Abstract 3905: Translational efficacy and safety modeling and simulation to support the clinical development of JNJ-64619178, a PRMT5 inhibitor

Protein arginine methyltransferase 5 (PRMT5) is an epigenetic enzyme with oncogenic properties. JNJ-64619178 (JNJ178) is a potent, selective, structurally unique PRMT5 inhibitor with good preclinical efficacy in inhibiting the growth of hematologic and solid tumor cell lines. Toxicology studies showed that JNJ178 decreased reticulocytes and neutrophils in rats and dogs. The objectives of translational modeling and simulation were to understand the exposure-response relationship of both safety and efficacy and provide guidance to the first-in-human clinical development of JNJ178.

Experimental data for the PK/PD (Pharmacokinetics/Pharmacodynamics) modeling included: plasma concentration after single dose of JNJ178 in non-tumor bearing mice, plasma concentration and PD markers of dimethylation of arginine (%SDMA in plasma and %SMD1/3-Me2 in tumor, respectively) after multiple doses (1 to 10 mg/kg) QD (once daily) of JNJ178 in H1048 (human small cell lung carcinoma) xenografts, and tumor volume in four xenograft mouse models (A427, human lung carcinoma; H441, human lung adenocarcinoma; H520, human squamous cell lung carcinoma; and H1048). Plasma PK were first described by a standard two-compartment model and used as a driver of PD and tumor volume (efficacy). Plasma and tumor PD were modeled using an indirect response model. A hybrid tumor growth coupled with transit compartment mediated tumor killing model was used to fit the tumor volume data. To predict the safety profile of JNJ178, lifespan based indirect response model for erythropoiesis and Friberg myelosuppression model were used to simulate hemoglobin and neutrophil kinetics in human.

The PK/PD model described the data well and validated the hypothesis that PD is driven by trough concentration. Based on the exposure-response relationship from the four xenograft models, the trough concentration needed to achieve tumor stasis for mouse was determined. In addition, the level of inhibition in tumor and plasma PD marker that was associated with tumor stasis was identified. Together with human PK parameters scaled using allometry, the dose range needed to achieve target therapeutic exposure for a typical human subject was predicted. Simulation results from erythropoiesis and Friberg myelosuppression models informed the optimal doing schedules for certain dose levels that would allow hematological toxicity to be manageable with <40% reduction in hemoglobin and >1.0 x 109/L neutrophil counts at all times. Overall, a translational modeling and simulation approach that considers safety and efficacy has been instrumental in the design of the first-in-human clinical development of PRMT5 inhibitor JNJ178 regarding selection of dose and schedule.

Citation Format: Yue Guo, Nahor Haddish-Berhane, Hillary J. Millar, Tinne Verhulst, Tony Greway, Junguo Zhou, Loeckie DeZwart, Dana Gaffney, Joseph Portale, Dirk Brehmer, An Boeckx, Erika Van Heerde, Daniele Ouellet. Translational efficacy and safety modeling and simulation to support the clinical development of JNJ-64619178, a PRMT5 inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3905.

Anti-PD-1 antibody cetrelimab (JNJ-63723283) in patients with advanced cancers: Updated phase I/II study results

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Background: Cetrelimab (JNJ-63723283) is an IgG4, anti-programmed cell death protein-1 (PD-1) antibody. Here we present updated results from an ongoing phase 1/2 study of cetrelimab in patients (pts) with advanced or refractory solid cancers. Methods: Part 2 of the study evaluated safety and efficacy of cetrelimab at 240 mg Q2W, a recommended phase 2 dose selected in Part 1 (Calvo JCO 2018; 36 suppl 5:58). Tumor types for Part 2 included non-small cell lung cancer (NSCLC), melanoma (MEL), bladder, renal cell, small cell lung cancer (SCLC), microsatellite-high (MSI-H)/DNA mismatch repair deficient (dMMR; locally or centrally tested) colorectal cancer (CRC) and gastric/esophageal cancer (GCA/EC). Tumor response was assessed by the investigator following RECIST v1.1. Results: As of 3 Sep 2018, 192 pts have been treated with cetrelimab from 80–800 mg Q2W and 480 mg Q4W. Median age was 60 years (23–86), and median prior regimens was 2 (1–12). Median duration of treatment was 85 days (1–561); 82 pts remain on treatment. Full receptor occupancy was maintained throughout dosing interval. Most common adverse events (AEs) were asthenia (19%), fatigue (19%), dyspnea (16%) and diarrhea (16%). Grade ≥3 AEs, regardless of causality, were reported in 45% of pts; most common were anemia (6%), dyspnea (4%), increased ALT (3%) and increased AST (3%). Observed serious AEs were dyspnea (4%), pleural effusion and intestinal obstruction (3% each). All grade and grade ≥3 immune-related AEs were reported in 30% and 7% of pts, respectively. Among response-evaluable pts (n = 156) from Parts 1 and 2, overall response rate (ORR) was 15%, with 2 complete and 22 partial responses. Half of pts had stable disease or better. ORR was 26% (7/27) in NSCLC (42% [5/12] in PD-L1+ NSCLC [≥50% by IHC]), 25% (12/49) in MEL (28% [12/43] in non-uveal MEL), 50% (1/2) in renal cancer, 8% (2/26) in MSI-H/dMMR CRC (recruited later per amendment) and 14% (2/14) in GCA/EC. No responses were observed in bladder cancer (n = 4) or SCLC (n = 10). Conclusions: The safety profile and preliminary activity of cetrelimab in immune-sensitive advanced cancers is consistent with known PD-1 inhibitors. The study is ongoing and analysis by PD-L1 status will be reported later. Clinical trial information: NCT02908906.

Fifth Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup: recurrent disease

This manuscript reports the consensus statements regarding recurrent ovarian cancer (ROC), reached at the fifth Ovarian Cancer Consensus Conference (OCCC), which was held in Tokyo, Japan, in November 2015. Three important questions were identified: (i) What are the subgroups for clinical trials in ROC? The historical definition of using platinum-free interval (PFI) to categorise patients as having platinum-sensitive/resistant disease was replaced by therapy-free interval (TFI). TFI can be broken down into TFIp (PFI), TFInp (non-PFI) and TFIb (biological agent-free interval). Additional criteria to consider include histology, BRCA mutation status, number/type of previous therapies, outcome of prior surgery and patient reported symptoms. (ii) What are the control arms for clinical trials in ROC? When platinum is considered the best option, the control arm should be a platinum-based therapy with or without an anti-angiogenic agent or a poly (ADP-ribose) polymerase (PARP) inhibitor. If platinum is not considered the best option, the control arm could include a non-platinum drug, either as single agent or in combination. (iii) What are the endpoints for clinical trials in ROC? Overall survival (OS) is the preferred endpoint for patient cohorts with an expected median OS < or = 12 months. Progression-free survival (PFS) is an alternative, and it is the preferred endpoint when the expected median OS is > 12 months. However, PFS alone should not be the only endpoint and must be supported by additional endpoints including pre-defined patient reported outcomes (PROs), time to second subsequent therapy (TSST), or time until definitive deterioration of quality of life (TUDD).

Abstract 3990: FGFR3 mutations as novel oncogenic targets

Fibroblast growth factors (FGFs) are a family of homologous secreted glycoproteins involved in signaling pathways responsible for embryonic development, cell proliferation, survival, and migration. FGF activity is mediated by four transmembrane fibroblast growth factor receptors (FGFRs) which are receptor tyrosine kinases. Typically, FGF binding induces FGFR dimerization, leading to phosphorylation of the intracellular tyrosine kinase domain. This leads to downstream activation of multiple signaling pathways, including the mitogen-activated protein kinase (MAPK), PI3K/AKT, signal transducer and activator of transcription (STAT), and phospholipase-C-γ cascades. Deregulated FGFR activity, through mutations or translocations, is often associated with oncogenic events. Aberrations in FGFR genes have been observed in several tumor types including bladder, gastric, colorectal, ovarian, and hematologic cancers. To date, several FGFR3 mutations have been identified in bladder cancer. In this study, we developed a TaqMan qRT-PCR-based approach to detect four FGFR3 mutations in formalin-fixed paraffin embedded tissue (FFPET) samples. Cell lines overexpressing FGFR3 mutations were generated to determine impact on cell signaling, and sensitivity to the small-molecule pan-FGFR inhibitor JNJ-42756493. To determine the role and significance of these FGFR3 mutations in cancer, mutation expression constructs were designed and individually transfected into normal rat kidney epithelial cells. Cells harboring the FGFR3 mutations exhibited anchorage-independent growth, increased proliferation, and showed increased sensitivity to the FGFR inhibitor JNJ-42756493 in vitro compared to parental lines. These findings underline the oncogenic potential of the FGFR3 mutation genes and highlight their unique potential as predictive biomarkers in the selection of patients for FGFR-targeted therapy.

Citation Format: Gabriela Martinez Cardona, Dana Gaffney, Katherine Bell, Joseph Portale, Matthew Dunworth, Matthew Lorenzi, Suso Platero, Jayaprakash Karkera. FGFR3 mutations as novel oncogenic targets. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3990.

Abstract 4326: Co-amplification of FGF receptors and ligands in FGFR inhibitor-sensitive cell lines

The fibroblast growth factor receptors (FGFR) play a key role during development and in adult function. FGFRs belong to a family of receptor tyrosine kinases which are single-pass transmembrane receptors with extracellular ligand binding domains and an intracellular tyrosine kinase domain. Upon binding of the ligand the kinase domain activates intracellular signaling networks that coordinate cellular processes such as proliferation, growth, differentiation, migration and survival. Fibroblast growth factors (FGFs) are a family of 18 ligands which are able to bind and activate distinct FGFRs. Deregulated FGFR activity, through mutations or translocations, is often associated with oncogenic events. Overexpression of FGFR or FGF may lead to increased cell proliferation, growth, differentiation, migration or survival, thus making it an interesting target.

In this study we optimized a TaqMan qRT-PCR-based approach to evaluate the copy number variation for several FGFRs (FGFR1, FGFR2, FGFR3 and FGFR4) and several FGF ligands (FGF1, FGF2, FGF3, FGF4, FGF10, FGF12, and FGF19) on a panel of 23 cell lines. The cell types covered a variety of diseases including bladder, breast, endometrial, gastric, kidney, liver, lymphoma, melanoma, sarcoma, small cell lung carcinoma and squamous cell carcinoma. These cell lines had been tested for sensitivity to the JNJ FGFR small molecule inhibitor JNJ42541707 which is a pan-FGFR inhibitor. We observed in the sensitive (IC50&lt;100nm) and moderately sensitive (IC50 100 nM - 1000 nM) cell lines a co-amplification of FGF receptor and ligand. Two of the most sensitive cell lines to FGFR inhibitor treatments had the greatest amplification of FGFR2 with a copy number value greater than 100. This finding that co-amplification occurs in receptor and ligand offers a new potential biomarker for patients that may be sensitive to small molecule FGFR inhibitors.

Citation Format: Katherine Bell, Dana Gaffney, Gabriela Martinez-Cardona, Jayaprakash Karkera, Suso Platero. Co-amplification of FGF receptors and ligands in FGFR inhibitor-sensitive cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4326. doi:10.1158/1538-7445.AM2015-4326

Abstract 4325: The role of FGFR fusion genes as novel oncogenic targets

Fusion genes are chromosomal aberrations that are found in many cancers and can be used as prognostic markers and drug targets in clinical practice. Gene fusions can lead to the production of oncogenic fusion proteins or to enhanced expression of oncogenes. Advances in next-generation sequencing technologies have made possible to identify more efficiently novel fusion proteins in cancer. Recently, several FGFR fusion genes with intact kinase domains have been identified in bladder, lung, breast, thyroid, oral, and prostate cancers, as well as other tumor types. To date, several FGFR3 partner genes have been identified. In this study, we focused on the FGFR3-BAIAP2L1 and FGFR3-TACC3 gene fusions and investigated their tumorigenic activity, mechanism of activation, and sensitivity to the FGFR inhibitor JNJ-42756493. To determine the role and significance of FGFR fusion genes in cancer, FGFR fusion expression constructs were designed and individually transfected into normal rat kidney epithelial cells. FGFR fusion overexpressing cells not only showed increased cell proliferation, but also exhibited anchorage-independent cell growth. Cells harboring the FGFR fusions showed increased sensitivity to the FGFR inhibitor JNJ-42756493 in vitro, whereas the wild-type FGFR3 did not in the absence of FGF ligands. In addition, Western blotting analyses indicated that the overexpression of the FGFR fusions resulted in highly activated proteins that induce signaling via the MAPK pathway. These findings underline the oncogenic potential of the FGFR fusion genes and highlight their unique potential as predictive biomarkers in the selection of patients for FGFR-targeted therapy.

Citation Format: Gabriela Martinez Cardona, Katherine Bell, Dana Gaffney, Joseph Portale, Suso Platero, Matthew Lorenzi, Jayaprakash Karkera. The role of FGFR fusion genes as novel oncogenic targets. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4325. doi:10.1158/1538-7445.AM2015-4325

Abstract 4666: Profiling mesothelin protein expression by immunohistochemistry and gene expression in adenocarcinoma and squamous cell carcinoma of lung

Mesothelin is a 40 kDa secreted glycoprotein expressed in normal mesothelial cells and over-expressed in several histological types of tumors. Detection of mesothelin by immunohistochemistry (IHC) may assist in the diagnosis of mesothelioma. Mesotheliomas are positive for mesothelin staining, but carcinomas of the lung may also be positive for this marker. Mesothelin positivity in adenocarcinoma of the lung reportedly ranges from 22% to 71% of cases depending upon the specific subtype. Mesothelin positivity in squamous cell carcinomas (SCC) of lung is reported to be 16% in non-keratinizing and 31% in keratinizing subtypes. We performed mesothelin IHC on a cohort of 50 lung carcinoma samples (16 adenocarcinomas and 34 SCC). Mesothelin expression was observed in 10 out of 16 (62.5%) lung adenocarcinoma samples, of which 8 showed greater than 10% of tumor cells with positive membrane staining of any intensity. Mesothelin expression was observed in 19 out of 34 (55.9%) lung SCC samples, of which only 3 samples showed greater than 10% of tumor cells with positive membrane staining of any intensity. These findings are in concordance with previous reports which show a higher prevalence of mesothelin protein expression in lung adenocarcinoma than in lung SCC. To correlate RNA expression with protein expression, we performed gene expression profiling on a subcohort of these lung cancer specimens. Out of 50 lung carcinoma samples, 28 samples (10 adenocarcinomas and 18 SCCs) provided adequate RNA yield for gene expression profiling for mesothelin. A total mean relative gene expression (mRGE) value of 13.64 with a standard deviation (SD) of ±3.71 was obtained for the adenocarcinoma samples and a mRGE value of 14.78 with a SD of 2.64 was obtained for the SCC samples. We next arbitrarily assigned samples with greater than 10% mesothelin stained cells as “positive” and the remainder as “negative”. Six negative adenocarcinoma samples yielded a mRGE value of 12.98 with a SD of ±3.84, and four positive adenocarcinoma samples yielded a mRGE value of 14.63 with SD of ±3.82. Sixteen negative SCC samples resulted in a mRGE 14.63 with SD of ± 2.75 and two positive SCC samples yielded a mRGE of 15.98 with a SD of ±1.37. There was no apparent correlation between mRGE values and IHC positivity. We also correlated gene expression with p53 mutation status. Sixteen wild type samples, composed of equal number of adenocarcinoma and SSC had a total mRGE of 14.29 with SD of ±3.32. Seven samples with p53 mutations had a total mRGE of 16.09 with SD ±1.93. These data indicate that mesothelin gene expression is not associated with p53 mutation status. Future studies with an increased number of samples may yield significant associations between protein expression, gene expression and mutation status.

Citation Format: Jackson Wong, Dana Gaffney, Michael Sharp, Brenda Hertzog, Jayaprakash Karkera, Suso Platero, John Alvarez. Profiling mesothelin protein expression by immunohistochemistry and gene expression in adenocarcinoma and squamous cell carcinoma of lung. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4666. doi:10.1158/1538-7445.AM2014-4666

Abstract 3467: Identification of androgen receptor splice variants, ESR1, CYP17, and CYP19 in human breast cancer

Many advances have been made in the diagnosis and treatment of breast cancer in recent years, but it still remains one of the leading causes of death in women. It is well known that the growth of breast cells is regulated by the interactions of different steroid hormones, in particular androgens and estrogens that are related due to their connected metabolic pathways. A number of novel inhibitors of steroidogenic enzymes have been developed that target pre-receptor events_those pertaining to the production, transport, and conversion of steroid ligands. Critical pre-receptor steps include the conversion of pregnenolone-like steroids into androgens, mediated largely by the 17α-hydroxylase/lyase (CYP17) enzyme complex, and the conversion of testosterone and androstenedione to estradiol and estrone, mediated by aromatase (CYP19). Both conversions are implicated in the emergence of tumor resistance and thus are targets for intervention.

Androgen Receptor (AR) is the sex hormone receptor most frequently found in both primary and secondary breast tumors, which is indicitative of the importance of AR in regulating the growth of breast cancer cells. It is estimated that 90% of human genes undergo alternative splicing and AR is no exception. Alternative splicing of the AR could culminate in a receptor that is capable of translocation, or can bind DNA without ligand, leading current AR therapies to be less efficacious.

Using TaqMan qRT-PCR we examined 213 female breast-cancer FFPET samples, 80 ER- PR- Her2- samples, 68 ER- PR- Her2+ samples, and 64 ER+ PR+ Her2- samples, as well as 8 breast-cancer cell lines for the presence of ESR1, CYP17, CYP19, full length AR and AR splice variants ARV1, ARV3/V7, ARV567, and Delta3AR. ARV3/V7 and Delta3AR were the most prevalent variants in the ER+ PR+ Her2- and ER- PR- Her2+ sample sets, with &gt;85% of these samples showing expression of either or both of these variants. On the other hand, ARV1, ARV3/V7, and ARV567 were the most prevalent variants in the ER- PR- Her2- sample set, with &gt;90% of these samples showing expression of one or a combination of these variants. Lower expression values of most of the AR variants were observed in higher grade ER+ PR+ Her2- and ER- PR- Her2+ samples as compared to the lower grade samples. CYP19 was highly prevalent in all sample sets with &gt;75% of all samples showing expression, while CYP17 expression was observed in &lt;30% of all the samples tested. Our findings show the relatively high expression of AR variants and CYP19 in breast cancer tissues, which may indicate their role in regulating the growth of these tumors. Hence increased expression of AR splice variants in breast cancer tumors may be an important biomarker of resistance and targets for AR related therapy.

Citation Format: Gabriela Martinez, Dana Gaffney, Katherine Bell, Suso Platero, Deborah Ricci, Weimin Li, Jayaprakash D. Karkera. Identification of androgen receptor splice variants, ESR1, CYP17, and CYP19 in human breast cancer. [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 3467. doi:10.1158/1538-7445.AM2013-3467

Abstract 3174: A real-time qPCR approach to detect fusions between the KIF5B and RET genes in non-small cell lung cancer

Lung cancer is the leading cause of death in cancer worldwide. There are two major forms of lung cancer, including small cell lung cancer (SCLC) which accounts for approximately 20% of all lung cancers and non-small cell lung cancer (NSCLC) which accounts for approximately 80% of lung cancers. Around 25% of these lung cancer patients are never smokers and these cancers tend to be the result of single somatic mutation events. Several somatic events have been reported in NSCLC, including mutations in EGFR and KRAS along with an EML4-ALK fusion gene, however more than 40% of these cancers are the result of unknown genetic events. Recently several papers have reported a novel fusion gene resulting from a 10.6 Mb inversion on chromosome 10 which leads to a fusion between the KIF5B and RET genes. The RET gene is a well-known tyrosine-kinase proto-oncogene which has been linked to papillary thyroid carcinomas and its expression is generally very low in lung. RET tyrosine kinase stimulates autophosphorylation of the tyrosine kinase unit which activates several pathways including STAT3, RAS/ERK, MAPK, PI3K/AKT and SRC. In the KIF5B-RET fusion KIF5B retains its coiled-coil domain necessary for homodimerization and the RET retains its kinase function leading to aberrant activation of several kinase pathways. Several fusion genes between the exons of KIF5B and RET have been previously reported including KIF5B15:RET12, KIF5B16:RET12, KIF5B22:RET12, KIF5B23:RET12, KIF5B15:RET11, KIF5B24:RET8 and KIF5B24:RET11. In this study we developed a TaqMan qRT-PCR-based approach to evaluate the expression of these seven (7) KIF5B-RET fusion transcripts in 64 NSCLC fresh frozen biopsies, ranging from stage I to stage III, including 25 adenocarcinoma and 37 squamous cell carcinoma samples, respectively. Our findings confirm the presence of the fusion between KIF5B15 (exon 15) and RET12 (exon 12) at a frequency of 1.56% in all subtypes. The clinicopathological background of the KIF5B/RET fusion-positive patient agrees with previously reported trends for this fusion event consisting of a caucasian female, non smoker, with adenocarcinoma subtype. Although this percentage is relatively small, it still represents around 12,000 individuals worldwide that express this fusion transcript, presenting a promising biomarker for targeted therapeutics in the treatment of NSCLC disease.

Citation Format: Katherine Bell, Dana Gaffney, Gabriela Martinez, Suso Platero, Jayaprakash Karkera. A real-time qPCR approach to detect fusions between the KIF5B and RET genes in non-small cell lung cancer. [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 3174. doi:10.1158/1538-7445.AM2013-3174

Prespecified candidate biomarkers identify follicular lymphoma patients who achieved longer progression-free survival with bortezomib-rituximab versus rituximab

PURPOSE

Identify subgroups of patients with relapsed/refractory follicular lymphoma deriving substantial progression-free survival (PFS) benefit with bortezomib-rituximab versus rituximab in the phase III LYM-3001 study.

EXPERIMENTAL DESIGN

A total of 676 patients were randomized to five 5-week cycles of bortezomib-rituximab or rituximab. The primary end point was PFS; this prespecified analysis of candidate protein biomarkers and genes was an exploratory objective. Archived tumor tissue and whole blood samples were collected at baseline. Immunohistochemistry and genetic analyses were completed for 4 proteins and 8 genes.

RESULTS

In initial pairwise analyses, using individual single-nucleotide polymorphism genotypes, one biomarker pair (PSMB1 P11A C/G heterozygote, low CD68 expression) was associated with a significant PFS benefit with bortezomib-rituximab versus rituximab, controlling for multiple comparison corrections. The pair was analyzed under dominant, recessive, and additive genetic models, with significant association with PFS seen under the dominant model (G/G+C/G). In patients carrying this biomarker pair [PSMB1 P11A G allele, low CD68 expression (≤50 CD68-positive cells), population frequency: 43.6%], median PFS was 14.2 months with bortezomib-rituximab versus 9.1 months with rituximab (HR 0.47, P < 0.0001), and there was a significant overall survival benefit (HR 0.49, P = 0.0461). Response rates were higher and time to next antilymphoma therapy was longer in the bortezomib-rituximab group. In biomarker-negative patients, no significant efficacy differences were seen between treatment groups. Similar proportions of patients had high-risk features in the biomarker-positive and biomarker-negative subsets.

CONCLUSIONS

Patients with PSMB1 P11A (G allele) and low CD68 expression seemed to have significantly longer PFS and greater clinical benefit with bortezomib-rituximab versus rituximab.

Abstract P5-01-09: Identification of Molecular Apocrine Triple Negative Breast Cancer Using a Novel 2-Gene Assay and Comparison with Androgen Receptor Protein Expression and Gene Expression Profiling by DASL

Background: The molecular apocrine (MA) subtype of breast cancer is identified by gene expression profiling. MA tumors are estrogen receptor (ER) negative and progesterone receptor (PR) negative, but still express estrogen responsive genes. The androgen receptor (AR) pathway may be driving growth in these tumors because androgen responsive genes are expressed in tumors with the MA gene signature. The MA gene signature is identified in approximately 10% of triple negative breast cancer (TNBC) and may predict patients with tumors responsive to agents that inhibit the AR pathway. AR protein expression, measured by immunohistochemistry (IHC), may be a surrogate for the MA gene signature, but to date, a careful comparison of gene expression profiles and AR protein expression has not been conducted. In this study, cohorts of TNBCs were assessed for the MA gene signature and these results were compared with AR IHC expression and with a novel gene expression assay that may predict tumors with the MA gene signature.

Methods: Formalin fixed, paraffin-embedded (FFPE) TNBC samples were commercially obtained. ER, PR and HER2 status of these samples was confirmed by IHC. AR expression was detected by IHC using two different antibody clones. Both staining intensity and percent positive cells were recorded for each sample. Gene expression data was collected from a cohort of TNBC FFPE samples using cDNA-mediated Annealing, Selection, extension, and Ligation (DASL) technology. A 2-gene classifier of the MA gene expression signature was derived by interrogating publically available gene expression data from ER-negative breast cancers. A reverse-transcriptase polymerase chain reaction (RT-PCR) assay to detect the 2-gene classifier was developed. Cell lines predicted to have the MA gene signature by the 2-gene assay were tested for sensitivity to R-1881 in vitro.

Results: Using computational approaches and publically available datasets, we confirmed the validity of the MA gene signature and estimated the prevalence to be between 12% and 37% in ER-negative breast tumors. The 2-gene classifier was 100% specific in determining MA tumors in a training set using gene expression data as a standard. In a validation set, the 2-gene assay was 66% correlative with AR IHC positivity when the IHC cut-off was set at 10% positive tumor cells. Cell lines predicted to express the MA gene signature by the 2-gene classifier proliferated in response to androgen. This effect was blocked by Flutamide.

Conclusions: These results indicate that AR IHC using a 10% cut-off may not completely correlate with the MA gene signature. Further refinement of AR IHC scoring criteria may produce greater specificity. Cell proliferation data suggests the 2-gene assay can predict tumors that will proliferate in response to androgen. Work is ongoing to determine the correlation between the 2-gene assay results, AR IHC and DASL gene expression data to fully understand the predictability of this assay. Understanding this correlation may allow use of simple clinical assays to accurately select patients responsive to agents that block AR signaling.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-09.

Local Therapy in BRCA1/2 Carriers with Operable Breast Cancer: Comparison of Breast Conservation and Mastectomy

Background: Women with inherited germline BRCA1/2 mutations have a 55-85% cumulative risk of breast cancer (BC) by age 70. Thus, knowledge of expected outcomes following various treatments is needed to advise these patients should they be diagnosed with BC. It is unclear whether breast conservation (BCT) offers similar rates of tumor control as mastectomy (M) in BRCA1/2 carriers and it is doubtful whether a randomized trial comparing these options could be performed. Thus, this analysis compares the outcomes between similarly staged women with BRCA1/2 mutations treated with BCT vs. M.Methods: Women with deleterious BRCA1/2 mutations diagnosed with operable BC and who consented to longitudinal studies were identified at 10 institutions in the US, Australia, Spain and Israel. Patient, clinical and treatment characteristics were compared between those receiving BCT and those receiving M +/- RT. Time-to-event endpoints included first failure of treatment, diagnosis of contralateral breast cancer (CBC), and overall and BC-specific survival. Cox regression models were constructed to detect significant associations between patient and clinical characteristics and time-to-event endpoints.Results: Clinical characteristics and outcomes for 302 BCT and 353 M patients were compared. With a median F/U of 8.2 years for BCT patients and 8.9 years following M, 15-year local failure as first failure was significantly higher with BCT vs. M (23.5% vs. 5.5%, p&lt;0.0001). Multivariate analysis indicted choice of local therapy as the only factor significantly predicting local recurrence, with a 4.5-fold risk of local failure with BCT compared to M (p&lt;0.0001). Local failure analyses by cohort revealed the presence of a BRCA2 mutation (HR 2.8; p=0.024) and no use of adjuvant chemotherapy (HR 5.4; p=0.0001) as significant predictors within the BCT group; presence of invasive lobular cancer (HR 9.9; p=0.004) was the only significant predictor within the M cohort. No significant differences were seen in distant failure, BC-specific or overall survival by local therapy. 15-year estimates of CBC were 52.1% with BCT; 41.4% with M; and 37.9% with M+RT (p=0.44). Analyses of BCT vs. M +/- RT and surgery +/- RT did not reveal significant differences in CBC by cohort.Conclusions: The higher risk of local failure in BRCA1/2-associated BC treated with BCT compared to M did not translate into an increased risk of distant failure or mortality. RT did not result in a detectable increase in CBC at 15 years above baseline elevated rates. These results at both the involved and contralateral breasts should be discussed when patients with BRCA1/2-associated BC are considering local treatment options.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 959.

Two Novel Mutations Causing Familial Benign Hypocalciuric Hypercalcaemia in Three Scottish Families

Background and Aims

Familial benign hypocalciuric hypercalcaemia (FBHH) is a benign autosomal dominantly inherited condition which results in elevated serum calcium and low urinary calcium. This condition is of clinical interest because it can be mistakenly diagnosed as primary hyperparathyroidism (PHP). In most cases FBHH can be shown to be due to a mutation in the calcium sensing receptor (CASR) gene and we aimed to find the causative mutation in three Scottish kindreds with FBHH.

Methods

We used a combination of denaturing gradient gel electrophoresis and direct DNA sequencing to detect mutations in the CASR gene.

Results

We detected a mutation in the CASR gene in each of the three kindreds. Two different mutations were detected (the same one was present in two kindreds). Neither mutation has been reported previously. All hypercalcaemic individuals from each kindred had the appropriate mutation while all normocalcaemic individuals did not.

Conclusion

In the vast majority of kindreds with FBHH which have been reported previously, the CASR mutation responsible is private to that kindred. In three Scottish kindreds we have identified two new mutations.

Clinical trials in gynecological cancer

The Gynecologic Cancer Intergroup is comprised representatives from international gynecological cancer trials organizations, which collaborate in multicenter studies to answer the clinical challenges in gynecological cancer. This review article highlights the key clinical questions facing clinical trialists over the next decade, the information and infrastructure resources available for trials, and the methods of trial development. We cover human papillomavirus (HPV)-associated neoplasia, including cervical cancer, together with endometrial cancer, ovarian cancer, and vulvar cancer. Infrastructure for clinical trials includes a database for trials, templates for protocol development, patient educational material, and financial support for clinical trials. Other critical issues include support from government and charities and government regulations.

Assessment of thiopurine methyltransferase enzyme activity is superior to genotype in predicting myelosuppression following azathioprine therapy in patients with inflammatory bowel disease

BACKGROUND

Myelosuppression occurs in 2-7% of inflammatory bowel disease (IBD) patients treated with azathioprine, and can be associated with reduced activity of thiopurine methyltransferase (TPMT) in some patients. It has been proposed that pretreatment assessment of TPMT status reduces the incidence of toxicity and is cost-effective.

AIMS

To determine if screening for TPMT status predicts side-effects to azathioprine in patients with IBD and to ascertain whether screening by TPMT enzyme activity or genotype is superior.

METHODS

Sequential IBD patients were identified and azathioprine tolerance recorded. Blood was collected for measurement of TPMT activity and TPMT*3C, TPMT*3A and TPMT*2 genotypes.

RESULTS

Of 130 patients, 25% stopped azathioprine because of toxicity. Four patients experienced severe myelosuppression (WCC < 2). Eleven of 17 patients with reduced TPMT activity were heterozygotes, including one patient with marked TPMT deficiency who experienced severe myelosuppression. There was no association between intermediate TPMT deficiency and any side-effect.

CONCLUSIONS

Moderate reduction of TPMT activity in heterozygotes was not associated with toxicity, but very low TPMT activity caused severe myelosuppression in one patient. This would have been predicted by measuring TPMT activity but not by genotyping. Measurement of TPMT activity may therefore be superior to genotype in predicting severe myelosuppression.

Twenty-four novel mutations in Wilson disease patients of predominantly European ancestry

Wilson disease (WND), an autosomal recessive disorder of copper transport, shows wide genotypic and phenotypic variability, with hepatic and/or neurological symptoms. The WND gene, ATP7B, encodes a copper transporting ATPase that is involved in the transport of copper into the plasma protein ceruloplasmin, and in the excretion of copper from the liver. ATP7B mutations result in copper storage in liver and brain. From 247 WND patients worldwide whose DNA has been sequenced in our laboratory, we have identified 24 new mutations. The origins of the patients were European white (one deletion, one nonsense, one splice site, and 18 missense), Chinese (one deletion, one missense) and Bangladeshi (one missense). Most of these had strong support as disease causing mutations, based on conservation between species, structural changes, and absence in controls. One missense mutation in a Chinese patient was considered uncertain because of its conservative nature and position in the protein. We also identified 15 nucleotide substitutions (11 of them new) causing silent or intronic changes, none of which produce an additional splice site that could lead to disease. Characterization of mutations, both disease-causing and normal variants, is essential for accurate molecular diagnosis of this condition.

Cost-effectiveness of thiopurine methyltransferase genotype screening in patients about to commence azathioprine therapy for treatment of inflammatory bowel disease

BACKGROUND

Azathioprine is a useful agent in the management of inflammatory bowel disease. Its use is limited by its side-effect profile. Marrow toxicity occurs in approximately 3.2% of patients and is known to be associated with diminished thiopurine methyltransferase enzyme activity resulting from genetic polymorphisms.

AIM

To evaluate the cost-effectiveness of screening for thiopurine methyltransferase gene polymorphisms prior to initiation of azathioprine therapy.

METHODS

Analysis of the literature was undertaken to calculate the expected frequency of leucopenia and its relationship with thiopurine methyltransferase polymorphisms in a model of theoretical inflammatory bowel disease patients. Decision analysis was then applied to assess the cost of a pre-treatment genotyping strategy, taking account of direct costs and cost per life-year saved.

RESULTS

In 1000 inflammatory bowel disease patients treated with azathioprine, 32 will develop myelosuppression and one will die because of this. Of those who develop myelosuppression during azathioprine therapy, 32% are attributable to lower thiopurine methyltransferase activity. Pre-treatment genotyping costs pound 347 per life-year saved for a 30 year old and pound 817 per life-year saved for a 60 year old. This compares favourably with other health care technologies.

CONCLUSION

The use of pre-treatment screening for thiopurine methyltransferase polymorphisms in inflammatory bowel disease patients commencing azathioprine therapy represents good value for money.

Haemochromatosis gene mutations and risk of coronary heart disease: a west of Scotland coronary prevention study (WOSCOPS) substudy

OBJECTIVES

To measure the frequency of genotypes of the HFE (haemochromatosis) gene in patients recruited to the west of Scotland coronary prevention study (WOSCOPS), and relate them to the subsequent occurrence of coronary clinical events.

DESIGN

Nested case-control study, drawing samples of DNA from the biological bank of a cohort study.

PATIENTS

Men aged 45-64 years in 1989, with moderate hypercholesterolaemia and no evidence of coronary heart disease at baseline.

INTERVENTIONS

Follow up for a mean period of 4.9 years. Typing for C282Y and H63D mutations of the HFE gene in 482 subjects with a subsequent coronary event and 1104 without an event.

RESULTS

The C282Y mutation was present in 81 of 482 cases (16.8%) and 182 of 1104 controls (16.5%). Comparing the prevalence of gene mutations in the cases and controls, there were no significant differences. The hazard ratio for C282Y heterozygotes was 1.03 (95% confidence interval (CI) 0.77 to 1.36) and for C282Y/H63D compound heterozygotes 1.04 (95% CI 0.50 to 2.14). Prespecified subgroup analyses of the pravastatin, placebo, smoking, and non-smoking groups showed no significant differences between cases and controls. Repeating the analyses after adjusting for possible confounding factors produced no change in the results.

CONCLUSIONS

In a population of moderately hypercholesterolaemic middle aged Scottish men who did not have any evidence of coronary heart disease at baseline, the presence of a C282Y mutation in the HFE gene did not predict the occurrence of coronary events over a mean follow up of 4.9 years.

Transcatheter closure of fontan fenestrations using the Amplatzer septal occluder: initial experience and follow-up

We have recently used the Amplatzer septal occluder to close Fontan fenestrations. Between June 1998 and December 1999, 13 patients underwent transcatheter occlusion of their Fontan fenestrations. Systemic blood flow decreased significantly without a concomitant decrease in pulmonary blood flow. All residual shunts detectable by oximetry were at sites separate from those into which occlusion devices were implanted. One patient developed severe tricuspid regurgitation following the procedure requiring surgical removal of the device. At the last follow-up, all patients were doing well clinically. There were no shunts detectable through or around the devices by echocardiography. Our experience indicates that the location of the fenestration within the Fontan baffle is critical to avoiding device interference with other intracardiac structures. The Amplatzer septal occluder offers an effective means of transcatheter closure of Fontan baffle fenestrations. Although more experience is needed, our current follow-up data suggest that long-term outcomes will be favorable. Cathet. Cardiovasc. Intervent. 51:301-304, 2000.

ACP Best Practice No 163. Wilson's disease: acute and presymptomatic laboratory diagnosis and monitoring

Wilson's disease, the most common inherited disorder of copper metabolism, is a recessive genetic condition. The clinical presentation of Wilson's disease is very variable. It is characterised by low serum copper and caeruloplasmin concentrations coupled with the pathological accumulation of copper in the tissues. However, there are diagnostic difficulties and these are discussed. The current value of DNA diagnosis, both in gene tracking in families or as applied to de novo cases, is examined. Wilson's disease can be treated successfully but treatment must be life long. Patients are best treated by specialist centres with experience and expertise in the condition.

Effect of radiotherapy after breast-conserving treatment in women with breast cancer and germline BRCA1/2 mutations

PURPOSE

Recent laboratory data suggest a role for BRCA1/2 in the cellular response to DNA damage. There is a paucity of clinical data, however, examining the effect of radiotherapy (RT), which causes double-strand breaks, on breast tissue from BRCA1/2 mutation carriers. Thus the goals of this study were to compare rates of radiation-associated complications, in-breast tumor recurrence, and distant relapse in women with BRCA1/2 mutations treated with breast-conserving therapy (BCT) using RT with rates observed in sporadic disease.

PATIENTS AND METHODS

Seventy-one women with a BRCA1/2 mutation and stage I or II breast cancer treated with BCT were matched 1:3 with 213 women with sporadic breast cancer. Conditional logistic regression models were used to compare matched cohorts for rates of complications and recurrence.

RESULTS

Tumors from women in the genetic cohort were associated with high histologic (P =.0004) and nuclear (P =.009) grade and negative estrogen (P=.0001) and progesterone (P=.002) receptors compared with tumors from the sporadic cohort. Using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity scoring, there were no significant differences in acute or chronic morbidity in skin, subcutaneous tissue, lung, or bone. The 5-year actuarial overall survival, relapse-free survival, and rates of tumor control in the treated breast for the patients in the genetic cohort were 86%, 78%, and 98%, respectively, compared with 91%, 80%, and 96%, respectively, for the sporadic cohort (P = not significant).

CONCLUSION

There was no evidence of increased radiation sensitivity or sequelae in breast tissue heterozygous for a BRCA1/2 germline mutation compared with controls, and rates of tumor control in the breast and survival were comparable between BRCA1/2 carriers and controls at 5 years. Although additional follow-up is needed, these data may help in discussing treatment options in the management of early-stage hereditary breast cancer and should provide reassurance regarding the safety of administering RT to carriers of a germline BRCA1/2 mutation.

Comparison of interpolated vs. calculated micromultileaf settings in dynamic conformal arc treatment

Stereotactic radiosurgery has developed into a technique where patient positioning and treatment delivery can be performed with submillimeter precision. Achievement of this level of precision has allowed margins to be significantly reduced, and in some cases, removed altogether. Joined with these reductions in treatment margin has come a desire to shape the radiation beam, further limiting dose to normal tissues. Initial applications of shaped radiosurgery fields utilized circular blocking apertures in an attempt to shape the beam to these small volumes. The resultant dose distributions conformed well to spherical treatment volumes but were inadequate for situations where the volume of interest was irregular in shape. Other techniques, such as applying these circular apertures through multiple isocenter positions to a single volume, have been investigated as possible ways to better conform dose distributions to these irregularly-shaped volumes. Recent technological advances allow the use of micromultileaf collimators which dynamically shape the beam by adjustment of individual leaves as the gantry rotates through the are. With margins potentially so tight, accurate evaluation of these dynamically adjusting treatment parameters becomes critical. Our current treatment planning software evaluates adjustments of the leaf positions in increments of 10 degrees and then does a linear interpolation between increments. Treatment delivery, however, is performed with adjustment in leaf position more consistent with a 1 degree increment. This paper compares the individual position of each leaf as determined for the 10 degrees interpolation to required changes in leaf position when the calculation is performed at increments of less than 10 degrees. Our data suggest that there are instances where improvements can be seen when corrections in leaf positions are made at these smaller increments.

Predominance of a 6 bp deletion in exon 2 of the LDL receptor gene in Africans with familial hypercholesterolaemia

In South Africa, the high prevalence of familial hypercholesterolaemia (FH) among Afrikaners, Jews, and Indians as a result of founder genes is in striking contrast to its reported virtual absence in the black population in general. In this study, the molecular basis of primary hypercholesterolaemia was studied in 16 Africans diagnosed with FH. DNA analysis using three screening methods resulted in the identification of seven different mutations in the coding region of the low density lipoprotein (LDLR) gene in 10 of the patients analysed. These included a 6 bp deletion (GCGATG) accounting for 28% of defective alleles, and six point mutations (D151H, R232W, R385Q, E387K, P678L, and R793Q) detected in single families. The Sotho patient with missense mutation R232W was also heterozygous for a de novo splicing defect 313+1G-->A. Several silent mutations/polymorphisms were detected in the LDLR and apolipoprotein B genes, including a base change (g-->t) at nucleotide position -175 in the FP2 LDLR regulatory element. This promoter variant was detected at a significantly higher (p<0.05) frequency in FH patients compared to controls and occurred in cis with mutation E387K in one family. Analysis of four intragenic LDLR gene polymorphisms showed that the same chromosomal background was identified at this locus in the four FH patients with the 6 bp deletion. Detection of the 6 bp deletion in Xhosa, Pedi, and Tswana FH patients suggests that it is an ancient mutation predating tribal separation approximately 3000 years ago.

The apolipoprotein B R3531C mutation. Characteristics of 24 subjects from 9 kindreds

Familial ligand-defective apolipoprotein B (apoB) is a group of disorders caused by mutations in the apoB gene. In this report the R3531C mutation is characterized further using a monoclonal antibody MB19/dynamic laser light scattering technique to measure ratios of Cys(3531) to normal low density lipoprotein (LDL) particles. All six subjects studied showed a preferential accumulation of particles carrying the defective apoB allotype. We determined binding properties of LDL from R3531C heterozygotes by measurement of high-affinity binding to LDL receptors on fibroblasts and its ability promote growth of U937 cells. LDL from R3531C heterozygotes, compared to normal LDL, had 49.3% of the binding affinity and was 74% as effective in a U937 cell proliferation assay. To identify new probands, we screened 2570 subjects for the R3531C mutation. Nine probands were found with 15 affected relatives. Of the seven haplotypes we uncovered, two were novel, while five were identical to one initially reported as associated with Cys3531. Three silent mutations were detected also: T3540T, N3542N and T3552T. Analysis of lipid profiles of R3531C families showed, as with the R3500Q mutation, variable expression of the phenotype, modulated by environmental and other genetic factors. Both mutations tend to produce lower plasma levels of LDL in affected subjects than do defects of the LDL receptor (familial hypercholesterolemia, FH). This study shows that the Cys(3531) LDL particles are not only defective at binding to the LDL receptor, as determined by two separate methods, but that in all cases they accumulate preferentially compared to the normal allotype.-Pullinger, C. R., D. Gaffney, M. M. Gutierrez, M. J. Malloy, V. N. Schumaker, C. J. Packard, and J. P. Kane. Apolipoprotein B R3531C mutation: characteristics of 24 subjects from 9 kindreds. .