Phase II Multicenter, Open-Label Study of Oral ENMD-2076 for the Treatment of Patients with Advanced Fibrolamellar Carcinoma

LESSONS LEARNED

The fibrolamellar carcinoma-associated DNAJB1-PRKACA gene fusion transcript RNA codes for the catalytic domain of protein kinase A and, thus, overexpression of Aurora kinase A. ENMD-2076 showed a favorable toxicity profile. The limited results, one patient (3%) with a partial response and 57% of patients with stable disease, do not support further evaluation of ENMD-2076 as single agent. Future studies will depend on the simultaneous targeting approach of DNAJB1-PRKACA and the critical downstream components.

BACKGROUND

Fibrolamellar carcinoma (FLC) represents approximately 0.85% of liver cancers. The associated DNAJB1-PRKACA gene fusion transcript RNA codes for the catalytic domain of protein kinase A and overexpression of Aurora kinase A (AURKA). ENMD-2076 is a selective anti-AURKA inhibitor.

METHODS

Patients aged >12 years with pathologically confirmed incurable FLC, with measurable disease, Eastern Cooperative Oncology Group performance status 0-2 or Lansky 70-100, and adequate organ function were eligible. Patients were prescribed ENMD-2076 based on body surface area. The primary endpoint was overall objective response rate by RECIST v1.1, with a null hypothesis of true response rate of 2% versus one-sided alternative of 15%. Secondary endpoints included 6-month progression-free survival (PFS) rate (Fig. 1), median PFS, time to progression (TTP), and overall survival (OS). Safety was evaluated throughout the study.

RESULTS

Of 35 patients who enrolled and received treatment, 1 (3%) had a partial response (PR) and 20 (57%) had stable disease (SD). Median TTP, PFS, and OS were 5, 3.9, and 19 months, respectively. The most frequently reported drug-related serious adverse event was hypertension in three patients. Three deaths were reported on-study-two due to disease progression and one due to pulmonary embolism not related to ENMD-2076.

CONCLUSION

The study provided no rationale for further studying ENMD-2076 as a single agent in FLC.

Phase I study of onapristone, a type I antiprogestin, in female patients with previously treated recurrent or metastatic progesterone receptor-expressing cancers

INTRODUCTION

Onapristone is a type I progesterone receptor (PR) antagonist, which prevents PR- mediated DNA transcription. Onapristone is active in multiple preclinical models and two prior studies demonstrated promising activity in patients with breast cancer. We conducted a study of extended release (ER) Onapristone to determine a recommended dose and explore the role of transcriptionally-activated PR (APR), detected as an aggregated subnuclear distribution pattern, as a predictive biomarker.

METHODS

An open-label, multicenter, randomized, parallel-group, phase 1 study (target n = 60; NCT02052128) included female patients ≥18 years with PRpos tumors. APR analysis was performed on archival tumor tissue. Patients were randomized to five cohorts of extended release (ER) onapristone tablets 10, 20, 30, 40 or 50 mg BID, or immediate release 100 mg QD until progressive disease or intolerability. Primary endpoint was to identify the recommended phase 2 dose. Secondary endpoints included safety, clinical benefit and pharmacokinetics.

RESULTS

The phase 1 dose escalation component of the study is complete (n = 52). Tumor diagnosis included: endometrial carcinoma 12; breast cancer 20; ovarian cancer 13; other 7. Median age was 64 (36-84). No dose limiting toxicity was observed with reported liver function test elevation related only to liver metastases. The RP2D was 50 mg ER BID. Median therapy duration was 8 weeks (range 2-44), and 9 patients had clinical benefit ≥24 weeks, including 2 patients with APRpos endometrial carcinoma.

CONCLUSION

Clinical benefit with excellent tolerance was seen in heavily pretreated patients with endometrial, ovarian and breast cancer. The data support the development of Onapristone in endometrial endometrioid cancer. Onapristone should also be evaluated in ovarian and breast cancers along with APR immunohistochemistry validation.

Exploring the in vitro potential of celecoxib derivative AR-12 as an effective antiviral compound against four dengue virus serotypes

Objectives

With no clinically effective antiviral options available, infections and fatalities associated with dengue virus (DENV) have reached an alarming level worldwide. We have designed this study to evaluate the efficacy of the celecoxib derivative AR-12 against the in vitro replication of all four DENV serotypes.

Methods

Each 24-well plate of Vero cells infected with all four DENV serotypes, singly, was subjected to treatments with various doses of AR-12. Following 48 h of incubation, inhibitory efficacies of AR-12 against the different DENV serotypes were evaluated by conducting a virus yield reduction assay whereby DENV RNA copy numbers present in the collected supernatant were quantified using qRT-PCR. The underlying mechanism(s) possibly involved in the compound's inhibitory activities were then investigated by performing molecular docking on several potential target human and DENV protein domains.

Results

The qRT-PCR data demonstrated that DENV-3 was most potently inhibited by AR-12, followed by DENV-1, DENV-2 and DENV-4. Our molecular docking findings suggested that AR-12 possibly exerted its inhibitory effects by interfering with the chaperone activities of heat shock proteins.

Conclusions

These results serve as vital information for the design of future studies involving in vitro mechanistic studies and animal models, aiming to decipher the potential of AR-12 as a potential therapeutic option for DENV infection.

The celecoxib derivatives AR-12 and AR-14 induce autophagy and clear prion-infected cells from prions

Prion diseases are fatal infectious neurodegenerative disorders that affect both humans and animals. The autocatalytic conversion of the cellular prion protein (PrP^C) into the pathologic isoform PrP^Sc is a key feature in prion pathogenesis. AR-12 is an IND-approved derivative of celecoxib that demonstrated preclinical activity against several microbial diseases. Recently, AR-12 has been shown to facilitate clearance of misfolded proteins. The latter proposes AR-12 to be a potential therapeutic agent for neurodegenerative disorders. In this study, we investigated the role of AR-12 and its derivatives in controlling prion infection. We tested AR-12 in prion infected neuronal and non-neuronal cell lines. Immunoblotting and confocal microscopy results showed that AR-12 and its analogue AR-14 reduced PrP^Sc levels after only 72 hours of treatment. Furthermore, infected cells were cured of PrP^Sc after exposure of AR-12 or AR-14 for only two weeks. We partially attribute the influence of the AR compounds on prion propagation to autophagy stimulation, in line with our previous findings that drug-induced stimulation of autophagy has anti-prion effects in vitro and in vivo. Taken together, this study demonstrates that AR-12 and the AR-14 analogue are potential new therapeutic agents for prion diseases and possibly protein misfolding disorders involving prion-like mechanisms.

Multi-kinase inhibitors can associate with heat shock proteins through their NH2-termini by which they suppress chaperone function

We performed proteomic studies using the GRP78 chaperone-inhibitor drug AR-12 (OSU-03012) as bait. Multiple additional chaperone and chaperone-associated proteins were shown to interact with AR-12, including: GRP75, HSP75, BAG2; HSP27; ULK-1; and thioredoxin. AR-12 down-regulated in situ immuno-fluorescence detection of ATP binding chaperones using antibodies directed against the NH₂-termini of the proteins but only weakly reduced detection using antibodies directed against the central and COOH portions of the proteins. Traditional SDS-PAGE and western blotting assessment methods did not exhibit any alterations in chaperone detection. AR-12 altered the sub-cellular distribution of chaperone proteins, abolishing their punctate speckled patterning concomitant with changes in protein co-localization. AR-12 inhibited chaperone ATPase activity, which was enhanced by sildenafil; inhibited chaperone – chaperone and chaperone – client interactions; and docked in silico with the ATPase domains of HSP90 and of HSP70. AR-12 combined with sildenafil in a GRP78 plus HSP27 –dependent fashion to profoundly activate an eIF2α/ATF4/CHOP/Beclin1 pathway in parallel with inactivating mTOR and increasing ATG13 phosphorylation, collectively resulting in formation of punctate toxic autophagosomes. Over-expression of [GRP78 and HSP27] prevented: AR-12 –induced activation of ER stress signaling and maintained mTOR activity; AR-12 –mediated down-regulation of thioredoxin, MCL-1 and c-FLIP-s; and preserved tumor cell viability. Thus the inhibition of chaperone protein functions by AR-12 and by multi-kinase inhibitors very likely explains why these agents have anti-tumor effects in multiple genetically diverse tumor cell types.

Trans-ungual Delivery of AR-12, a Novel Antifungal Drug

AR-12 is a novel small molecule with broad spectrum antifungal activity. Recently, AR-12 was found to be highly active against Trichophyton rubrum, one of the predominantly responsible organisms that cause onychomycosis. The primary objective of this project was to investigate the ability of AR-12 to penetrate into and across the human nail plate followed by improving its trans-ungual permeation using different penetration enhancers. TranScreen-N™, a high throughput screening method was utilized to explore the potential nail penetration enhancers to facilitate the drug delivery through the nail. This screen demonstrated that dexpanthenol and PEG 400 were the most efficient enhancers. The in vitro permeation studies were performed across the human cadaver nail plates for 7 days with three AR-12 (5% w/v) formulations containing 10% w/v dexpanthenol (Formulation A), 10% w/v PEG 400 (Formulation B), and a combination of 10% w/v dexpanthenol + 10% w/v PEG 400 (Formulation C). The in vitro studies concluded that dexpanthenol and PEG 400 were able to deliver a significant amount of AR-12 into and across the nail plate that was found to be more than MIC 50 level of the drug.

Phase 1-2 study of progesterone receptor (PR) inhibition with extended-release (ER) onapristone (ONA) alone or in combination with abiraterone (AA) in patients (pts) with castration-resistant prostate cancer (CRPC) incorporating plasma DNA analysis to define androgen receptor (AR) status

5071

Background: An urgent need exists for new therapies after progression (PD) onAA and enzalutamide (ENZ). Increased PR expression or progesterone-activating AR mutations have been associated with resistance to AR targeting. We aimed to test ONA, a type I PR antagonist with clinical activity in PRpos cancers, in AA/enz-resistant CRPC. In a prospectively defined exploratory analysis, we aimed to report outcome by plasma AR status ( pAR). Methods: This was a multi-institution, open label phase I/II clinical trial in pts progressing after ENZ/AA. Pts were first treated with single agent (SA) ONA using a randomised dose escalation design. ONA at 2 doses was then combined with AA (1000mg od with pred 5mg bid) in pts progressing on AA. The primary end-points were safety, pharmacokinetics (PK) and anti-tumor activity split by p AR. Archival and metastatic biopsies were collected when possible and tested for PR status. p AR was studied using previous methods (Romanel STM 2015). Results: 21 pts received SA ONA (5 = 10mg/ 5 = 20mg/ 4 = 30mg/ 4 = 40mg /3 = 50mg BID) and 15 pts received ONA-AA combination (5 = 30mg ONA BID, 10 = 50mg ONA BID). There were not DLTs or significant LFT abnormalities and no G3/4 adverse events (AE), no treatment discontinuations due to AEs and no SAEs considered related to ONA. PK in SA ONA observed active plasma concentrations and no interaction with AA. Of 32 evaluated pts 15 had a 2105T > A (p.L702H) or 2632A > G (p.T878A) AR mutation detected in plasma pre-treatment and 1 had AR copy number gain. PSA declines were not observed with SA ONA but in 2 pts with combination (-30%, -7%) who were AR normal. The rPFS on SA ONA was 2.8 months for AR normal and 2.6 for AR aberrant (Hazard ratio (HR) 1.41; 95% CI, 0.62-3.72; P 0.48) and on combination was 4.4 months for AR normal (8/15) and 2.2 for AR aberrant (7/15) (HR 6.08; 95%CI, 6.32-221.9; P < 0.001). Conclusions: ONA is safe in CRPC as SA and in combination with AA. There was no difference in rPFS by p AR status for SA ONA but on the combination with AA, pts who were plasma AR normal had a significantly longer rPFS. Clinical trial information: NCT02049190.

Abstract 4523: Population pharmacokinetic (PPK) modeling of onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers

Background: Onapristone is a type I PR antagonist, which prevents PR-induced DNA transcription. Onapristone anti-cancer activity is well documented. An extended-release (ER) tablet formulation of onapristone was designed to address the liver function test (LFT) elevations seen with immediate-release (IR) onapristone. A phase 1 study with onapristone in patients with tumors expressing PR is underway. Objectives included determining the PK profile of ER onapristone using a PPK approach.

Materials and methods: This is an ongoing multi-center, open-label, randomized, parallel-group, 2-stage ph1 study. Female pts ≥18 yrs with tumors expressing PR are eligible. The Stage 1 primary endpoint is the recommended ph2 dose of ER onapristone; secondary endpoints include: safety, efficacy, and PK. Pts received onapristone ER 10, 20, 30, 40 or 50 mg BID, or onapristone IR tablets 100 mg QD until progressive disease or intolerability. PK blood samples from 8 time points were collected over 12 h post-dose Day 1 for the ER and 9 blood samples over 24 h post-dose for the IR formulation. Onapristone plasma concentrations were measured using validated UPLC with tandem mass spectrometry detection (range 1-250 ng/mL). Monolix V4.1 was used to calculate absorption constant (Ka); apparent clearance (CL/F); inter-compartmental clearance (Q); apparent distribution volume (V1/F), 2nd compartment distribution volume (V2) and bioavailability (F) of ER vs IR.

Results: Stage 1 is complete. 42 pts have validated PK data. A 2-compartment open model adequately described the total onapristone time-concentration curve with linear elimination. Results are in Table 1.

Table 1.Estimated PK parameters for onapristone in pts with PR-expressing cancers (n = 42)ParameterValueRelative standard error (%)Ka0.191 h-114CL/F1.51 L/h20Q3.11 L/h25V1/F5.41 L25V241.1 L45F60%20

Conclusions: The PPK modeling described the plasma onapristone time-concentration curves well. A central volume equivalent to the circulating blood volume and a large volume of the deep compartment suggest a large tissue diffusion. PPK/PD modeling to explore safety and efficacy is ongoing, with no overt PK/safety relationship detected.

Citation Format: Keyvan Rezai, Paul Cottu, Samuel Huguet, Mario Campone, Antoine Italiano, Andrea Varga, Jacques Bonneterre, Alexandra Leary, Marie-Paule Sablin, Stefan Proniuk, Alice Bexon, Erard Gilles, Joseph Bisaha, Alexander Zukiwski, Francois Lokiec. Population pharmacokinetic (PPK) modeling of onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers. [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 4523. doi:10.1158/1538-7445.AM2015-4523

Abstract 3471: Comparative assessment of in vitro activity and aactivated progesterone receptor (APR) biomarker predictivity for multiple antiprogestins

Background: In absence of ligand, PRA and PRB are evenly distributed in nuclei in cell lines. Upon ligand binding, PRA and PRB dimerizes and form discrete focal subnuclear distribution patterns, which are associated with transcriptional activation of PR. This pattern corresponds to the transcriptionally active form of PR and serves as an APR biomarker. The expression of APR in cell lines was demonstrated to be predictive of onapristone antiproliferative effects (Serin, Abs # 473, NCI-AACR-EORTC 2012). In this study the correlation of APR to the antiproliferative effects of different antiprogestins (Type I & type II, and steroidal/non-steroidal chemical structures) is examined. Method: T47D and CAMA-1, two PR expressing breast cancer cell lines, were grown in either FBS or Steroid Free FBS (SFFBS). In FBS, single agent anti-progestins were studied; in SFFBS, cell lines were stimulated with estradiol (E2) or progesterone (P4) and antiprogestins tested. All experiments were performed in duplicate. APR was analyzed at 6h and 30h using paraffin embedded cellular pellets, and processed with standard IHC techniques. Cellular viability was measured by the MTS assay at 30h, 4d and 7d. Antiprogestin drugs tested included: Aglepristone, Mifepristone, Onapristone, PF02413873, ZK230211, and ZM150271. Results: In the T47D cell line, in FBS between zero and ∼ 40% antiproliferative activity was observed from D1 to D7 for all antiprogestins. In SFFBS, T47D proliferation at D7 was increased &gt;300% by E2 and &gt;200% by P4. All antiprogestins opposed P4 and E2 proliferative effects at D7, with a max of 80% inhibition relative to control. In the CAMA-1 cell line, in FBS weak antiprogestin antiproliferative effect was observed (&lt;20% inhibition); with SFFBS, P4 and E2 were weakly stimulatory and antiprogestins had an inconsistent and weak treatment effect. The effect of antiprogestins were not dose dependent. APR: in T47D and FBS, APR was observed at 6h consistently for PR A and PR B. At 30h, controls were APR positive, and with Aglepristone, Mifepristone and Onapristone treatment, the surviving cells were APR neg; PF02413873, ZK230211and ZM150271 APR effect was inconsistent. Specimens from SFFBS are under evaluation. For CAMA-1, in FBS PRA and PRB were weakly expressed i.e. in 5% of the cells; APR was always negative. Specimens from SFFBS are under evaluation. Conclusion: The cell line expressing APR, T47D, is sensitive to direct antiprogestins effect in FBS, to E2 and P4 growth stimulation in SFFBS. In T47D, there was an antagonism by all antiprogestins at D7 and APR status was reversed at 30 h completely in 3/6 cases and incompletely in 3/6. CAMA-1 does not express APR, is weakly stimulated by E2 and P4, and antiprogestins have inconsistent effects in this cell line. APR status is a predictor of antiprogestin action.

Citation Format: Alexander Zukiwski, Erard Gilles, Guillaume Serin, Jacques Bosq, Charline Alleaume. Comparative assessment of in vitro activity and aactivated progesterone receptor (APR) biomarker predictivity for multiple antiprogestins. [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 3471. doi:10.1158/1538-7445.AM2015-3471

Abstract 4512: Onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers: PK results from part 1 of a randomized, parallel-dose phase 1 study

Background:  Onapristone is a type I PR antagonist, which prevents PR-induced DNA transcription; its anti-cancer activity is well-documented. The reported T1/2 is 2-4h, so an extended-release (ER) tablet was designed to mitigate Cmax spikes, which may be involved in the liver function test (LFT) elevations seen with an immediate-release (IR) onapristone.

Materials and methods:   The expansion cohort of this multi-center, open-label, randomized, parallel-group, 2-stage Ph1 study (NCT02052128) is ongoing in endometrioid cancers. Female pts ≥18 years with PR-expressing tumors (including endometrial, ovarian, breast) were eligible. The primary endpoint was to recommend a Ph2 dose of ER onapristone (RP2D), with a 57-day DLT observation period; secondary endpoints include: safety, efficacy, and real-time PK. Pts received onapristone ER 10, 20, 30, 40 or 50 mg BID, or IR tablets 100 mg QD until progressive disease or intolerability in Stage 1.

Results: 52 pts are enrolled (by 2 December 2014). Validated PK data are available for 35 pts. Onapristone AUC and Cmax are dose-proportional across all dose levels including 100mg IR (Table 1), with coefficients of determination (r2) of 0.76 and 0.79, respectively. The bioavailability of onapristone ER vs IR is high. Steady state is consistently attained at approximately 8 days (200 h), with T1/2 at 8-12 h, longer than previously published, with no evidence of onapristone accumulation through day 57.

Table 1.Onapristone PK parameters following first doseOnapristone formERERERERERIRDose (mg)10 bid20 bid30 bid40 bid50 bid100 qdn666566Mean AUC (μg/L*h)51761765015450174403161067980CV%47.7202.722.943.070.555.1Min348029411200038091515033330Median4654860815040207302593062270Max952440000214302667062500125000Mean Cmax (μg/L)226.8676.3767.3641.614594296CV%46.0140.115.693.646.862.8Min922206762914591556Median218403732.547414953726Max4031466988134424927507

Conclusions: This study reveals a longer than anticipated onapristone T1/2, which nevertheless supports using an ER formulation. AUC and Cmax data are dose proportional and allow dosing flexibility. Protracted exposure minimizing Cmax spikes is best achieved with a twice-daily, ER formulation. There were no LFT elevations in the absence of liver metastases in 30 patients exposed to the ER formulation. The RP2D is 50 mg bid based on safety and PK, to be further explored in the endometrioid cohort.

Citation Format: Francois Lokiec, Antoine Italiano, Andrea Varga, Jacques Bonneterre, Mario Campone, Alexandra Leary, Keyvan Rezai, Marie-Paule Sablin, Alice Bexon, Stefan Proniuk, Erard Gilles, Joseph Bisaha, Alexander Zukiwski, Paul Cottu. Onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers: PK results from part 1 of a randomized, parallel-dose phase 1 study. [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 4512. doi:10.1158/1538-7445.AM2015-4512

A single-dose PK study of onapristone including the effect of food on absorption

PURPOSE

Onapristone is an antiprogestin with activity in breast cancer and is under investigation for use in endometrial, ovarian and prostate cancers. Megestrol acetate and abiraterone generally show variability in absorption and, depending on the formulation, food effect. This study was conducted to determine the effect of food on 10 mg oral immediate-release (IR) onapristone and to help identify a formulation to minimize variability.

METHODS

This is an open-label, randomized, crossover study to determine the pharmacokinetic profile of onapristone and its main metabolite, N-mono-desmethyl onapristone. Twelve healthy female subjects received 10 mg of oral IR onapristone after an overnight fast, or within 30 min of a high-fat, high-calorie meal with a 2-week washout between dosing periods.

RESULTS

Onapristone plasma t1/2 (mean ± SD) was 4.36 ± 0.81 h for the fasted state and 3.76 ± 0.36 h for the fed state. Following food, onapristone tmax was delayed from 1 to 4 h. Food intake was also associated with a small increase in AUC0-∞ of approximately 13 % and a statistically significant decrease in Cmax of approximately 18 %. One subject experienced a 23-day delay in menses after one 10 mg onapristone dose, while another subject experienced transient grade 2 NCI-CTCAE liver enzyme elevation 3 weeks post dose.

CONCLUSION

The results are consistent with previous observations, indicating that there is a small increase in onapristone exposure and a significant decrease in Cmax when taken with food. These changes are within acceptable limits set out by the FDA. Thus, our findings indicate that onapristone could be administered without regard to food.

Abstract P6-08-19: Activated form of the estrogen receptor α (ER) in breast cancer (BC) and its correlation with prognosis

Background: About 50% of ER positive (ERpos) BCs are resistant to hormone treatment. In absence of ligand, ERs are evenly distributed in nuclei in normal tissue. Upon ligand binding, ERs dimerizes and form a discrete focal subnuclear distribution pattern (FDP), which is associated with transcriptional activation of ER and can be visualized with high powered microscopy. We have developed an IHC method to characterize the FDP in archival BC specimens (ASCO 2013 abst#592). We hypothesized that, in BC, the presence/absence of FDP of ER could predict anti-estrogen (anti-E) activity. We could determine two tumor phenotypes for ERpos tumors: a diffuse nuclear ER staining or "D-ER" corresponding to the expression of non-functional ER, which is the pattern observed in vitro or in vivo when no ligand are bound to steroid receptors (SR); D-ER thus is thought to predict lack of treatment effect of anti-E. And an aggregated nuclear pattern which corresponds to a similar pattern observed in vitro or in vivo when ligand is bound to ER; A-ER would suggest that ER is activated and a potential target to anti-Es.

Methods: A previously reported study (ASCO 2013 abst #592) was expanded from 254 evaluable cases to 755 with paraffin embedded formalin fixed (PEFF) BC specimens with clinical and pathology data. Specimens were analyzed for standard HES, ER, progesterone receptor (PR) and Ki67. The A-ER and D-ER nuclear patterns were analyzed at 1000x magnification.

Results: Mean age; 57 (17 -89). Histology: ductal 85% lobular 13%, other 2%; 82% ERpos and 78% either PRApos or PRBpos, 10% ERpos and 6% PRpos only. 92% of ERpos cases had received anti-Es; Adj. Chemotherapy 36%, Stage: I 47%, II 45%, III 8 %. Grade: I 25%, II 52%, III 23%. Median follow up 42 months. ER status was D-ER in 71% and A-ER in 29% of the specimens. With DFS defined as time to PD or death (5 year cut off), 125/755 events were observed. ERpos was better that ERneg (HR= 0.36, p = 0.00001). Within ERpos tumors group, in univariate analysis, a time-dependent Cox model showed that A-ER pattern was associated with better DFS vs D-ER pattern (HR = 0.03, p=0.02, time interaction = 0.01). A-ER was not correlated with SBR Grade, and was associated with its anisonucleosis (Aniso) index (0.02), with histology (ductal, 0.005) but not age, stage or HER2 status. Ki67 testing is ongoing. In monovariate analysis stage (0.00004), grade (p &lt; 10-6), PR (p &lt; 10-6) were prognostic on DFS, but not histology and HER2. In a time-dependent multivariate Cox model, A-ER remained an independent predictor (p = 0.013), with grade (p =0.001 with Mitotic Index 0.002, Differentiation 0.023, Aniso NS), stage 0.001, time interaction 0.009), PR and HER2 NS.

Conclusions: This study supports the hypothesis that anti-Es are mainly active in BC with A-ER pattern, which is targetable by anti-Es. Independent statistical significance was reached after adjusting for well-established prognostic factors. Given the 10-year hormonal treatment adjuvant recommendation guidelines, a better assay than the simple ER status determination would have important implications in BC management.

Citation Format: Erard Gilles, Jacques Bosq, Charline Alleaume, Alexander Zukiwski, Emile Hutt, Jacques Bonneterre. Activated form of the estrogen receptor α (ER) in breast cancer (BC) and its correlation with prognosis [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-19.

Abstract P5-02-13: Triple negative breast cancer, the impact of isotype-specific progesterone receptor antibodies on the diagnosis results

Background: Given the poor therapeutic outcomes for triple negative breast cancer (TNBC), diagnostic accuracy is vital. In routine IHC testing, the progesterone receptor (PR) is determined using bispecific antibodies (Ab) that recognize epitopes common to PRA and PRB. PRA and PRB expression can be imbalanced in BC. Relative expression of the PR isotypes appears to be prognostic in BC evaluated with a bispecific Ab (Hopp 2004). Tumors can express PRA or PRB on different cells in the same tumor (Mote 2008), which differs from those expressing ERα (Zukiwski 2013). A true TN phenotype might escape detection with the use of one single Ab to detect both PRA and B epitopes, depending on sensitivity/specificity. This study evaluated the use of two isotype-specific PR Abs to fully characterize the PR status.

Methods: 83 dual ERα and HER2 negative archived BC specimens with clinical data were obtained from the Oscar Lambret Cancer Center, Lille, FR. IHC was performed using anti-PRA, anti-PRB, and the bispecific anti-PR Pg636 antibodies. PR tumor positivity was explored using 2 cut-offs, ≥ 1% or ≥ 5% stained tumor cells. PR positive tumors were defined as either PRA or PRB positive.

Results: For PR positive tumors with ≥ 1% positive cells, average PRA positivity was 41%, PRB was 38% (PRA vs PRB p = NS), and PRAB 3% (PRA vs PRAB = 0.001, PRB vs PR AB p = 0.0001). Using 1% as positivity cut off PRA and PRB were discordant in 14% of the cases, PRA and PR AB in 12%. PR B and PR AB were discordant in 2%. Discordance between PR positivity (either A or B) and PRAB positivity was 7% with no PR negative PRAB positive tumors i.e. no positivity was missed using two PR A and B antibodies while all 7% cases were missed by the PRAB antibody. Using 5% as a cut off, the discordance rate was 8% between PRA and PRB, 25% between PRA and PRAB and no PRA negative and PRAB positive case were found, and 26% between PRB and PRAB with no PRB negative PRAB positive cases either. PR positivity (A or B) was missed in 30% of the cases with a PRAB. Patients with tumors identified as PR positive (≥ 5%) using the isotype specific antibodies and PR negative with the PRAB antibody have a better prognosis (DFS).

Conclusion: In TNBC, there is a different staining pattern when using isotype-specific vs bispecific anti-PR anti-bodies. The average percent of positive tumors cells is substantially reduced when using a bispecific Ab as compared to isotype-specific AB. This translates into potential false negative PRAB testing which varies from 7% to 30% depending of the cut off criteria. TNBC reclassified by the use of isotype-specific anti-PR antibodies may be appropriate for investigation with anti-progestins.

Citation Format: Jacques Bonneterre, Jacques Bosq, Charline Alleaume, Erard Gilles, Philippe Jamme, Alexander Zukiwski. Triple negative breast cancer, the impact of isotype-specific progesterone receptor antibodies on the diagnosis results [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-02-13.

Abstract 1646: Synthesis of [11C]onapristone for clinical investigation

Background: Onapristone is a type I anti-progestin, which prevents the progesterone receptor (PR) monomers from dimerizing, inhibits ligand-induced phosphorylation and prevents association of the PR with its co-activators, thus preventing PR-induced transcription. Onapristone has the potential to treat patients with endometrial cancer, breast cancer, uterine sarcomas, a potential subset of ovarian cancer, prostate cancer and other tumors in which the progesterone receptor plays a role in growth, proliferation and metastasis. [11C]-radiolabeled onapristone and its visualization via PET-scan, coupled with pharmacokinetic (PK) studies, has the potential to determine tissue-specific and blood PK parameters including tumor/tissue and plasma concentrations, whole body distribution and half-life of onapristone. The aim of this study is the development of a rapid Good Manufacturing Product (GMP) synthesis of parentally administered [11C]onapristone.

Methods: The production of [11C]-labeled radiopharmaceuticals used a Tracerlab® FX c-Pro (GEMS) synthesis module. Carbon-11 was produced at Institut Curie-Hôpital René Huguenin via the 14N(p,α)11C nuclear reaction using a PETTrace cyclotron (GEMS) equipped with a carbon-11 target. Carbon-11 is delivered from the cyclotron as [11C]CO2 in the synthesis module, and reduced to [11C]CH4. Methane is halogenated to [11C]CH3I and converted to [11C]methyl triflate (CH3OTf). To prepare [11C]onapristone, the module was loaded with 1mg of N-desmethyl-onapristone (Arno Therapeutics) and 500µL of DMSO in the reaction vessel (Sigma®). [11C]CH3OTf was bubbled into the reaction vessel and heated at +50°C for 10 minutes. The reaction mixture was then diluted with 1 ml of mobile phase and purified using a semi-preparative HPLC column: Sunfire C18 5µm 250X10mm (Waters®), mobile phase: acetonitrile (Sigma®)/water (Waters®) 50/50 v/v; flow rate 4 mL/min. The product fraction was collected in 40mL of sterile water and was passed through a C18 SEP PAK (Waters®). This fraction was eluted with isotonic saline (Braun®) and ethanol (Sigma®). The resulting formulation was passed through a 0.22µm sterilizing filter into a sterile dose vial.

Results: 10 tests were performed. Time of synthesis was 50 minutes. The amount of carbon-11 delivered was 12-14GBq for the irradiation parameters as follows: 10 min; 10µA. The decay-corrected yield of reducing [11C]CO2 to [11C]CH4 was &gt;99%. The yields of preparing [11C]CH3I were 27-29%. Time retention of [11C]onapristone was 8.5-9.5 minutes and the non-decay-corrected radiolabelling yields were 1-2%.

Conclusions: We have successfully developed a fully-automated production of [11C]onapristone ready for use in clinical trials.

Citation Format: Olivier Madar, Julien Fouque, Stefan Proniuk, Keyvan Rezai, Samuel Huguet, Alexander Zukiwski, Erard M. Gilles, Alice S. Bexon, François Lokiec. Synthesis of [11C]onapristone for clinical investigation. [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 1646. doi:10.1158/1538-7445.AM2014-1646

Abstract 5567: Impact of progesterone receptor (PR) isotype-specific immunohistochemistry (IHC) on the diagnosis of triple negative breast cancer (BC)

Background: Given the poor therapeutic outcomes for triple negative BC, diagnostic accuracy is vital. In routine IHC, PR is measured using bispecific antibodies (Ab) that recognize epitopes common to PRA and PRB. PR A and B expression is imbalanced in BC. Relative expression of the PR isotypes appears to be prognostic in tumors evaluated with a bispecific Ab (Hopp 2004). Tumors can express PRA or PRB on different cells in the same tumor (Mote 2008), which differ from those expressing ERα (Zukiwski 2013). A true triple negative phenotype might escape detection with the use of one single Ab to detect both PR A and B epitopes, depending on its sensitivity/specificity. This study evaluated the use of two isotype-specific PR Abs to fully characterize PR status.

Methods: 312 archived BC specimens with clinical data came from Oscar Lambret Cancer Center, Lille. HER2 status was previously determined. IHC was performed using anti-ERα, anti-PRA and PRB Abs. ERα and PR tumor positivity was defined as ≥ 1% stained tumor cells.

Results: 276 cases had complete data. Table 1 shows ERα, PRA and PRB status. 38/276 cases (14%) were ERα and HER2 negative: 22 were PR A or B negative, 9 were PR A and B positive, 2 were positive only for PRA and 5 only for PRB. Discussion: Bispecific PR Abs rarely report PRA and PRB similarly (Mote 2001). PR Phosphorylation and activation may vary across tumors. Potentially only one PR isotype may drive BC tumor growth. Triple-negative BC status determination could be PR Ab-dependent. These cases are currently being tested with a standard bispecific PR Ab to understand which would be considered triple-negative with routine IHC.

Conclusion: Further evaluation of IHC with specific PRA and PRB Abs is warranted to determine if certain patients, currently classified as having triple-negative BC, could respond to antiprogestins, which have shown activity in BC.

Table 1% of276 casesPR (PRA or PRB)PRAPRBERαNegativePositiveTotalNegativePositiveTotalNegativePositiveTotalNegative148221742115722Positive77178146579106868Total217910031691002575100

Citation Format: Erard Gilles, Jacques Bosq, Laura Caplier, Alice Bexon, Alexander Zukiwski, Jacques Bonneterre. Impact of progesterone receptor (PR) isotype-specific immunohistochemistry (IHC) on the diagnosis of triple negative breast cancer (BC). [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 5567. doi:10.1158/1538-7445.AM2014-5567

A phase I study of recombinant human interferon alpha-2b combined with 5-fluorouracil and cisplatin in patients with advanced cancer

To determine the maximum tolerated dose (MTD) of escalating doses of interferon-alpha-2b (IFN, Intron A) with 5-fluorouracil (5-FU) and cisplatin (DDP) in patients with advanced cancer, 15 patients were accrued between May 1990 and July 1991. Primary sites were unknown (3), colorectal (3), head and neck (2), lung (2), gynecologic (1), gallbladder (1), sarcoma (1), anal canal (1) and pancreas (1). IFN was given s.c. on days 1-5 and then three times weekly with DDP (75 mg/m2, day 1) and 5-FU [750 mg/m2, days 1-5, continuous infusion (CI) on a 28-day cycle. The first two patients treated at level I (3 x 10(6) U/m2 s.c.) experienced possible neurotoxic deaths [massive cerebrovascular accident (CVA) and metabolic encephalopathy], and patient 3 had a grade 4 toxicity of performance status decline. Analysis of these events led us to exclude the enrollment of patients on i.v. morphine and of those with prior exposure to DDP. This resulted in grade 3 toxicity in terms of nausea, vomiting, fatigue and leukopenia but in no further CNS event. All patients were evaluable for toxicity but only ten were evaluable for response. Only two partial responses were seen, one in a patient with an unknown primary tumour and one in a patient with head and neck cancer. The combination of IFN is possible with 5-FU and DDP. The recommended dose of IFN is 2 x 10(6) U/m2 s.c. in patients with no prior exposure to DDP or i.v. morphine, given together with 5-FU (750 mg/m2, days 1-5, CI) and DDP (75 mg/m2, day 1) on a 28-day cycle.

5-Fluorouracil and interferon-alpha in chemotherapy refractory bladder carcinoma: an effective regimen

Seventy-seven patients with metastatic transitional cell carcinoma of the bladder who were unable to receive primary Cisplatin-based therapy or failed primary chemotherapy received one of three sequential 5-Fluorouracil-based salvage regimens: a) 5-Fluorouracil (1000 mg/m2 B.S.A. x 5 days) and Mitomycin-C (14 mg/m2 B.S.A. 6 week intervals), b) 5-Fluorouracil (750 mg/m2 B.S.A. x 5 days) and a-Interferon (5 miu/m2 B.S.A. daily x 5 then 3 times a week (TIW), c) 5-Fluorouracil (500 mg/m2 B.S.A. x 5 days), a-Interferon (5 miu/m2 B.S.A. x 5 days then TIW) and 13-Cis Retinoic Acid in escalating doses daily. Only 1 (6%) of the patients with regimen A responded, whereas 9 (30%) of the patients with regimen B and 8 (27%) in regimen C responded. Although all responses were partial remissions, responses were seen in patients with advanced and initially refractory transitional cell carcinomas. This data reveals that a-Interferon and 5-Fluorouracil is an effective combination in the treatment of metastatic transitional cell carcinoma and worthy of further study.

A phase I study of escalating interferon alpha-2a combined with 5-fluorouracil and leucovorin in patients with gastrointestinal malignancies

On the basis of preclinical data showing synergy between 5-fluorouracil (5-FU), leucovorin (LV) and IFN-alpha-2a, a phase I study was carried out to determine the maximum tolerable dose (MTD) of IFN-alpha-2a with this combination in patients with gastrointestinal malignancies. The treatment consisted of 370 mg/m2 5-FU and 200 mg/m2, LV on days 1 to 5, and IFN-alpha-2a on days 1 to 5 of the first week of chemotherapy and on days 1, 3, 5 of each subsequent week, on a 28-day cycle. Six patients with colorectal, 3 with pancreas, 2 with oesophagus, 2 with hepatocellular and one with gastric cancer were treated. At level III (5 x 10(6) U/m2) all patients experienced grade 3 or 4 toxicity during the first 56 days of treatment and the MTD was declared level II. Grade 3 toxicity comprised of anorexia, mucositis, diarrhoea, and fatigue; in one instance, grade 4 neutropenia occurred. Ten patients were evaluable for response, one patient with an oesophageal cancer had a minor response and one patient with rectal cancer and liver metastases had a radiological complete response lasting 3 months. The recommended dose for this schedule in phase II studies is 5-FU 370 mg/m2, LV 200 mg/m2, and IFN-alpha-2a 4 x 10(6) U/m2.

Indium-111-labeled B72.3 monoclonal antibody in the detection and staging of breast cancer: a phase I study

Sixteen patients with primary breast cancer were studied with a pancarcinoma monoclonal antibody B72.3, an IgG1 molecule directed against tumor-associated glycoprotein (TAG-72) present in several tumors. Five millicuries of 111In was used to label 0.2 mg (six patients), or 2 mg (six patients), or 20 mg using the site-directed bifunctional DTPA method (at carbohydrate moiety). Digital, planar, and SPECT images were obtained at 2, 48, 72 and 96 hr when possible. HAMA levels were obtained before the Mab infusion and at 1, 3, and 6 wk postinfusion. Fourteen of 14 known primary breast lesions were detected by imaging (100% sensitivity). Two fibrocystic lesions were negative. Seven of 14 patients had lymph node metastases by histologic methods, but all were missed by radioimmunoscintigraphy. Tumor uptake of Mab ranged 0.00054%-0.0038% of the ID/g. The tumor-to-normal breast tissue ratio was 4.3 +/- 0.91 (mean +/- s.e.m.). Lymph nodes localization of 111In-B72.3 by tissue analysis was similar for tumor-bearing and normal nodes (0.0039 +/- 0.0023 versus 0.0025 +/- 0.0019). Pharmacokinetics revealed mean plasma half-life of 33.3-41.2 hr for the different doses. There was no statistical difference between any of the pharmacokinetic parameters of different doses. HAMA was positive only in 17% of the patients. The study suggests that this antibody has 100% sensitivity for primary breast cancers, but very poor detection rate of metastatic lesions in axillary lymph nodes; thus making it of questionable value in the initial staging process of this disease.