Anastrozole and everolimus in advanced gynecologic and breast malignancies: activity and molecular alterations in the PI3K/AKT/mTOR pathway

BACKGROUND

Since PI3K/AKT/mTOR pathway activation diminishes the effects of hormone therapy, combining aromatase inhibitors (anatrozole) with mTOR inhibitors (everolimus) was investigated.

PATIENTS AND METHODS

We evaluated anastrozole and everolimus in 55 patients with metastatic estrogen (ER) and/or progesterone receptor (PR)-positive breast and gynecologic tumors. Endpoints were safety, antitumor activity and molecular correlates.

RESULTS

Full doses of anastrozole (1 mg PO daily) and everolimus (10 mg PO daily) were well tolerated. Twelve of 50 evaluable patients (24%) (median = 3 prior therapies) achieved stable disease (SD) ≥ 6 months/partial response (PR)/complete response (CR) (n = 5 (10%) with PR/CR): 9 of 32 (28%) with breast cancer (n=5 (16%) with PR/CR); 2 of 10 (20%), ovarian cancer; and 1 of 6 (17%), endometrial cancer. Six of 22 patients (27%) with molecular alterations in the PI3K/AKT/mTOR pathway achieved SD ≥ 6 months/PR/CR. Six of 8 patients (75%) with SD ≥ 6 months/PR/CR with molecular testing demonstrated at least one alteration in the PI3K/AKT/mTOR pathway: mutations in PIK3CA (n=3) and AKT1 (n=1) or PTEN loss (n=3). All three responders (CR (n = 1); PR (n=2)) who had next generation sequencing demonstrated additional alterations: amplifications in CCNE1, IRS2, MCL1, CCND1, FGFR1 and MYC and a rearrangement in PRKDC.

CONCLUSIONS

Combination anastrozole and everolimus is well tolerated at full approved doses, and is active in heavily-pretreated patients with ER and/or PR-positive breast, ovarian and endometrial cancers. Responses were observed in patients with multiple molecular aberrations. CLINICAL TRAILS INCLUDED: NCT01197170.

MABp1, a first-in-class true human antibody targeting interleukin-1α in refractory cancers: an open-label, phase 1 dose-escalation and expansion study

BACKGROUND

Inflammation is an important feature of the malignant phenotype and promotes angiogenesis, tumour invasiveness, metastases, and cachexia. We used a first-in-class, monoclonal antibody (MABp1) cloned from a human being to target interleukin-1α, a mediator of chronic inflammation. We aimed to assess the safety and tolerability of MABp1 for interleukin-1α blockade in a refractory cancer population.

METHODS

We did an open-label, dose-escalation, and phase 1 study of MABp1 in adults with metastatic cancer at the MD Anderson Clinical Center for Targeted Therapy (Houston, TX, USA). We used a standard 3+3 design to identify the maximum tolerated dose. Patients received MABp1 intravenously once every 3 weeks through four dose levels: 0.25 mg/kg, 0.75 mg/kg, 1.25 mg/kg, and 3.75 mg/kg. After the dose-escalation phase, a second dosing arm was started with dosing every 2 weeks at the maximum tolerated dose. The primary objectives were safety, tolerability, characterisation of the pharmacokinetic profile, and identification of the recommended phase 2 dose. Secondary endpoints included pharmacodynamic effects and antitumour activity. All patients who received at least one dose of MABp1 were included in the safety analyses. This trial is registered with ClinicalTrials.gov, NCT01021072.

FINDINGS

Between March 15, 2010, and July 30, 2012, 52 patients with metastatic cancer (18 tumour types) received anti-interleukin-1α monotherapy in dose-escalation and expansion groups. MABp1 was well tolerated, with no dose-limiting toxicities or immunogenicity. Thus, the recommended phase 2 dose was concluded to be 3.75 mg/kg every 2 weeks. Pharmacokinetic data were consistent at all dose levels and showed no evidence of accumulation or increased clearance of MABp1 at increasing doses. For 42 assessable patients, median plasma interleukin-6 concentrations had decreased from baseline to week 8 by a median of 2.7 pg/mL (IQR -12.6 to 3.0; p=0.08). Of the 34 patients restaged, one patient had a partial response and ten had stable disease. 30 patients were assessable for change in lean body mass, which increased by a mean of 1.02 kg (SD 2.24; p=0.02) between baseline and week 8. The most common adverse events possibly related to the study drug were proteinuria (n=11; 21%), nausea (7; 13%), and fatigue (7; 13%). The most frequent grade 3-4 adverse events (regardless of relation to treatment) were fatigue (3; 6%), dyspnoea (2; 4%), and headache (2; 4%). Two patients (4%) had grade 5 events (death due to disease progression), which were unrelated to treatment.

INTERPRETATION

MABp1 was well tolerated, no dose-limiting toxicities were experienced in this study, and disease control was observed. Further study of MABp1 anti-interleukin-1α antibody therapy for advanced stage cancer is warranted.

FBXW7 mutations in patients with advanced cancers: clinical and molecular characteristics and outcomes with mTOR inhibitors

PURPOSE

FBXW7 is a tumor suppressor gene responsible for the degradation of several proto-oncogenes. Preclinical data suggest that FBXW7 mutations sensitize cells to mTOR inhibitors. Clinicopathologic characteristics of cancer patients with FBXW7 mutations and their responses to mTOR inhibitors remain unknown.

METHODS

Using multiplex gene panels we evaluated how the FBXW7 mutation affected the cancer phenotype of patients referred to a phase I clinic starting January 2012. Whenever possible patients positive for FBXW7 mutation were treated with regimens containing an mTOR inhibitors and their outcomes were reviewed.

RESULTS

FBXW7 mutations were detected in 17 of 418 patients (4.0%). Among tumor types with more than 10 patients tested, FBXW7 mutations occurred in colorectal cancer (7/49; 14.3%), squamous cell cancer of head and neck (2/18; 11.1%), liver (1/13; 7.7%), and ovarian cancers (1/40; 2.5%). No one clinical, pathological or demographic feature was characteristic of the FBXW7-mutated patient population. The mutation occurred in isolation in only 2/17 (12%) patients, and KRAS was frequently found as a concomitant mutation, especially in patients with colorectal cancer (6/7; 86%). Ten patients were treated on a protocol containing an mTOR inhibitor, with a median time to treatment failure of 2.8 months (range, 1.3-6.8). One patient with liver cancer (fibrolamellar subtype) continues to have a prolonged stable disease for 6.8+ months.

CONCLUSION

In patients with advanced cancers, somatic mutations in FBXW7 usually occur with other simultaneous molecular aberrations, which can contribute to limited therapeutic efficacy of mTOR inhibitors.

P53 mutations in advanced cancers: clinical characteristics, outcomes, and correlation between progression-free survival and bevacizumab-containing therapy

Background

Mutations in the p53 gene are amongst the most frequent aberrations seen in human cancer. Our objective was to characterize the clinical characteristics associated with p53 mutation in patients with advanced cancer.

Methods

We retrospectively reviewed and analyzed the clinical features and response to standard systemic therapy of 145 patients with documented tumor p53 mutational status (mutant-type [mtp53] vs. wild-type [wtp53]) referred to the Clinical Center for Targeted Therapy.

Results

Sixty-six (45.5%) patients had mtp53. Mutations in p53 occurred more frequently in older patients (p= 0.015) and in Caucasians (p=0.024). The incidence of liver metastases was 69.2% vs. 43%, p=0.002 in mtp53 and wtp53, respectively. PTEN loss by immunohistochemistry was found more frequently in mtp53-bearing tumors compared to wtp53 (33.3% vs. 10%, p=0.007). The best progression-free survival (PFS) on standard systemic therapy was significantly longer with bevacizumab-containing regimens as compared to non-bevacizumab containing regimen in patients with mtp53 (median 11.0 [95% CI 5.9-16.0], n=22 vs. 4.0 months [95% CI 3.6-5.7], n=35, p<0.0001) but not those with wtp53 (median 5.0 [95% CI 2.0-7.6] vs. 6.0 [95% CI 4.0-7.5] months, p=0.318. The median overall survival from diagnosis in patients with mtp53 and wtp53 was 7.4 [95% CI 6.3-9.8] vs. 11.8 [95% CI 2.9-21.5] years, respectively (p=0.365).

Conclusion

Patients with mtp53 tumors were older at diagnosis, had more incidence of liver metastasis, and more frequent PTEN loss. The best PFS on standard systemic therapy was significantly longer with bevacizumab-containing regimens in patients with mutant p53 tumors but not in those with wtp53.

Phase I clinical trial of bendamustine and bevacizumab for patients with advanced cancer

Bendamustine, a cytotoxic alkylating agent, has shown promising results in solid tumors. An investigator-initiated phase I clinical trial of the anti-vascular endothelial growth factor agent bevacizumab and bendamustine was conducted in patients with advanced cancer, because the 2 drugs have different mechanisms of antitumor activity and nonoverlapping toxicity. Patients were treated with escalating doses of intravenous bendamustine (70, 80, 90, and 100 mg/m(2); days 1 and 2) and intravenous bevacizumab (10 mg/kg; days 1 and 15). A conventional "3 + 3" study design was used. Forty-two patients were treated: 23 women and 19 men. The median age was 60 years. Patients had received a median of 4 prior therapies (range, 1-10). The most common cancer types were colorectal (n=9), head and neck (n= 8), non-small cell lung (n=6), and breast (n=5). Overall, 117 cycles were administered (median per patient, 2; range, 1-8). No dose-limiting toxicities were noted during the escalation phase. Therefore, the highest dose (level 4) of bendamustine (100 mg/m(2)) was used in the expansion phase. The most common toxicities were fatigue (n=22), nausea (n=14), anorexia (n=9), and thrombocytopenia (n=7). Of 38 patients who were evaluable for response, 23 (61%) had stable disease, including 2 (5.2%) who had stable disease for 6 months or more (1 with adenoid cystic carcinoma and 1 with non-small cell lung cancer). This regimen of bendamustine (100 mg/m(2)) and bevacizumab (10 mg/kg) was well tolerated and yielded disease stabilization in selected heavily pretreated patients with advanced cancer.

Assessing PIK3CA and PTEN in early-phase trials with PI3K/AKT/mTOR inhibitors

Despite a wealth of preclinical studies, it is unclear whether PIK3CA or phosphatase and tensin homolog (PTEN) gene aberrations are actionable in the clinical setting. Of 1,656 patients with advanced, refractory cancers tested for PIK3CA or PTEN abnormalities, PIK3CA mutations were found in 9% (146/1,589), and PTEN loss and/or mutation was found in 13% (149/1,157). In multicovariable analysis, treatment with a phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) inhibitor was the only independent factor predicting response to therapy in individuals harboring a PIK3CA or PTEN aberration. The rate of stable disease ≥6 months/partial response reached 45% in a subgroup of individuals with H1047R PIK3CA mutations. Aberrations in the PI3K/AKT/mTOR pathway are common and potentially actionable in patients with diverse advanced cancers. This work provides further important clinical validation for continued and accelerated use of biomarker-driven trials incorporating rational drug combinations.

Abstract P1-08-18: PIK/AKT/MTOR pathway activation in triple negative breast cancer and outcomes with matched therapy in phase I clinical trials: Response in both patients with and without direct molecular alterations

Introduction

The PI3K/AKT/MTOR pathway is a known driver in triple negative breast cancers (TNBC). We analyzed patients with TNBC seen in our Phase I clinic including molecular subtyping and correlation with response to therapies targeting the PI3K/AKT/mTOR pathway.

Methods

Patients with advanced TNBC [negative (&lt;1%) expression for estrogen and progesterone receptors and negative Her 2 (&lt;/ = 1+ by IHC or non-amplified by FISH)] whose tumors had undergone molecular profiling (including PIK3CA/PTEN mutation analysis and/or PTEN immunohistochemistry (IHC)). We evaluated sequential patients seen in the Phase I clinic at M.D. Anderson Cancer Center treated on at least one Phase I clinical trial and correlated molecular status with clinical outcomes on therapy. Molecular profiling methods including hotspot analysis, next generation sequencing and IHC.

Results

Forty-four patients (median age 56, range 27-81; all female; white race76%) with a median of 2 (0-7) prior therapies (40% received ≥3 prior systemic therapies) and 2 metastatic sites (range, 1-6) were included. Histology: invasive ductal carcinoma 29 (66%), metaplastic 12 (27%), other 3 (7%). Nine out of 42 patients tested (19%) had a PIK3CA mutation and, 11 out of 33 patients tested (33%) demonstrated PTEN loss on IHC and 2 patients had PTEN mutations. Altogether, 21 out of 44 patients had at least one alteration in the PI3K/AKT/mTOR pathway. Sixteen of these 21 patients received “matched” therapy consisting of at least one agent targeting the PI3K/AKT/mTOR pathway. Four out of 16 patients (25%) with at least one molecular alteration, treated with one or more regimens containing at least one agent targeting the PI3K/AKT/mTOR pathway (“matched” therapy), demonstrated clinical benefit: complete response (CR) (N = 1)/partial response (PR) (N = 1)/stable disease ≥ 6 months (SD) (N = 2). Similarly, three out of 12 patients (25%) who did not demonstrate a direct molecular alteration in the PI3K/AKT/mTOR pathway and who were treated with PI3K-directed therapy, had either CR (N = 1)/PR (N = 1)/SD ≥ 6 months (N = 1). Twenty-eight patients received PI3K/AKT/mTOR pathway directed therapy yielding CR (N = 2), PR (N = 3) and CR/PR/ SD ≥ 6 months (N = 1) while those who received other therapies had CR (N = 0), PR (N = 1) and CR/PR/SD&gt;6mo (N = 3)and a median TTF of 3.1 (2.1-4.8) vs. 1.8 (1.4-2.5) months (p = 0.23).

Conclusions

A significant percentage of patients with TNBC demonstrate a direct alteration in the PI3K/AKT/mTOR pathway. Our data shows that PI3K-directed therapies benefit both those patients with and without direct molecular alterations in this pathway. Further molecular testing results will be presented. This data suggests that there may be additional molecular alterations that activate PI3K/AKT/mTOR in patients with TNBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-18.

A pilot study of temsirolimus and body composition

PURPOSE

Body weight and composition play a role in cancer etiology, prognosis, and treatment response. Therefore, we analyzed the weight, body composition changes, and outcome in patients treated with temsirolimus, an mTor inhibitor that has weight loss as one of its side effects.

PATIENTS AND METHODS

Sixteen patients with advanced solid tumors treated with temsirolimus were studied; body composition was evaluated utilizing computerized tomography images. Sarcopenia was defined as skeletal muscle index lower than 38.5 cm(2)/m(2) for women and 52.4 cm(2)/m(2) for men.

RESULTS

Five of 16 patients (31 %) were men; median age, 60 years. Forty-four percent (7/16) of patients were sarcopenic. Fatigue, anemia, hyperglycemia, and hyperlipidemia were common. Baseline sarcopenia and body composition did not correlate with worse toxicity or treatment outcome. However, there was a trend for greater loss of adipose area (p = 0.07), fat mass (p = 0.09), and adipose index (p = 0.07) for patients with grade 3 or 4 toxicities versus those with grade 1 and 2 side effects.

CONCLUSION

Patients with higher grade toxicities tended to lose more body fat, suggesting a possible end-organ metabolic effect of temsirolimus. These observations merit exploration in a larger cohort of patients.

Abstract A212: Next generation sequencing (NGS) in 57 patients with advanced or metastatic breast cancer: Identification of unique genomic profiles and correlation with response

Background: Next generation sequencing (NGS) has revealed significant heterogeneity among patients’ tumors. Molecular aberrations may be both prognostic and predictive.

Methods: We retrospectively analyzed 57 patients with advanced or metastatic breast cancer, with NGS profiling of their tumors, treated on Phase I trials at MD Anderson Cancer Center and UCSD-Moores Cancer Center. The objectives of this study were to: 1) characterize molecular aberrations and, 2) correlate molecular aberrations with response to targeted therapies.

Results: Fifty-seven patients with advanced or metastatic breast cancer with NGS profiling of their tumors were included. Fifty-six of 57 patients (98%) with NGS analysis of their tumors demonstrated at least one molecular aberration. A total of 216 somatic aberrations in 71 different genes were identified including variants in the same gene. There were 99 mutations, 97 amplifications, 11 deletions, 5 splices, 2 truncations, 1 fusion and 1 rearrangement. The most commonly mutated genes were: TP53 (26 patients, 46%); PIK3CA (18 patients, 32%); PIK3R1, GATA3 (5 patients, 9% each); BRCA2, CDH1, and NF1 (3 patients, 5% each). The most common amplifications occurred at: CCND1, MYC (12 patients, 21% each); HER2 (official gene name ERBB2), MCL1 (7 patients, 12% each); and FGFR1 (6 patients, 11%). In addition, PTEN deletion and CDKN2 deletion were found in 6 (11%) and 3 (5%) patients, respectively. Among those genes with the highest number of gene variants included: TP53 (26 variants); PIK3CA (7 variants); GATA (5 variants); PIK3R1 (4 variants); and BRCA 2 (4 variants). No two patients demonstrated the same spectrum of molecular aberrations. Forty-four of 57 patients were evaluable for response on targeted therapies excluding single-agent hormone therapy (13 patients did not receive targeted therapy). Thirty-seven patients received therapies that were either directly or indirectly matched to NGS aberrations resulting in 2 patients with complete responses (CR), 5 with partial response (PR), 10 with stable disease ≥ 6 months (SD) and, 20 with progressive disease (PD). Seven patients who did receive matched therapy demonstrated SD (3 patients) and PD (4 patients) 3 SD (Fisher's exact test, p=0.88).

Conclusion: Unique profiles of genomic aberrations in patients with breast cancer were demonstrated. Further evaluation NGS in larger patient cohorts is warranted including studies that prospectively match aberrations to targeted therapies.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A212.

Citation Format: Jennifer J. Wheler, Barbara A. Parker, Jack Lee, Roman Yelensky, Stacy Moulder, Apostolia M. Tsimberidou, Filip Janku, Johnique T. Atkins, Ralph Zinner, Richard Q. Schwab, Maria Schwaederle, Vivek Subbiah, Siqing Fu, Philip J. Stephens, Razelle Kurzrock. Next generation sequencing (NGS) in 57 patients with advanced or metastatic breast cancer: Identification of unique genomic profiles and correlation with response. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A212.

Abstract C203: BRAF and KRAS mutation testing in cell-free DNA and circulating tumor cells from blood of patients with metastatic cancers

Background: Cell-free (cf) DNA and circulating tumor cells (CTC) in the blood of cancer patients offer an easily obtainable, low-risk, inexpensive, and repeatedly available source of biologic material for mutation analysis and monitoring of molecular changes throughout cancer therapy.

Methods: DNAs from plasma and CTC from patients with advanced cancers who progressed on systemic therapy were tested for BRAF V600 and KRAS G12/G13 mutations using the ICE-COLD-PCR platform. ICE COLD-PCR, "Improved and Complete Enrichment COamplification at Lower Denaturation” selectively amplifies mutant DNA by exploiting differences in denaturation temperatures between mutant DNA duplexes and normal “wild-type” DNA duplexes. KRAS Exon 2 and BRAF Exon 15 ICE COLD-PCR was performed on plasma samples, and from matched CTCs collected using ScreenCell® MB kits (ScreenCell, Sarcelles, France). Amplicons were analyzed by Sanger sequencing methods and results were compared to the mutation status of the archival primary or metastatic tumor tissue as determined in a CLIA-certified lab.

Results: Blood samples from 59 patients with advanced cancers (colorectal cancer, n=32; melanoma, n=12; non-small cell lung cancer, n=7; other cancers, n=8), were obtained before treatment and, if possible, sequentially during therapy and tested for BRAF (30), KRAS (29) or BRAF and KRAS (1) mutations. BRAF mutations were detected in 97% (30/31) of archival tumor samples compared to 65% (20/31) of cfDNA samples (agreement 68%) and to 3% (1/31) of CTC samples (agreement 6%). KRAS mutations were detected in 90% (26/29) of archival tumor samples compared to 86% (25/29) of cfDNA samples (agreement 83%) and to 10% (3/29) of CTC samples (agreement 21%); however, CTCs had different KRAS mutation subtypes than those in tumor tissue. Of interest, in 3 patients with serial blood collection for cfDNA BRAF mutations, 2 (melanoma, Erdheim-Chester disease) had BRAF V600E cfDNA mutations at baseline, which disappeared during the response to subsequent therapy. Another patient (melanoma) did not have a BRAF V600E cfDNA mutation immediately after being taken off BRAF inhibitor therapy due to intolerance, but a BRAF V600E cfDNA mutation emerged when the patient was treated with non-BRAF targeting therapy. In 2 patients with serial blood collections for cfDNA KRAS mutations, 2 (colorectal cancer) did not have KRAS cfDNA mutations at baseline, but KRAS cfDNA mutations (G13D, G12D, respectively) emerged following disease progression and subsequent therapy. Conclusions: Detection of BRAF and KRAS mutations in cfDNA can provide a fast and noninvasive alternative to mutation testing in tumor tissue. Although these mutations can be also detected in CTC, the level of concordance with tumor tissue results is low.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C203.

Citation Format: Filip Janku, Ben Legendre, Katherine Richardson, Gerald S. Falchook, Aung Naing, Veronica R. Holley, David S. Hong, Ralph G. Zinner, Siqing Fu, Apostolia M. Tsimberidou, Vivek Subbiah, Daniel D. Karp, Sarina A. Piha-Paul, Jennifer J. Wheler, Vanda M. Stepanek, Goran Cabrilo, Rajyalakshmi Luthra, Funda Meric-Bernstam, Amy Kruempel, Jaclyn Pope, Courtney Cubrich, Grant Wu, Yanggu Shi, Marcia Lewis, Razelle Kurzrock. BRAF and KRAS mutation testing in cell-free DNA and circulating tumor cells from blood of patients with metastatic cancers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C203.

Abstract B175: Detection and monitoring of BRAF and KRAS mutations in cell-free urinary DNA of metastatic cancer patients by droplet digital PCR

Background: Detection and monitoring of oncogenic mutations in cell-free urinary DNA opens the possibility of a new paradigm for a truly non-invasive method of individualized care for metastatic cancer patients, enabling the quantitation of mutational tumor load and respective concordance to therapeutic responsiveness followed by detection of emerging genomic alterations underlying acquired resistance.

Methods: Cell-free DNA was isolated from single and/or multiple sequential urine samples from patients with advanced cancers and BRAF V600E, KRAS G12D or G12V mutations in the tumor tissue from a CLIA-certified laboratory, who progressed on systemic therapy. Assays for quantitative assessment of BRAF V600E, KRAS G12D and G12V mutations in cell-free urinary DNA were developed using droplet digital PCR methodology (RainDance, MA) with enrichment of mutation-containing DNA fragments by pre-amplification of BRAF and KRAS genes. Mutation sensitivity of at least 0.03% was achieved by spike-in experiments of input DNA from cell-lines containing BRAF and KRAS mutations. Healthy controls (N=6) yielded baseline signals that were ∼10-fold less than observed for 0.03% sensitivity.

Results: Cell-free DNA was extracted from urine of 25 patients with diverse advanced cancers (colorectal cancer, n=8; melanoma, n=7; non-small cell lung cancer, n=6; papillary thyroid carcinoma, n=2; appendiceal carcinoma, n=1; and glioblastoma, n=1) with BRAF V600E (N=18), KRAS G12D (N=5) and KRAS G12V (N=2) in the tumor tissue. Of 18 patients with BRAF V600E mutations in the tumor, 17 (94%) had the same mutation in urinary cell-free DNA. In addition, all 5 (100%) patients with KRAS mutations (G12D, n=5; G12V, n=2) in the tumor tissue DNA had these same mutations in urinary cell-free DNA.A total of 5 patients with BRAF V600E mutations had longitudinal analysis of percentage of cell-free urinary DNA BRAF V600E mutation to wild-type in sequentially collected urine samples. Although the numbers are small the detected amount of BRAF mutant copies are in agreement with a clinical course.

Conclusion: Our preliminary data suggest that detecting BRAF V600E, KRAS G12D, and G12V mutations in cell-free DNA from urine can offer a noninvasive alternative to mutation testing of tumor tissue with excellent concordance, and should be investigated further for testing and monitoring of mutation status in patients with cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B175.

Citation Format: Filip Janku, Gerald S. Falchook, Sarina A. Piha-Paul, Aung Naing, Apostolia M. Tsimberidou, Veronica R. Holley, Daniel D. Karp, Ralph G. Zinner, Siqing Fu, Jennifer J. Wheler, David S. Hong, Funda Meric-Bernstam, Vanda M. Stepanek, Rayjalakshmi Luthra, Lorieta Leppin, Latifa Hassaine, Karena Kosco, Jason C. Poole, Mark G. Erlander. Detection and monitoring of BRAF and KRAS mutations in cell-free urinary DNA of metastatic cancer patients by droplet digital PCR. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B175.

Transient severe hyperbilirubinemia after hepatic arterial infusion of oxaliplatin in patients with liver metastases

PURPOSE

We have observed severe, but rapidly reversible, hyperbilirubinemia in patients receiving hepatic arterial infusion (HAI) of oxaliplatin. We performed a retrospective analysis to characterize this unusual phenomenon.

METHODS

We reviewed the electronic medical records of 113 consecutive patients receiving HAI oxaliplatin to describe the associated hyperbilirubinemia.

RESULTS

Four of 113 patients (3.5 %) presented with transient, severe (grade 3/4) hyperbilirubinemia post-HAI oxaliplatin. Peak levels of total bilirubin within 10-16 h of starting HAI oxaliplatin were 4.6, 12.2, 12.8, and 21.2 mg/dL and declined rapidly (within 24 after stopping treatment). One out of four patients experienced severe abdominal pain, and another patient had an infusion reaction (hypertension and hypoxemia) that reversed after discontinuation of infusion. Total bilirubin was predominantly direct. No significant decline in hemoglobin or increase in alkaline phosphatase occurred. Increase in liver transaminases post-infusion was mild to moderate (grades 1-3) and was seen after HAI oxaliplatin regardless of the emerged hyperbilirubinemia.

CONCLUSIONS

Severe hyperbilirubinemia is a rare but rapidly reversible adverse effect of HAI oxaliplatin and may be accompanied by an abdominal pain syndrome or infusion reaction. Treating physicians should be aware for the potential of this reaction. The mechanism of this unusual reaction merits further investigation.

Target-based therapeutic matching in early-phase clinical trials in patients with advanced colorectal cancer and PIK3CA mutations

Target-matched treatment with PI3K/AKT/mTOR pathway inhibitors in patients with diverse advanced cancers with PIK3CA mutations have shown promise. Tumors from patients with colorectal cancer were analyzed for PIK3CA, KRAS, and BRAF mutations. PIK3CA-mutated tumors were treated, whenever feasible, with agents targeting the PI3K/AKT/mTOR pathway. Of 194 patients analyzed, 31 (16%) had PIK3CA mutations and 189 (97%) were assessed for KRAS mutations. Patients with PIK3CA mutations had a higher prevalence of simultaneous KRAS mutations than patients with wild-type PIK3CA (71%, 22/31 vs. 43%, 68/158; P = 0.006). Of 31 patients with PIK3CA mutations, 17 (55%) were treated with protocols containing PI3K/AKT/mTOR pathway inhibitors [median age, 57 years; median number of prior therapies, 4; mTORC1 inhibitors (11), phosphoinositide 3-kinase (PI3K) inhibitors (5), or an AKT inhibitor (1)]. None (0/17) had a partial or complete response (PR/CR) and only 1 [6%, 95% confidence interval (CI), 0.01-0.27] had stable disease 6 months or more, which was not significantly different from a stable disease ≥6 month/PR/CR rate of 16% (11/67; 95% CI, 0.09-0.27) in patients with colorectal cancer without PIK3CA mutations treated with PI3K/AKT/mTOR pathway inhibitors (P = 0.44). Median progression-free survival was 1.9 months (95% CI, 1.5-2.3). In conclusion, our data provide preliminary evidence that in heavily pretreated patients with PIK3CA-mutant advanced colorectal cancer, protocols incorporating PI3K/AKT/mTOR inhibitors have minimal activity. PIK3CA mutations are associated with simultaneous KRAS mutations, possibly accounting for therapeutic resistance.

Hepatic arterial infusion therapy in advanced cancer and liver-predominant disease: the MD Anderson Experience

BACKGROUND/AIMS

Liver metastases in patients with cancer are associated with a poor prognosis. We assessed the clinical outcomes in patients with advanced cancer and predominant liver involvement treated on hepatic arterial infusion (HAI chemotherapy protocols.

METHODOLOGY

We retrospectively analyzed the outcomes of patients referred to the Phase I Clinical Trials Program between April 2004 and September 2009.

RESULTS

Overall, 202 consecutive patients were identified. Of 189 evaluable patients, the rates of partial response (PR) and stable disease (SD) >4 months were 6.3% and 23%, respectively. In patients with hepatocellular carcinoma or cholangiocarcinoma (n = 15), 5 (33%) had SD ≥ 4 months. In patients with colorectal cancer (n = 67) treated with HAl oxaliplatin or irinotecan combination therapy, the rates of PR and SD ≥ 4 months were 7.5% and 34.3%, respectively. In patients with breast cancer (n = 17) treated with HAI cisplatin-based therapy, the rates of PR and SD -4 months were 17.6% and 35.3%, respectively. The median survival of patients with PR and SD ≥ 4 months was 11.6 months. Independent factors predicting shorter survival were male gender; decreased albumin and hemogloblin; and elevated bilirubin, lactate dehydrogenase and alanine aminotransferase.

CONCLUSIONS

HAI combination therapies have antitumor activity in selected heavily pretreated patients with certain tumor types and liver involvement.

Dual EGFR inhibition in combination with anti-VEGF treatment: a phase I clinical trial in non-small cell lung cancer

BACKGROUND

Preclinical data indicate EGFR signals through both kinase-dependent and independent pathways and that combining a small-molecule EGFR inhibitor, EGFR antibody, and/or anti-angiogenic agent is synergistic in animal models.

METHODS

We conducted a dose-escalation, phase I study combining erlotinib, cetuximab, and bevacizumab. The subset of patients with non-small cell lung cancer (NSCLC) was analyzed for safety and response.

RESULTS

Thirty-four patients with NSCLC (median four prior therapies) received treatment on a range of dose levels. The most common treatment-related grade ≥2 adverse events were rash (n=14, 41%), hypomagnesemia (n=9, 27%), and fatigue (n=5, 15%). Seven patients (21%) achieved stable disease (SD) ≥6 months, two achieved a partial response (PR) (6%), and two achieved an unconfirmed partial response (uPR) (6%) (total=32%). We observed SD≥6 months/PR/uPR in patients who had received prior erlotinib and/or bevacizumab, those with brain metastases, smokers, and patients treated at lower dose levels. Five of 16 patients (31%) with wild-type EGFR experienced SD≥6 months or uPR. Correlation between grade of rash and rate of SD≥6 months/PR was observed (p less than 0.01).

CONCLUSION

The combination of erlotinib, cetuximab, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with NSCLC.

Combining erlotinib and cetuximab is associated with activity in patients with non-small cell lung cancer (including squamous cell carcinomas) and wild-type EGFR or resistant mutations

Preclinical data suggest that combined EGF receptor (EGFR) targeting with an EGFR tyrosine kinase inhibitor and an anti-EGFR monoclonal antibody may be superior over single-agent targeting. Therefore, as part of a phase I study, we analyzed the outcome of 20 patients with non-small cell lung cancer treated with the combination of erlotinib and cetuximab. EGFR mutation status was ascertained in a Clinical Laboratory Improvement Amendment-approved laboratory. There were 10 men; median number of prior therapies was five. Overall, two of 20 patients (10%) achieved partial response (PR), one of whom had a TKI-resistant EGFR insertion in exon 20, time to treatment failure (TTF) = 24+ months, and the other patient had squamous cell histology (EGFR wild-type), TTF = 7.4 months. In addition, three of 20 patients (15%) achieved stable disease (SD) ≥6 six months (one of whom had wild-type EGFR and squamous cell histology, and two patients had an EGFR TKI-sensitive mutation, one of whom had failed prior erlotinib therapy). Combination therapy with ertotinib plus cetuximab was well tolerated. The most common toxicities were rash, diarrhea, and hypomagnesemia. The recommended phase II dose was erlotinib 150 mg oral daily and cetuximab 250 mg/m(2) i.v. weekly. In summary, erlotinib and cetuximab treatment was associated with SD ≥ six months/PR in five of 20 patients with non-small cell lung cancer (25%), including individuals with squamous histology, TKI-resistant EGFR mutations, and wild-type EGFR, and those who had progressed on prior erlotinib after an initial response. This combination warrants further study in select populations of non-small cell lung cancer.

PIK3CA mutations in advanced cancers: characteristics and outcomes

PIK3CA mutations are frequently diagnosed in diverse cancers and may predict response to PI3K/AKT/mTOR inhibitors. It remains unclear whether they are associated with other characteristics. We analyzed characteristics and outcome of 90 consecutive patients with diverse advanced tumors and PIK3CA mutations and 180 wild-type PIK3CA controls matched by tumor type, gender, and age referred to the Clinical Center for Targeted Therapy. PIK3CA and MAPK mutations (KRAS, NRAS, and BRAF) were analyzed using polymerase chain reaction-based DNA sequencing. The most frequent PIK3CA mutations were E545K (31/90, 34%), E542K (16/90, 18%) in exon 9, and H1047R (20/90, 22%) in exon 20. PIK3CA mutations compared to wild-type PIK3CA were associated with simultaneous KRAS (p=0.047) and MAPK mutations (p=0.03), but only MAPK mutations were confirmed as having an independent association in multivariate analysis. Rates of lung, bone, liver and brain metastases were similar in PIK3CA-mutant and wild-type patients. Patients with PIK3CA mutations treated on trials with PI3K/AKT/mTOR inhibitors had a higher partial/complete response (PR/CR) rate than wild-type PIK3CA patients treated with their best phase I therapy (10/56, 18% vs. 12/152, 8%; p=0.045), but not a prolonged progression-free survival. Patients with H1047R PIK3CA mutations had higher PR/CR rate with PI3K/AKT/mTOR inhibitors compared to wild-type PIK3CA patients treated with their best phase I therapy (6/16, 38% vs. 12/152, 8%; p=0.003). In conclusion, PIK3CA mutations in diverse cancers were not associated with clinical characteristics, but were correlated with MAPK mutations. PIK3CA mutations, especially, H1047R, were associated with attaining a PR/CR to PI3K/AKT/mTOR pathway inhibitors.

Phase I-II clinical trial of oxaliplatin, fludarabine, cytarabine, and rituximab therapy in aggressive relapsed/refractory chronic lymphocytic leukemia or Richter syndrome

BACKGROUND

To improve outcomes of patients with Richter syndrome (RS) and relapsed/refractory chronic lymphocytic leukemia (CLL), we modified the OFAR1 regimen (oxaliplatin and cytarabine doses of the oxaliplatin, fludarabine, cytarabine, and rituximab) for this phase I-II study (OFAR2).

PATIENTS AND METHODS

OFAR2 consisted of oxaliplatin at 30 mg/m(2) on days 1 to 4, fludarabine at 30 mg/m(2), cytarabine at 0.5 g/m(2), rituximab at 375 mg/m(2) on day 3, and pegfilgrastim at 6 mg on day 6. Fludarabine and cytarabine were given on days 2 and 3 (cohort 1), days 2 to 4 (cohort 2), or days 2 to 5 (cohort 3) every 4 weeks. Phase II followed the "3 + 3" design of phase I.

RESULTS

The 102 patients (CLL, 67; RS, 35) treated had heavily pretreated high-risk disease. Twelve patients were treated in phase I; cohort 2 was the phase II recommended dose. The most common toxicities were hematologic. Response rates (phase II) were 38.7% for RS (complete response [CR], 6.5%) and 50.8% for relapsed/refractory CLL (CR, 4.6%). The median survival durations were 6.6 (RS) and 20.6 (CLL) months. Among 9 patients who underwent allogeneic stem cell transplantation (SCT) as post-remission therapy, none has died (median follow-up, 15.9 months).

CONCLUSION

OFAR2 had significant antileukemic activity in RS and relapsed/refractory CLL. Patients undergoing SCT as post-remission therapy had favorable outcomes.

Phase I clinical trial of lenalidomide in combination with sorafenib in patients with advanced cancer

BACKGROUND

Preclinical data have shown that lenalidomide and sorafenib target endothelial cells, inhibiting growth of ocular melanoma cells in a xenograft model. We conducted a Phase I study of lenalidomide and sorafenib in patients with advanced cancer.

METHODS

During the escalation phase, lenalidomide (days 1-21) and sorafenib (days 1-28) were given orally once daily at the following respective doses: level 1 (10 mg, 200 mg); level 2 (10 mg, 400 mg); level 3 (20 mg, 400 mg); and level 4 (25 mg, 400 mg) (1 cycle = 28 days). A "3 + 3" study design was used.

RESULTS

Forty-one patients were treated (median age: 50 years). The most common diagnoses were adenoid cystic carcinoma (N = 9), ovarian adenocarcinoma (N = 7), and melanoma (N = 6); 142 cycles (median: 3) were administered. No dose-limiting toxicities were noted. The maximum tested dose (dose level 4) was used in the expansion phase. Grade 3-4 treatment-related toxicities were neutropenia, thrombocytopenia, skin rash, and thromboembolism. Of 38 patients who were evaluable for response, stable disease (SD) was noted in 53 % of patients (SD ≥6 months: 16 %). Tumor types with SD ≥ 6 months were as follows: ocular melanoma, 2/2 (100 %); other melanoma, 1/4 (25 %); adenoid cystic carcinoma, 2/9 (22 %); and ovarian cancer, 1/6 (17 %). The median progression-free survival duration was 3.5 months (95 % CI, 1.9-5.0), and the median overall survival duration was 12.3 months (95 % CI, 10.1-14.5).

CONCLUSIONS

Lenalidomide and sorafenib was well tolerated and associated with disease stabilization for ≥6 months in patients with melanoma, adenoid cystic carcinoma, and ovarian adenocarcinoma.

Strategies to overcome clinical, regulatory, and financial challenges in the implementation of personalized medicine

This article highlights major developments over the last decade in personalized medicine in cancer. Emerging data from clinical studies demonstrate that the use of targeted agents in patients with targetable molecular aberrations improves clinical outcomes. Despite a surge of studies, however, significant gaps in knowledge remain, especially in identifying driver molecular aberrations in patients with multiple aberrations, understanding molecular networks that control carcinogenesis and metastasis, and most importantly, discovering effective targeted agents. Implementation of personalized medicine requires continued scientific and technological breakthroughs; standardization of tumor tissue acquisition and molecular testing; changes in oncology practice and regulatory standards for drug and device access and approval; modification of reimbursement policies by health care payers; and innovative ways to collect and analyze electronic patient information that are linked to prospective clinical registries and rapid learning systems. Informatics systems that integrate clinical, laboratory, radiologic, molecular, and economic data will improve clinical care and will provide infrastructure to enable clinical research. The initiative of the EurocanPlatform aims to overcome the challenges of implementing personalized medicine in Europe by sharing patients, biologic materials, and technological resources across borders. The EurocanPlatform establishes a complete translational cancer research program covering the drug development process and strengthening collaborations among academic centers, pharmaceutical companies, regulatory authorities, health technology assessment organizations, and health care systems. The CancerLinQ rapid learning system being developed by ASCO has the potential to revolutionize how all stakeholders in the cancer community assemble and use information obtained from patients treated in real-world settings to guide clinical practice, regulatory decisions, and health care payment policy.

Revisiting clinical trials using EGFR inhibitor-based regimens in patients with advanced non-small cell lung cancer: a retrospective analysis of an MD Anderson Cancer Center phase I population

PURPOSE

Single-agent EGFR inhibitor therapy is effective mainly in patients with lung cancer and EGFR mutations. Treating patients who develop resistance, or who are insensitive from the outset, often because of resistant mutations, other aberrations or the lack of an EGFR mutation, probably requires rational combinations. We therefore investigated the outcome of EGFR inhibitor-based combination regimens in patients with heavily-pretreated non-small cell lung cancer (NSCLC) referred to a Phase I Clinic.

METHODS

We reviewed the electronic records of patients with NSCLC treated with an EGFR inhibitor-based combination regimen: erlotinib and cetuximab; erlotinib, cetuximab and bevacizumab; erlotinib and dasatinib; erlotinib and bortezomib; or cetuximab and sirolimus.

RESULTS

EGFR mutations were detected in 16% of patients (21/131). EGFR inhibitor-based combination regimens were administered to 15 patients with EGFR-mutant NSCLC and 24 with EGFR wild-type disease. Stable disease (SD) ≥6 months/partial remission (PR) was attained in 20% of EGFR-mutant patients (3/15; two with sensitive mutations and secondary resistance to prior erlotinib, and one with a resistant mutation), as well as 26% of evaluable patients (5/19) with wild-type disease. One of three evaluable patients with squamous cell histology achieved SD for 26.5 months (EGFR wild-type, TP53-mutant, regimen=erlotinib, cetuximab and bevacizumab).

CONCLUSIONS

Eight of 34 evaluable patients (24%) with advanced, refractory NSCLC evaluable for response achieved SD ≥6 months/PR (PR=3; SD ≥6 months=5) on EGFR inhibitor-based combination regimens (erlotinib, cetuximab; erlotinib, cetuximab and bevacizumab; and, erlotinib, bortezomib), including patients with secondary resistance to single-agent EGFR inhibitors, resistant mutations, wild-type disease, and, squamous histology.

Abstract 4126: BRAF mutation testing with a novel, rapid, fully-automated molecular diagnostics prototype platform

Background: Mutations in the BRAF gene provide actionable targets for cancer therapy, and can be found in diverse cancers including melanoma, papillary thyroid and colorectal cancers. Novel, fast, and accurate diagnostic systems are needed for further implementation of personalized cancer therapy.

Methods: The molecular diagnostics (MDx) prototype platform (Biocartis, Mechelen, Belgium) is a fully integrated real-time PCR-based system with high sensitivity (1%) and quick turnaround time (&lt; 90 minutes), which requires no sample preparation and &lt;2 min hands-on time. Archival formalin-fixed paraffin-embedded tumor samples (1x to 5x of 10 μm shavings) from patients with advanced cancers previously tested for V600 BRAF mutations in the CLIA-certified Molecular Diagnostic Laboratory (PCR-based sequencing or Sequenom MassARRAY) were tested with a BRAF V600 mutation prototype assay using the MDx prototype platform for research only purposes. Concordance between methods and treatment outcomes with BRAF/MEK inhibitors were analyzed.

Results: Thirty-eight patients (melanoma, n=21; colorectal, n=7; other cancers, n=10) with available tissue and CLIA laboratory BRAF results were identified (BRAF V600 mutation, n=28; wild-type BRAF, n=10). Of the 36 patients for whom the same tissue block was used for MDx and CLIA, BRAF results were concordant in 35 (97%; kappa 0.93; 95% CI 0.80-1.06) of them. BRAF results by MDx were discordant with CLIA in a total of 3 of 38 patients (mutations found by CLIA, but not MDx), but in two of these individuals, different tissue blocks were used for MDx versus CLIA interrogation. Of 25 patients with BRAF mutations detected by MDx, 21 had previously been treated (on the basis of the CLIA lab results) with BRAF/MEK targeted therapies and 7 (33%) had a partial response (PR). Both of the patients with discrepant BRAF status (mutations found by CLIA, but not MDx) who were treated with a BRAF/MEK inhibitor did not respond. Detailed patient characteristics, mutation types and additional discrepancy analysis will be presented.

Conclusions: The BRAF V600 mutation MDx prototype platform is a fast (turn-around time about 1.5 hours) and simple (&lt;2 minutes hands-on time) test to determine BRAF mutation status. When identical tissue blocks are used, results from the MDx prototype platform and from CLIA laboratory PCR-based sequencing or Sequenom MassARRAY demonstrate 97% concordance.

Citation Format: Filip Janku, Laura S. Angelo, Benoit Devogelaere, Gerald S. Fachook, Siqing Fu, Helen J. Huang, Apostolia M. Tsimberidou, David S. Hong, Vanda M. Stepanek, Veronica R. Holley, Mark J. Routbort, Erwin Sablon, Geert Maertens, Razelle Kurzrock. BRAF mutation testing with a novel, rapid, fully-automated molecular diagnostics prototype platform. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4126. doi:10.1158/1538-7445.AM2013-4126

Abstract 3514: A dose-escalation study of anastrozole and everolimus in patients with advanced gynecologic and breast malignancies: tolerance, biological activity, and molecular alterations in the PI3K/AKT/mTOR pathway

Background

Combining aromatase inhibitors with PI3K/AKT/mTOR inhibitors is synergistic and may overcome hormone resistance.

Patients and Methods

We evaluated anastrozole and everolimus in patients with metastatic estrogen receptor (ER) and/or progesterone receptor (PR)-positive breast and gynecologic tumors. Endpoints were safety, antitumor activity and molecular correlates.

Results

Fifty-five patients were enrolled. Full doses of anastrozole (1 mg PO daily) and everolimus (10 mg PO daily) were well tolerated. Fifty patients were evaluable for response with a median age of 57 (range: 24-82) and a median number of prior therapies of 3 (range: 0-13). Twelve of 50 patients (24%) achieved stable disease (SD) ≥ 6 months/partial response (PR)/complete response (CR), including 9 of 32 patients (28%) with breast cancer, 2 of 9 patients (22%) with ovarian cancer and 1 of 6 patients (17%) with uterine cancer. Six of 8 patients (75%) with SD ≥ 6 months/PR/CR with molecular testing demonstrated at least one alteration in the PI3K/AKT/mTOR pathway including mutations in PIK3CA (n=3) and AKT1 (n=1) or PTEN loss (n=3). All 3 patients who had next generation sequencing demonstrated additional alterations: amplifications in CCNE1, IRS2, MCL1, CCND1, FGFR1 and MYC and a rearrangement in PRKDC. Six of 22 patients (27%) with molecular alterations in the PI3K/AKT/mTOR pathway achieved SD ≥ 6 months/PR/CR.

Conclusion

Combination anastrozole and everolimus is well tolerated at full approved doses and active in heavily pretreated patients with ER and/or PR-positive breast, ovarian and endometrial cancers. Patients with SD ≥ 6 months/PR/CR frequently had alterations in the PI3K/AKT/mTOR pathway.

Citation Format: Jennifer J. Wheler, Stacey L. Moulder, Aung Naing, Filip Janku, Sarina A. Piha-Paul, Gerald S. Falchook, Ralph Zinner, Apostolia M. Tsimberidou, Siqing Fu, David S. Hong, Johnique T. Atkins, Maureen Cronin, Roman Yelensky, Phil Stephens. A dose-escalation study of anastrozole and everolimus in patients with advanced gynecologic and breast malignancies: tolerance, biological activity, and molecular alterations in the PI3K/AKT/mTOR pathway. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3514. doi:10.1158/1538-7445.AM2013-3514

Abstract 164: PIK3CA mutation, aspirin use and mortality in patients with metastatic colorectal cancer participating in early-phase clinical trials

Background: Regular use of aspirin use has been associated with reduced risk of colorectal cancer (CRC) and CRC-specific mortality. Preclinical data demonstrates that aspirin down-regulates phosphatidylinositol 3-kinase (PI3K) signaling activity by inhibiting cyclooxygenase-2. Recently, regular use of aspirin was found to be associated with better survival among patients with mutated, but not wild-type PIK3CA CRC.

Methods: 296 patients with CRC referred to the Clinical Center for Targeted Therapy (CCTT) at the MD Anderson Cancer Center from 10/2008 were analyzed for PIK3CA mutation status. Survival and medication data was collected from 243 patients who participated in early-phase clinical trials. Aspirin use was defined as regular aspirin use at the time of the initial CCTT clinic visit. Primary outcome was time from the initial CCTT visit till the last day of follow up or death. Cox proportional-hazards model was used to compute the multivariate hazard ratio (HR) for mortality.

Results: Mean age of the study cohort was 58 years (standard deviation, 11 years). 55% was male and 72% were Caucasian, 15%, Afro-American, and 10%, Hispanic. Median survival was 8.8 months. PIK3CA mutation was found in 38 patients (15.6%), and 25 (10.3%) of them were using aspirin. Aspirin users and nonusers were similar in clinical characteristics except for older age in aspirin users (mean difference of 8.6 years, p&lt;0.001). There was no difference in PIK3CA mutation status between aspirin users and nonusers (14.6% vs. 16.5%, p=0.79). Prognostic impact of the Royal Marsden Hospital (RMH) score (albumin &lt;3.5 vs. ≥3.5 g/dL, lactate dehydrogenase (LDH) &gt; upper limit of normal (ULN) vs. ≤ULN, and &gt;2 vs. ≤2 sites of metastases) was ascertained in our cohort.

Aspirin use was not associated with difference in survival (HR=1.37, 95% confidence interval [CI]=0.80-2.35, p=0.25). This was also true with adjustment for the RMH score (adjusted HR [AHR]=1.56, 95%CI=0.91-2.67, p=0.11). Among patients with wild-type PIK3CA CRC, aspirin use was associated with inferior survival (AHR=1.80, 95%CI=1.01-3.23, p=0.04). In contrast, among patients with mutated PIK3CA, aspirin use did not impact survival (AHR=0.75, 95% CI=0.17 to 3.20, P=0.70)

Conclusion: Aspirin use was associated with shorter survival in patients with wild-type PIK3CA metastatic CRC treated with early-phase clinical trials, but not in patients with mutated PIK3CA. Larger studies are required to further explore and validate possible interactive effect between PIK3CA mutation and aspirin use on survival of patients with metastatic CRC.

Citation Format: Young Kwang Chae, Kunwha Kim, David S. Hong, Gerald S. Falchook, Sarina A. Piha-Paul, Jennifer J. Wheler, Aung Naing, Siqing Fu, Apostolia M. Tsimberidou, Raph G. Zinner, Vivek Subbiah, Vanda M. Stepanek, Robert A. Wolff, Razelle Kurzrock, Filip Janku. PIK3CA mutation, aspirin use and mortality in patients with metastatic colorectal cancer participating in early-phase clinical trials . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 164. doi:10.1158/1538-7445.AM2013-164