A randomized Phase I pre-operative window trial of transdermal endoxifen in women planning mastectomy: Evaluation of dermal safety, intra-mammary drug distribution, and biologic effects

Breast cancer prevention only requires local exposure of the breast to active drug. However, oral preventive agents entail systemic exposure, causing adverse effects that limit acceptance by high-risk women. Drug-delivery through the breast skin is an attractive option, but requires demonstration of dermal safety and drug distribution throughout the breast. We formulated the tamoxifen metabolite (E/Z)-endoxifen for transdermal delivery and tested it in a placebo-controlled, double-blinded Phase I trial with dose escalation from 10 to 20 mg daily. The primary endpoint was dermal toxicity. Thirty-two women planning mastectomy were randomized (2:1) to endoxifen-gel or placebo-gel applied to both breasts for 3-5 weeks. Both doses of endoxifen-gel incurred no dermal or systemic toxicity compared to placebo. All endoxifen-treated breasts contained the drug at each of five sampling locations; the median per-person tissue concentration in the treated participants was 0.6 ng/g (IQR 0.4-1.6), significantly higher (p < 0.001) than the median plasma concentration (0.2 ng/mL, IQR 0.2-0.2). The median ratio of the more potent (Z)-isomer to (E)-isomer at each breast location was 1.50 (IQR 0.96-2.54, p < 0.05). No discernible effects of breast size or adiposity on tissue concentrations were observed. At the endoxifen doses and duration used, and the tissue concentration achieved, we observed a non-significant overall reduction of tumor proliferation (Ki67 LI) and significant downregulation of gene signatures known to promote cancer invasion (FN1, SERPINH1, PLOD2, PDGFA, ITGAV) (p = 0.03). Transdermal endoxifen is an important potential breast cancer prevention agent but formulations with better dermal penetration are needed.

Presurgical Oral Tamoxifen vs Transdermal 4-Hydroxytamoxifen in Women With Ductal Carcinoma In Situ: A Randomized Clinical Trial

Importance

Oral tamoxifen citrate benefits women with ductal carcinoma in situ (DCIS), but concern about toxic effects has limited acceptance. Previous pilot studies have suggested transdermal 4-hydroxytamoxifen gel has equivalent antiproliferative efficacy to oral tamoxifen, with low systemic exposure.

Objective

To demonstrate that 4-hydroxytamoxifen gel applied to the breast skin is noninferior to oral tamoxifen in its antiproliferative effect in DCIS lesions.

Design, Setting, and Participants

This randomized, double-blind, phase 2 preoperative window trial was performed at multicenter breast surgery referral practices from May 31, 2017, to January 27, 2021. Among 408 women with estrogen receptor-positive DCIS who were approached, 120 consented and 100 initiated study treatment. The most common reasons for nonparticipation were surgical delay, disinterest in research, and concerns about toxic effects. Data were analyzed from January 26, 2021, to October 5, 2022.

Intervention

Random assignment to oral tamoxifen citrate, 20 mg/d, and gel placebo or 4-hydroxytamoxifen gel, 2 mg/d per breast, and oral placebo, for 4 to 10 weeks, followed by DCIS resection.

Main Outcomes and Measures

The primary end point was absolute change in DCIS Ki-67 labeling index (Ki67-LI). Secondary end points included 12-gene DCIS Score, breast tissue tamoxifen metabolite concentrations, tamoxifen-responsive plasma protein levels, and patient-reported symptoms. Noninferiority of Ki67-LI reduction by 4-hydroxytamoxifen gel was tested using analysis of covariance; within- and between-arm comparisons were performed with paired t tests for mean values or the Wilcoxon rank sum test for medians.

Results

Of 90 participants completing treatment (mean [SD] age, 55 [11] years; 8 [8.9%] Asian, 16 [17.8%] Black, 8 [8.9%] Latina, and 53 [58.9%] White), 15 lacked residual DCIS in the surgical sample, leaving 75 evaluable for the primary end point analysis (40 in the oral tamoxifen group and 35 in the 4-hydroxytamoxifen gel group). Posttreatment Ki67-LI was 3.3% higher (80% CI, 2.1%-4.6%) in the 4-hydroxytamoxifen gel group compared with the oral tamoxifen group, exceeding the noninferiority margin (2.6%). The DCIS Score decreased more with oral tamoxifen treatment (-16 [95% CI, -22 to -9.4]) than with 4-hydroxytamoxifen gel (-1.8 [95% CI, -5.8 to 2.3]). The median 4-hydroxytamoxifen concentrations deep in the breast were nonsignificantly higher in the oral tamoxifen group (5.7 [IQR, 4.0-7.9] vs 3.8 [IQR, 1.3-7.9] ng/g), whereas endoxifen was abundant in the oral tamoxifen group and minimal in the 4-hydroxytamoxifen gel group (median, 13.0 [IQR, 8.9-20.6] vs 0.3 [IQR, 0-0.3] ng/g; P < .001). Oral tamoxifen caused expected adverse changes in plasma protein levels and vasomotor symptoms, with minimal changes in the transdermal group.

Conclusions and Relevance

In this randomized clinical trial, antiproliferative noninferiority of 4-hydroxytamoxifen gel to oral tamoxifen was not confirmed, potentially owing to endoxifen exposure differences. New transdermal approaches must deliver higher drug quantities and/or include the most potent metabolites.

Trial Registration

ClinicalTrials.gov Identifier: NCT02993159.

Naproxen chemoprevention induces proliferation of cytotoxic lymphocytes in Lynch Syndrome colorectal mucosa

Background

Recent clinical trial data from Lynch Syndrome (LS) carriers demonstrated that naproxen administered for 6-months is a safe primary chemoprevention that promotes activation of different resident immune cell types without increasing lymphoid cellularity. While intriguing, the precise immune cell types enriched by naproxen remained unanswered. Here, we have utilized cutting-edge technology to elucidate the immune cell types activated by naproxen in mucosal tissue of LS patients.

Methods

Normal colorectal mucosa samples (pre- and post-treatment) from a subset of patients enrolled in the randomized and placebo-controlled 'Naproxen Study' were obtained and subjected to a tissue microarray for image mass cytometry (IMC) analysis. IMC data was processed using tissue segmentation and functional markers to ascertain cell type abundance. Computational outputs were then used to quantitatively compare immune cell abundance in pre- and post-naproxen specimens.

Results

Using data-driven exploration, unsupervised clustering identified four populations of immune cell types with statistically significant changes between treatment and control groups. These four populations collectively describe a unique cell population of proliferating lymphocytes within mucosal samples from LS patients exposed to naproxen.

Conclusions

Our findings show that daily exposure of naproxen promotes T-cell proliferation in the colonic mucosa, which paves way for developing combination of immunoprevention strategies including naproxen for LS patients.

Abstract PD15-12: PD15-12 A pre-surgical window trial of oral tamoxifen versus transdermal 4-hydroxytamoxifen gel in women with estrogen receptor positive duct carcinoma in situ (DCIS)

Background: Adjuvant oral tamoxifen (TAM) benefits women with DCIS, but toxicity concerns have limited its acceptance. Transdermal therapy with 4-hydroxy tamoxifen (4-OHT) gel applied to the breast skin is a possible solution. Previous pilot data suggest equivalent anti-proliferative efficacy of TAM and 4-OHT gel, but minimal systemic exposure with transdermal therapy. We report a prospective double blinded randomized phase 2 trial comparing TAM to 4-OHT gel in women with DCIS. Methods: 107 women with estrogen receptor positive (≥10%) DCIS were randomized to TAM (20 mg/day + placebo gel) or 4-OHT gel (2mg 4-OHT gel/breast, bilaterally + oral placebo), for 4-10 weeks prior to surgery. The primary endpoint was reduction in DCIS Ki67 labeling index (LI). Secondary endpoints included the 12-gene DCIS Score assay (Exact Sciences), breast tissue and plasma concentrations of 4-OHT and endoxifen, TAM-responsive circulating proteins, and patient reported symptoms (Breast Eight Symptom Scale). We estimated that 80 evaluable participants would provide 80.5% power to establish non-inferiority of 4-OHT, defined as relative Ki67-LI decline &gt;35% and absolute decline &gt;2.6%, with one-sided 𝛼=0.10. Non-inferiority of 4-OHT gel for Ki67-LI reduction was tested using an ANCOVA model. Statistical comparisons within- and between-arms were calculated with paired t-test and Welch Two Sample t-test, respectively. Results: 72 of 87 women adhered to the protocol, and were evaluable for the primary endpoint (39 TAM and 33 4-OHT gel). Mean treatment duration was 47 days for TAM and 44 days for 4-OHT gel (p=0.2). The median absolute decline in Ki67 labeling index was significant in the oral TAM (-3.7%, p&lt; 0.001) but not in 4-OHT gel arm (-1.3%, p=0.2) (p=0.002). Ki67 results following menopausal stratification also favored the TAM arm: (-1.3%; p=0.06 in 37 premenopausal women and -3.7%; p=0.02 in 35 postmenopausal women). Similarly, DCIS score showed a significantly greater reduction in the TAM (-14, p&lt; 0.001) but not in the 4-OHT gel arm (-4, p=0.1). Tissue 4-OHT concentrations were non-significantly higher in the TAM arm and were similar between superficial and deep sampling locations (superficial 6.1 and 4.2 ng/g for TAM and 4-OHT gel, respectively, p= 0.55; deep 5.7 and 3.8 ng/g, respectively, p= 0.06), whereas plasma 4-OHT concentration was markedly lower in the gel group (2 ng/mL and 0.24 ng/mL for TAM and 4-OHT gel, respectively, P &lt; 0.001). Endoxifen was abundant in plasma (11 ng/mL) and deep tissue (13 ng/g) of the TAM arm, but present in trace amounts in the 4-OHT gel arm (undetectable in plasma and 0.31 ng/g in tissue; p &lt; 0.001). Circulating TAM responsive markers (insulin like growth factor 1, sex hormone binding globulin, von Willebrand factor, and protein S total) and vasomotor symptoms were significantly and unfavorably modulated by TAM, but not by 4-OHT gel therapy. Conclusions: The non-inferiority of transdermal 4-OHT gel to Tam in terms of anti-proliferative effect in DCIS lesions was not demonstrated at the doses used for this study. DCIS Score analysis gave similar results. Tissue 4-OHT concentration in 4-OHT gel and Tam-treated subjects was roughly similar. However, endoxifen exposure was higher with oral TAM therapy and may partially explain the observed differences in major endpoints. In future studies, use of higher 4-OHT gel doses, longer duration of treatment, or different formulation may overcome these.

Citation Format: Oukseub Lee, Xinlei Mi, Yanfei Xu, Luis Blanco, Azza M. Akasha, Kelly Benante, Shanshan Zhang, Carissa LaBoy, Thomas Helland, Melissa Pilewskie, Amy Degnim, Zahraa Al-Hilli, Amanda L. Amin, E Shelley Hwang, Joseph M. Guenther, Simon Steinar Hustad, Demirkan B. Gursel, Masha Kocherginsky, Gunnar Mellgren, Eileen Dimond, Marjorie Perloff, Brandy M. Heckman-Stoddard, Seema Khan. PD15-12 A pre-surgical window trial of oral tamoxifen versus transdermal 4-hydroxytamoxifen gel in women with estrogen receptor positive duct carcinoma in situ (DCIS) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD15-12.

Phase I Dose Escalation Study of Topical Bexarotene in Women at High Risk for Breast Cancer

PREVENTION RELEVANCE

Bexarotene is a rexinoid that has been shown to prevent mammary tumors in mouse models but oral dosing has toxicities. This phase I study evaluates topical bexarotene, as a potential chemoprevention agent, for safety and toxicity in high-risk women for breast cancer.

Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa

OBJECTIVE

Patients with Lynch syndrome (LS) are at markedly increased risk for colorectal cancer. It is being increasingly recognised that the immune system plays an essential role in LS tumour development, thus making an ideal target for cancer prevention. Our objective was to evaluate the safety, assess the activity and discover novel molecular pathways involved in the activity of naproxen as primary and secondary chemoprevention in patients with LS.

DESIGN

We conducted a Phase Ib, placebo-controlled, randomised clinical trial of two dose levels of naproxen sodium (440 and 220 mg) administered daily for 6 months to 80 participants with LS, and a co-clinical trial using a genetically engineered mouse model of LS and patient-derived organoids (PDOs).

RESULTS

Overall, the total number of adverse events was not different across treatment arms with excellent tolerance of the intervention. The level of prostaglandin E2 in the colorectal mucosa was significantly decreased after treatment with naproxen when compared with placebo. Naproxen activated different resident immune cell types without any increase in lymphoid cellularity, and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Naproxen demonstrated robust chemopreventive activity in a mouse co-clinical trial and gene expression profiles induced by naproxen in humans showed perfect discrimination of mice specimens with LS and PDOs treated with naproxen and control.

CONCLUSIONS

Naproxen is a promising strategy for immune interception in LS. We have discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity.

TRIAL REGISTRATION NUMBER

gov Identifier: NCT02052908.

Local Transdermal Delivery of Telapristone Acetate Through Breast Skin, Compared With Oral Treatment: A Randomized Double-Blind, Placebo-Controlled Phase II Trial

Oral breast cancer prevention medications entail systemic exposure, limiting acceptance by high-risk women. Delivery through the breast skin, although an attractive alternative, requires demonstration of drug distribution throughout the breast. We conducted a randomized double-blind, placebo-controlled phase II clinical trial comparing telapristone acetate, a progesterone receptor antagonist, administered orally (12 mg/day) or transdermally (12 mg/breast) for 4 ± 1 weeks to women planning mastectomy. Plasma and tissue concentrations, measured at five locations in the mastectomy specimen using liquid chromatography tandem mass spectrometry were compared. In 60 evaluable subjects, median drug concentration (ng/g tissue) was 103 (interquartile range (IQR): 46.3-336) in the oral vs. 2.82 (IQR: 1.4-5.5) in the transdermal group. Despite poor dermal permeation, within-breast drug distribution pattern was identical in both groups (R2  = 0.88, P = 0.006), demonstrating that transdermally and orally delivered drug is distributed similarly through the breast, and is strongly influenced by tissue adiposity (P < 0.0001). Other skin-penetrant drugs should be tested for breast cancer prevention.

Abstract PS8-12: Interim analysis of a phase I dose escalation study of topical bexarotene in women at high risk for breast cancer

Background: Breast cancer prevention with anti-estrogens, including tamoxifen, raloxifene, and exemestane, has been shown to reduce the incidence of hormone receptor-positive breast cancer. However, agents that can reduce the incidence of hormone receptor negative breast cancer are currently lacking. Rexinoids such as bexarotene are vitamin A analogues that have been shown to be involved in cell differentiation, growth, and apoptosis. In preclinical mouse models that develop ER-negative breast cancers, bexarotene showed a significant reduction in mammary tumor development. Oral bexarotene has been evaluated in BRCA mutation carriers and significant decreases in cyclin D1 were noted in breast cells suggesting biological activity of bexarotene on breast tissue. Systemic side effects of hyperlipidemia and hypothyroidism were also found. Data from chemoprevention studies with topical 4-hydroxytamoxifen support the concept of topical agents penetrating into the breast tissue and exhibiting biological activity. We hypothesize that topical bexarotene can be applied to the breast as a prevention agent with penetration into the breast tissue and without subsequent systemic side effects as seen with oral bexarotene. Methods: Women at high risk for breast cancer were recruited and assigned to escalating doses of 1% topical bexarotene: 10mg (1ml) every other day, 10mg (1ml) daily and 20mg (2ml) daily for 4 weeks. Cohorts of 3-4 participants were enrolled and fully evaluated through 4 weeks prior to enrolling the next cohort. Each dose level enrolled a maximum of 10 participants. The primary endpoint of the study was to determine the recommended phase II dose of topical bexarotene 1% gel for evaluation in healthy at-risk women. Dose Limiting Toxicity (DLT) was defined as a grade 2 skin adverse event that persists for at least 6 days or any grade 3 or greater adverse event related to the study drug. A grade 2 skin adverse event that recurs and persists for at least 3 days is also a DLT. The Maximum Tolerated Dose (MTD) was defined as the highest dose level at which no more than 2 participants experience a DLT among 10 participants treated. Once the MTD was determined, interim biomarker analysis will be completed to assess bexarotene levels in serum and tissue samples. An expansion cohort of an additional 10 patients will be recruited at the MTD to further evaluate safety and toxicity. Secondary endpoints include serum bexarotene level, tissue bexarotene levels, and changes in thyroid function tests, lipid profile, and calcium. Results: Ten women were enrolled at the dose level of 10mg every other day and 9/10 participants experienced Grade 1 skin related events at the application site. Two participants reported Grade 2 skin related events at the application site but did not last long enough to be considered DLTs. Four women were enrolled at the second dose level of 10mg daily and 3/4 experience Grade 2 skin related events including 2 DLTs which stopped accrual to the study. Therefore, the MTD was determined to be 10mg every other day. No laboratory abnormalities were noted across either dose level and no grade 3 or 4 adverse events were reported. Conclusion: Maculopapular rash at treatment site was the most common adverse event related to study drug and resolved with discontinuation. Analysis is ongoing to assess bexarotene drug levels in serum and breast tissue samples.

Citation Format: Parijatham S Thomas, Anisha B Patel, Diane Liu, J. Jack Lee, Seema Khan, Miguel Muzzio, Alejandro Contreras, Lana Vornik, Eileen P Dimond, Marjorie Perloff, Brandy Heckman-Stoddard, Powel H Brown. Interim analysis of a phase I dose escalation study of topical bexarotene in women at high risk for breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS8-12.

Abstract CT111: Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa

Patients diagnosed with germline mutations in MMR genes (Lynch Syndrome, LS) have up to 70-80% lifetime risk of colorectal cancer. Therefore, this high-risk population has the potential to benefit from effective chemopreventive strategies. Naproxen is an NSAID widely used for pain treatment with an excellent safety profile that has demonstrated to be more efficacious preventing colorectal cancer compared to aspirin in vivo using an intestinal tissue-specific mouse model of LS (VC-Msh2-LoxP). The ‘Naproxen trial' was designed to evaluate the modulation of PGE2 levels in colorectal mucosa, evaluate safety and tolerability, and discover novel molecular pathways involved in the chemopreventive activity of naproxen in LS patients. Methods: Participants were randomized to naproxen 440 mg (HD), 220 mg (LD) and placebo by mouth daily for 6 months. Modulation of prostaglandin levels, number of adverse events (AEs) observed in each treatment arm and gene expression profiles by next-generation sequencing (mRNAseq) in normal colorectal mucosa of LS patients after 6 months of intervention were examined. Results: Eighty participants diagnosed with LS were randomized, 25 participants to HD, 27 to LD, and 28 to placebo. From these patients, 54 were considered evaluable per-protocol analysis: 16 in the HD group, 15 in the LD and 23 in placebo. The level of prostaglandin E2 in the colorectal mucosa decreased significantly after treatment with both LD and HD naproxen when compared to placebo (-91.2%±14.1, -93.6%±7.9, and 23.8%±108.4, P-value&lt;0.001, respectively). Moreover, levels of PGE2 urinary metabolite (PGE-M) were significantly changed in both treatment groups when compared to placebo (-47.7%±56.9, -41.1%±40.5, 7.6%±94.3, P-Value&lt;0.018). The intervention was well tolerated, no severe AEs related to treatment were reported, and the total number of AEs was not different across treatment arms. LD and HD naproxen promoted the activity of the immune system by activating different immune cell types without any effect on lymphoid cellularity and changed the expression patterns of the intestinal crypt towards epithelial differentiation and stem cell regulation. Conclusions: Naproxen is a promising strategy for immune interception in LS that induces immune-modulation coupled with changes in the dynamics of the intestinal crypt. We have also discovered naproxen-induced gene expression profiles for their potential use as predictive biomarkers of drug activity.

Citation Format: Laura Reyes Uribe, Wenhui Wu, Ozkan Gelincik, Prashant V. Bommi, Alejandro Francisco-Cruz, Luisa M. Solis, Patrick M. Lynch, Ramona Lim, Elena Stoffel, Priyanka Kanth, N. Jewel Samadder, Maureen E. Mork, Melissa W. Taggart, Ginger L. Milne, Lawrence J. Marnett, Lana Vornik, Diane D. Liu, Maria Revuelta, Kyle Chang, Y. Nancy You, Levy Kopelovich, Ignacio I. Wistuba, J. Jack Lee, Shizuko Sei, Robert H. Shoemaker, Eva Szabo, Ellen Richmond, Asad Umar, Marjorie Perloff, Powell H. Brown, Steven M. Lipkin, Eduardo Vilar. Naproxen chemoprevention promotes immune activation in Lynch syndrome colorectal mucosa [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT111.

Abstract OT3-15-02: A randomized, double-blind, placebo-controlled study of 4-hydroxytamoxifen topical gel in women with mammographically dense breasts

Background: Tamoxifen uptake for risk reduction has remained low due to concerns about toxicity despite the efficacy and effectiveness data available. Studies of tamoxifen in the adjuvant and preventive setting have demonstrated that a decline in mammographic density (MD) of approximately 10% is consistently associated with better outcomes. Additionally, MD is one of the strongest independent predictors of breast cancer risk, apart from older age and BRCA1/2 mutation, among women. 4-hydroxytamoxifen topical gel (4-OHT) is a transdermal agent, shown in preliminary studies to be well-tolerated with similar decreases in Ki-67 to oral tamoxifen in presurgical DCIS studies and significant drug concentration in breast parenchyma but very low levels in the systemic circulation. This study examines changes in MD, a potential surrogate biomarker of prevention activity, as the primary endpoint for this one-year early-phase prevention trial using 4-OHT gel in high risk women.

Trial design: Multicenter, randomized, placebo-controlled study of 4-OHT gel (2mg per breast) versus placebo in 152 women with heterogeneously or extremely dense breast tissue for 12 months using standard of care imaging, stratified by enrollment site and baseline breast density category. The primary objective of this study is to evaluate the change in percent MD (using Cumulus software) from baseline to the week 52 in women applying 4 mg (2mg per breast) 4-OHT gel versus placebo. The secondary objectives are to compare the Cumulus vs Volpara breast density measurement methods; evaluate the percentage of women with lowering of BIRADS density; estimate percentage of women with ≥ 10% absolute decrease in quantitative MD percentage; explore patient reported experience assessed by BESS questionnaire; laboratory toxicity assessment (F VIII, vWB factor, SHBG, lipid profile); compare the 2D vs. 3D breast density measurement methods to estimate percent change in mammographic breast density; evaluate serum measurements of parent drug and related metabolite levels and factors related to 4-OHT exposures, such as IGF pathway members, CRP, estradiol, and 4-OHT; collect tissue for biomarkers (among women undergoing optional pre- and post-treatment biopsies); examine the persistence in change of mammographic density one year after 4-OHT vs. placebo gel application has stopped.

Eligibility criteria: Inclusion: Women age 40-69 years, or less than 40 years if 5-year breast cancer Gail risk is greater than/equal to 1.66%; heterogeneously or extremely dense breast tissue based on mammography. Exclusion: abnormal uterine bleeding, or prior diagnosis of endometrial hyperplasia, endometrial polyps, or endometrial cancer; prior use of SERMS and AIs, except for a maximum of 3 months and at least 12 months prior.

Statistical methods: Considering an attrition rate of 15%, 128 evaluable women are expected to have both baseline and 52-week measurements of percent MD. With 64 women in each group, there is 80% power to detect a decrease of 6% in the 4-OHT group versus 2% in the placebo group with a common standard deviation of 8% using a two-sided t-test with a significance level of 0.05. Study accrual: Activated January 2018, as of July 1, 2019, 92 patients have been recruited and 79 were randomized.

Citation Format: Banu K. Arun, Gretchen Gierach, Marion E Scoggins, Seema Khan, Sandra S Rao, Judy Garber, Sughra Raza, Nagi B. Kumar, Heather H Han, John Heine, Bethany Niell, Pavani Chalasani, Kimberly Fitzpatrick, Lee G Wilke, Amy Fowler, Heather C Beckwith, Carrie Mays, Saba Abutaseh, Lana Vornik, Oukseub Lee, Eileen Dimond, Marjorie Perloff, Diane Liu, J. Jack Lee, Powell Brown, Brandy Heckman-Stoddard. A randomized, double-blind, placebo-controlled study of 4-hydroxytamoxifen topical gel in women with mammographically dense breasts [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-15-02.

Phase I trial of endoxifen gel versus placebo gel in women undergoing breast surgery

TPS1588

Background: Despite large Phase III clinical trials that have established the success of selective estrogen receptor modulators (SERMs) for breast cancer prevention and therapy of duct carcinoma in situ (DCIS), acceptance by women likely to benefit has been low, primarily because of toxicity related to systemic exposure. Local drug delivery to the breast in gel form is an attractive alternative since low systemic levels could minimize toxicity. Endoxifen (ENX) is an active metabolite of tamoxifen, that has unique activity compared with 4-hydroxytamoxifen (4-OHT). It is smaller and more polar than 4-OHT making it potentially more suitable for transdermal delivery. The NCI PREVENT program has developed ENX transdermal alcoholic gel products. Methods: We are conducting a randomized, double-blinded, placebo-controlled, Phase I trial to establish the dermal tolerability and safety of endoxifen (ENX) gel. 38 women planning unilateral or bilateral mastectomy will be enrolled across 3 institutions in 3 cohorts: (a) ENX gel 10mg (N = 8) vs. placebo gel (N = 4) daily; (b) ENX gel 20mg (N = 8) vs. placebo gel (N = 4) daily; (c) the maximum tolerated dose (N = 8) with last dose 72 hours prior to surgery. Treatment duration will be 4 ± 1 weeks. All participants will be evaluated for toxicity and skin tolerability. Secondary endpoints include TAM metabolite measurements in breast tissue and plasma; serum hormone concentrations, serum estrogenic response, changes in coagulation parameters, gene expression changes reflective of therapeutic effects, and experienced symptoms. 65 potential participants have been pre-screened for eligibility. 33 were ineligible prior to contact, most commonly due to the use of neoadjuvant chemotherapy. Of 32 potential participants who have been eligible to be contacted, 21 did not consent for screening, most commonly because they were too overwhelmed with their recent diagnosis. 7 have consented, 4 are pending consent, and 6 have started study intervention. No adverse events have been reported to date. This pre-surgical trial testing transdermal ENX for breast cancer prevention is accruing as projected. The results will establish the skin safety of this agent, provide data on skin permeability, and the duration of drug retention in the breast. Clinical trial information: NCT03317405.

Abstract P6-21-12: Local transdermal therapy (LTT): Drug permeation and distribution of telapristone acetate (TPA) in a pre-surgical window study of women undergoing mastectomy

Background: Low uptake and poor adherence to oral drugs for breast cancer prevention and ductal carcinoma in situ has led to an interest in local routes of delivery with the intent of decreasing systemic exposure and reducing toxicity. LTT has emerged as a possible alternative; previous studies have shown selectively higher concentrations in the breast than in the serum with this delivery route. A question related to LTT is whether or not the drug will permeate and distribute throughout the breast, as is expected with oral delivery.

Methods: We conducted a double-blind study of oral versus LTT delivery of the selective progesterone receptor modulator, telapristone acetate (TPA), in a presurgical window setting, enrolling 82 women planning therapeutic or prophylactic mastectomy. We randomized 67 women 1:1, to oral TPA 12 mg daily, or gel TPA applied to both breasts daily (12 mg/breast), for 4 weeks ±1 week. Mastectomy specimens were sampled at 5 non-tumor locations as well as the tumor and lymph node when available. Samples were split in two: drug concentration (conc.) assay using LC-MS/MS and histological evaluation of tissue composition (fat, fibrous stroma, epithelium). The primary endpoint was mean drug conc. across all breast locations (anticipating that the gel would deliver a mean concentration that was &gt;50% of the mean in the oral group). A secondary endpoint was the drug distribution pattern across the breast, expecting that the distribution would be similar. The tumor sample was saved for biomarker assays related to TPA action; these are ongoing, for a pre-planned pooled analysis of data with NCT01800422 (reported in SABCS abstract 851863).

Results: Of 63 evaluable women (33 oral and 30 gel group), 27 had unilateral and 36 had bilateral mastectomy. The mean drug conc. in the oral group was 166.3 ng/G (SE 11.7), and in the gel group was 10.6 ng/G (SE 10.8), (p&lt;.0001). The conc. was variable across the 7 locations tested in both groups. High concentrations were found in the superficial and deep central locations, retroareolar and lateral locations ranked in the middle, and the medial location was discrepant, being high in the oral and low in the gel group. The variation in drug concentration across all locations was not significantly different between groups (Kolmogorov-Smirnov p=0.99). Among women with bilateral mastectomy, drug concentrations were similar between breasts in both oral and gel groups. In the gel group, despite low TPA concentrations, there was evidence of drug metabolism. The major metabolite, CDB 4453 was detectable in 192/193 samples with detectable parent drug. Analysis of drug concentration adjusted for tissue composition is ongoing.

Conclusions: The gel formulation of TPA did not permeate the skin well. However, the drug delivered to the breast was distributed throughout the breast, similar to the oral delivery route, with the highest concentration in the deep central location. These drug distribution data are novel; drug distribution at multiple locations throughout the breast has not previously been shown. Further work is needed to understand breast distribution with formulations known to have good dermal permeation.

Citation Format: Lee O, Pilewskie M, Xu Y, Benante K, Blanco L, Helenowski I, Tull MB, Muzzio M, Jovanovic B, Karlan S, Hansen N, Bethke K, Kulkarni S, Perloff M, Dimond EP, Heckman-Stoddard BM, Khan SA. Local transdermal therapy (LTT): Drug permeation and distribution of telapristone acetate (TPA) in a pre-surgical window study of women undergoing mastectomy [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 P6-21-12.

Abstract OT2-09-02: A phase I dose escalation study of topical bexarotene in women at high risk for breast cancer

Background: Breast cancer prevention with anti-estrogens, including tamoxifen, raloxifene, and exemestane, has been shown to reduce the incidence of hormone receptor-positive breast cancer. However, agents that can reduce the incidence of hormone receptor negative breast cancer are currently lacking. Rexinoids such as bexarotene are vitamin A analogues that have been shown to be involved in cell differentiation, growth, and apoptosis. In preclinical mouse models that develop ER-negative breast cancers, bexarotene showed a significant reduction in mammary tumor development. Oral bexarotene has been evaluated in BRCA mutation carriers and significant decreases in cyclin D1 were noted in breast cells suggesting biological activity of bexarotene on breast tissue. Systemic side effects of hyperlipidemia and hypothyroidism were also found. Data from chemoprevention studies with topical 4-hydroxytamoxifen support the concept of topical agents penetrating into the breast tissue and exhibiting biological activity in the tissue. We hypothesize that topical bexarotene can be applied to the breast as a chemoprevention agent with penetration to the breast tissue without subsequent systemic side effects and toxicity as seen with oral bexarotene.

Trial Design: Women at high risk for breast cancer will be recruited and assigned to one of three different dose levels: 10mg (1ml) every other day, 10mg (1ml) daily, 20mg (2ml) daily to one unaffected breast for 4 weeks. The primary endpoint of the study is to determine the recommended phase II dose of topical bexarotene 1% gel for evaluation in healthy at-risk women. Dose Limiting Toxicity (DLT) is defined as a grade 2 skin adverse event that persists for at least 6 days or any grade 3 or greater adverse event related to the study drug. A grade 2 skin adverse event that recurs and persists for at least 3 days is also a DLT. The Maximum Tolerated Dose (MTD) will be defined as the highest dose level at which no more than 2 participants experience a DLT among 10 participants treated. A conservative modification of the standard “3+3” design will be applied. The first three participants will be assigned to the lowest dose level. New cohorts of 3-4 participants will not be treated until toxicity has been fully evaluated for all current participants through 4 weeks. Once the MTD has been determined, an expansion cohort of an additional 10 patients will be recruited at the MTD to further evaluate safety and toxicity at this dose level as well bexarotene concentration in the breast tissue. Secondary endpoints include serum bexarotene level, tissue bexarotene levels, and changes in thyroid function tests, lipid profile, and calcium. The planned accrual for this study if maximally accrued to all dose levels and the dose expansion cohort will be 40 participants.

Citation Format: Thomas PS, Patel AB, Contreras A, Liu DD, Lee JJ, Khan S, Vornik LA, Dimond EP, Perloff M, Heckman-Stoddard BM, Brown PH. A phase I dose escalation study of topical bexarotene in women at high risk for breast cancer [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 OT2-09-02.

Abstract OT1-04-01: A phase IIB pre-surgical trial of oral tamoxifen (TAM) versus transdermal 4-hydroxytamoxifen (4-OHT) in women with DCIS of the breast

Background

Ductal carcinoma in situ (DCIS) is diagnosed in 60,000 women annually in the US. TAM is proven to reduce risk of local recurrence and new primary breast cancer in women with estrogen receptor (ER) positive DCIS. However, acceptance of TAM has been low, primarily because of toxicity related to systemic exposure. Local delivery to the breast is an attractive alternative since low systemic levels could minimize toxicity. 4-OHT is an active metabolite of TAM. When formulated as a gel and applied to the breast skin, it is well tolerated, and results in 4-OHT breast tissue drug levels comparable oral TAM. In small pilot studies, its anti-proliferative effects on invasive breast tumors and DCIS are also similar to oral TAM [Lee O, et al. PMID 25028506]. The goal of our study is to validate these results in preparation for a Phase III trial of 4-OHT gel in comparison to oral TAM.

Methods

We are conducting a randomized, double-blinded, placebo-controlled, Phase IIB pre-surgical trial to demonstrate that daily application of 4-OHT gel will result in a reduction in the Ki-67 labeling index of DCIS lesions that is not inferior to that seen in women receiving daily oral TAM 20 mg daily. Ki-67 of the base-line diagnostic core needle biopsy will be compared to that of the therapeutic surgical excision sample after oral TAM or 4-OHT gel for 8 ± 2 weeks. Secondary endpoints include changes in Oncotype DCIS-Score, IHC markers (CD68, COX2, p16), hormone levels, coagulation markers, drug concentration in the plasma and breast tissue, the fraction of women with no residual DCIS in the surgical sample, and experienced symptoms. 100 women (assuming 20% non-evaluable samples or compliance issues) with DCIS (10% ER-positive) will be enrolled across six institutions into two intervention arms: oral TAM 20 mg daily, placebo gel and 4-OHT gel 4mg daily (2mg/breast), placebo capsule. All participants will be evaluable for toxicity from their first dose. All samples from all participants who receive drug will be evaluated and included in the primary analysis, which will be based on intent to treat principle. To date 15 of 100 participants have been enrolled across six institutions including: Northwestern University in Chicago, IL, St. Elizabeth Healthcare in Edgewood, KY, Duke University Medical Center in Durham, NC, Cleveland Clinic in Cleveland, OH, Memorial Sloan Kettering Cancer Center in New York, NY, and Mayo Clinic in Rochester, MN. Since study open, 69 potential participants have been contacted, 52 did not consent for screening, 17consented for screening, 2 are pending consent, and 15 have started study intervention. The most common reasons potential participants chose not to consent are wanting to schedule surgery as soon as possible, attitudes toward medical research, and current use of a prohibited concomitant medication such as a potent inhibitor of tamoxifen metabolism or exogenous sex steroid.

Funding Source: NCI Contract # HHSN2612201200035I.

Citation Format: Benante KA, Xu Y, Tull MB, Segura AJ, Alber KM, Kalinichenko K, Hou L, Jovanovic B, Perloff M, Heckman-Stoddard B, Dimond E, Khan SA. A phase IIB pre-surgical trial of oral tamoxifen (TAM) versus transdermal 4-hydroxytamoxifen (4-OHT) in women with DCIS of the breast [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 OT1-04-01.

Abstract CT065: A phase Ib biomarker trial of naproxen in patients at risk for DNA mismatch repair deficient colorectal cancer

Background: Patients diagnosed with Lynch Syndrome (LS) have an approximately 70% lifetime risk of colorectal cancer (CRC) due to the presence of germline mutations in the mismatch repair (MMR) genes. Cyclooxygenases (COX) are key enzymes in the metabolism of Prostaglandins (PGs) being COX-2 induced at sites of inflammation as well as in ~85% of CRC and 50% of premalignant adenomas. Non-steroidal anti-inflammatory drugs (NSAIDs) such as Aspirin and Naproxen exert their therapeutic effects through the inhibition of both COX-1 and COX-2, which causes a reduction in PGs. However, other known non-canonical effects include inhibition of cell growth, induction of cell cycle arrest, and apoptosis. Aspirin has demonstrated chemopreventive properties in LS patients at high doses. Naproxen is widely used for the treatment of pain with an excellent safety profile. In addition, pre-clinical in vivo data using a genetically-engineered mouse model of Lynch Syndrome (Villin-Cre;Msh2LoxP/LoxP) has demonstrated that Naproxen is the most effective NSAID in preventing colorectal tumors and has shown to be superior to Aspirin. The present clinical trial was designed to assess the safety and tolerability of long-term chemoprevention with Naproxen in LS and also to discover novel biomarkers of drug activity.

Methods: LS patients at 4 participating sites (The University of Texas MD Anderson Cancer Center, Dana Farber Cancer Institute, The University of Michigan Comprehensive Cancer Center, and Huntsman Cancer Institute) were randomly assigned to Naproxen 440 mg, 220 mg, or placebo once daily for 6 months. To determine the safety profile and tolerability of Naproxen, adverse events (AEs) were reported using CTCAE V4.03. To assess the activity of the drug intervention we measured Prostaglandin E2 (PGE2) levels in normal colorectal mucosa, its metabolite in urine (PGE-M), levels of Naproxen in plasma and colorectal mucosa at baseline and 6 months after treatment. Response to treatment was defined as 30% reduction in PGE2 levels. Results: A total of 86 patients were registered to this study, 28 randomized to Placebo, 25 to Naproxen 440 mg, and 27 to Naproxen 220 mg. Mean age was 44.6 years, 64% of the patients were females, 53% were unaffected carriers, and MLH1 and MSH2 were the most frequently mutated genes. Fifty-eight completed the study (67%). A total of 183 AEs were recorded in 61 patients, 77% were unrelated or unlikely related to the treatment, only 8 were reported as grade 3 AEs and none of these were related to Naproxen. In the group that received Naproxen at 440 mg, the levels of Naproxen in plasma and normal colorectal mucosa were the highest and the levels of PGE2 and PGE-M were significantly lower when compared to patients in the Placebo arm (P=0.027). In addition, the response rate was the highest among patients receiving Naproxen at 440 mg daily compared to Naproxen at 220 mg and Placebo (87.5% vs 75% vs 13%, respectively).

Conclusions: The tolerance and safety of long-term chemoprevention with Naproxen at a dose of 440 mg for 6 months was excellent. There was evidence of decreased inflammatory activity among LS patients treated with high dose Naproxen compared to Placebo. Biomarker studies to discover novel non-canonical effects of Naproxen via modulation of miRNA and mRNA profiles using next-generation sequencing approaches are currently ongoing.

Citation Format: Laura Reyes Uribe, Ramona Lin, Elena M. Stoffel, N. Jewel Samadder, Patrick Lynch, Priyanka Kanth, Ginger Milne, Lawrence J. Marnett, Valerie Sepeda, Diane D Liu, Y. Nancy You, Lana A. Vornik, J. Jack Lee, Ellen Richmond, Asad Umar, Marjorie Perloff, Steven M. Lipkin, Powel H. Brown, Eduardo Vilar-Sanchez. A phase Ib biomarker trial of naproxen in patients at risk for DNA mismatch repair deficient colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT065.

Selenomethionine and methyl selenocysteine: multiple-dose pharmacokinetics in selenium-replete men

According to the Nutritional Prevention of Cancer (NPC) trial, a selenized yeast supplement containing selenium, 200 mcg/day, decreased the incidence of total cancer, cancers of the prostate, colon and lung, and cancer mortality. The active agent in the selenized yeast supplement was assumed to be selenomethionine (SEMET), although the supplement had not been well speciated. The SELECT study, largely motivated by the NPC trial, enrolling nearly 40 times as many subjects, showed unequivocally that selenium 200 mcg/day, with selenium in the form of SEMET, does not protect selenium-replete men against prostate or other major cancer. The agent tested by SELECT, pure SEMET, could have been different from the selenized yeast tested in NPC. One of the selenium forms suspected of having chemopreventive effects, and which may have been present in the NPC agent, is methyl selenocysteine (MSC). This study, with 29 selenium-replete patients enrolled in a randomized, double-blind trial, compared the multiple-dose toxicity, pharmacokinetics and pharmacodynamics of MSC and SEMET. Patients were on trial for 84 days. No toxicity was observed. Although SEMET supplementation increased blood selenium concentration more than MSC did, neither form had a more than minimal impact on the two major selenoproteins: selenoprotein P(SEPP1) and glutathione peroxidase(GPX).

Double-Blind, Randomized Trial of Alternative Letrozole Dosing Regimens in Postmenopausal Women with Increased Breast Cancer Risk

Aromatase inhibitors (AI) profoundly suppress estrogen levels in postmenopausal women and are effective in breast cancer prevention among high-risk postmenopausal women. Unfortunately, AI treatment is associated with undesirable side effects that limit patient acceptance for primary prevention of breast cancer. A double-blind, randomized trial was conducted to determine whether low and intermittent doses of letrozole can achieve effective estrogen suppression with a more favorable side-effect profile. Overall, 112 postmenopausal women at increased risk for breast cancer were randomized to receive letrozole at 2.5 mg once daily (QD, standard dose arm), 2.5 mg every Monday, Wednesday, and Friday (Q-MWF), 1.0 mg Q-MWF, or 0.25 mg Q-MWF for 24 weeks. Primary endpoint was suppression in serum estradiol levels at the end of letrozole intervention. Secondary endpoints included changes in serum estrone, testosterone, C-telopeptide (marker of bone resorption), lipid profile, and quality-of-life measures (QoL) following treatment. Significant estrogen suppression was observed in all dose arms with an average of 75% to 78% and 86% to 93% reduction in serum estradiol and estrone levels, respectively. There were no differences among dose arms with respect to changes in C-telopeptide levels, lipid profile, adverse events (AE), or QoL measures. We conclude that low and intermittent doses of letrozole are not inferior to standard dose in estrogen suppression and resulted in a similar side-effect profile compared with standard dose. Further studies are needed to determine the feasibility of selecting an effective AI dosing schedule with better tolerability.

Phase Ib Randomized, Double-Blinded, Placebo-Controlled, Dose Escalation Study of Polyphenon E in Patients with Barrett's Esophagus

This study was conducted to determine the safety and efficacy of the green tea-derived Polyphenon E (Poly E) in patients with Barrett's Esophagus (BE). Subjects were randomized to a 6-month, twice daily (BID) oral treatment of placebo or Poly E (200, 400, or 600 mg). Endoscopic evaluation, including biopsies, was performed before and after treatment. The primary objective was to demonstrate safety; secondary objectives investigated catechin accumulation and effects in clinical specimens. Of the 44 enrolled subjects, 11 received placebo, and 33 received Poly E. No dose-limiting toxicities were encountered, and a maximum tolerated dose (MTD) was not reached. The recommended phase II dose was 600 mg twice daily. The most common treatment-related adverse events (AE) in Poly E-treated subjects were grade I and II nausea, grade I belching, and grade I lactate dehydrogenase (LDH) elevation. No treatment-related AEs were reported in placebo-treated subjects, aside from grade I laboratory abnormalities. Pill counts and subject diaries were not consistently collected, and compliance was difficult to determine. However, on the basis of an intention-to-treat analysis, there was a significant relationship between Poly E dose and esophageal EGCG level--mean changes (pmol/g) of 0.79 (placebo), 6.06 (200 mg), 35.67 (400 mg), and 34.95 (600 mg); P = 0.005. There was a possible relationship between Poly E dose and urine PGE-M concentration. In conclusion, Poly E was well-tolerated, and treatment with Poly E (400 and 600 mg) but not Poly E (200 mg) or placebo resulted in clinically relevant and detectable EGCG accumulation in the target organ, esophageal mucosa.

Abstract P5-12-04: De-escalating doses of letrozole in post menopausal women at high risk for breast cancer

Background: Although breast cancer (BC) may occur at any age, its prevalence is greater postmenopause. Greater than 75 % of postmenopausal BCs are hormone dependent. Aromatase inhibitors suppress postmenopausal estrogen biosynthesis. Letrozole has demonstrated efficacy against BC in the adjuvant and metastatic setting at the treatment dose of 2.5 mg daily. Its potential role in BC prevention has been inferred from reductions in contralateral BCs. Its side effect profile, similar to other AIs, includes exacerbation of menopausal symptoms that negatively impact quality of life (QOL) and may result in discontinuation of the drug. Both anastrazole and exemestane have been demonstrated to reduce BC in high-risk women.

Hypothesis: Lower and intermittent doses of letrozole effectively suppress estrogen in the high-risk postmenopausal woman and provide a better side effect profile.

Methods: A randomized, double-blind study comparing the impact of varying letrozole doses (2.5 mg daily, 2.5 mg MWF, 1.0 mg MWF, or 0.25 mg MWF) on estrogen suppression and side effects--lipids, bone resorption, menopause, and QOL-- was conducted. Participants randomized to intermittent dosing received placebo on nontreatment days.

Results: 112 participants were enrolled at 2 clinical sites. Mean patient age was 62.8 years, and average BMI was 29.8. Analysis of available data after 24 weeks of therapy revealed statistically significant increase in triglycerides (N=94): 114.67±48.39 to 125.79±54.31 (p&lt;0.01); vasomotor symptoms (N=95): 2.25±1.26 to 2.74±1.67 (p&lt;0.01); and C-telopeptide (N=75): 0.39±0.23 to 0.55±0.28 (p&lt;0.0001). Statistically significant decrease in estradiol (N=68): 5.57±5.19 to 1.26±1.41 (p&lt;0.0001) and estrone (N=68): 22.39±13.02 to 1.64±2.66 (p&lt;0.0001) were observed. No differences in QOL (SF 36) were noted after letrozole treatment. P-values were derived from paired t-test (signed rank test) for the difference between baseline and after 24 weeks of study drug.

Conclusions: De-escalating doses of letrozole suppress postmenopausal estrogen effectively and result in statistically significant increases in triglycerides, C-telopeptide and vasomotor symptoms without impact on QOL. Presentation will include unblinded intervention arm outcomes.

Citation Format: Ana Maria Lopez, Hsiao Hui Sherry Chow, Denise Frank, Sandhya Puthi, Judy Boughey, Paul Hsu, Jose Guillen, Marjorie Perloff, Michelle Ley, Julie E Lang. De-escalating doses of letrozole in post menopausal women at high risk for breast cancer [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 P5-12-04.

Bowman birk inhibitor concentrate and oral leukoplakia: a randomized phase IIb trial

Oral premalignancy serves as an ideal model for study of chemopreventive agents. Although 13-cis-retinoic acid showed reversal of oral premalignancy, toxicity, and reversal of clinical response after cessation of therapy obviated its widespread use. A search for nontoxic agents with cancer preventive activity led us to evaluate Bowman Birk Inhibitor (BBI) formulated as BBI Concentrate (BBIC). We previously reported encouraging results in a phase IIa trial of BBIC in patients with oral leukoplakia with measurable clinical responses and favorable biomarker changes. On the basis of these results, we undertook a randomized, placebo controlled phase IIb trial with patients receiving BBIC or placebo for 6 months, with assessment of clinical response and change in lesion area as primary end point and an intent-to-treat analysis. One hundred and thirty two subjects were randomized; and 89 subjects completed six months on study drug or placebo. Both placebo and BBIC showed a statistically significant decrease in mean lesion area of 17.1% and 20.6%, respectively, and partial or greater clinical responses of 30% and 28% respectively. No significant difference between placebo and study drug arms was observed. Histologic review, review of photographs of lesions, and comparison of serum neu protein and oral mucosal cell protease activity also did not show significant differences between study arms. Probable reasons for these negative results were considered, are discussed, and include a placebo with non-BBIC clinical activity and reduced pharmacokinetic availability of the second batch of BBIC. This experience should be a strong cautionary note to those considering "Green" chemoprevention.

Abstract C48: Phase Ib randomized, double-blinded, placebo-controlled, dose escalation study of Polyphenon E in patients with Barrett's esophagus

Patients with Barrett's Esophagus (BE) have an increased risk of developing esophageal adenocarcinoma. Preclinical models of BE and esophageal cancer have demonstrated the antitumor activity of the green-tea derived Polyphenon E (Poly E) and identified potential biomarkers for following its activity in clinical specimens. We conducted a multicenter trial of Poly E in patients with BE with or without low-grade dysplasia. Subjects were randomized to a 6-month, twice daily (BID) treatment of either placebo or Poly E (200 mg, 400 mg, 600 mg dose cohorts). Endoscopic evaluation, including multiple biopsies, was performed at baseline and after treatment. The primary objective of this study was to demonstrate safety (i.e., determine the maximum tolerated dose (MTD). Secondary objectives investigated accumulation of Poly E catechin constituents (e.g., EGCG) in esophageal tissue and biologic effects of Poly E in clinical specimens, including high throughput effects on mucosal protein expression using functional proteomics.

Of the 44 randomized subjects, 11 received placebo, and 33 received Poly E (200 mg (6), 400 mg (7), 600 mg (20)). No dose-limiting toxicities were encountered, and the MTD was 600 mg BID. The most common treatment-related adverse events (AEs) reported in Poly E-treated subjects were grade 1-2 nausea (12%), grade 1 burping (6%), and grade 1 elevated serum LDH (6%). No treatment-related AEs were reported in placebo-treated subjects, aside from grade 1 laboratory abnormalities. Pill counts and daily patient diaries were not consistently collected, and compliance was difficult to determine for the majority of subjects. However, based on an intention-to-treat analysis there was a dose-exposure relationship (p=0.01, Spearman correlation test) between the dose of Poly E and EGCG levels in esophageal mucosa – mean changes (pmol/g) with treatment were 1.68 (placebo; n=9), 6.06 (200 mg; n=5), 31.66 (400 mg; n=6), and 30.86 (600 mg, n=10). There was a possible relationship between the dose of Poly E and urine PGEM concentration – mean urine PGEM concentrations (ng/mg creatinine) with treatment were 4.86 (placebo; n=9), 6.78 (200 mg; n=3), 9.02 (400 mg; n=5), and 7.89 (600 mg; n=11); however, this was not statistically significant. Treatment with Poly E or placebo did not reduce the length of Barrett's epithelium and did not lead to any statistically significant changes in mucosal protein expression. However, Poly E treatment may have affected the expression of stearoyl-CoA desaturase (SD1), PI3Kinase-alpha, and acetyl Coenzyme A Carboxylase (ACC); p-values ≥ 0.05, although false discovery rates were 0.93.

In conclusion, Poly E was well-tolerated in all dose cohorts, with only grade 1 AEs seen more commonly in Poly E-treated subjects. There were no apparent significant effects of treatment on either tissue histology or mucosal biomarker expression. However, treatment with Poly E (400 mg and 600 mg) but not Poly E (200 mg) or placebo resulted in clinically relevant and detectable EGCG accumulation in the target organ, esophageal mucosa. Clinical development of this compound may include a phase 2 trial of Poly E administered at the 600 mg BID dose for a longer duration.

Supported by NCI, DCP Contract N01-CN-035159 to the UT MD Anderson Early Phase Chemoprevention Consortium

Citation Format: Andrew K. Joe, Felice Schnoll-Sussman, Robert S. Bresalier, Julian A. Abrams, Hanina H. Hibshoosh, Kenneth Cheung, Richard A. Friedman, Chung S. Yang, Ginger Milne, Diane D. Liu, Kazeem Abdul, Michelle Bigg, Jessica Foreman, Shing Lee, Tao Su, Aqeel Ahmed, Alfred I. Neugut, Esther Akpa, Scott Lippman, Marjorie Perloff, Powel H. Brown, Charles J. Lightdale. Phase Ib randomized, double-blinded, placebo-controlled, dose escalation study of Polyphenon E in patients with Barrett's esophagus. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr C48.

Early-phase development of cancer prevention agents: challenges and opportunities

Chemoprevention is the administration of agents (drugs, biologics, dietary supplements, or nutrients) to reduce the risk of developing cancer or prevent the recurrence of cancer. The National Cancer Institute, Division of Cancer Prevention (NCI, DCP), is a major sponsor of cancer preventive preclinical and clinical research. As such, it has developed a comprehensive drug development program specifically designed to meet the requirements needed for cancer preventive drugs to achieve initial regulatory approval. Clinical development of cancer prevention agents presents unique challenges that are not encountered with most cancer therapeutic agents. To meet these challenges, NCI, DCP has implemented new approaches and programs, including phase 0 clinical trial designs and microdose studies. In addition, the PREVENT Cancer Program was recently implemented by NCI, DCP to offer a formalized structure for moving drugs forward in the prevention pipeline using a continue/not continue decision process. Likewise, DCP has implemented a Clinical Trials Consortium to further develop these agents. These and other approaches will be discussed in this commentary.

Methyl selenocysteine: single-dose pharmacokinetics in men

The recently published report of the SELECT evaluation of selenium and vitamin E provided strong evidence that selenium 200 μg per day in the form of selenomethionine does not protect selenium-replete men against prostate or any other cancer. This seems to refute the result of the much smaller Nutritional Prevention of Cancer (NPC) trial of selenium. Because SELECT did not test the NPC agent, it is possible that the difference between the two trials stems partly from the use of different agents: selenomethionine in SELECT, and selenized yeast in the NPC trial. One of the organic selenium forms suspected of having strong chemopreventive effects, and which may have been present in the NPC agent, is methyl selenocysteine. This study characterizes the single-dose pharmacokinetics of methyl selenocysteine.

Abstract B82: Two factors contribute to negative results of a phase-IIB chemoprevention trial of Bowman-Birk inhibitor concentrate on oral leukoplakia

Our recently concluded Phase-IIB trial of Bowman-Birk Inhibitor Concentrate (BBIC) in patients with oral leukoplakia was negative, despite a foundation of earlier work suggesting BBIC has chemoprevention potential. As presented at the 2010 Frontiers meetings, there was no statistically significant difference in relative percent change in total lesion area between the BBIC arm and the placebo arm after six months of therapy. This result is unexpected, given both our earlier demonstration of a dose-response relationship in a Phase-IIA trial, and the interim analysis of the Phase-IIB trial. The aim of this presentation is to illuminate two factors possibly contributing to the negative final results: 1) an apparently active placebo, and 2) a change across time in the potency of the BBIC dispensed. We present here admittedly post-hoc, but thought-provoking, analyses to support these notions.

BBIC has protease-inhibitor activity, but any such activity in the placebo was unanticipated. The interim analysis of the Phase-IIB trial showed the 95-percent interval estimate of relative percent change in total lesion area straddled zero in the placebo arm (95%CI: −39.0 to +4.5, N=30). In contrast, the corresponding interval for the BBIC arm was entirely below zero (95%CI: −49.3 to −10.9, N=25). Thus the interim results seemed to predict a positive final result. The final analysis, however, showed the mean relative percent change in total lesion area was significantly less than zero in each of the two study arms (placebo mean: −17.1, N=46; BBIC mean: −20.6, N=43; both sign-rank tests p &lt; 0.05). Reassessment of the placebo showed &lt;10 chymotrypsin inhibitor units/gram and therefore the changes in total lesion area among placebo subjects were likely to be due to other mechanisms of action in the placebo.

The juxtaposition of the interim and final results led us to examine data in the BBIC arm by randomization date. Relative percent reduction in total lesion area was greater for subjects enrolled earlier, relative to those enrolled later (Spearman r = 0.31, p &lt; 0.05, N=43), consistent with a decline in agent potency. (There was no such trend in the placebo group: Spearman r=0.22, p &gt; 0.44, N=46). Of necessity, different batches of BBIC were used in the trial. It is known that the potency of BBIC can be greatly reduced by maintenance at refrigerated or frozen temperatures, and that some companies have stored BBIC under such conditions. We hypothesize that the BBIC batches used later in this trial had reduced potency, possibly due to storage conditions that compromised its ability to serve as a cancer chemoprevention agent by reducing bioavailability of the drug. Our data provide evidence that the later batches of BBIC had compromised chemoprevention activity. Median relative percent change in total lesion area was −32% (N=36) for the earlier batches but +6.5% (N=7) for the batches dispensed later in the trial. There was a similar pattern in relative percent change in buccal-cell neu protein (older batches median:-16.6, N=14; newer batches median: +24.6, N=7), relative percent change in protease activity (older batches median: +1.6, N=14; newer batches median +136.5, N=7), and relative percent change in serum neu (older batches median: −4.1, N=13; newer batches median −2.6, N=6). While many factors contribute to trial outcome, these data suggest our Phase-IIB trial was affected by the reduced potency of BBIC over time. Further, the apparent, and not understood, activity of the placebo raised the bar for declaring BBIC a success in this context.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B82.

Phase 0 clinical chemoprevention trial of the Akt inhibitor SR13668

SR13668, an orally active Akt pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability. Healthy adult volunteers were randomly assigned to receive a single, 38-mg oral dose of SR13668 in one of five different formulations, with or without food. On the basis of existing animal data, SR13668 in a PEG400/Labrasol oral solution was defined as the reference formulation. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration-time curve (AUC(0-∞)) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size. Participants (n = 20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. AUC(0-∞) values were highest in the fed state (range = 122-439 ng/mL × hours) and were statistically significantly different across formulations (P = 0.007), with Solutol HS15 providing the highest bioavailability. SR13668 time to peak plasma concentration (3 hours; range, 2-6 hours) and half-life were (11.2 ± 3.1 hours) were not formulation-dependent. Using a novel, highly efficient study design, we rapidly identified a lead formulation of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development.

Triterpenoids as potential agents for the chemoprevention and therapy of breast cancer

Breast cancer remains a major cause of death in the United States as well as the rest of the world. In view of the limited treatment options for patients with advanced breast cancer, preventive and novel therapeutic approaches play an important role in combating this disease. The plant-derived triterpenoids, commonly used for medicinal purposes in many Asian countries, posses various pharmacological properties. A large number of triterpenoids are known to exhibit cytotoxicity against a variety of tumor cells as well as anticancer efficacy in preclinical animal models. Numerous triterpenoids have been synthesized by structural modification of natural compounds. Some of these analogs are considered to be the most potent antiinflammatory and anticarcinogenic triterpenoids known. This review examines the potential role of natural triterpenoids and their derivatives in the chemoprevention and treatment of mammary tumors. Both in vitro and in vivo effects of these agents and related molecular mechanisms are presented. Potential challenges and future directions involved in the advancement of these promising compounds in the prevention and therapy of human breast cancer are also identified.

Abstract CN02-03: Phase 0 chemoprevention trial of SR13668, a novel AKT inhibitor, in normal volunteers

Purpose: SR13668, an orally active AKT pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability.

Patients and Methods: Healthy adult volunteers were randomly assigned to receive a single 38-mg oral dose of SR13668 in one of five different formulations, with or without food. Based on existing animal data, SR13668 in a PEG400/Labrasol@ oral solution (formulation 1) was defined as the reference formulation. Four self-emulsifying solid dispersion test formulations in capsules were also investigated: Solutol@ HS 15 (formulation 2), Solutol@ HS 15/Vitamin E TGPS (50/50 w/w %) (formulation 3), Vitamin E TGPS (formulation 4), and Myrj 53 (formulation 5). SR163668 bioavailability was compared using a two-stage study design. In stage I, participants were randomized to receive the formulation 1 with or without a high-fat meal after an overnight fast. In Stage II, participants were randomly assigned to receive the test formulations, using the preferred dietary condition identified in stage I. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration-time curve (AUC) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size.

Results: Participants (N=20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. The time to peak plasma concentration and half-life values for SR13668 were 3 hours (range, 2 — 6 hours) and 11.2 ± 3.1 hours, respectively, and were not dependent on the formulation. In stage I, the oral bioavailability of SR13668 in formulation 1 was greater under the fed versus fasting dietary state (p = 0.05, Wilcoxon rank-sum test). Therefore, the fed state was selected as the preferred dietary condition for stage II. In stage II, the bioavailability of SR13668 for each of the test formulations were compared with the bioavailability of formulation 1 in the fed state. While not significantly different from formulation 1, formulation 2 AUC0-24h was significantly different (p = 0.004, ANOVA) from formulation 3, 4, and 5 (AUC0-24h, formulation 1- 222 ± 53 ng/ml·hr; AUC0-24h, formulation 2 — 302 ± 78 ng/ml·hr; AUC-177±39ng/ml·hr; AUC-144±29 0-24h, formulation30-24h, formulation 4 ng/ml·hr; AUC0-24h, formulation 5- 98 ± 21 ng/ml·hr). Formulation 1 AUC0-24h was almost 40% lower than the value achieved with formulation 2, and not significantly different from formulation 3, 4, and 5. Thus, formulation 2 provided the highest bioavailability of SR13668.

Conclusions: Using a novel, highly efficient study design, we rapidly identified a lead formulation (Solutol@ HS 15) of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development. Supported by NIH grants N01-CN-35000, CA15083-34C3 and UL1 RR024150.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):CN02-03.

Repeat dose study of the cancer chemopreventive agent resveratrol in healthy volunteers: safety, pharmacokinetics, and effect on the insulin-like growth factor axis

Resveratrol, a naturally occurring polyphenol, has cancer chemopreventive properties in preclinical models. It has been shown to downregulate the levels of insulin-like growth factor-1 (IGF-I) in rodents. The purpose of the study was to assess its safety, pharmacokinetics, and effects on circulating levels of IGF-I and IGF-binding protein-3 (IGFBP-3) after repeated dosing. Forty healthy volunteers ingested resveratrol at 0.5, 1.0, 2.5, or 5.0 g daily for 29 days. Levels of resveratrol and its metabolites were measured by high performance liquid chromatography-UV in plasma obtained before and up to 24 hours after a dose between days 21 and 28. IGF-I and IGFBP-3 were measured by ELISA in plasma taken predosing and on day 29. Resveratrol was safe, but the 2.5 and 5 g doses caused mild to moderate gastrointestinal symptoms. Resveratrol-3-O-sulfate, resveratrol-4'-O-glucuronide, and resveratrol-3-O-glucuronide were major plasma metabolites. Maximal plasma levels and areas under the concentration versus time curve for the metabolites dramatically exceeded those for resveratrol, in the case of areas under the concentration versus time curve, by up to 20.3-fold. Compared with predosing values, the ingestion of resveratrol caused a decrease in circulating IGF-I and IGFBP-3 (P<0.04 for both), respectively, in all volunteers. The decrease was most marked at the 2.5 g dose level. The results suggest that repeated administration of high doses of resveratrol generates micromolar concentrations of parent and much higher levels of glucuronide and sulfate conjugates in the plasma. The observed decrease in circulating IGF-I and IGFBP-3 might contribute to cancer chemopreventive activity.

Clinical pharmacology of resveratrol and its metabolites in colorectal cancer patients

Resveratrol is a phytochemical with chemopreventive activity in preclinical rodent models of colorectal carcinogenesis. Antiproliferation is one of the many chemopreventive modes of action it has been shown to engage in. Concentrations of resveratrol, which can be achieved in human tissues after p.o. administration, have not yet been defined. The purpose of this study was to measure concentrations of resveratrol and its metabolites in the colorectal tissue of humans who ingested resveratrol. Twenty patients with histologically confirmed colorectal cancer consumed eight daily doses of resveratrol at 0.5 or 1.0 g before surgical resection. Resveratrol was found to be well tolerated. Normal and malignant biopsy tissue samples were obtained before dosing. Parent compound plus its metabolites resveratrol-3-O-glucuronide, resveratrol-4'-O-glucuronide, resveratrol-3-O-sulfate, resveratrol-4'-O-sulfate, resveratrol sulfate glucuronide, and resveratrol disulfate were identified by high-performance liquid chromatography (HPLC) with UV or mass spectrometric detection in colorectal resection tissue. Quantitation was achieved by HPLC/UV. Cell proliferation, as reflected by Ki-67 staining, was compared in preintervention and postintervention tissue samples. Resveratrol and resveratrol-3-O-glucuronide were recovered from tissues at maximal mean concentrations of 674 and 86.0 nmol/g, respectively. Levels of resveratrol and its metabolites were consistently higher in tissues originating in the right side of the colon compared with the left. Consumption of resveratrol reduced tumor cell proliferation by 5% (P = 0.05). The results suggest that daily p.o. doses of resveratrol at 0.5 or 1.0 g produce levels in the human gastrointestinal tract of an order of magnitude sufficient to elicit anticarcinogenic effects. Resveratrol merits further clinical evaluation as a potential colorectal cancer chemopreventive agent.

Clinical pharmacology of resveratrol and its metabolites in colorectal cancer patients

Resveratrol is a phytochemical with chemopreventive activity in preclinical rodent models of colorectal carcinogenesis. Antiproliferation is one of the many chemopreventive modes of action it has been shown to engage in. Concentrations of resveratrol, which can be achieved in human tissues after p.o. administration, have not yet been defined. The purpose of this study was to measure concentrations of resveratrol and its metabolites in the colorectal tissue of humans who ingested resveratrol. Twenty patients with histologically confirmed colorectal cancer consumed eight daily doses of resveratrol at 0.5 or 1.0 g before surgical resection. Resveratrol was found to be well tolerated. Normal and malignant biopsy tissue samples were obtained before dosing. Parent compound plus its metabolites resveratrol-3-O-glucuronide, resveratrol-4'-O-glucuronide, resveratrol-3-O-sulfate, resveratrol-4'-O-sulfate, resveratrol sulfate glucuronide, and resveratrol disulfate were identified by high-performance liquid chromatography (HPLC) with UV or mass spectrometric detection in colorectal resection tissue. Quantitation was achieved by HPLC/UV. Cell proliferation, as reflected by Ki-67 staining, was compared in preintervention and postintervention tissue samples. Resveratrol and resveratrol-3-O-glucuronide were recovered from tissues at maximal mean concentrations of 674 and 86.0 nmol/g, respectively. Levels of resveratrol and its metabolites were consistently higher in tissues originating in the right side of the colon compared with the left. Consumption of resveratrol reduced tumor cell proliferation by 5% (P = 0.05). The results suggest that daily p.o. doses of resveratrol at 0.5 or 1.0 g produce levels in the human gastrointestinal tract of an order of magnitude sufficient to elicit anticarcinogenic effects. Resveratrol merits further clinical evaluation as a potential colorectal cancer chemopreventive agent.

Resveratrol modulates drug- and carcinogen-metabolizing enzymes in a healthy volunteer study

Resveratrol has been shown to exhibit cancer-preventive activities in preclinical studies. We conducted a clinical study to determine the effect of pharmacologic doses of resveratrol on drug- and carcinogen-metabolizing enzymes. Forty-two healthy volunteers underwent baseline assessment of cytochrome P450 (CYP) and phase II detoxification enzymes. CYP1A2, CYP2D6, CYP2C9, and CYP3A4 enzyme activities were measured by the metabolism of caffeine, dextromethorphan, losartan, and buspirone, respectively. Blood lymphocyte glutathione S-transferase (GST) activity and GST-pi level and serum total and direct bilirubin, a surrogate for UDP-glucuronosyl transferase (UGT) 1A1 activity, were measured to assess phase II enzymes. After the baseline evaluation, study participants took 1 g of resveratrol once daily for 4 weeks. Enzyme assessment was repeated upon intervention completion. Resveratrol intervention was found to inhibit the phenotypic indices of CYP3A4, CYP2D6, and CYP2C9 and to induce the phenotypic index of 1A2. Overall, GST and UGT1A1 activities were minimally affected by the intervention, although an induction of GST-pi level and UGT1A1 activity was observed in individuals with low baseline enzyme level/activity. We conclude that resveratrol can modulate enzyme systems involved in carcinogen activation and detoxification, which may be one mechanism by which resveratrol inhibits carcinogenesis. However, pharmacologic doses of resveratrol could potentially lead to increased adverse drug reactions or altered drug efficacy due to inhibition or induction of certain CYPs. Further clinical development of resveratrol for cancer prevention should consider evaluation of lower doses of resveratrol to minimize adverse metabolic drug interactions.

Abstract 2899: Multiple-dose phase 1 study of 3,3′-diindolylmethane (DIM): Pharmacokinetics and biological effects

We have completed our examination of the safety, tolerability, pharmacokinetics, and effects of twice daily doses of 100 mg and 200 mg of 3, 3’-diindolylmethane (DIM) for four weeks. Healthy adult subjects self-administered an absorption-enhanced formulation of DIM (BR-DIM). Eight subjects received the low dose, and six subjects received the high dose of BR-DIM. Based on medical histories, physical examinations and a battery of blood and urine tests we concluded that BR-DIM in this dosing regimen was very well tolerated, with no significant adverse effects. The pharmacokinetics of DIM were determined at each dose for both the first dose and last dose of BR-DIM in these subjects. The first dose Cmax and AUC values obtained for the two doses were similar to the results of our previous single ascending dose study of BR-DIM. Surprisingly, after four weeks of twice daily dosing, the mean Cmax of DIM fell by 29% and 73% and the mean AUC fell by 46% and 71% in the low and high dose groups, respectively. Multiple daily dosing with BR-DIM clearly altered expression either of specific transporters or of enzymes that biotransform DIM, resulting in a marked decrease in bioavailability. This decreased systemic exposure, however, must be considered in light of the observed induction of CYP1A2, one of our primary biomarkers of effect. Mean CYP1A2 activity increased by 250% at the low dose and by 181% at the high dose, suggesting that effective concentrations of DIM or an active metabolite were achieved in the liver, and that this resulted in induction of hepatic CYP1A2. No effects of BR-DIM were seen on activities of CYPs 2C9, 2D6, or 3A4. The lack of systemic exposure to DIM could result either from induced hepatic metabolism of DIM or from increased biliary secretion of DIM. This proposal for the altered pharmacokinetics of DIM, allowing hepatic effects but not extrahepatic effects, is consistent with the very modest effects of BR-DIM we observed on peripheral blood lymphocyte GST activity, and suggests that the lymphocyte activity may not be an accurate surrogate for hepatic effects of DIM. The lack of significant change in the 2-hydroxyestrone:16α-hydroxyestrone ratio, judged by us to be a key biomarker of efficacy in our previous trial with the DIM precursor indole-3-carbinol, raises the possibility that the change in that ratio is based to a significant extent on extrahepatic hydroxylation of estrone, rather than modulation of hepatic estrogen metabolism. Supported by NCI N01 CN-35008-38 and P20RR021940.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2899.

Abstract A57: High-dose resveratrol modulates drug and carcinogen metabolizing enzymes in a healthy volunteer study

Purpose: Resveratrol (RES) or 3, 4′, 5-trihydroxystilbene has been shown to inhibit carcinogenesis by affecting various molecular events in the initiation, promotion and progression stages. The cancer chemopreventive activity of RES has been demonstrated in vivo in a wide variety of tumors including skin, mammary, gastrointestinal, and liver cancer models. Modulation of Phase I and Phase II enzymes has been suggested to be one of the mechanisms responsible for the cancer preventive effect of RES. We conducted a clinical study to determine the effect of pharmacological doses of RES on drug and carcinogen metabolizing enzymes.

Methods: Forty-two healthy volunteers underwent baseline assessment of Phase I and Phase II enzymes. A cocktail of cytochrome P450 (CYP) metabolic probe drugs, including caffeine, dextromethorphan, losartan, and buspirone, were administered to assess the activity of CYP1A2, 2D6, 2C9, and 3A4, respectively. Blood and urine samples were collected for 8 hours after probe drug administration to determine parent probe drug and metabolite concentrations for measurements of CYP enzyme activities. Blood lymphocyte glutathione S-transferase (GST) activity and GST-π level, and serum total and direct bilirubin, a surrogate for UDP-glucuronosyl transferase (UGT) 1A1 activity, were measured to assess Phase II enzymes. After the baseline evaluation, study participants took 1 gm of RES once daily for 4 wks. Enzyme assessment was repeated upon intervention completion.

Results: RES intervention was found to suppress the activity of CYP3A4, 2D6, and 2C9. The geometric mean change of the activity index of CPY3A4, 2D6, and 2C9 was 33% (p = 0.01), 70% (p = 0.01), and 171% (p &lt; 0.0001), respectively. CYP1A2 activity was induced; the geometric mean change of the activity index was 16% (p = 0.005). The overall GST and UGT1A1 activity index were minimally affected by the intervention while an induction of GST-π level (84%, p = 0.002) and UGT1A1 activity index (20%, p = 0.0089) was observed in individuals with baseline enzyme level/activity in the lowest tertile.

Conclusion: We conclude that high doses of RES administration may modulate enzyme systems involved in carcinogen activation and detoxification, which may be one mechanism by which RES inhibits carcinogenesis. However, high doses of RES administration may lead to clinically relevant metabolic drug interactions. Further clinical studies are needed to determine whether lower doses of RES could be used to achieve cancer preventive activities. (Supported by N01CN35158 from the National Cancer Institute, Division of Cancer Prevention)

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A57.

Phase I dose escalation pharmacokinetic study in healthy volunteers of resveratrol, a potential cancer chemopreventive agent

The red grape constituent resveratrol possesses cancer chemopreventive properties in rodents. The hypothesis was tested that, in healthy humans, p.o. administration of resveratrol is safe and results in measurable plasma levels of resveratrol. A phase I study of oral resveratrol (single doses of 0.5, 1, 2.5, or 5 g) was conducted in 10 healthy volunteers per dose level. Resveratrol and its metabolites were identified in plasma and urine by high-performance liquid chromatography-tandem mass spectrometry and quantitated by high-performance liquid chromatography-UV. Consumption of resveratrol did not cause serious adverse events. Resveratrol and six metabolites were recovered from plasma and urine. Peak plasma levels of resveratrol at the highest dose were 539 +/- 384 ng/mL (2.4 micromol/L, mean +/- SD; n = 10), which occurred 1.5 h post-dose. Peak levels of two monoglucuronides and resveratrol-3-sulfate were 3- to 8-fold higher. The area under the plasma concentration curve (AUC) values for resveratrol-3-sulfate and resveratrol monoglucuronides were up to 23 times greater than those of resveratrol. Urinary excretion of resveratrol and its metabolites was rapid, with 77% of all urinary agent-derived species excreted within 4 h after the lowest dose. Cancer chemopreventive effects of resveratrol in cells in vitro require levels of at least 5 micromol/L. The results presented here intimate that consumption of high-dose resveratrol might be insufficient to elicit systemic levels commensurate with cancer chemopreventive efficacy. However, the high systemic levels of resveratrol conjugate metabolites suggest that their cancer chemopreventive properties warrant investigation.

Safety and efficacy of weekly oral oltipraz in chronic smokers

Cigarette smoking is thought to contribute to carcinogenesis by formation of DNA adducts of tobacco smoke constituents leading to genotoxic damage. The dithiolethione, oltipraz, is a putative cancer chemopreventive agent that induces phase II detoxifying enzymes in preclinical models and reduces aflatoxin adducts in humans living in areas with high dietary levels. To determine if oltipraz could reduce adduct levels of tobacco smoke constituents in the lungs and other target organs, chronic smokers were enrolled to one of three arms: 400 or 200 mg/wk oral oltipraz or placebo. Endobronchial tissue and bronchoalveolar lavage were done before and after 12 weeks of drug treatment; peripheral blood, urine, and oral saline rinse were also collected. Toxicity was assessed every 4 weeks. Fifty-nine of the 77 enrolled subjects completed the study. Of those receiving oltipraz, 15% experienced grade 2/3 toxicity, which was predominantly gastrointestinal. All subject withdrawals occurred in the oltipraz groups. There was no significant difference between pre- and post-polycyclic aromatic hydrocarbon-DNA adduct levels in lung epithelial cells measured by immunoperoxidase staining between treatment and placebo groups. Likewise, no significant differences were found in polycyclic aromatic hydrocarbon or benzo(a)pyrene-7,8-diol-9,10-epoxide adducts measured in blood, oral lining cells, or bladder lining cells. There was also no increase in mRNA or enzymatic activity of phase II enzymes and no change in glutathione levels. Thus, despite moderate drug-related toxicity, there was no significant effect on pharmacodynamic or surrogate risk biomarkers. Other agents with lower toxicity and greater activity to induce phase II enzymes are needed to definitively test the detoxification-induction paradigm in smokers.

Fenretinide: a prototype cancer prevention drug

Fenretinide (N-4-hydroxyphenylretinamide [4-HPR]) is a synthetic retinoid that has been examined in in vitro assays, preclinical animal models and clinical trials as a cancer chemopreventive agent. Its pharmacology, toxicity and mechanisms of action initially suggested an increased therapeutic index relative to native retinoids for the control of tumours of the breast, prostate, bladder, colon, cervix and head and neck. Although fenretinide at the doses and schedules used in several pivotal Phase II and III clinical trials has not been proven to be efficacious in reducing the incidence of cancer or in retarding the development of preneoplastic lesions, encouraging observations regarding unanticipated preventative activity, such as for ovarian cancer control, have arisen from these studies. Research in cancer therapy and the elucidation of molecular pathways activated by fenretinide have also yielded clues about how this agent might be better used in a prevention setting. Current trials are underway to re-examine both dose and schedule of fenretinide administration as well as the target tissues of interest. Investigations of potential synergism between fenretinide and other candidate chemopreventative molecules with complementary mechanisms of action may support future assessments of this prototype cancer prevention drug or its newer analogues.

Relationships between plasma insulin-like growth factor-I and insulin-like growth factor binding protein-3 and second breast cancer risk in a prevention trial of fenretinide

PURPOSE

High circulating insulin-like growth factor (IGF) -I and/or low IGF-binding protein (IGFBP) -3 levels are associated with increased breast cancer risk in unaffected premenopausal women. We determined whether IGF-I and IGFBP-3 predict second breast cancer risk, and whether their changes during fenretinide explain observed reductions in second breast cancer in women </=50 years of age.

EXPERIMENTAL DESIGN

Within a Phase III trial, we measured baseline and 1-year levels of IGF-I, IGFBP-3, and their ratio in 302 subjects on fenretinide and 220 controls who provided plasma samples. The prognostic effect of IGF-I and IGFBP-3, and the surrogate effect of IGF-I during fenretinide were assessed by Cox models after 9.4 years.

RESULTS

Among controls, high IGF-I and low IGFBP-3 were associated with elevated second breast cancer risk [top versus bottom tertile, IGF-I, hazard ratio (HR) = 1.94, 95% confidence interval (CI), 0.87-4.31, P = 0.105; and IGFBP-3, HR = 0.40, 95% CI, 0.18-0.93, P = 0.033]. Fenretinide induced reductions of IGF-I, IGFBP-3, and IGF-I:IGFBP-3 of 8% (95% CI, 2-12%; P = 0.004), 3% (95% CI, 1-5%; P = 0.002), and 5% (95% CI, 0-10%; P = 0.050), respectively. Second breast cancer risk was reduced by 39% (HR = 0.61; 95% CI, 0.40-0.94; P = 0.026). The percentage of treatment effect explained by IGF-I and IGF-I:IGFBP-3 reductions were 4.8% (95% CI, 0.8-28.9%) and 3.1% (95% CI, 0.5-20.8%), respectively.

CONCLUSIONS

Fenretinide induced a moderate reduction of IGF-I, which marginally explains observed cancer risk reductions in women </=50 years of age. In this age group high IGF-I and particularly low IGFBP-3 levels predict second breast cancer risk.

Transforming growth factor-alpha: a surrogate endpoint biomarker?

BACKGROUND

Dysplastic oral leukoplakia (DOL) has been the index lesion in prevention trials for upper aerodigestive tract squamous cell carcinoma (SCC). Vitamin A derivatives, including 13-cis retinoic acid (13-CRA), have been used to treat DOL and to reduce the risk of subsequent SCC. Results from a trial of 13-CRA in patients with DOL are presented here. Transforming growth factor-alpha (TGF-alpha) and the epidermal growth factor receptor messenger RNA (mRNA) expression were studied to validate their use as surrogate endpoint biomarkers in prevention trials for SCC.

STUDY DESIGN

In a prospective, randomized, double-blind trial of 13-CRA in 28 patients with DOL, TGF-alpha and epidermal growth factor receptor mRNA expression were analyzed in sequential biopsy specimens of DOL and of adjacent normal-appearing mucosa, utilizing a quantitative, competitive, reverse transcriptase polymerase chain reaction and were compared using the Wilcoxon signed-rank test for paired comparisons.

RESULTS

In biopsy specimens of DOL, TGF-alpha mRNA expression at baseline, but not baseline expression of epidermal growth factor receptor mRNA, was significantly elevated when compared with its expression in specimens from adjacent normal-appearing mucosa (p = 0.003). In patients randomized to 13-CRA who had > or = 50% clearance of DOL during treatment, significant modulation of TGF-alpha mRNA overexpression was seen after 6 months of treatment (p = 0.016). TGF-alpha mRNA overexpression at baseline predicted a subsequent response to 13-CRA (p 0.066).

CONCLUSIONS

The full extent of the association between TGF-alpha overexpression and the development of SCC is unknown. Evidence is presented in this article that TGF-alpha overexpression mediates the relationship between 13-CRA and DOL, but there is no direct evidence that it mediates the relationship between 13-CRA and the prevention of SCC. Determination of the extent to which TGF-alpha overexpression mediates this relationship and complete validation of TGF-alpha's role as a surrogate endpoint biomarker await the results of animal and human trials that utilize reduction in the incidence of SCC as their endpoint.

Randomized trial of fenretinide in superficial bladder cancer using DNA flow cytometry as an intermediate end point

Retinoids have shown a potential activity in preventing tumor recurrence in superficial bladder cancer. We assessed the activity of the synthetic retinoid fenretinide in superficial bladder cancer using DNA flow cytometry and conventional cytology as surrogate biomarkers. A total of 99 subjects with resected superficial bladder cancer (pTa, pT1) were randomized to either fenretinide (200 mg day p.o. for 24 months) or no intervention. Cystoscopy and bladder washing for DNA flow cytometry end points (proportion of DNA aneuploid histograms, hyperdiploid fraction, and percentage of apoptotic cells) and proportion of abnormal cytological examinations were repeated every 4 months for up to 36 months. The primary study end point was the proportion of DNA aneuploid histograms after 12 months. This figure was 48.9% in the fenretinide arm and 41.9% in the control arm (odds ratio, 1.16; 95% confidence interval, 0.44-3.07). There was no difference in any other response biomarker between the two groups up to 36 months, nor was any biomarker able to predict recurrence risk. Recurrence-free survival was comparable between the arms (27 events in the fenretinide arm versus 21 in the control arm; P = 0.36). Twelve subjects in the fenretinide arm complained of diminished dark adaptability, and nine subjects in the fenretinide arm versus one control subject had mild dermatological alterations. We conclude that fenretinide showed a lack of effect on the DNA content distribution and the morphology of urothelial cells obtained in serial bladder washings. Recurrence-free survival was comparable between groups. Because our data are hampered by the lack of predictivity of the selected biomarkers, additional studies are necessary to assess the activity of fenretinide in preventing bladder cancer.

Association of angiogenesis in lymph node metastases with outcome of breast cancer

BACKGROUND

Microvessel density (MVD) is a measure of the extent of new blood vessel growth or angiogenesis, which is required for tumor progression. Increased MVD in primary breast cancers appears to adversely affect disease-free survival and overall survival in patients with breast cancer. However, the clinical implications of angiogenesis in breast cancer metastases have not been well studied. The purpose of this study was to compare intratumoral MVD in primary breast cancer tissues with MVD in axillary lymph node metastases and to evaluate the relationships among primary- and metastatic-tumor MVD, disease-free survival, and overall survival in patients with lymph node-positive, stage II breast cancer who were treated with adjuvant chemotherapy in Cancer and Leukemia Group B Protocol 8082.

METHODS

Immunostaining for factor VIII-related antigen was performed on tissue sections from 47 primary tumors and 91 axillary lymph nodes containing metastases from 110 patients with lymph node-positive breast cancer. Sections were examined for the presence or absence of focal areas of relatively intense neovascularization (vascular hot spots), and a quantitative assessment of intratumoral MVD was performed.

RESULTS

The presence of vascular hot spots in axillary lymph node metastases, but not primary breast cancers, was associated with statistically significantly decreased disease-free survival (P =.006) and overall survival (P =.004) by univariate analysis. Similarly, increased MVD in metastases, but not in primary tumors, was statistically significantly associated with diminished overall survival in these patients (P =.02). In multivariate analysis, the number of positive axillary lymph nodes and the presence of vascular hot spots in axillary lymph node metastases predicted decreased disease-free survival (P =.0001 and.02, respectively) and overall survival (P =.0001 and.007, respectively). All P values were two-sided.

CONCLUSION

This pilot study suggests that assessing neovascularization in axillary lymph node metastases may provide clinically useful information regarding survival in patients with primary breast cancer.

Randomized trial of fenretinide to prevent second breast malignancy in women with early breast cancer

BACKGROUND

Fenretinide, a vitamin A analogue, has been shown to inhibit breast carcinogenesis in preclinical studies. We determined the efficacy of fenretinide in preventing a second breast malignancy in women with breast cancer.

METHODS

We randomly assigned 2972 women, aged 30-70 years, with surgically removed stage I breast cancer or ductal carcinoma in situ to receive for 5 years either fenretinide orally (200 mg/day) or no treatment. The primary end point was the incidence of contralateral breast cancer or ipsilateral breast cancer 7 years after randomization. Other end points considered post hoc were the same outcomes stratified by menopausal status, incidence of distant metastases, overall mortality, and tumors in other organs. The hazards of breast cancer occurrence were determined by Cox proportional hazards regression analysis. Statistical tests were two-sided.

RESULTS

At a median observation time of 97 months, there were no statistically significant differences in the occurrence of contralateral breast cancer (P =.642) or ipsilateral breast cancer (P =.177) between the two arms. However, an interaction was detected between fenretinide treatment and menopausal status in both outcomes (P for interaction in both outcomes =.045), with a possible beneficial effect in premenopausal women (contralateral breast cancer: adjusted hazard ratio [HR] = 0.66, and 95% confidence interval [CI] = 0.41-1.07; ipsilateral breast cancer: adjusted HR = 0.65, and 95% CI = 0.46-0. 92) and an opposite effect in postmenopausal women (contralateral breast cancer: adjusted HR = 1.32, and 95% CI = 0.82-2.15; ipsilateral breast cancer: adjusted HR = 1.19, and 95% CI = 0.75-1. 89). There were no statistically significant differences between the two arms in tumors in other organs, incidence of distant metastasis, and all-cause mortality.

CONCLUSIONS

Fenretinide treatment of women with breast cancer for 5 years appears to have no statistically significant effect on the incidence of second breast malignancies overall, although a possible benefit was detected in premenopausal women. These studies, particularly the post hoc analyses, are considered exploratory and need to be confirmed.

Strategies for identification and clinical evaluation of promising chemopreventive agents

Strategies for chemopreventative drug development are based on the use of well-characterized agents, intermediate biomarkers correlating to cancer incidence, and suitable cohorts for efficacy studies. Since chemoprevention is applied over the long-term, chemopreventive drugs must have low toxicity. Strategies for enhancing chemopreventive drug efficacy and minimizing toxicity include combinations of drugs with complementary mechanisms and/or synergistic activity; coadministration of drugs to counter the toxicity of the chemopreventive agents; and pursuit of related compounds that retain efficacy with reduced side effects. Because of its slow development, cancer is not a feasible end point for clinical evaluation of chemoprevention, and so intermediate biomarkers that can serve as surrogate end points are crucial. Particularly important biomarkers are the morphometric and cytometric changes defining intraepithelial neoplasia (IEN). Cohorts for chemoprevention trials should have high incidences of the cancer or intermediate biomarker(s) under study within the trial duration.

Plasma alpha-tocopherol concentrations after supplementation with water- and fat-soluble vitamin E

The objective of this study was to examine differences in plasma alpha-tocopherol concentrations after oral administration of pharmacologic doses of vitamin E to normal healthy subjects as RRR-alpha-tocopheryl glycol 1000 succinate (TPGS; water-miscible form) and RRR-alpha-tocopheryl acetate (TA; fat-soluble form). The study was designed to evaluate the administration of three different single doses and multiple doses for 4 wk with both preparations. Administration of 400 IU (269 mg), 800 IU (537 mg), and 1200 IU (807 mg) TPGS as a single dose resulted in slight elevation of plasma alpha-tocopherol concentrations. Administration of multiple daily doses at all three amounts of TPGS for 28 consecutive days resulted in a slight elevation of plasma alpha-to-copherol concentrations. A significant increase in plasma alpha-to-copherol concentrations was observed after ingestion of a single dose or equivalent multiple doses of TA at all three doses. As reported in the literature, in cases of cholestasis and other forms of lipid malabsorption, oral administration of TPGS is the treatment of choice. It appears that for normal adults and patients with normal lipid absorption, fat-soluble forms of vitamin E are preferable for therapeutic and prophylactic uses.

Psychological symptoms and disease-free and overall survival in women with stage II breast cancer. Cancer and Leukemia Group B

BACKGROUND

The possible link between psychological factors and length of cancer survival has generated a literature of contradictory findings. Associations usually have not been found when general psychological symptoms are assessed. Associations usually have been found for predictors related to expressive versus repressive emotional coping (e.g., depression, "fighting spirit," hostility, and type C personality); however, even these associations have been relatively small, when compared with those for medical factors. Yet few studies have adequately controlled for medical and treatment-related factors.

PURPOSE

Within a Cancer and Leukemia Group B (CALGB) national clinical trial of four adjuvant therapy regimens for stage II breast cancer (CALGB 8082), this study prospectively examined the contribution of potential psychological predictors to length of disease-free and overall survival over a 15-year period.

METHODS

Subjects were 280 women with stage II breast cancer, out of a total of 899, who were randomly assigned to receive CMFVP (cyclophosphamide-methotrexate-fluorouracil-vincristine-prednisone) for two 6-week cycles or six 4-week cycles, then subsequently randomly assigned to receive or not to receive VATH (vinblastine-doxorubicin-thiotepa-fluoxymesterone). Subjects were recruited during the period between October 1980 and August 1984, inclusive, and followed until January 1996. Prior to chemotherapy, psychological symptoms were assessed using the Symptom Check List-90-Revised (SCL-90-R). SCL-90-R scores were trichotomized into categories representing high, medium, and low distress. Basic base-line sociodemographic data (including age, ethnicity, education, and marital status) and medical data (including lymph node status, estrogen receptor status, menopausal status, and performance status) were collected. Subjects with psychosocial data differed from those without psychosocial data solely in their higher percentage of classification in the mild limitation category of the Zubrod (Eastern Cooperative Oncology Group) performance status rating (subjects with psychosocial data: 14%; subjects without psychosocial data: 8%).

RESULTS

In stepwise Cox regression analyses that controlled for sociodemographic and medical variables, there was no significant predictive effect of the level of distress (as measured by the SCL-90-R trichotomized scores) on length of disease-free and overall survival of the study subjects. Risk ratios for low versus high distress were 1.01 (95% confidence interval [CI] = 0.62-1.66) for disease-free survival and 1.03 (95% CI = 0.58-1.82) for overall survival.

CONCLUSIONS

This study failed to provide evidence that psychological factors contributed to length of disease-free or overall survival of women who received adjuvant chemotherapy (either CMFVP alone or CMFVP followed by VATH) for treatment of stage II breast cancer.

IMPLICATIONS

In the context of far more potent medical factors, the contribution of psychological factors to disease-free and overall survival is likely to be relatively small. Future research should focus on specific theory-driven predictors rather than on general psychological symptoms. Moreover, it should be based on clinical studies using a controlled, prospective design, in which the effects of medical factors may be distinguished and psychological predictors are clear antecedents of survival outcomes.

Postsurgical adjuvant chemotherapy of stage II breast carcinoma with or without crossover to a non-cross-resistant regimen: a Cancer and Leukemia Group B study

PURPOSE

To compare two cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) regimens with a doxorubicin-based regimen--vinblastine, doxorubicin, thiotepa, and Halotestin (Upjohn, Kalamazoo, MI) (VATH)--in patients with stage II node-positive breast carcinoma.

METHODS

Nine hundred forty-five women were treated with a 6-week induction course of CMFVP. They were then randomized to receive one of two consolidation CMFVP regimens: 6-week courses or 2-week courses. Following completion of CMFVP consolidation, patients were again randomized to either continue the CMFVP regimen or to receive six escalating doses of VATH.

RESULTS

Among all patients, with a median follow-up time of 11.5 years, there is no statistically significant difference in disease-free survival (DFS) between the two consolidation CMFVP regimens. VATH intensification treatment is statistically significantly superior to CMFVP in terms of DFS (P = .0040). For patients with one to three involved nodes, there is currently no significant difference between VATH and CMFVP; however, among those with four or more positive lymph nodes, there is a significant difference in favor of VATH (P = .0037). There is also improved overall survival with VATH (P = .043; median, > 14 years v 10 years). This difference is also statistically significant in patients with four or more involved lymph nodes, among postmenopausal patients, and among postmenopausal estrogen receptor-positive patients.

CONCLUSION

Chemotherapy with crossover to escalating doses of VATH following CMFVP was well tolerated and effective. Inauguration of VATH as a treatment intensification at the eighth month produced a major increase in relapse-free and overall survival. The observation that sensitivity to VATH is retained so long after mastectomy raises questions about the proper duration of adjuvant chemotherapy and lends support to further investigation of cross-over designs in future trials to postoperative adjuvant chemotherapy regimens.