Association of Timely Comprehensive Genomic Profiling With Precision Oncology Treatment Use and Patient Outcomes in Advanced Non-Small-Cell Lung Cancer

PURPOSE

Timely biomarker testing remains out of reach for many patients with advanced non-small-cell lung cancer (aNSCLC). Here, we studied the quality-of-care implications of closing the gap in timely receipt of comprehensive genomic profiling (CGP) to inform first-line (1L) decisions.

METHODS

Using a real-world clinicogenomic database, we studied testing and 1L treatment patterns in aNSCLC after the approval of pembrolizumab in combination with pemetrexed and carboplatin (May 10, 2017). To estimate the association of timely CGP results with therapy selection and patient outcomes, we identified patients with no previous genomic testing beyond PD-L1 immunohistochemistry and dichotomized patients by whether CGP results were available before or after 1L therapy initiation.

RESULTS

In total, 2,694 patients were included in the 1L therapy decision impact assessment. Timely CGP increased matched targeted therapy use by 14 percentage points (17% with CGP v 2.8% without) and precision immune checkpoint inhibitor (ICPI) use by 14 percentage points (18% with CGP v 3.9% without). Receipt of timely CGP resulted in an estimated 31 percentage point decrease in ICPI use among ALK/EGFR/RET/ROS1-positive patients at an expected per-patient reduction in ineffective ICPI therapy cost of $13,659.37 with timely CGP to inform 1L treatment selection. Patient benefit of CGP extended to real-world time to therapy discontinuation (median time to therapy discontinuation: 3.9 v 10 months [hazard ratio, HR, 0.54 [95% CI, 0.42 to 0.70]; P = 1.9E-06; adjusted hazard ratio [aHR], 0.50 [95% CI, 0.38 to 0.67]; P = 2.0E-06) in 1L driver-positive patients. This effect was not significant for real-world overall survival (median overall survival: 32 v 29 months [HR, 1.2 [95% CI, 0.84 to 1.67]; P = .33; aHR, 1.4 [95% CI, 0.92 to 1.99]; P = .12).

CONCLUSION

Timely CGP is associated with the quality of patient care as measured by 1L matched targeted therapy use, time to therapy discontinuation, and avoidance of ineffective, costly ICPIs.

Abstract P5-13-16: A real-world assessment of PIK3CA testing and alpelisib treatment patterns among metastatic breast cancer patients in a community oncology setting

Background: Alpelisib (PIQRAY®) in combination with fulvestrant was approved by the US- FDA in May of 2019 for patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) PIK3CA mutant advanced or metastatic breast cancer (aBC or mBC) following progression on aromatase inhibitors. Prior to the US-FDA approval of alpelisib, routine molecular profile testing for this patient population was not supported by NCCN guidelines. Thus, data on the natural history of HR+/HER2- mBC patients, particularly in terms of biomarker testing and treatment patterns in a real-world patient setting, are limited. To understand integration of alpelisib into clinical practice for this patient population, this retrospective non-interventional study assessed biomarker testing, treatment patterns, and patient characteristics for patients at Texas Oncology (TxO) from 2015 to 2020.Methods: The study index date was defined as the first date of a new diagnosis of advanced BC (de novo or recurred mBC) between January 2015 and June 2020 with a minimum follow-up opportunity of 6 months follow-up. Treatment patterns were assessed until December 2020, allowing assessment of alpelisib real-world utilization post the US-FDA approval. Databases curated included the EMR (iKM), the TxO Precision Medicine (PM) Molecular databases. Information mined included total number of mBC patients, HR and HER2 status, and the presence and classification of PIK3CA mutations. Treatment patterns were also examined. Results: Study cohort consisted of 1093 patients for whom PIK3CA, HR, HER2 status and systemic treatment were known. Of these, 768 (70%) were HR+/HER2-, 220 (20%) were HR-/Her2HER2-, 73 (7%) were HR+/Her2HER2+ and 32 (3%) were HR-/Her2HER2+. Among all subtypes, 410 (38%) were PIK3CA mutant, and within HR+/HER2- cohort, 333 (43%) were PIK3CA mutant. Of the 105 patients treated with alpelisib, 102 (97%) were treated after drug approval, and the remaining 3 patients (3%) received alpelisib via compassionate use program. Within the HR+/HER2-/PIK3CA mutant patient cohort (n=333), 97 (29%) were treated with alpelisib. The most frequent alpelisib-containing regimen is alpelisib+fulvestrant, given to 84 (87%) of patients. It is most frequently given as a second- (n=28, 29%), third- (n=16, 16%) and fourth-line (n=16, 16%) lines of therapy. Out of 97 patients, 69 (71%) were treated previously with a cyclin-dependent kinase 4/6 inhibitor. The median duration of alpelisib therapy was 4.6 months. As of December 30, 2020, 34 of the 97 patients had treatment with alpelisib ongoing, 24 expired, 14 were referred to hospice,18 completed last recorded line of therapy prior to study end date, and 7 patients progressed to the next line of therapy. There was no noteworthy difference in patients treated vs. not treated with alpelisib with respect to age (mean 61.5 vs. 59.3 yrs.) or performance status (Karnofsky) (29% vs. 25% at 100%, 42% vs. 49% at 90% respectively). In PIK3CA mutant cancers, the most frequent PIK3CA mutations were H1047R, E545K, E542K, N345K and H1047L, and 43 (10%) had 2 or more mutations. Patient outcomes including the median progression free survival was also determined for this cohort and will be reported. Conclusions: This retrospective study demonstrates that 38% of mBC patients’ cancers across all sub-types harbored a PIK3CA mutation where multiple testing platforms were utilized in the community setting. Approximately 30% of patients with HR+/HER2-/PIK3CA mutant status did receive alpelisib. Co-morbidities and other clinically relevant factors between PIK3CA mutant patients who did and did not receive alpelisib, such as those on oral diabetes medication, insulin or had elevated HgbA1c, should be studied further.

Citation Format: Joyce O'Shaughnessy, MD, Steven Paulson, MD, Lorraine Brisbin, M.S, James Lindsey, Anna Williford, Ph.D, Monica Lisi, Rohan C. Parikh, Ph.D, Stacey Simmons, MD and Sanjeev Balu, Ph.D. A real-world assessment of PIK3CA testing and alpelisib treatment patterns among metastatic breast cancer patients in a community oncology setting [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-16.

Frequency distribution of SPARC in triple-negative breast cancer patients

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Background: SPARC (secreted protein acid rich in cysteine) belongs to a group of extracellular matrix proteins and promotes adhesion of cells from the matrix. It plays an important role in tumor development in breast cancer and has a significant bearing on patient prognosis and long term survival. It is also known to predict response to nab-paclitaxel in certain tumor types including breast cancer. In 2005, FDA approved a solvent free formulation of paclitaxel for the treatment of metastatic breast cancer that utilizes albumin bound (nab) technology (nab-paclitaxel). Clinical studies have shown that nab-paclitaxel is significantly more effective than paclitaxel. Our study evaluated the frequency distribution of SPARC among triple negative breast cancer patients in which identification of a novel therapeutic target is warranted.

Methods: In a total of 951 breast cancer patients, we analyzed tumor SPARC expression by immunohistochemistry (IHC) using a monoclonal (R&D Systems) and a polyclonal antibody (Exalpha Biologicals). Immunoreactivity was assessed by scoring the percentage of cells stained in each field and by the intensity of staining. A cutoff point of 2+ and >30% stained tumor cells were considered as positive.

Results: From our analysis of 951 breast cancer patients profiled, a total of 165 patients (17%) were triple negative for ER, PR and HER2. Within this pathologic subtype, 29% patients stained positive with SPARC monoclonal antibody and 21% stained positive with SPARC polyclonal antibody. The correlation of SPARC tumor staining with hormone receptor status will be presented in detail.

Conclusions: We conclude that SPARC over-expression is a functionally important feature of a subset of triple negative breast cancer patients. The triple negative subset of tumors generally has a more aggressive clinical course and does not benefit from conventional targeted therapies. Our study suggests that nab-paclitaxel may serve as a therapeutic agent for the subset of triple negative patients that over-express SPARC. To the best of our knowledge, this is the first study involving a large patient pool in which SPARC has been investigated in a single clinical laboratory using standardized IHC with two different SPARC antibodies.

A modified ultrasensitive assay to detect quantified HIV-1 RNA of fewer than 50 copies per milliliter

We compared the sensitivity and specificity of versions 1.0 and 1.5 and a modified version 1.5 of the AMPLICOR HIV-1 MONITOR ultrasensitive RNA assay (Roche, Indianapolis, IN) by using a virus stock dilution series and plasma samples from HIV-1-infected and uninfected subjects. The modified assay was linear and consistently positive down to 12 copies per milliliter vs 25 copies per milliliter for the other 2 assays. Versions 1.0, 1.5, and modified 1.5, respectively, detected 9 (23%) of 39, 11 (28%) of 40, and 43 (61%) of 71 replicates of a 4-copy-number and 11 (28%) of 40, 17 (46%) of 37, and 88 (90%) of 98 replicates of a 10-copy-number standard. Of 44 patient samples with undetectable levels using version 1.0, 32 (73%) had detectable levels on the modified assay, and 5 (25%) of 20 had detectable levels on version 1.5. None of the assays detected HIV-1 RNA in HIV-1 antibody-negative samples. The modified version 1.5 of the RNA assay is more sensitive for detecting HIV-1 RNA in significantly more patients than are versions 1.0 and 1.5.