Neratinib + fulvestrant + trastuzumab for HR-positive, HER2-negative, HER2-mutant metastatic breast cancer: outcomes and biomarker analysis from the SUMMIT trial

BACKGROUND

HER2 mutations are targetable alterations in patients with hormone receptor-positive (HR+) metastatic breast cancer (MBC). In the SUMMIT basket study, patients with HER2-mutant MBC received neratinib monotherapy, neratinib + fulvestrant, or neratinib + fulvestrant + trastuzumab (N + F + T). We report results from 71 patients with HR+, HER2-mutant MBC, including 21 (seven in each arm) from a randomized substudy of fulvestrant versus fulvestrant + trastuzumab (F + T) versus N + F + T.

PATIENTS AND METHODS

Patients with HR+ HER2-negative MBC with activating HER2 mutation(s) and prior cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) therapy received N + F + T (oral neratinib 240 mg/day with loperamide prophylaxis, intramuscular fulvestrant 500 mg on days 1, 15, and 29 of cycle 1 then q4w, intravenous trastuzumab 8 mg/kg then 6 mg/kg q3w) or F + T or fulvestrant alone. Those whose disease progressed on F + T or fulvestrant could cross-over to N + F + T. Efficacy endpoints included investigator-assessed objective response rate (ORR), clinical benefit rate (RECIST v1.1), duration of response, and progression-free survival (PFS). Plasma and/or formalin-fixed paraffin-embedded tissue samples were collected at baseline; plasma was collected during and at end of treatment. Extracted DNA was analyzed by next-generation sequencing.

RESULTS

ORR for 57 N + F + T-treated patients was 39% [95% confidence interval (CI) 26% to 52%); median PFS was 8.3 months (95% CI 6.0-15.1 months). No responses occurred in fulvestrant- or F + T-treated patients; responses in patients crossing over to N + F + T supported the requirement for neratinib in the triplet. Responses were observed in patients with ductal and lobular histology, 1 or ≥1 HER2 mutations, and co-occurring HER3 mutations. Longitudinal circulating tumor DNA sequencing revealed acquisition of additional HER2 alterations, and mutations in genes including PIK3CA, enabling further precision targeting and possible re-response.

CONCLUSIONS

The benefit of N + F + T for HR+ HER2-mutant MBC after progression on CDK4/6is is clinically meaningful and, based on this study, N + F + T has been included in the National Comprehensive Cancer Network treatment guidelines. SUMMIT has improved our understanding of the translational implications of targeting HER2 mutations with neratinib-based therapy.

Abstract TF1-2: ER+ word salad decoded: SERD, SERM, SERCA, CERAN, PROTAC

Estrogen receptor (ER) plays an important role in gene transcription and the proliferation of ER positive (ER+) breast cancers. Selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs) and fulvestrant, a selective estrogen receptor degrader (SERD) are currently approved therapeutic approaches for ER positive breast cancers. While these treatment strategies are highly effective, de novo and secondary resistance remains a challenge. Despite resistance mechanisms including due to mutations in the ligand binding domain of the ERα gene (ESR1 mutations), ER+ breast cancers continue to rely on receptor activity for growth signaling, underscoring the need for more effective treatments. To overcome the limitations of the existing endocrine therapies, there has been a quest to develop more potent and selective ER antagonists by altering aspects of drug binding or induction of proteolytic degradation of the receptor through different mechanisms. These orally bioavailable agents offer the potential for low toxicity and improved activity and are in various phases of clinical development either as monotherapy or in combination with targeted therapies.

Citation Format: K Jhaveri. ER+ word salad decoded: SERD, SERM, SERCA, CERAN, PROTAC [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr TF1-2.

Characterization of on-target adverse events caused by TRK inhibitor therapy

BACKGROUND

The tropomyosin receptor kinase (TRK) pathway controls appetite, balance, and pain sensitivity. While these functions are reflected in the on-target adverse events (AEs) observed with TRK inhibition, these AEs remain under-recognized, and pain upon drug withdrawal has not previously been reported. As TRK inhibitors are approved by multiple regulatory agencies for TRK or ROS1 fusion-positive cancers, characterizing these AEs and corresponding management strategies is crucial.

PATIENTS AND METHODS

Patients with advanced or unresectable solid tumors treated with a TRK inhibitor were retrospectively identified in a search of clinical databases. Among these patients, the frequency, severity, duration, and management outcomes of AEs including weight gain, dizziness or ataxia, and withdrawal pain were characterized.

RESULTS

Ninety-six patients with 15 unique cancer histologies treated with a TRK inhibitor were identified. Weight gain was observed in 53% [95% confidence interval (CI), 43%-62%] of patients and increased with time on TRK inhibition. Pharmacologic intervention, most commonly with glucagon-like peptide 1 analogs or metformin, appeared to result in stabilization or loss of weight. Dizziness, with or without ataxia, was observed in 41% (95% CI, 31%-51%) of patients with a median time to onset of 2 weeks (range, 3 days to 16 months). TRK inhibitor dose reduction was the most effective intervention for dizziness. Pain upon temporary or permanent TRK inhibitor discontinuation was observed in 35% (95% CI, 24%-46%) of patients; this was more common with longer TRK inhibitor use. TRK inhibitor reinitiation was the most effective intervention for withdrawal pain.

CONCLUSIONS

TRK inhibition-related AEs including weight gain, dizziness, and withdrawal pain occur in a substantial proportion of patients receiving TRK inhibitors. This safety profile is unique relative to other anticancer therapies and warrants careful monitoring. These on-target toxicities are manageable with pharmacologic intervention and dose modification.

Abstract P6-20-03: Tumor epichaperome expression using 124I PU-H71 PET (PU-PET) as a biomarker of response for PU-H71 plus nab-paclitaxel in HER2 negative (HER2-) metastatic breast cancer (MBC)

Background: The epichaperome is a new cancer target required for tumor survival (Joshi et al. Nature Reviews Cancer 2018). PU-H71 is a synthetic, purine scaffold epichaperome inhibitor that binds to the ATP-binding site of HSP90 specifically when HSP90 is integrated into the epichaperome (Rodina et al. Nature 2016). It has demonstrated antitumor activity in multiple xenograft models. Furthermore, sequential administration of nab-paclitaxel and PU-H71 in TNBC xenograft models augmented epichaperome levels, and in turn resulted in super-synergistic drug action with ablation of xenografted tumors and cures in mice.

Methods: This is an open label phase1b study of PU-H71 + nab-paclitaxel in pts with HER2- MBC. Pts received nab-paclitaxel at a standard dose of 260mg/m2 IV Q 3weeks. PU-H71 was administered IV 6 hrs (+/-1 hr) post nab-paclitaxel Q3weeks in 2 escalating dose levels (225mg/m2 and 300 mg/m2). All pts underwent FDG PET/CT every 6 weeks. Additionally, patients had the option to enroll on a separate diagnostic PU-PET protocol to measure epichaperome expression prior to initiating treatment on the phase 1b study, wherein they received a single dose of up to 11mci of 124I-PU-H71 IV and underwent imaging at 3-4hrs and 20-24 hrs. Primary objective was to establish the MTD/RP2D of this regimen. Secondary objectives were to assess PK of PU-H71 + nab-paclitaxel and clinical efficacy. Exploratory analysis included correlation of epichaperome expression at baseline using PU-PET with tumor response.

Results: 12 patients (5 ER+/HER2- ; 7 TNBC) were enrolled (6 at 225mg/m2 of PU-H71 and 6 at 300mg/m2). Median Age: 54 yrs (range: 37-71). Median ECOG: 0. Median lines of therapy in the metastatic setting: 6 (range 1-11) including prior taxanes in 75% of pts. Most common toxicities included diarrhea G1 58%; G2 7%, G3 7%) that was easily managed with anti-diarrheal agents, G1 fatigue (25%), G1/2 peripheral neuropathy (17%), G1 hyperglycemia (67%), G1 increases in alk phos (58%), AST (50%) and ALT (42%). Hematological toxicities included G3 leukopenia (42%), G3/4 neutropenia (67%), G3 anemia (50%) and G2 thrombocytopenia (17%). There were no DLTs. 33% (4/12) had PR, 58% (7/12) achieved SD with only 1 PD at the time of first scan; 5 pts are currently ongoing including 2 TNBC pts with PR who have been on therapy > 7 months. PK data will be presented. 8/12 patients also underwent PU-PET at baseline. A higher tumor to muscle SUV ratio at 24 hrs on PU-PET predicted response and increased PU-H71 retention on PU-PET at 24 hrs correlated with a longer duration of response.

Conclusion: The RP2D of PU-H71 was 300mg/m2 with 260mg/m2 of nab-paclitaxel administered IV every 3 weeks. The regimen is well tolerated with promising clinical activity in this heavily pre-treated cohort. Tumor epichaperome expression at baseline using PU-PET has the potential to serve as a predictive biomarker of response. A Phase 2 trial of this combination along with baseline PU-PET is currently planned.

Citation Format: Jhaveri K, Dunphy M, Wang R, Comen E, Fornier M, Moynahan ME, Bromberg J, Ma W, Patil S, Taldone T, Rodina A, Sterlin V, Khoshi S, Lewis J, Norton L, Chiosis G, Modi S. Tumor epichaperome expression using 124I PU-H71 PET (PU-PET) as a biomarker of response for PU-H71 plus nab-paclitaxel in HER2 negative (HER2-) metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-03.

Abstract PD1-08: Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 for estrogen receptor-positive (ER+) advanced breast cancer (ABC) with progression on endocrine therapy (ET)

Background: LSZ102 is an orally bioavailable SERD that inhibits ER gene transcription, induces receptor degradation, and blocks ER-dependent cell growth in preclinical models. This study is evaluating LSZ102 as a single agent and in combination with the CDK 4/6 inhibitor ribociclib (LEE011) or the PI3K inhibitor alpelisib (BYL719) in patients (pts) with ER+ ABC. The LSZ102 single agent data are presented below; combination data are not discussed.

Methods: In the dose-escalation phase evaluating single-agent LSZ102 (Arm A), pts (age ≥18 years; ECOG PS 0-1) with histologically confirmed ER+ ABC and progression on endocrine therapy (ET) received LSZ102. The starting dose was 200 mg once daily. The primary objective of Arm A was to characterize the safety and tolerability of LSZ102 and identify a recommended dose for expansion (RDE). Secondary objectives included preliminary antitumor activity and pharmacokinetics (PK).

Results: As of January 22, 2018, 57 pts were enrolled to Arm A (LSZ102 200 mg, n=4; 400 mg, n=6; 450 mg fasted, n=15; 450 mg with food, n=6; 600 mg, n=20; 900 mg, n=6). Median age was 60 years, 75% (n=43) of pts had an ECOG PS of 0, 56% (n=32) had received prior fulvestrant, and 58% (n=33) had received prior CDK4/6 inhibitors; median number of prior lines of therapy (all settings) was 6. At data cut-off, 48 pts had discontinued treatment, most (n=45, 94%) due to disease progression. Dose-limiting toxicities across treatment groups included diarrhea (2 pts in the 900-mg group), vomiting (1 pt in the 600-mg group), and AST and ALT elevation (1 pt in the 450-mg with food group). The most common treatment-related adverse events (AEs) in the treatment period were diarrhea (60%), nausea (56%), and vomiting (30%). In the treatment period, treatment-related grade 3 AEs (12%) were infrequent, and there were no such grade 4 events. Six pts (11%) required dose reduction due to AEs (nausea, vomiting or diarrhea); 4/6 of the dose reductions occurred at 900 mg. Preliminary PK assessment showed rapid absorption and dose-proportional increases in LSZ102 exposure; trough concentrations were above the predicted tumorostatic concentrations at doses of ≥400 mg. Based on PK results for the 450-mg fasted and fed cohorts, LSZ102 exposure does not appear to be affected by dosing with a regular meal. Evidence of ER modulation by immunohistochemistry was observed in paired baseline and on-treatment biopsies. 18F-fluoroestradiol positron emission tomography (FES-PET) analysis (n=6) demonstrated abrogation of FES-PET signal for pts in the 450-mg and 600-mg dose groups. Seventeen pts (29.8%) had a best response of stable disease, and 1 pt, who happened to be in the 600-mg group, achieved a partial response.

Conclusion: In heavily pretreated pts, LSZ102 was well tolerated, demonstrated antitumor activity, and achieved effective exposure levels based on PK and pharmacodynamics. Food intake did not appear to significantly alter the PK profile of LSZ102. Dose escalation for LSZ102 in combination with ribociclib or alpelisib is ongoing and will be reported in a future analysis. An update on the recommended single agent dose and schedule will be presented.

Citation Format: Jhaveri K, Curigliano G, Yap Y-S, Cresta S, Duhoux FP, Terret C, Takahashi S, Ulaner GA, Kundamal N, Baldoni D, Liao S, Crystal A, Juric D. Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 for estrogen receptor-positive (ER+) advanced breast cancer (ABC) with progression on endocrine therapy (ET) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-08.

Abstract OT1-03-01: Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 in combination with alpelisib (BYL719) in estrogen receptor-positive (ER+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) with progression on endocrine therapy (ET)

Background: Although ET remains the basis of therapy for ER+, HER2– ABC, treatment resistance frequently occurs. Novel strategies to target the receptor and/or alternative pathways to overcome therapeutic resistance are under investigation. LSZ102 is a novel, orally bioavailable, nonsteroidal SERD. Preclinically, LSZ102 inhibits ER gene transcription, induces receptor degradation, blocks ER-dependent cell growth, and has synergistic activity with the phosphoinositide 3-kinase (PI3K)-alpha inhibitor alpelisib (BYL719). The present study is evaluating the safety and tolerability of LSZ102 plus alpelisib in patients with ER+, HER2– ABC with progression on ET.

Trial Design: This phase 1/1b, open-label study is enrolling ˜18-30 patients (men and women of any menopausal status) in Arm C of the dose-escalation part of the study, which investigates the combination of LSZ102 and alpelisib; additional study arms will investigate LSZ102 as a single agent or in combination with ribociclib. Enrollment in Arm C started after identification of a safe and tolerable single-agent dose for LSZ102. Alpelisib dosing began at 200 mg/day and will not be escalated beyond the maximum tolerated dose (MTD) determined in the alpelisib single-agent arm of study CBYL719X2101 (400 mg/day). Dose escalation of alpelisib in combination with LSZ102 is guided by BLRM and integrates Cycle 1 DLT rates, lower grade and later cycle AE, PK, PD and preliminary activity to identify a recommended dose for expansion (RDE). Patients will receive treatment until disease progression, unacceptable toxicity, or withdrawal of consent. For inclusion in the study, patients must have histologically confirmed ER+, HER2– ABC and disease progression after ET for ABC or recurrence on/within 12 months of completion of adjuvant ET. In the escalation part of the study, patients are eligible regardless of PIK3CA status. Premenopausal women must receive concomitant treatment with a gonadotropin-releasing hormone agonist. Eligible patients must have adequate bone marrow and organ function, Eastern Cooperative Oncology Group performance status of 0 or 1, and have completed and recovered from acute toxicities of radiotherapy and/or prior anticancer therapy. Exclusion criteria include symptomatic central nervous system metastases, clinically significant cardiac disease or impaired cardiac function (including a QT interval corrected for heart rate using Fridericia's formula [QTcF] >460 ms in women or >450 ms in men), uncontrolled diabetes mellitus type II (or type I), and prior treatment with a PI3K inhibitor. The primary objectives are characterization of safety and tolerability for the combination and identification of a recommended dose. Secondary objectives include characterization of pharmacokinetic properties and pharmacodynamic effects. Recruitment for Arm C is ongoing. NCT02734615

Citation Format: Curigliano G, Cresta S, Yap Y-S, Juric D, Duhoux FP, Terret C, Takahashi S, Layman RM, Kundamal N, Baldoni D, Liao S, Crystal A, Jhaveri K. Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 in combination with alpelisib (BYL719) in estrogen receptor-positive (ER+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) with progression on endocrine therapy (ET) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-03-01.

Abstract P1-19-03: A phase I trial of sorafenib with whole brain radiotherapy (WBRT) in breast cancer patients with brain metastases and a correlative study of FLT-PET brain imaging in patients receiving WBRT with or without sorafenib

Background: WBRT is a standard therapy for metastatic breast cancer (MBC) patients (pts) with brain metastases (BM), but disease progression in the brain is common. Sorafenib, a tyrosine kinase inhibitor with anti-VEGF activity, has demonstrated anti-tumor efficacy in MBC and radiosensitizing activity preclinically. [18F] 3'deoxy-3'-fluorothymidine (FLT) is a new PET tracer which correlates with cellular proliferation and may improve response assessment in the brain. Methods: A phase I trial of sorafenib with WBRT in MBC pts with BM was conducted using a 3+3 design. Sorafenib was given orally daily at the start of WBRT for a total of 21 days with 3 doses levels: 200mg, 400mg, and 600mg. The primary endpoints were to determine a maximum tolerated dose (MTD) and to evaluate safety and toxicity. The secondary endpoint was central nervous system progression-free survival (CNS-PFS). Macdonald Criteria were used for response assessment with serial MRI brain imaging. Key eligibility criteria include MBC with new or progressive ≥ 1cm BM, ECOG PS 0-2, non-escalating corticosteroid dose, and no other concurrent anti-tumor therapy except trastuzumab. In parallel, we conducted a correlative FLT-PET imaging study (baseline, 7-10 days (FU1), and 10-12 weeks (FU2) after the WBRT) to assess radiographic changes among pts receiving WBRT + sorafenib and in a separate WBRT only cohort. FLT standard uptake value (SUV) and kinetic parameter data were obtained. Results: 13 pts were treated in the dose escalation phase and evaluable for dose-limiting toxicity (DLT). The median age was 56 years (range: 43-77). There were 4 HER2 positive (31%) and 3 triple negative (23%) pts. 2 pts had prior stereotactic radiosurgery. DLTs were: Grade (G) 4 increased lipase at 200mg (1 pt) and G3 rash at 400mg (3 pts) level. MTD was determined to be 200mg. 10 pts were evaluable for response (at least 1 follow up brain imaging). The overall response rate was 70%: 4 complete responses (CR) + 3 partial responses. All 13 pts were evaluated for CNS PFS with a median follow up of 29.7 months (min 19.6, max 57.4mo). Median CNS-PFS was 8.2 months (95%CI: 3.4-31.8). Median OS was 15.4 months (95% CI: 3.4-NR). A total of 10 pts with WBRT and sorafenib and 5 pts with WBRT only were enrolled in the FLT-PET study: all 15 pts had baseline FLT PET, 14 with FU1, and 9 with FU2. 55 baseline lesions, 38 at FU1 and 15 at FU2 were observed and analyzed. All lesions with FLT uptake had MRI correlates. Decline in average SUVmax of ≥25% was seen in 9/10 (90%) of WBRT+sorafenib and 2/4(50%) of WBRT only pts at FU1. A complete disappearance of FLT uptake was noted in 1 pt at FU1 and 2 more pts at FU2. Conclusions: Concurrent WBRT with sorafenib appears safe at 200mg daily dose with a higher rate of CR compared to historical WBRT data. We are currently enrolling patients in the safety-expansion cohort. This combination should be considered for further efficacy evaluation. Additional analysis of FLT-PET as a complementary imaging modality to MRI is currently ongoing. Clinical trial registry: NCT01724606 and NCT01621906. Support: Bayer, Susan G Komen, ASCO Gianni Bonadonna Breast Cancer Award

Citation Format: Morikawa A, Jhaveri K, Grkovski M, Tang K, Humm JL, Holodny A, Beal K, Schoder H, Seidman AD. A phase I trial of sorafenib with whole brain radiotherapy (WBRT) in breast cancer patients with brain metastases and a correlative study of FLT-PET brain imaging in patients receiving WBRT with or without sorafenib [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-19-03.

Abstract P5-21-04: Phase I/Ib study of the SERD LSZ102 alone or in combination with ribociclib in ER+ breast cancer

Background: LSZ102 is an orally bioavailable selective estrogen receptor degrader (SERD) that inhibits estrogen receptor (ER) gene transcription, induces receptor degradation, and blocks ER-dependent cell growth in preclinical models. This Phase I/Ib, open-label study is evaluating LSZ102 as a single agent and in combination with the CDK4/6 inhibitor ribociclib (LEE011) or the PI3K inhibitor alpelisib (BYL719) in patients (pts) with locally advanced/metastatic ER-positive (ER+) breast cancer (BC).

Methods: The primary objective is to characterize the safety and tolerability, and identify a recommended dose and regimen of LSZ102 alone (Arm A) or in combination with ribociclib (Arm B) or alpelisib (Arm C). Secondary objectives include evaluation of preliminary antitumor activity and pharmacokinetics (PK). Eligible pts (aged ≥18 yrs; ECOG PS 0-1) have histologically confirmed ER+ BC that has progressed after endocrine therapy.

Results: As of March 14, 2017, dose escalation evaluating 16 pts in Arm A (LSZ102 200 mg [n=4], 400 mg [n=6], and 600 mg [n=6]) had completed (median age 57.5 yrs; 81% ECOG PS 0; 63% received prior fulvestrant). Five pts (median age 59.0 yrs; 80% ECOG PS 0; 60% received prior fulvestrant) had enrolled in the first cohort of Arm B (LSZ102 200 mg QD + ribociclib 300 mg 3 weeks on/1 week off) with evaluation ongoing. Arm C (LSZ102 + alpelisib) had yet to open. As of March 14, 2017, 9/16 (56%) pts in Arm A had discontinued treatment, all due to progressive disease (PD); in Arm B all pts were still receiving treatment. There were no dose-limiting toxicities in either arm at the dose levels evaluated; dose escalation is ongoing. The most common drug-related adverse events (AEs) were diarrhea (Grade [Gr] 1: 7/16; Gr 2: 2/16 pts), nausea (Gr 1: 6/16; Gr 2: 2/16 pts), and vomiting (Gr 1: 3/16 pts) in Arm A, and hot flush, nausea, vaginal discharge (all Gr 1: 2/5 pts), thrombocytopenia (Gr 1: 1/5; Gr 2: 1/5 pts), and neutropenia (Gr 2: 1/5, Gr 3: 1/5 pts) in Arm B. There were no drug-related Gr 3/4 AEs reported in Arm A; in Arm B, Gr 3 neutropenia, leukopenia, and lymphopenia each occurred in 1/5 pts. Preliminary PK assessment showed single-agent LSZ102 exposure increased dose-proportionally from 200 to 600 mg QD. In combination with ribociclib, exposures were consistent with those of the single agent at the same dose. In Arm A, preliminary evidence of antitumor activity was observed. Efficacy data for Arms B and C were not available as of March 14, 2017. One pt, whose tumor harbored an ESR1 D538G mutation, had been treated with multiple prior therapies in the metastatic setting, including letrozole, exemestane, tamoxifen, exemestane + everolimus, and anastrozole, as well as fulvestrant for 120 days prior to PD, and letrozole + palbociclib for 94 days prior to PD. As of March 14, 2017, this pt had been on LSZ102 treatment (400 mg QD) for 167 days, with a best response of stable disease (14% reduction in sum of diameter of target lesions).

Conclusions: Oral single-agent LSZ102 appears well-tolerated, with a manageable safety profile. Preliminary data also suggest tolerability when combined with ribociclib. Preliminary evidence of single-agent antitumor activity was seen in heavily pretreated pts with ER+ BC in a post-fulvestrant setting.

Citation Format: Juric D, Curigliano G, Cresta S, Yap Y-S, Terret C, Duhoux FP, Takahashi S, Kundamal N, Bhansali S, Liao S, Crystal A, Jhaveri K. Phase I/Ib study of the SERD LSZ102 alone or in combination with ribociclib in ER+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-04.

Abstract P6-12-03: A phase I study of AZD9496, a novel oral, selective estrogen receptor degrader (SERD) in women with estrogen receptor positive, HER-2 negative advanced breast cancer (ABC)

Background AZD9496 is a potent orally bioavailable ER antagonist and degrader that has shown antitumor efficacy in a range of preclinical xenograft models including ESR1wild-type tamoxifen-resistant and long term estrogen deprived models and an ESR1 mutant model.

Methods This is a phase I, open label global multicenter study in women with ER+ HER2–ve BC either metastatic or locoregionally recurrent, not amenable to treatment with curative intent. Patients are post-menopausal, or pre-menopausal women receiving LHRH agonist therapy, with disease progression after ≥6 months endocrine therapy for ER+ BC (no limit on number of prior endocrine therapies; ≤2 prior chemotherapies in advanced setting). The primary objective is to determine the safety and tolerability of AZD9496. Cohorts of 3-6 patients received daily oral therapy and dose limiting toxicities (DLTs) occurring in cycle 1 (28 days) were assessed. Patients are dosed until MTD (defined as ≤1/6 patients with a DLT) or maximum feasible dose (MFD) is reached. Key secondary objectives include determination of single and multiple dose pharmacokinetics (PK), and preliminary antitumor efficacy. ER target modulation by protein and gene expression is evaluated in circulating tumor cells and paired tumor biopsies.

In addition to the dose escalation phase, expansion cohort(s) in patients with or without ESR1 mutations can be enrolled to examine the safety, tolerability, PK and biological activity of AZD9496 further.

Results Preliminary data as of 30th April 2016: 45 patients (median age 62 (range 41-83); 38 post-menopausal, 7 pre/perimenopausal; visceral metastases 76%, prior fulvestrant 25/45) received AZD9496 in 7 dose escalation cohorts: 20mg QD n=4, 40mg BID n=6, 80mg BID n=5, 150mg BID n=6, 250mg BID n=6, 400mg BID n=6, 600mg BID n=6 and also a 250mg BID expansion cohort n=6. The majority of adverse events (AEs) were grade 1 or 2; the most common treatment-related AEs (≥10%) have been diarrhoea (33%), fatigue (27%), nausea (22%), upper abdominal pain (13%) and increased liver function tests (13%). Six patients had treatment-related grade 3 AEs, 5 of which were manageable with dose interruption +/- dose reduction. Specifically, three had DLTs: grade 3 increased AST/ALT/GGT-150mg BID, serious adverse reaction (SAR) leading to withdrawal; grade 3 diarrhoea and grade 3 increased AST/ALT/GGT-400mg BID, SAR, manageable with dose reductions; grade 3 diarrhoea 600mg BID, manageable with dose reduction. The MTD/MFD has not been reached.

Following the first dose up to 400mg the AZD9496 exposure increased in reasonable proportion to increasing dose. At 600mg a more than dose-proportional increase in exposure was observed. Evidence of reduced ER and Ki67 has been observed in on-study biopsies at 150mg BID and above. 10 subjects received treatment for >3-<6 months (5 ongoing, 5 discontinued),4 subjects >6-<12 months (3 ongoing, 1 discontinued), 3 subjects ≥1 year (2 ongoing, 1 discontinued).

Conclusions AZD9496 has a tolerable safety profile, evidence of PD biomarker modulation and prolonged stabilisation of disease in women with heavily pre-treated ER+ve ABC.

Citation Format: Hamilton E, Patel M, Armstrong A, Baird R, Jhaveri K, Hoch M, Morgan S, Dowdall T, Schiavon G, Klinowska T, Weir H, Bujac S, Nash T, Im S-A. A phase I study of AZD9496, a novel oral, selective estrogen receptor degrader (SERD) in women with estrogen receptor positive, HER-2 negative advanced breast cancer (ABC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-03.

Abstract P4-21-34: Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy

Background: The combination of taxanes with trastuzumab (H) and pertuzumab (P) for first line treatment of HER2-positive metastatic breast cancer (MBC) is associated with improved progression-free survival (PFS) and overall survival (OS). Treatment per physician's choice with anti-HER2 therapy after second line therapy is associated with a median PFS of 3 months. While continued use of H in therapeutic combinations after progression on H-based therapy is common, the efficacy of continuing HP-based treatment after progression on P-based therapy is unknown.

Methods: This is a single arm phase II trial of gemcitabine (G) with HP. Eligible patients had HER2-positive (IHC 3+ or FISH ≥ 2.0) MBC with prior HP-based treatment and ≤ 3 prior chemotherapies. Patients received G (1200 mg/m2) on days 1 and 8 of a q 3 week (w) cycle, and H (8 mg/kg load → 6 mg/kg) and P (840 mg load → 420 mg) q3w. The primary endpoint is PFS at 3 months. Secondary endpoints include OS, safety and tolerability. An exploratory endpoint is to compare PFS by RECIST criteria versus 18-F FDG-PET response criteria. Using a Simon optimal 2-stage design, 21 patients were enrolled in stage 1. The successful 3-month PFS rate for stage 1 was set at 57% to allow accrual to stage 2 for a total of 45 patients. The study therapy will be considered successful if at least 27/45 (60%) patients are progression free at 3 months.

Results: As of June 9, 2016, 28 patients are enrolled; 21 are evaluable at 3 months and 7 have not had 3-month evaluation. At 3 months, 16/21 (76%) are progression free; 5 patients have progressed. The 3 month-PFS results for evaluable patients will be updated. There are no cardiac or febrile neutropenic events to date. Initially, 5 of 22 (23%) patients required G dose reduction (4 due to grade 3 neutropenia and 1 due to grade 3 vomiting) and the study was amended to lower initial G dose to 1000 mg/m2.

Conclusions: The preliminary 3 month-PFS is 76% (95% CI 55% to 89%) in evaluable patients, and updated data will be presented. These findings suggest clinical benefit when P is continued beyond progression.

Citation Format: Iyengar NM, Smyth L, Lake D, Gucalp A, Singh JC, Traina TA, DeFusco P, Dickler MN, Fornier MN, Goldfarb S, Jhaveri K, Modi S, Troso-Sandoval T, Argolo D, Jack K, Ulaner G, Jochelson M, Baselga J, Norton L, Hudis CA, Dang CT. Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-34.

Abstract P6-11-03: A phase 2 open-label study of lucitanib in patients (pts) with FGF aberrant metastatic breast cancer (MBC)

BACKGROUND: Lucitanib is a potent, oral antiangiogenic tyrosine kinase inhibitor of Vascular Endothelial Growth Factor Receptors 1-3 (VEGFR1-3), Platelet-Derived Growth Factor Receptors alpha and beta (PDGFRα/β), and Fibroblast Growth Factor Receptors 1-3 (FGFR1-3). FGF aberrancies (amplification of FGFR1,or 11q[amplicon containing FGF ligands 3, 4, and 19]), are genomic alterations observed in over 20% of breast cancer pts and promote cancer proliferation and survival.

METHODS: MBC pts who had received at least 1 metastatic line of therapy were randomized 1:1 to 10 or 15 mg QD of lucitanib. Stratification was based on local assessment of FGF aberrancy; pts with both FGFR1 and 11q-amplified tumors were stratified as FGFR1 amplified. Central confirmation of FGFR1 or 11q amplification was done using Abbott FISH probes (FGFR1 or 11q copy number ≥ 6 and a ratio of FGFR1 or 11q to centromere ≥ 2). Investigator-assessed progression-free survival (PFS) was the primary endpoint. Secondary endpoints included objective response rate (ORR) per RECIST 1.1, disease control rate (DCR), duration of response (DR), and incidence of treatment-emergent adverse events (TEAE).

RESULTS: Enrollment completed in 3/2016; 178 pts that received at least 1 dose of lucitanib are included in this analysis (baseline characteristics in Table 1). Due to grade 3 hypertension in the 15 mg group (46% vs 37% in 10 mg group), enrollment to the 15 mg group was halted. Overall, most pts (97%) experienced at least 1 TEAE, with the most frequently (≥ 30%) occurring events being hypertension (73%), fatigue (48%), nausea (43%), hypothyroidism (40%), and headache (33%). Grade ≥ 3 TEAEs occurred in 66% of pts, with hypertension as the most frequent event (40%) followed by proteinuria and hyponatremia (both 6%). AEs were manageable with dose interruption or reduction, with approximately 8% of pts ending treatment due to an AE. Current median PFS is 3.5 mos (95% CI 2.8-4.6; range 0.62-12.95) and 2.6 mos (95% CI 1.8-2.9; range 0.82-18.87) respectively for the 10 mg and 15 mg treatment groups. No differences in clinical activity were observed by treatment group, FGF aberrancy, hormone receptor or HER2 status. Of the 168 evaluable pts, confirmed ORR was 3%; overall DCR was 27% (32% for pts in the 10 mg group compared to 20% for the 15 mg group); overall mean (standard deviation) DR of 3.3 (1.8) mos.

Baseline Characteristics 10 mg QD15 mg QD N=109N=69Age (years)Median5653Range27-8227-80SexFemale109 (100%)67 (97%)Male02 (3%)ECOG PSmissing5 (5%)2 (3%)051 (47%)30 (43%)153 (49%)37 (54%)Number of prior anticancer therapies in the metastatic setting> 332 (29%)21 (30%)3-648 (44%)32 (46%)> 629 (27%)16 (23%)Endocrine/HER2 statusmissing7 (6%)1 (1%)ER+ or PR+74 (68%)50 (73%)HER2+12 (11%)7 (10%)TNBC16 (15%)11 (16%)FGFR aberrancyFGFR1 amplified54 (49%)29 (42%)11q amplified31 (28%)24 (35%)FGFR1 and 11q amplified13 (12%)9 (13%)FGFR1 and 11q non-amplified11 (10%)7 (10%)

CONCLUSION: At 10 mg QD, lucitanib has modest activity with manageable toxicity in this heavily pretreated pt population. Future clinical development for lucitanib may focus on alternative biomarkers to identify sensitive tumors and rational combinations with other anti-cancer drugs.

Citation Format: Mayer IA, Arteaga CL, Nanda R, Miller KD, Jhaveri K, Brufsky AM, Rugo H, Yardley DA, Vahdat LT, Sadeghi S, Audeh MW, Rolfe L, Litten J, Knox A, Raponi M, Tankersley C, Isaacson J, Wride K, Morganstern DE, Vogel C, Connolly RM, Gradishar WJ, Patel R, Pusztai L, Abu-Khalaf M. A phase 2 open-label study of lucitanib in patients (pts) with FGF aberrant metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-11-03.

Abstract P4-14-21: A phase I trial of ganetespib (heat shock protein 90 inhibitor) in combination with paclitaxel and trastuzumab in patients with human epidermal growth factor receptor-2 positive (HER2+) metastatic breast cancer (MBC)

Introduction: Targeted therapies in HER2+ MBC significantly improve outcomes but efficacy is limited by therapeutic resistance. HSP90 is a molecular chaperone involved in the stability and function of multiple signaling onco-proteins. HER2 is an acutely sensitive HSP90 client and HSP90 inhibition can overcome trastuzumab resistance. Our group reported objective responses with 17-AAG plus trastuzumab in HER2+ MBC. Ganetespib, a synthetic, second generation HSP90 inhibitor has increased potency and tolerability compared with earlier agents. We reported anti-tumor activity in metastatic HER2+ and triple negative breast cancer with single agent ganetespib. Preclinically, HSP90 inhibition has synergistic anti-tumor activity with taxanes and trastuzumab. This study will define the MTD and RP2D of ganetespib plus paclitaxel and trastuzumab in HER2+ MBC.

Methods: In this 3+3 phase I dose escalation study, patients with trastuzumab-resistant HER2+ MBC receive weekly trastuzumab and paclitaxel (80mg/m2) with ganetespib on day 1, 8, 15 of a 28 day cycle. HR+ positive patients are required to have at least one prior line of endocrine therapy. DLT of ganetespib monotherapy is diarrhea and therefore patients receive prophylactic anti-motility agents. Based on prior experience with ganetespib plus docetaxel in NSCLC, only 3 dose levels of ganetespib were explored: 100mg/m2, 150mg/m2 and a 3rd cohort of 125mg/m2, if needed. Secondary endpoints include evaluation of effects of ganetespib on the pharmacokinetics (PK) of paclitaxel and preliminary efficacy assessment.

Results: The dosing cohorts (100 mg/m2 (n=3) and 150 mg/m2 (n=6)) have been completed without any DLTs. Median age was 46 years (range 29-65), median prior lines of chemotherapy and anti-HER2 therapy were 3 (range 2-6) and 3 (range 2-4) respectively, including prior pertuzumab in 9/9 and T-DM1 in 8/9 patients. There were no grade 3/4 adverse events (AEs) related to ganetespib. Most common AEs related to ganetespib were diarrhea, fatigue, anemia and rash. Paclitaxel PK data available from 6/9 patients are not appreciably different from those reported in literature. Overall response rate was 25% (2/8 had PR in 150 mg/m2 cohort; 1 patient was not evaluable), SD in 63% (5/8), and clinical benefit rate (CR+PR+SD>24 weeks) was 50% (4/8). 3 patients remain on study.

Conclusion: The RP2D of ganetespib is 150mg/m2 in combination with paclitaxel and trastuzumab. The combination was safe and well tolerated. Updated PFS and PK data will be presented. Despite prior taxanes, pertuzumab and T-DM1, clinical activity of this triplet regimen in this heavily pre-treated cohort is very promising and together with our prior experience with 17-AAG plus trastuzumab and single agent ganetespib warrants further study in HER2+ MBC. A phase 2 trial is being planned in trastuzumab-refractory HER2+ MBC who have progressed on prior pertuzumab and T-DM1. Additionally, the protocol is amended to assess the safety of ganetespib in combination with paclitaxel, trastuzumab and pertuzumab in the first-line setting.

Citation Format: Jhaveri K, Teplinsky E, Chandarlapaty S, Solit D, Cadoo K, Speyer J, D'Andrea G, Adams S, Patil S, Haque S, Friedman K, Neville D, Esteva F, Hudis C, Modi S. A phase I trial of ganetespib (heat shock protein 90 inhibitor) in combination with paclitaxel and trastuzumab in patients with human epidermal growth factor receptor-2 positive (HER2+) metastatic breast cancer (MBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-21.

Abstract P2-11-11: Phase II trial of exemestane with immunomodulatory oral cyclophosphamide in metastatic hormone receptor (HR)-positive breast cancer: Prolonged progression-free survival (PFS) in patients with distinct T regulatory cell (Treg) profile

Background: Resistance to endocrine therapies in HR-positive breast cancer is a significant challenge. The steroidal aromatase inhibitor (AI) exemestane (EXE) has demonstrated short-term efficacy in metastatic HR-positive HER2-negative breast cancer (mHR+BC) that has progressed during treatment with a non-steroidal AI. Combination strategies have not shown a survival benefit. Immunotherapy represents a promising approach as it may increase durability of responses. Low dose cyclophosphamide (CTX) has demonstrated efficacy in combination with neoadjuvant letrozole in HR+BC, conceivably by enhancing anti-tumor immune responses. Here we investigated whether EXE combined with immunomodulatory CTX could provide durable responses in heavily pretreated patients and assessed immunological profiles (NCT01963481).

Methods: Phase II trial of EXE (25mg PO daily) with CTX (50 mg PO daily) enrolled postmenopausal women (n=23) with mHR+BC who had progressed on prior endocrine therapy (including nonsteroidal AI, tamoxifen, and/or fulvestrant); prior chemotherapy was allowed. The primary endpoint was PFS (per RECIST 1.1) at 3 months; secondary endpoints were response rate, tolerability, and immune correlates. Detailed functional immune profiling of peripheral T cell subsets were performed by flow cytometry at baseline, 1, 3, 6, 9 & 12 months, with healthy donors available as controls.

Results: All 23 patients have been enrolled, and 21 are evaluable for response. Median age was 54 (range 31-77), median prior lines of endocrine therapy was 2 (1-3) and chemotherapy was 1 (0-5). The majority (15/23) had visceral organ involvement. Combination treatment was well tolerated with one grade 3 urinary tract infection but no grade 4 or 5 toxicity. An objective response was observed in 19% of patients (4/21, 1 CR and 3 PR) and an additional 33% (7/21) had SD, resulting in a 3-month-PFS of 48.5% (95% CI, 30.5-77.1). Responses were durable in all patients, lasting =/> 9 months and included patients with liver metastases.

Comparison of peripheral immune cell subsets of patients (n=16) at baseline to age/sex-matched healthy controls demonstrated an increased proportion of CD4+ memory T cells with central memory phenotype (CD45RO+CD27+, p<0.0001). When patients were stratified based on PFS at 3 months, the proportion of naïve Tregs (CD4+CD45RO-FOXP3+Helios+) at baseline was significantly lower (p=0.003) in the non-progressor group compared to patients with progression. Remarkably, when these patient groups were compared for changes in T cell subsets during treatment, the proportion of both naïve and memory Treg subsets increased from baseline to 3 months (p<0.01), but only in the non-progressor patient group. While preliminary, these findings are possibly indicative of novel predictive biomarkers.

Conclusion: EXE and CTX had a favorable safety profile with evidence of clinical activity in patients with heavily pretreated mHR+BC, including durable responses in liver and bone. Correlative studies are ongoing to identify potential biomarkers of response or resistance to therapy.

Citation Format: Kwa M, Novik Y, Oratz R, Jhaveri K, Wu J, Gu P, Meyers M, Muggia F, Bonakdar M, Abidoglu C, Kozhaya L, Li X, Joseph B, Iwano A, Friedman K, Goldberg JD, Unutmaz D, Adams S. Phase II trial of exemestane with immunomodulatory oral cyclophosphamide in metastatic hormone receptor (HR)-positive breast cancer: Prolonged progression-free survival (PFS) in patients with distinct T regulatory cell (Treg) profile. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-11.

Abstract PD5-6: Sustained hyperactivated mTOR & JAK2/STAT3 pathways in inflammatory breast cancer (IBC): Evidence for mTOR plus JAK2 therapeutic targeting

Background: IBC is an aggressive form of breast cancer with poor prognosis. Combined multi-modality therapy results in a 5 year OS of 30%, underscoring the unmet need for targeted therapy. Our preclinical research in cell lines & xenograft tumor models has identified a role for hyper-activated PI3K/mTOR signaling in IBC. IBC cells express IL-6 and IL-8, which recruit tumor activated macrophages (TAMs) that further induce inflammatory cytokines and activate the JAK2/STAT3 pathway. We investigated the independent and combined activity of these pathways in IBC patient tissues.

Methods: Archived tissue specimens of 42 IBC patients (dx 1999-2009) and 27 non-IBC patients (dx 2001-2005) with invasive ductal carcinoma (IDC) were obtained. Surrounding non-tumor normal tissue from IBC (companion controls) was also utilized. All specimens were analyzed using immunohistochemistry (IHC) and scored by 3 independent pathologists. Results were defined as 0 = negative; 1+,2+ = positive for activated mTOR (P-S6); activated JAK2/STAT3 (P-JAK2; P-STAT3); cytokine (IL-6); macrophage infiltration (CD68) and TAM (CD163). Proportions of IBC cases with positive expression were compared with non-IBC cases (Fisher's exact test) & companion controls (McNemar's test). Clinical & survival data were obtained.

Results: Median age at diagnosis: 46 yrs (31-62) in early stage IBC [EIBC] (n = 37) & 41 yrs (29-57) in pts with de novo metastatic IBC [MIBC] (n = 5). In EIBC, 19/36: HER2+ (1 unk); 8/19: ER+/HER2+; 8/36: ER-/HER2-. In MIBC, all were ER- (1 unk) & 3/4 were HER2+ (1 unk). 88% were rx with neoadjuvant &/or adjuvant anthracycline & taxane w/o adjuvant trastuzumab. There were 24 pt deaths (5/5 MIBC). Median f/u for EIBC: 6.3 yrs and for MIBC: 3.4 yrs. Median OS: 81.4 mo (95% CI lower 48 mo) for EIBC & 41 mo (95% CI 8-81 mo) for MIBC. Median RFS: 18 mo (95% CI 18-79 mo) for 23 pts (13 NED; 1 unk). The non-IBC patients were all stage 2-3 with median age at diagnosis: 58 yrs (39-94). 19/27: ER+; 7/25 HER2+ (2 unk); 15/25 ER+/HER2-; 3/25 ER-/HER2-. 78% were rx with adjuvant anthracycline & taxane, 4% were rx with FEC and 18% did not receive adjuvant chemotherapy. 18% received adjuvant trastuzumab. Median f/u: 8.0 yrs. Median OS: not yet reached and median RFS: 111.3 mo (95% CI lower 34.5 mo). EIBC cases were compared with non-IBC cases & companion controls (Table 1). PS6, pJAK2 and pSTAT3 expression was significantly increased in IBC compared to non-IBC. Of the 29 EIBC patients with complete biomarker data who were PS6+, 28/29 (97%) were JAK2+, 15/29 (52%) were STAT3+, 26/29 (90%) were CD68+, 20/29 (69%) were CD163+ and 28/29 (97%) were IL6+.

Conclusion: This is the first study to validate preclinical findings & show a strong co-association between hyper-activation of mTOR & JAK/STAT pathways in most IBC patient tumors when compared to surrounding non-tumor tissue and non-IBC (IDC) tumors and tissues. These findings suggest a key role for dual blockade of mTOR & JAK/STAT pathways for IBC in phase I trials.

BiomarkerMcNemars p-value: Early Stage IBC vs companion controls (N = 37)Fishers p-value: Early stage IBC (N = 37)vs non-IBC (N = 27)PS6<0.00010.0315pJAK2<0.0001<0.0001pSTAT30.0003<0.0001CD163<0.00010.0908CD68<0.00010.0582IL60.00030.3882

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD5-6.

Molecular characterization of mutant mouse strains generated from the EUCOMM/KOMP-CSD ES cell resource

The Sanger Mouse Genetics Project generates knockout mice strains using the EUCOMM/KOMP-CSD embryonic stem (ES) cell collection and characterizes the consequences of the mutations using a high-throughput primary phenotyping screen. Upon achieving germline transmission, new strains are subject to a panel of quality control (QC) PCR- and qPCR-based assays to confirm the correct targeting, cassette structure, and the presence of the 3' LoxP site (required for the potential conditionality of the allele). We report that over 86 % of the 731 strains studied showed the correct targeting and cassette structure, of which 97 % retained the 3' LoxP site. We discuss the characteristics of the lines that failed QC and postulate that the majority of these may be due to mixed ES cell populations which were not detectable with the original screening techniques employed when creating the ES cell resource.

Eastern Canadian colorectal cancer consensus conference: application of new modalities of staging and treatment of gastrointestinal cancers

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Ottawa, Ontario, October 22-23, 2010. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer, such as the use of epidermal growth factor inhibitors in metastatic colon cancer, the benefit of calcium and magnesium with oxaliplatin chemotherapy, the role of microsatellites in treatment decisions for stage II colon cancer, the staging and treatment of rectal cancer, and the management of colorectal and metastatic pancreatic cancers.

Current and emerging techniques in gastrointestinal imaging

This review is devoted to current and emerging techniques in gastrointestinal (GI) imaging. It is divided into three sections focusing on areas that are both interesting and challenging: imaging of the small bowel and appendix, imaging of the colon and rectum and finally liver and pancreas in the upper abdomen. The first section covers cross-sectional imaging of the small bowel using the techniques of multidetector computed tomography (MDCT) (including CT enterography) and magnetic resonance imaging (MRI). The evaluation of mesenteric ischemia and GI tract bleeding using MDCT angiography is also reviewed. Current imaging practice in the evaluation of appendix is also reviewed and illustrated. The second section reviews CT and MR colonography and imaging of the rectum. It describes CT virtual colonoscopy (CTVC) with emphasis on the advantages and disadvantages of the technique with discussion of the role of CTVC in screening. The intriguing topic of MR colonography (MRC) is also reviewed. Imaging of the rectum with emphasis on imaging of rectal cancer is described with the roles of CT, MR, endoluminal ultrasound and positron emission tomography scanning discussed. The final section reviews current and emerging techniques in liver imaging with the role of ultrasound including contrast ultrasound, MDCT and MR (including contrast agents) discussed. The new developments and applications of imaging of pancreatic disease are discussed with emphasis on the role of MDCT and MRI with gadolinium. This review highlights the current role and advancement of imaging techniques with new diagnostic and prognostic information pertinent to gastrointestinal disease continuing to emerge.

Genitourinary imaging: current and emerging applications

This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT) and magnetic resonance (MR) in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

Pseudocyst rupture into the portal vein diagnosed with MRI

We report on the first documented case of rupture of a pancreatic pseudocyst into the portal vein diagnosed with MRI.

Halo sign: useful CT sign for differentiating benign from malignant colonic disease

AIM

To evaluate the halo sign for accurately distinguishing benign from malignant colonic wall thickening.

MATERIALS AND METHODS

Computed tomography (CT) examinations of 92 patients (70 men; 22 women; mean age 57 years) with pathologically proven colonic wall thickening (51 benign and 41 malignant) were retrospectively reviewed in a blinded fashion. The affected segment was assessed for presence of the halo sign, degree and uniformity of thickness and density of the intramural stratum.

RESULTS

The halo sign was present in 74.5% (38/51) patients with benign and 7.3% (3/41) patients with malignant bowel disease. The presence of the halo sign was 75.4% sensitive and 92.5% specific for benign bowel wall thickening. All 38 benign halos showed uniform, continuous stratification; only one of three malignant halos met the strict criteria for benign halo.

CONCLUSION

The halo sign is a moderately sensitive and highly specific sign for distinguishing benign from malignant bowel wall thickening. However, it is not pathognomonic for benign disease. Detailed analysis of halo characteristics is necessary to improve the usefulness of this finding.

Predictive value of benign percutaneous adrenal biopsies in oncology patients

PURPOSE

Percutaneous CT guided biopsy is accepted as a safe procedure for the diagnosis of indeterminate adrenal masses in oncologic patients. The purpose of this study was to evaluate the accuracy of a 'negative for tumour' adrenal biopsy in the oncologic patient population by assessing subsequent outcome including clinical course, size and imaging characteristics of the adrenal lesions on follow-up imaging studies and pathological findings at re-biopsy or following adrenal mass resection.

MATERIALS AND METHODS

Retrospective analysis of 225 oncological patients (FM, 128;87; age range 33-87 years, mean age 66 years) who had undergone CT guided biopsies of an adrenal mass over a 5-year period was performed. Those patients with a report consistent with 'negative for malignancy' were evaluated by reviewing the medical records for patient demographics, primary malignancy, histology of adrenal tumour, subsequent surgical interventions, repeat adrenal biopsy under image guidance, by open surgery or at autopsy, subsequent abdominal imaging in which the adrenal gland was imaged, and long-term outcome including hospital admissions, or death.

RESULTS

Of the 225 CT-guided adrenal biopsies performed, 41 (18%) were negative for neoplasm. The primary neoplasm in these 41 patients included lung cancer (n=32), breast (n=5), renal cell carcinoma (n=2), bladder (n=1), and prostate (n=1). The size of the adrenal lesions ranged from 2.8-5 cm. Of the 41 biopsies, which were negative for tumour; 10 were identified as adenomas and the rest showed benign adrenal cortical cells or hyperplasia on cytopathology and histopathology. Repeat biopsies were obtained in 13/41 (31%) patients; whereas 2/41 (5%) had their adrenal gland analyzed on post mortem examination. None of these 15 repeat evaluations yielded tumour.

CONCLUSION

In oncological patients, pathological analysis of tissue samples obtained by CT-guided percutaneous biopsy, suggesting benign aetiology, is reliable and predicts a benign course on long-term follow-up. A negative or benign pathology result for a CT guided percutaneous adrenal biopsy can be regarded as a true negative evaluation in oncological patients with no necessity to repeat the biopsy.

Comprehensive evaluation of patients with haematuria on multi-slice computed tomography scanner: protocol design and preliminary observations

An imaging protocol with a multi-slice CT scanner that allows comprehensive assessment of patients with haematuria is described. This protocol allows evaluation of the kidneys, ureters and bladder in a single examination using CT. This approach should streamline the diagnostic work-up of patients with haematuria.

ICMR task force study on hormonal contraception. Transfer of levonorgestrel (LNG) administered through different drug delivery systems from the maternal circulation into the newborn infant's circulation via breast milk

The transfer of levonorgestrel (LNG) from the maternal plasma via breast milk to the infant was studied in 38 fully lactating and breast-feeding women at 4-6 weeks postpartum, for a duration of 28 days. These volunteers were provided with LNG contraceptive treatment delivered through three, different routes of drug delivery system: (i) intrauterine devices impregnated with LNG (LNG-IUD); (ii) subdermal implant (Norplant (R)-2); and (iii) minipills (LNG 30 micrograms daily). On the first day after either the LNG-IUD (n = 14 women) or Norplant (R)-2 (n = 14 women) insertion, the maternal blood and breast milk samples were collected at 2, 4 and 8 hourly intervals. This was followed by daily collection of these samples as well as infant's blood from days 2 to 4 and thereafter on days 7, 14 and 28. For infant's blood samples from LNG minipill users (n = 10 women), only a single 4-hour sample was collected on the first day and no samples were collected on days 3 and 4. The rest of the schedule for collection of maternal blood and breast milk as well as infant's blood samples were the same in minipill users as for the other two treatment groups. The study revealed a lower LNG percentage transfer from maternal sera to breast milk--11.8 +/- 2, 7 +/- 2 and 8 +/- 1 and relatively higher percentage LNG transfer from breast milk to infant's sera--75 +/- 17, 68 +/- 20 and 32 +/- 3, in LNG-IUD, Norplant (R)-2 and minipill users, respectively. Therefore, LNG contraceptive steroid is transferred into the infant's circulation, the biological significance of which remains to be established.

The endocervical smear as a simple and quick method for the determination of ovulation

The endocervix undergoes cyclic changes in every menstrual cycle, as reflected by the rheologic properties of the cervical mucus. A study was therefore undertaken to establish whether there were any morphologic changes in the endocervical columnar cells, as seen in the endocervical smears, that could be correlated with ovulation and anovulation. An endocervical smear was collected in the luteal phase of the cycle from patients in whom an endometrial biopsy or D & C was being done as a part of an infertility investigation. A significant correlation was observed between the endocervical smear interpretation and the endometrial histology as to whether the cycle was ovulatory or anovulatory.