HALT-D: a randomized open-label phase II study of crofelemer for the prevention of chemotherapy-induced diarrhea in patients with HER2-positive breast cancer receiving trastuzumab, pertuzumab, and a taxane

PURPOSE

To assess whether crofelemer would prevent chemotherapy-induced diarrhea (CID) diarrhea in patients with HER2-positive, any-stage breast cancer receiving trastuzumab (H), pertuzumab (P), and a taxane (T; docetaxel or paclitaxel), with/without carboplatin (C; always combined with docetaxel rather than paclitaxel).

METHODS

Patients scheduled to receive ≥ 3 consecutive TCHP/THP cycles were randomized to crofelemer 125 mg orally twice daily during chemotherapy cycles 1 and 2 or no scheduled prophylactic medication (control). All received standard breakthrough antidiarrheal medication (BTAD) as needed. The primary endpoint was incidence of any-grade CID for ≥ 2 consecutive days. Secondary endpoints were incidence of all-grade and grade 3/4 CID by cycle/stratum; time to onset and duration of CID; stool consistency; use of BTAD; and quality of life (Functional Assessment of Chronic Illness Therapy for Patients With Diarrhea [FACIT-D] score).

RESULTS

Fifty-one patients were randomized to crofelemer (n = 26) or control (n = 25). There was no statistically significant difference between arms for the primary endpoint; however, incidence of grade ≥ 2 CID was reduced with crofelemer vs control (19.2% vs 24.0% in cycle 1; 8.0% vs 39.1%, in cycle 2). Patients receiving crofelemer were 1.8 times more likely to see their diarrhea resolved and had less frequent watery diarrhea.

CONCLUSION

Despite the choice of primary endpoint being insensitive, crofelemer reduced the incidence and severity of CID in patients with HER2-positive breast cancer receiving P-based therapy. These data are supportive of further testing of crofelemer in CID.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02910219, prospectively registered September 21, 2016.

Abstract OT1-03-01: Inhibiting fatty acid synthase to improve efficacy of neoadjuvant chemotherapy

Background Human Fatty Acid Synthase (FASN) is the sole cytosolic enzyme responsible for de novo synthesis of long chain fatty acids. Unlike normal tissues, cancer cells require FASN dependent fatty acid synthesis for survival. FASN is overexpressed in 70% of newly diagnosed triple negative breast cancer (TNBC) and associated with significantly shorter disease free and overall survival. In vitro, FASN overexpression induces resistance to multiple DNA damaging agents including doxorubicin and cisplatin. Proton pump inhibitors (PPI), particularly omeprazole can selectively inhibit FASN enzyme activity at a Ki of 3.4umol. Inhibition of FASN activity with PPIs induces apoptosis selectively in cancer cells with minimal effect on non-malignant breast cell lines. PPIs are well tolerated and are FDA approved for a variety of gastro-intestinal disorders. We hypothesize that PPIs will effectively inhibit FASN activity and improve clinical efficacy of neoadjuvant chemotherapy with minimal added toxicity in operable TNBC. Materials and Methods This is a single arm multi -center phase II study of omeprazole 80mg PO BID in combination with standard neoadjuvant anthracycline-weekly taxane chemotherapy (AC-T; Adriamycin 60mg/m2 Cyclophosphamide 600mg/m2 given every q2w with G-CSF or q 3wk x 4 followed by weekly paclitaxel 80mg/m2 x 12) in patients with newly diagnosed clinically stage II or greater TNBC (NCT02595372). Neoadjuvant carboplatin may be offered with weekly paclitaxel at treating physician’s discretion. Patients with prior over the counter or prescription PPI use within 12 months are excluded. An initial core biopsy is performed at baseline, after which patients begin omeprazole monotherapy for a brief period (4-7 days). This is followed by a second research core biopsy and initiation of standard AC-T. PPI is continued until night before definitive surgery. Study follow up ends with definitive surgery and after resolution of known adverse events (<=G1). The primary endpoint is the rate of pCR (defined as no residual invasive disease in breast or axilla) in study patients with FASN expression. Relevant secondary endpoints include rate of pCR in all patients, change in FASN expression, enzymatic activity and downstream target gene expression from baseline to surgery; safety and limited omeprazole PK sampling during the study. Assuming that 70% of newly diagnosed TNBC have FASN expression, a single stage phase II trial to detect a pCR rate of 60% (null= pCR-40%) with 80% power and alpha of 0.10 requires 30 FASN patients (or 42 patients total). This sample size also provides approximately 80% power to identify a change in FASN expression and/or activity of 0.5 SDs using a paired t-test and significance level of 0.05. Conclusion The study enrolled its last participant in May 2019. Six patients are in follow-up who have yet to undergo definitive surgery. Final study patient is anticipated to have surgery in October 2019, with final data analysis planned in the last quarter of 2019. Funding This work has been supported by the Breast Cancer Research Foundation.

Citation Format: Sagar Sardesai, Alexandra Thomas, Christopher Gallagher, Filipa Lynce, Yvonne Ottaviano, Tarah Ballinger, Brian P Schneider, Anna Maria Storniolo, Susan Perkins, Jian Tian Zhang, Kathy D Miller. Inhibiting fatty acid synthase to improve efficacy of neoadjuvant chemotherapy [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 OT1-03-01.

Targeting Barriers of Systems of Care in a Growing Multi-disciplinary Field

PURPOSE OF REVIEW

Cardio-oncology is a growing multi-disciplinary field that focuses on treating and preventing cardiovascular complications in cancer survivors and patients. This review summarizes the current clinical needs and system-based approaches to target barriers of care.

RECENT FINDINGS

The field of cardio-oncology has experienced significant growth in recent years, and an increasing number of programs have been developed across the nation to provide improved and multi-disciplinary care to this patient population. Despite this burgeoning growth, practitioners in the field continue to face important challenges which include lack of administrative and departmental support, funding limitations, and gaps in the areas of mentoring, education, and research. Despite continued growth, cardio-oncology providers continue to face a multitude of challenges. Early inclusion of multi-disciplinary stakeholders, oncologists, cardiovascular team members, and administrative leadership provides an opportunity to collaborate and achieve unique patient care and health system benefits, such as prevention of adverse cardiovascular outcomes, and facilitates the delivery of optimal oncologic treatment.

Video intervention increases participation of black breast cancer patients in therapeutic trials

There is a striking racial and ethnic disparity in incidence and mortality of cancer yet minorities remain markedly underrepresented in clinical trials. This pilot study set out to determine the impact of a 15-min culturally tailored educational video on three outcomes relating to clinical trials: likely participation, attitudes (assessed based on six barriers), and actual enrollment. Breast cancer patients with Stage I-III, if diagnosed within previous 6 months, or metastatic disease who self-identified as black or African American were invited to participate. The primary outcome measure was the decision to participate in a therapeutic clinical trial after the intervention. Patients’ intention to enroll on a therapeutic clinical trial and the change in attitudes toward clinical trials were measured by the previously developed Attitudes and Intention to Enroll in Therapeutic Clinical Trials (AIET) questionnaire. Of the 200 patients that participated, 39 (19.5%) patients signed consent to participate in a therapeutic clinical trial; 27 (13.5%) patients enrolled, resulting in a 7.5% increase from our baseline comparison of 6% clinical trial enrollment rate in black cancer patients (p < .001). Pre-test versus post-test assessment demonstrated the proportion of patients expressing likelihood to enroll in a therapeutic trial following the intervention increased by 14% (p < .001). Among 31 AIET items, 25 (81%) showed statistically significant and positive change post-intervention. The findings suggest the promising utility of a culturally tailored video intervention for improving black patients’ attitudes regarding clinical trial participation and resultant enrollment. Future efforts should continue to target facilitators of population-specific recruitment, enrollment, and retention in therapeutic and non-therapeutic clinical trials.

A culturally tailored educational video can boost participation among black patients in clinical trials of new breast cancer treatments. A US team led by Sandra Swain from Georgetown University Medical Center in Washington, DC, created a 15-min video designed to address six of the concerns commonly cited by blacks about human subjects research. The researchers showed the video to 200 black patients, and saw a large bump in the number of women willing to sign up for a therapeutic trial. On average, only 6% of black cancer patients typically enroll in clinical trials. But in the video intervention study, 19.5% agreed to participate and then 13.5% went ahead with a trial. Video watchers also reported a positive change in their attitude toward clinical research. The study points to the need for population-specific recruitment efforts.

Abstract P3-10-02: Increasing participation in research - breast cancer (Inspire-BrC)

Background: Increasing Black patients' participation in cancer clinical trials is important because of the population's lower survival rate. Accrual for Blacks is the lowest of all groups at 0.5-1.5%. Our study aims to increase trial participation rates among Black breast cancer patients by testing the effectiveness of a culturally tailored video intervention on the decision to participate in a clinical trial.

Methods: We hypothesized that the intervention would increase clinical trial enrollment by 6 percentage points compared to our 2012 enrollment baseline of 6% (22/384). Self- identified Black patients with invasive breast cancer at 5 MedStar Hospitals watched a 15' video about clinical trials, targeting six cultural and attitudinal barriers to participation. The Attitudes and Intention to Enroll in therapeutic clinical Trials (AIET) pre-/post-/follow-up tests with 31 items was used to determine the impact of the video on three domains: actual trial enrollment; likely participation in trials; and attitudes toward trials. The pre-test was conducted at baseline; post-test immediately after video; and follow-up 7-21 days after the intervention. Participants were followed for 6 months to assess trial enrollment status. Descriptive statistics were used to describe study subjects with respect to basic characteristics; means and standard deviations for continuous variables; and frequencies and percentages for categorical variables. Repeated measures analysis of variance was used to examine whether the changes in attitudinal barriers were statistically significant over time. The primary outcome measure was the proportion of Black breast cancer patients who signed consent and/or enrolled in a therapeutic clinical trial.

Results: From Mar/2014 to Sept/2015, 279 patients were approached to join INSPIRE-BrC prior to discussion about therapeutic clinical trials; 52 declined participation. 208 signed consent and 200 completed it. Average age was 59 yrs (SD=12), 75% were stage I-III; 29% were married; 85% had 1 or more children; 29% attended some college or technical school; 53% had private insurance, 31% Medicare, 16% Medicaid; and 53% had a household income &lt;$40,000/yr. A total of 41 INSPIRE-BrC participants (20.5%) signed consent and 29 (14.5%) enrolled onto a therapeutic study (one-sided p=0.027 vs H0: P=0.06). Pre-video, 52% of patients expressed that it was likely they would participate in a hypothetical therapeutic clinical trial; immediately post-video, 67% (p=&lt;0.001) and 7-21 days after the intervention, 64% (p=0.003). Among 31 AIET items, 25 (81%) showed statistically significant and positive change after the intervention. Specifically, trust in the doctor increased and, suspicion in trials decreased (p&lt;0.001). Further, patient views on fairness for treatment of poor people and Blacks became significantly more positive (p&lt;0.001).

Conclusion: Study findings show that the video is a promising tool for rapid dissemination of a theory-driven, evidence-based model to enhance clinical trial accrual among Black cancer patients. The video also has the potential to positively change attitudes about clinical trial participation.

The study was supported by the Breast Cancer Research Foundation.

Citation Format: Swain S, Robinson BN, Newman AF, Tefera E, Herbolsheimer P, Nunes R, Gallagher C, Randolph-Jackson P, Omogbehin A, Dilawari A, Pohlmann P, Mohebtash M, Ottaviano Y, Mohapatra A, Lynce F, Mete M. Increasing participation in research - breast cancer (Inspire-BrC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-02.

Impact of genomic testing and patient-reported outcomes on receipt of adjuvant chemotherapy

Practice guidelines incorporate genomic tumor profiling, using results such as the Oncotype DX Recurrence Score (RS), to refine recurrence risk estimates for the large proportion of breast cancer patients with early-stage, estrogen receptor-positive disease. We sought to understand the impact of receiving genomic recurrence risk estimates on breast cancer patients' well-being and the impact of these patient-reported outcomes on receipt of adjuvant chemotherapy. Participants were 193 women (mean age 57) newly diagnosed with early-stage breast cancer. Women were interviewed before and 2-3 weeks after receiving the RS result between 2011 and 2015. We assessed subsequent receipt of chemotherapy from chart review. After receiving their RS, perceived pros (t = 4.27, P < .001) and cons (t = 8.54, P < .001) of chemotherapy increased from pre-test to post-test, while perceived risk of breast cancer recurrence decreased (t = 2.90, P = .004). Women with high RS tumors were more likely to receive chemotherapy than women with low RS tumors (88 vs. 5 %, OR 0.01, 0.00-0.02, P < .001). Higher distress (OR 2.19, 95 % CI 1.05-4.57, P < .05) and lower perceived cons of chemotherapy (OR 0.50, 95 % CI 0.26-0.97, P < .05) also predicted receipt of chemotherapy. Distressed patients who saw few downsides of chemotherapy received this treatment. Clinicians should consider these factors when discussing chemotherapy with breast cancer patients.

Patterns of care regarding adjuvant hormonal agents and treatment of bone health in postmenopausal women with breast cancer in community and academic centers before and after the availability of ATAC (Adjuvant Tamoxifen, Armidex or Combination) study

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Background: Results from the ATAC trial comparing Tamoxifen to the Aromatase inhibitors (AIs) anastrozole in PM women with early stage breast cancer were initially presented in San Antonio, Texas, in December 2001. ASCO issued guidelines for the adjuvant use of AIs in 2002, updated in 2003. We compared patterns of usage of adjuvant hormonal agents and bone health management before and after availability of the ATAC data in community versus academic centers. Methods: We conducted a retrospective analysis of 432 patients between 1999–2005 from group practices affiliated with two large community hospitals and one academic center. Data were collected from tumor registries regarding demographics, first-line hormonal agent choice, and use of bone density studies, vitamin D/calcium supplements and bisphosphonates. Results: Demographics were identical in both groups before and after January 2002. Before 2002, 96% of the patients were prescribed Tamoxifen in both community and academic centers. After the initial presentation of the ATAC data, 55.08% (65/118) of patients from the community centers versus only 17.11% (19/111) from the academic center were prescribed AIs (p=0.0001). Of the 84 patients who received an AI after January 2002, similar proportions of patients had baseline bone density scans (38.5% community vs. 36.8% academic; p=0.89) and follow up annual/biannual scans (33 % vs. 32%; p=0.85). In addition, similar proportions of patients on AIs were prescribed calcium/vitamin D supplements (47.4% vs. 52.6%; p=0.69) and bisphosphonates (36.8% vs. 21.05%; p=0.20) in community and academic centers, respectively. Conclusions: Community oncologists adopted AIs into clinical practice sooner than academic physicians on the basis of unpublished clinical trial results, even before ASCO published guidelines. Although patients on AIs are deemed to be at higher risk for bone fractures, fewer than 40% were evaluated with baseline or surveillance bone density scans in both community and academic practices. Similar proportions of patients received calcium/vitamin D supplements or bisphosphonates among centers.

No significant financial relationships to disclose.

Specific proteolytic cleavage of poly(ADP-ribose) polymerase: an early marker of chemotherapy-induced apoptosis

Apoptosis is a morphologically and biochemically distinct form of cell death that occurs under a variety of physiological and pathological conditions. In the present study, the proteolytic cleavage of poly(ADP-ribose) polymerase (pADPRp) during the course of chemotherapy-induced apoptosis was examined. Treatment of HL-60 human leukemia cells with the topoisomerase II-directed anticancer agent etoposide resulted in morphological changes characteristic of apoptosis. Endonucleolytic degradation of DNA to generate nucleosomal fragments occurred simultaneously. Western blotting with epitope-specific monoclonal and polyclonal antibodies revealed that these characteristic apoptotic changes were accompanied by early, quantitative cleavage of the M(r) 116,000 pADPRp polypeptide to an M(r) approximately 25,000 fragment containing the amino-terminal DNA-binding domain of pADPRp and an M(r) approximately 85,000 fragment containing the automodification and catalytic domains. Activity blotting revealed that the M(r) approximately 85,000 fragment retained basal pADPRp activity but was not activated by exogenous nicked DNA. Similar cleavage of pADPRp was observed after exposure of HL-60 cells to a variety of chemotherapeutic agents including cis-diaminedichloroplatinum(II), colcemid, 1-beta-D-arabinofuranosylcytosine, and methotrexate; to gamma-irradiation; or to the protein synthesis inhibitors puromycin or cycloheximide. Similar changes were observed in MDA-MB-468 human breast cancer cells treated with trifluorothymidine or 5-fluoro-2'-deoxyuridine and in gamma-irradiated or glucocorticoid-treated rat thymocytes undergoing apoptosis. Treatment with several compounds (tosyl-L-lysine chloromethyl ketone, tosyl-L-phenylalanine chloromethyl ketone, N-ethylmaleimide, iodoacetamide) prevented both the proteolytic cleavage of pADPRp and the internucleosomal fragmentation of DNA. The results suggest that proteolytic cleavage of pADPRp, in addition to being an early marker of chemotherapy-induced apoptosis, might reflect more widespread proteolysis that is a critical biochemical event early during the process of physiological cell death.

Phosphorylation of the nuclear lamins during interphase and mitosis

The nuclear lamina is a polymeric protein assembly that is proposed to function as an architectural framework for the nuclear envelope. Previous work suggested that phosphorylation of the major polypeptides of the lamina (the "lamins") may induce disassembly of this structure during mitosis. To further investigate the possible involvement of phosphorylation in regulation of lamina structure, we characterized lamin phosphorylation occurring in mammalian tissue culture cells during interphase and mitosis. Phosphorylation occurs continuously throughout all interphase periods (coordinately with nuclear envelope growth), and takes place mainly on the assembled lamina. When the lamina is disassembled during cell division, the lamins are modified with approximately 1-2 molecules of associated phosphate. This level of mitotic phosphorylation is 4-7-fold higher than the average interphase level. Lamin phosphate occurs predominantly as phosphoserine, and is distributed over numerous tryptic peptides, many of which are modified during both interphase and mitotic periods. Significantly, phosphorylation is the only detectable charge-altering postsynthetic modification of the lamins that occurs specifically during mitosis. The results of this study support the notion that phosphorylation is important for regulation of interphase and mitotic lamina structure.

Identification of a major polypeptide of the nuclear pore complex

The nuclear pore complex is a prominent structural component of the nuclear envelope that appears to regulate nucleoplasmic molecular movement. Up to now, none of its polypeptides have been defined. To identify possible pore complex proteins, we fractionated rat liver nuclear envelopes and microsomal membranes with strong protein perturbants into peripheral and intrinsic membrane proteins, and compared these fractions on SDS gels. From this analysis, we identified a prominent 190-kilodalton intrinsic membrane polypeptide that occurs specifically in nuclear envelopes. Lectin binding studies indicate that this polypeptide (gp 190) is the major nuclear envelope glycoprotein. Upon treatment of nuclear envelopes with Triton X-100, gp 190 remains associated with a protein substructure of the nuclear envelope consisting of pore complexes and nuclear lamina. We prepared monospecific antibodies to gp 190 for immunocytochemical localization. Immunofluorescence staining of tissue culture cells suggests that gp 190 occurs exclusively in the nucleus during interphase. This polypeptide becomes dispersed throughout the cell in mitotic prophase when the nuclear envelope is disassembled, and subsequently returns to the nuclear surfaces during telophase when the nuclear envelope is reconstructed. Immunoferritin labeling of Triton-treated rat liver nuclei demonstrates that gp 190 occurs exclusively in the nuclear pore complex, in the regions of the cytoplasmic (and possibly nucleoplasmic) pore complex annuli. A polypeptide that cross-reacts with gp 190 is present in diverse vertebrate species, as shown by antibody labeling of nitrocellulose SDS gel transfers. On the basis of its biochemical characteristics, we suggest that gp 190 may be involved in anchoring the pore complex to nuclear envelope membranes.