenna Shaw, Sarina Piha-Paul, Funda Meric-Bernstam. Targeting HER2 (ERBB2) amplification identified by next-generation sequencing (NGS) in patients with advanced or metastatic solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A167.

Abstract A76: Prospective evaluation of two-phase NGS platform coupled to active precision oncology decision support in the therapeutic management of patients with advanced cancers

Background: We initiated a prospective, institution-wide study to determine whether genomic testing with a 409-gene panel in solid tumors can identify new actionable genomic information (beyond that identified by smaller hot-spot panels) and lead to enrollment in genotype matched trials using agents relevant to the alteration(s) identified when coupled with robust decision support tools.

Methods: Eligible patients (pts) had no remaining standard of care therapy anticipated to extend life by more than 3 months, ECOG performance status of ≤ 1, and a willingness to consider clinical trial enrollment. The patients' tumors were initially sequenced using a hotspot panel (predominantly a 50-gene panel, Life Technology, Ion Torrent), and if no actionable alterations were found, then tumor and paired germline were sequenced with a 409-full-length (Ion Proton) gene panel. Actionable genes were defined as those for which a matched genotype selected trial exists in the institution.

Results: 471 pts across more than 30 tumor types were consented and underwent 409-gene testing. Data for each mutation, relevant therapeutic agents and corresponding clinical trials were annotated. Each variant was annotated for the level of evidence that associated a specific alteration in a potentially actionable cancer gene with a potential therapeutic opportunity with appropriate references. Specific mutations, copy number variants and fusions were linked to targeted agents, clinical trials, and functional data. Data were distributed via a publicly accessible website, reports and proactive clinical trial alert notifications. Alterations in a potentially actionable gene were found in 48.0% of patients. Novel alterations in an actionable gene not found on a previous hot-spot panel were found in 36.9% of pts (174 pts). Of the 434 mutations found in actionable genes in these 174 pts, the specific variant in the gene was of known activity based on existing literature in only 17%; for 41% the variant was of unknown significance. Approximately one-quarter of patients with mutations in actionable genes were enrolled on clinical trials using matched-therapies during the period of data review. Reasons for non-enrollment were the treating physician's opinion that there was insufficient evidence for the functional significance of the variant, exclusion criteria or lack of available slots, or other reasons including pt choice.

Conclusions: A significant population of patients with variants in potentially actionable cancer genes not evaluated in a traditional hot-spot cancer gene panel can be identified using a 409-gene targeted gene panel. The high number of variants of unknown significance represents a knowledge gap of clinical importance. While a number of factors contribute to bottlenecks in utilizing the expanded sequencing results, expanded genomic testing combined with robust decision support can facilitate trial enrollment.

Citation Format: Kenna R. Shaw, Scott Kopetz, Vijaykumar Holla, Beate C. Litzenburger, Walter Kinyua, Blessy Sajan, J. Jack Lee, Russell Broaddus. Prospective evaluation of two-phase NGS platform coupled to active precision oncology decision support in the therapeutic management of patients with advanced cancers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A76.

Abstract B17: Phase I prevention study of atorvastatin in women at increased risk for breast cancer

Background: Currently FDA approved chemopreventive agents for breast cancer risk reduction include the selective estrogen receptor modulators (SERMs) tamoxifen and raloxifen. However, acceptance amongst high risk women is low due to side effects that include thromboembolic events, uterine cancer and menopausal symptoms. Furthermore, SERMs only reduce the incidence of estrogen receptor (ER) negative breast cancer. Therefore, agents with a favorable toxicity profile that reduce incidence of ER negative and ER positive breast cancer are urgently needed. Atorvastatin is a statin that inhibits 3-hydroxy-3-methylglutaryl-coenzyme A (HMGcoA) reductase. Observational studies have demonstrated a decreased incidence of cancers among users of HMG CoA reductase inhibitors and a reduced risk of recurrence among statin users diagnosed with early stage breast cancer. In animal models, statins have been shown to be also effective against ER negative breast cancer. The aim of this study was to evaluate atorvastatin's potential chemopreventive effect by first demonstrating changes in breast cancer risk biomarkers in women at increased risk for breast cancer.

Methods: High risk patients were randomized 1:1:1:1 to daily 10mg, 20mg, or 40mg Atorvastatin for 3 months, or to no treatment. High risk was defined as having a previous history of ductal carcinoma insitu (DCIS), lobular carcinoma insitu (LCIS), or atypical hyperplasia, or life time breast cancer risk greater than 20% by models including Gail, Claus, Tyrer-Cuzick, Boadicea, or BRCAPRO. All patients underwent baseline and 3 months blood collection and fine needle aspiration (FNA) of the breast for analysis of modulation in biomarkers. Biomarkers to be examined included in the blood: CRP, lipid profile, levels of atorvastatin, HMGcoA genotype and in breast FNA samples: Cytology, Ki 67, EGFR, bcl-2, CC3, and LXR evaluated by immunohistochemistry.

Results: Between 2008 and 2012, 66 high risk women were randomized and 60 completed the study. Mean age was 51.8 years (range 27-69). One patient in the 20 mg arm experienced grade 3 toxicity (myalgia) that was not study drug related; 5 patients in the control arm, 6 in the 10mg, 9 in the 20mg and 4 in the 40 mg arm experienced grade 2 toxicity; only minority of them related to the study drug (arthraligia, myalgia, skin rash); 2 patients in the control arm, 3 in the 10 mg, 4 in the 20mg and 12 in the 40mg arm experienced grade 1 toxicity; only 10% of them possibly related to the study drug (arthralgia, myalgia, diarrhea, skin rash).

Conclusion: Compliance during our atorvastatin phase I biomarker modulation study was very good. Atorvastatin was well tolerated with minority of the patients experiencing side effects, most of which were not related to the study drug. Biomarker analysis is ongoing and will be presented. This study was supported by the NCI N01CN35159 award.

Citation Format: Banu Arun, Yun Gong, Diane Liu, Jennifer Litton, Angelica Gutierrez-Barrera, Blessy Sajan, Jack j. Lee, Lana A. Vornik, Terri Cornelison, Gabriel N. Hortobagyi, Scott Lippman, Powel H. Brown, nour Sneige. Phase I prevention study of atorvastatin in women at increased risk for breast cancer. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr B17.

A Phase 1 Study To Assess the Safety, Tolerability and Pharmacokinetics of ARRY-380 – An Oral Inhibitor of HER2

Background: ARRY-380 is a potent, orally active small molecule that selectively inhibits HER2 signaling in vitro and in vivo and significantly inhibits tumor growth in a variety of HER2-dependent tumor xenograft models. Based on its preclinical activity, tolerability and pharmacokinetic (PK) profile, a Phase 1 study was initiated to evaluate the safety, tolerability and PK profile of ARRY-380 as a single agent in patients with solid tumors and to establish the maximum tolerated dose (MTD).Methods: Patients with HER2 positive breast cancer or other tumor types for which published evidence of HER2 expression exists were treated with ARRY-380 as a single oral dose on Cycle 1 Day 1, followed by continuous twice-daily (BID) oral dosing starting on Cycle 1 Day 3. ARRY-380 was escalated in cohorts of 3 to 4 patients, using standard dose-limiting toxicity (DLT) criteria during Cycle 1 to determine dose escalation. Serial PK assessments were made during Cycle 1 on Days 1, 2, 3 and at steady-state on Day 15.Preliminary Results: As of June 1, 2009, 15 patients have been treated in 5 dosing cohorts at doses of 25 to 300 mg BID. Patients had a median age of 61 years (range, 37-77 years) and ECOG PS of 0 to 2. Cancer types included HER2+ breast cancer (8), colorectal (6) and salivary gland (1). No DLTs have been observed and drug-related adverse events have included Grade 1 nausea, rash and fatigue and Grade 2 fatigue in 2 patients at the 200 mg BID dose level. Preliminary PK analyses indicate a trend for increasing Cmax and AUC with increasing dose, a median Tmax of 2 hours and a mean t1/2 of 4.6 hours across all cohorts. Two patients with HER2+ breast cancer have had stable disease for ≥ 4 months with no significant toxicity. One of these two patients had a notable reduction in liver metastases (28%) after 2 cycles of ARRY-380 and is currently on study.Conclusions: ARRY-380 has demonstrated an acceptable safety and PK profile and preliminary signs of clinical benefit. Dose escalation continues to determine the MTD.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5111.