Real-World Performance of a Comprehensive Genomic Profiling Test Optimized for Small Tumor Samples

PURPOSE

Tissue-based comprehensive genomic profiling (CGP) is increasingly used for treatment selection in patients with advanced cancer; however, tissue availability may limit widespread implementation. Here, we established real-world CGP tissue availability and assessed CGP performance on consecutively received samples.

MATERIALS AND METHODS

We conducted a post hoc, nonprespecified analysis of 32,048 consecutive tumor tissue samples received for StrataNGS, a multiplex polymerase chain reaction (PCR)-based comprehensive genomic profiling (PCR-CGP) test, as part of an ongoing observational trial (NCT03061305). Sample characteristics and PCR-CGP performance were assessed across all tested samples, including exception samples not meeting minimum input quality control (QC) requirements (< 20% tumor content [TC], < 2 mm2 tumor surface area [TSA], DNA or RNA yield < 1 ng/µL, or specimen age > 5 years). Tests reporting ≥ 1 prioritized alteration or meeting TC and sequencing QC were considered successful. For prostate carcinoma and lung adenocarcinoma, tests reporting ≥ 1 actionable or informative alteration or meeting TC and sequencing QC were considered actionable.

RESULTS

Among 31,165 (97.2%) samples where PCR-CGP was attempted, 10.7% had < 20% TC and 59.2% were small (< 25 mm2 tumor surface area). Of 31,101 samples evaluable for input requirements, 8,089 (26.0%) were exceptions not meeting requirements. However, 94.2% of the 31,101 tested samples were successfully reported, including 80.5% of exception samples. Positive predictive value of PCR-CGP for ERBB2 amplification in exceptions and/or sequencing QC-failure breast cancer samples was 96.7%. Importantly, 84.0% of tested prostate carcinomas and 87.9% of lung adenocarcinomas yielded results informing treatment selection.

CONCLUSION

Most real-world tissue samples from patients with advanced cancer desiring CGP are limited, requiring optimized CGP approaches to produce meaningful results. An optimized PCR-CGP test, coupled with an inclusive exception testing policy, delivered reportable results for > 94% of samples, potentially expanding the proportion of CGP-testable patients and impact of biomarker-guided therapies.

Improved tolerability of neratinib in patients with HER2-positive early-stage breast cancer: the CONTROL trial

BACKGROUND

Neratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for extended adjuvant treatment in early-stage HER2-positive breast cancer based on the phase III ExteNET study. In that trial, in which no antidiarrheal prophylaxis was mandated, grade 3 diarrhea was observed in 40% of patients and 17% discontinued due to diarrhea. The international, open-label, sequential-cohort, phase II CONTROL study is investigating several strategies to improve tolerability.

PATIENTS AND METHODS

Patients who completed trastuzumab-based adjuvant therapy received neratinib 240 mg/day for 1 year plus loperamide prophylaxis (days 1-28 or 1-56). Sequential cohorts evaluated additional budesonide or colestipol prophylaxis (days 1-28) and neratinib dose escalation (DE; ongoing). The primary end point was the incidence of grade ≥3 diarrhea.

RESULTS

Final data for loperamide (L; n = 137), budesonide + loperamide (BL; n = 64), colestipol + loperamide (CL; n = 136), and colestipol + as-needed loperamide (CL-PRN; n = 104) cohorts, and interim data for DE (n = 60; completed ≥six cycles or discontinued; median duration 11 months) are available. No grade 4 diarrhea was observed. Grade 3 diarrhea rates were lower than ExteNET in all cohorts and lowest in DE (L 31%, BL 28%, CL 21%, CL-PRN 32%, DE 15%). Median number of grade 3 diarrhea episodes was one; median duration per grade 3 episode was 1.0-2.0 days across cohorts. Most grade 3 diarrhea and diarrhea-related discontinuations occurred in month 1. Diarrhea-related discontinuations were lowest in DE (L 20%, BL 8%, CL 4%, CL-PRN 8%, DE 3%). Decreases in health-related quality of life did not cross the clinically important threshold.

CONCLUSIONS

Neratinib tolerability was improved with preemptive prophylaxis or DE, which reduced the rate, severity, and duration of neratinib-associated grade ≥3 diarrhea compared with ExteNET. Lower diarrhea-related treatment discontinuations in multiple cohorts indicate that proactive management can allow patients to stay on neratinib for the recommended time period. CLINICALTRIALS.GOV: NCT02400476.

A randomized, double-blind, placebo-controlled, dose ranging study to assess the efficacy and safety of eltrombopag in patients receiving carboplatin/paclitaxel for advanced solid tumors

OBJECTIVES

Eltrombopag, an oral, nonpeptide thrombopoietin receptor agonist, has been shown to increase platelet counts in adults with chronic immune thrombocytopenia and chronic hepatitis C. This multicenter phase 2 study assessed the efficacy and safety of eltrombopag in patients receiving first-line carboplatin/paclitaxel for the treatment of advanced solid tumors.

RESEARCH DESIGN AND METHODS

Patients (N = 183) were randomized to placebo or eltrombopag 50 mg, 75 mg, or 100 mg given orally following chemotherapy on days 2 through 11 of each 21-day cycle, for at least two cycles. The primary endpoint was the difference in platelet count from day 1 in cycle 2 to the platelet nadir in cycle 2.

CLINICAL TRIAL REGISTRY NUMBER

NCT00102726.

RESULTS

Although the primary endpoint was not met, postnadir platelet counts increased during cycles 1 and 2 in all eltrombopag treatment groups compared with placebo. The most commonly reported adverse events across all study arms (including placebo) were nausea and alopecia and eltrombopag was generally well tolerated.

CONCLUSIONS

This study provides preliminary information that eltrombopag does increase platelets in patients receiving chemotherapy for advanced solid tumors. Further investigation is needed to identify the optimal dose(s) and schedule of eltrombopag in patients receiving myelosuppressive chemotherapy.

Hepatobiliary (HB) safety of eltrombopag administered after carboplatin+paclitaxel (Carb+Pac) in patients (pts) with solid tumors

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Background: Eltrombopag is an oral, small molecule, non-peptide, TPO-receptor agonist studied for the treatment of thrombocytopenia (TCP) due to various causes, including chemotherapy (CT)-induced TCP and is approved for the treatment of chronic ITP in the US. Since eltrombopag is excreted primarily through the liver and liver function is an important safety parameter, HB lab values and AEs were analyzed in a double-blind, placebo (pbo)-controlled, multicenter ph II study. Methods: The safety of eltrombopag was evaluated in adults with advanced solid tumors (mainly NSCLC and ovarian). Pts received up to 8 cycles of Carb (AUC 5–6 IV) + Pac (175–225 mg/m2 IV), both administered on day 1 q 21 days. 183 pts were randomized to eltrombopag 50, 75, 100mg, or pbo (1:1:1:1). Eltrombopag or pbo were taken from Day 2 - 11 in each cycle of CT. Results: Baseline characteristics, prior medical conditions and number of CT cycles during the study were similar between the treatment groups. At baseline, one pt reported liver metastases (75mg group). Similar numbers of pts had HB lab abnormalities in all groups ( table ). Additionally, HB AEs (34 AEs) occurred in 15 pts across all treatment groups ( table ). Conclusions: In this study, eltrombopag did not increase the incidence of HB AEs or HB lab abnormalities compared to pbo.

[Table: see text]

[Table: see text]