Clinical implications for patients with discordant oncotype and MammaPrint results

560

Background: Genomic tests provide critical information regarding risk of recurrence and inform treatment plans by identifying those patients who may safely forgo chemotherapy (CT) or shorten endocrine therapy (ET) duration. The IMPACT trial demonstrated that the 70 -gene risk of recurrence assay MammaPrint (MP) and 80-gene subtyping assay BluePrint (BP) inform treatment planning and increase physician confidence. However, not all genomic tests yield the same results. To examine consistency among genomic tests, we analyzed therapy implications for patients who received results from both MP/BP and Recurrence Score (RS). Methods: Using the FLEX cohort (NCT03053193), we examined 723 patients who received both MP/BP, and RS genomic assays. We assessed the potential clinical impact by examining the standardized reports of RS and MP/BP results. MP classified tumors as either ultralow, low, or high risk and BP further classified them as luminal, basal, or HER2. RS classified tumors as low (RS0-10), intermediate (RS11-25), or high (RS26-100). Clinical impact was defined as discordant genomic resulting in different treatment recommendations. Undertreatment indicates patients who may not have received CT based on RS but may have based on MP/BP and overtreatment those patients who would have received CT based on RS, but not based on MP/BP. ET duration too long is indicative of those patients that are ultralow risk by MP, regardless of RS classification, as those patients may have safely reduced the duration of their ET. Although outcomes are not available, treatment impacts are presuming a patient received both tests, but the treating physician opted to guide therapy according to the RS results rather than MP/BP. Results: We observed discordant results with a clinical impact in 49% (354) of patients, with 34% (244) who may be undertreated, 2% (11) potentially overtreated, and 14% (99) who may not be given the option to decrease ET to two years based on ultralow MP genomic risk. Of 114 concordant High-Risk tumors, 14% (16) were genomically Basal, and likely to require more aggressive CT than typically used in ER+ cancers. The table below summarizes the results. Conclusions: More than half of the patients in this cohort were at potential risk for undertreatment or overtreatment. The risk to patients is far more significant in the event of undertreatment, as this may result in incurable metastatic recurrence. Discordance between RS and MP/BP most often results in potential undertreatment if RS is used for treatment decision-making. Clinical trial information: NCT03053193.

Whole transcriptome analysis of tumors with discordant oncotype and MammaPrint results in the FLEX trial

556

Background: Genomic tests, such as MammaPrint (MP) and Oncotype DX Breast Recurrence Score (RS), assess risk of recurrence in patients with early breast cancer (EBC). Using both assays may yield discordant results which leads to uncertainty in treatment recommendations. The assays differ in technology and genes analyzed. RS relies on RT-PCR to query 16 cancer-related genes and 5 controls. MP uses a microarray to query 70 cancer-related genes and 465 normalization controls. Here we explore the genetic basis for discordance by using the FLEX whole transcriptome database to examine differentially expressed genes among patients who received discordant RS and MP results. Methods: Patients with EBC enrolled in the FLEX study (NCT03053193) undergo standard of care MP and BluePrint (BP) tests, and consent to clinically annotated whole transcriptome data collection. MP stratifies risk of recurrence as Low risk and High. RS classifies patients as Low Risk (RS 0-10), Intermediate (RS 11-25), and High Risk (RS 26-100). Due to low representation of BP Basal and BP HER2-type tumors in this data set, we only examined BP Luminal-type tumors (N = 705). We used full genome transcriptomes to compare gene expression among discordant cases. Gene expression data were quantile normalized and analyzed using R package ‘limma’. Genes were considered differentially expressed at a fold change of at least 1.7 and an adjusted p-value of lower than 0.05. To keep the analysis as unbiased as possible, comparisons between RS categories only included tumors within the same MP score range and similarly comparisons of MP categories only contained tumors within the same RS score range. Results: The comparisons between discordant cases, their numbers and the amount of differentially expressed genes (DEGs) are shown below. Sample sizes are shown in parentheses. Of the 49 DEGs found in the RS Intermediate group, several are associated with increased proliferation or increased metastatic potential. SCUBE2 and MMP9 were among the 49 genes and are among the 70-genes assayed by MP. Conclusions: The comparisons highlight the genomic diversity of the RS Intermediate (RS11-25) group, as seen with the high number of DEGs. MP separates cases into more genomically distinct categories, as reflected by fewer DEGs. Clinical trial information: NCT03053193. [Table: see text]

A two-part, phase II, multi-center study of the ERK inhibitor ulixertinib (BVD-523) for patients with advanced malignancies harboring MEK or atypical BRAF alterations (BVD-523-ABC)

TPS3172

Background: Ulixertinib (BVD-523) is a small molecule inhibitor of extracellular signal-regulated kinases 1/2 (ERK1/2) in development as a novel anti-cancer drug. Early clinical data demonstrated anti-tumor activity, especially for patients with tumors harboring atypical BRAF or MEK1/2 alterations (Sullivan et al., Cancer Discov. 2018;8(2):184-195). Atypical BRAF (non-V600) alterations can be categorized according to characteristics of molecular signaling (Class II or III), are seen in approximately 3% of all human cancers, and there are currently no approved therapies for this indication. Similar to atypical BRAF alterations, the incidence of MEK1/2 alterations are rare in human tumors (< 1 %). Preclinical data have demonstrated activity of ulixertinib in MEK mutant models. Ulixertinib has FDA fast-track designation for patients with solid tumors, other than CRC, with specific BRAF mutations (G469A, L485W, or L597Q). Designed with intent to register, the BVD-523-ABC clinical trial will continue evaluation of ulixertinib in patients with tumors harboring any atypical BRAF or MEK1/2 alteration (NCT04488003). Methods: This multi-center, phase II study, will be conducted in two parts and assess the clinical benefit, safety, pharmacokinetics, and pharmacodynamics of ulixertinib in patients with advanced malignancies. Ulixertinib will be administered at the RP2D of 600 mg BID for 28-day treatment cycles. Eligible patients will have locally advanced or metastatic cancer which progressed following standard systemic therapies, or for which the patient is not a candidate or refused systemic therapy. Planned correlative analyses include reverse phase protein array and transcriptomics of tumor tissue. Part A is open-label and tumor agnostic, except for group 4 and 6 (CRC patients only). Patients will enroll into one of six groups based on BRAF (groups 1-4) or MEK1/2 (groups 5-6) tumor alteration (38 patients per group). Overall response rate (ORR) is the primary endpoint for Part A, with secondary endpoints including duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Part B is tumor histology specific. Patients will be randomized to receive either ulixertinib or physician's choice of treatment in a 2:1 ratio. Up to three specified tumor histologies will be defined, guided by available Part A data (n = 80-100 per histology). The primary endpoint of Part B is PFS, and secondary endpoints include OS, ORR, and DOR. This study has enrolled 43 patients of the planned 228 in Part A at the time of abstract submission. Clinical trial information: NCT04488003.

Preliminary results of the phase 2 study of zanubrutinib in patients with previously treated B-cell malignancies intolerant to ibrutinib and/or acalabrutinib

e19506

Background: Many patients (pts) with B-cell malignancies require continuous treatment with Bruton tyrosine kinase inhibitors (BTKi). Adverse events (AEs) are a common reason for ibrutinib (ibr) or acalabrutinib (acala) discontinuation. Early data from BGB-3111-215 showed zanubrutinib (zanu) was well tolerated in pts with B-cell malignancies intolerant to ibr or acala. We report preliminary results with a median follow-up of 4.2 mo. Methods: Pts meeting protocol criteria for intolerance to ibr, acala or both (without documented progressive disease) were given zanu monotherapy (160 mg twice daily or 320 mg once daily). Recurrence of AEs that led to intolerance of prior BTKi and additional safety measures were assessed based on the Common Terminology Criteria for AEs v5.0. Investigators determined responses using disease status at study entry as baseline. Results: As of November 1, 2020 (cutoff), 44 pts (n=34 chronic lymphocytic leukemia/small lymphocytic lymphoma, n=6 Waldenström macroglobulinemia, n=2 mantle cell lymphoma, n=2 marginal zone lymphoma) were enrolled, received ≥1 dose of zanu, and analyzed for safety. Median age was 70.5 y (range, 49-91); median duration of treatment was 4.2 mo (range, 0.1-12.6). Median number of prior regimens was 2 (range, 1-12). Regarding prior BTKi, 39 pts received ibr only, 4 received ibr and acala, and 1 received acala only. The median number of ibr- or acala-intolerant AEs per pt was 2 (range, 1-5). 83% of ibr and 78% of acala intolerant events did not reccur on zanu; Table. At data cutoff, 43 pts remained on treatment; 1 withdrew consent due to zanu-unrelated grade 3 syncope. Overall, 34 pts (77.3%) reported any AE; most commonly reported AEs were myalgia (n=9; 20.5%), contusion (n=8; 18.2%), dizziness (n=7; 15.9%), fatigue (n=7; 15.9%), and cough (n=5; 11.4%). Grade ≥3 AEs were reported in 6 pts (13.6%), serious AEs in 1 pt (2.3%, febrile neutropenia and salmonella infection), AEs requiring dose interruptions in 6 pts (13.6%), and AEs leading to dose reduction in 2 pts (4.5%). No AEs led to zanu discontinuation. No deaths were reported. All efficacy evaluable pts (26/26 [100%]) maintained (10 [38.5%]) or achieved deepening (16 [61.5%]) of their response. Conclusions: Zanu provides an additional treatment option after intolerance to other BTKi, demonstrating tolerability and sustained or improved efficacy. Updated results will be presented. Recurrence and Severity Change of AEs Leading to Ibr or Acala Intolerance. Clinical trial information: NCT04116437. [Table: see text]

Longitudinal trajectory of frailty and related factors in 376 breast cancer patients aged 50+ compared to controls

e21532

Background: Frailty, a clinical syndrome of vulnerability, is associated with adverse outcomes; however, the trajectory of frailty in cancer patients is not well understood. This longitudinal analysis evaluates frailty, and related factors, over the course of chemotherapy in breast cancer patients (BCa pts) aged 50+. Methods: BCa pts aged 50+ scheduled to receive adjuvant/neoadjuvant chemotherapy (n = 376) and age matched controls without cancer (n = 234) were recruited from the University of Rochester NCI Community Oncology Research Program as part of an observational study. Frailty was assessed by a modified Fried frailty score (range 0-4) using self-reported weakness, exhaustion, physical activity, and walk speed. Cognition was assessed objectively (Controlled Oral Word Association [COWA]) and subjectively (FACT-Cog). Frailty and cognition were measured pre- and post-chemotherapy (similar time lapse for controls). Linear regression models evaluated associations between cognition and frailty, controlling for age, race, marital status, education, performance status and baseline frailty score. Results: Average age was 59 (50-64: 77%; 65-79: 23%). At baseline, the cancer group had more people aged 65+ (24% vs 20%, p = 0.002), a higher mean frailty score (1.2 vs 0.73, p < 0.001), and lower mean FACT-Cog score (158.5 vs 167.4, p < 0.001) compared to controls. In unadjusted analysis, BCa pts had greater increase in frailty and cognitive problems than controls over time (mean change frailty score: cancer 0.87 vs control 0.05; mean change FACT-Cog: cancer 12.78 vs control 1.58; mean change COWA: cancer -0.41 vs control 0.43; p < 0.001 for all). In adjusted analysis, cancer (p < 0.001) and lower baseline FACT-Cog score (p = 0.01) were associated with an increase in frailty score over time. In a separate model, a decline in subjective and objective cognition was associated with increased frailty score (COWA p = 0.03, FACT-Cog p = 0.07). Conclusions: Frailty is prevalent in BCa pts prior to chemotherapy and increases during treatment. Lower baseline cognition and decline in cognition were associated with increased frailty. Frailty and cognition are important survivorship factors for BCa pts aged 50+.

Phase II trial of carboplatin, pemetrexed, and bevacizumab in metastatic nonsquamous (NSC) lung cancer

e18122

Background: The trial was designed to examine PFS, OS and toxicities of a novel 3 drug combination in advanced NSC lung cancer. The first patient was entered 3/08 and the last in 5/11. Methods: Treatment consisted of Carboplatin AUC 5,Pemetrexed %00mg/m2, Bevacizumab 15mg/kg q21d x 6 cycles; then Bev maintenaince q3wk for up to one year. Eligibile pts. had metastatic non-squamous NSC lung ca, EGOG 0-1, first line Rx. Fifty patients were entered, all available for response and toxicity analysis: 26 M, median age 64, 45 white. Results: 52% RR by RECIST (2% CR, 50% PR); 26% SD. Median PFS 24 wks; median overall survival will be in excess of 49 weeks. 62% of patients received all planned 6 cycles and went on to maintenance. Treatment was out-patient and well tolerated with modest toxicities, including 2 DVT's, one PE, one TIA and one episode of F+N Conclusions: The 3 drug combination of Carboplatin, Pemetrxed and Bevacizumab for met NSC lung cancer is effective and well tolerated; and is a resonable choice of Rx for patients with non-squamous tumors hoping to avoid more neurotoxic or myelotoxic options.