Barriers & facilitators to healthcare and social services among undocumented Latino(a)/Latinx immigrant clients: Perspectives from frontline service providers in Southeast Michigan

Immigration- and enforcement-related policies and laws have significantly and negatively impacted the health and well-being of undocumented immigrants. We examine barriers and facilitators to healthcare and social services among undocumented Latino(a)/Latinx immigrants specifically in the post 2016 US presidential election socio-political climate. By grounding our study on the perspectives of frontline providers, we explore their challenges in meeting the needs of their undocumented clients. These include client access to healthcare and social services, the barriers providers face in providing timely and effective services, and avenues to reduce or overcome factors that impede service provision to improve quality of care for this population. Data are from 28 in-depth interviews with frontline healthcare and social service providers. Based on data analysis, we found that the domains of the Three Delays Model used in obstetric care provided a good framework for organizing and framing the responses. Our findings suggest that these undocumented clients encounter three phases of delay: delay in the decision to seek care, delay in identifying and traveling to healthcare facilities, and delay in receiving adequate and appropriate care at healthcare facilities. Given the current socio-political climate for immigrants, healthcare and social services organizations that serve undocumented clients should adapt existing services or introduce new services, including those that are not site-based.

SUN-413 Thyroid Stimulating Hormone Levels Amongst Reproductive Age Latinas: Findings from the ELLAS Study

BACKGROUND: National population data on thyroid disease in women comes largely from NHANES. Prior research utilizing data from NHANES 1999-2002 indicated a 3.1% prevalence of hypothyroidism and 0.6% prevalence of hyperthyroidism among reproductive aged women. In this dataset, Mexican Americans had a similar risk of hypothyroidism but a slightly higher rate of hyperthyroidism when compared to non-Hispanic whites. We present data from a prospective cohort study of reproductive aged Hispanic women residing in the United States (US) in order to examine thyroid disease prevalence in this population.

Methods: The Environment, Leiomyomas, Latinas and Adiposity Study (ELLAS) is a prospective NIMHD funded longitudinal cohort study of reproductive age Latinas/Latinx females in Southeast Michigan. Demographic and health data were collected via bilingual interviewers. Height, weight, and body composition were measured by trained staff using a Tanita MC780U scale. Fasting morning venipuncture was performed and samples were collected in a serum separating tube and sent to a commercial lab (Labcorp – Burlington, NC) for TSH electrochemiluminescence immunoassay [normal reference range 0.45-4.5 mIU/L]. The data were analyzed using SAS version 9.4 (Cary, NC).

Results: 516 patients have enrolled in ELLAS and 450 of these have completed the first study visit. Mean age, BMI, and body fat % were 37.7 ± 7.0 years, 29.9 ± 6.8 kg/m2, 36.3% ± 6.6% (mean ± SD) respectively. Reported countries of birth were Mexico (76.2%), US (9.8%), Central America (6.7%), South America (5.6%), and the Caribbean Islands (0.7%). 34 (7.6%) participants reported a pre-existing thyroid condition. Of those, 28 reported they had been treated for a thyroid condition in the past, and 14 were currently taking prescription medication for thyroid disease. TSH levels were available on 418 women. Of those with a known thyroid condition, 6.5% had TSH values < 0.45 and 16.1% had elevated TSH values (> 4.5) at the time of their study visit, compared to 1.7% and 7.4% overall. 0.2% had TSH > 10. Among those without a known history of thyroid disease, 1.3% had TSH < 0.45 and 6.7% had TSH > 4.5 at their visit. BMI, body fat %, and country of birth were not associated with TSH levels, but there was a small yet significant effect of age on TSH (p=0.009).

Conclusion: In this US cohort of Hispanic women of reproductive age, we observed a high prevalence of thyroid dysfunction in those without pre-existing disease. In women with a known thyroid condition, the prevalence of abnormal TSH values was also high, representing both under- and over-treatment with thyroid hormone. Screening for thyroid disease in this population is important and presents a potential opportunity for intervention in an often underserved population.

Barriers, beliefs, and practices regarding hygiene and vaccination among the homeless during a hepatitis A outbreak in Detroit, MI

Appropriate hygiene practices and vaccine acceptance are key factors impacting the health of homeless individuals. A recent outbreak of hepatitis A in Michigan, especially impacting Detroit, prompted us to investigate the practices and attitudes of Detroit's homeless population toward hygiene measures and vaccinations, as well as barriers to such resources. We developed a questionnaire as a means to collect our data, and participants were interviewed at shelters and soup kitchens. While the majority of participants adhered to healthy hygiene practices, approximately 89% reported barriers to accessing public showers. More than half the participants (64%) reported receiving their hepatitis A vaccine prior to the study, while 23% reported previously refusing or hesitating to receive vaccinations. Despite an overall favorable adherence to hygiene practices, substantial barriers are yet to be overcome. Moreover, active measures should be taken to establish higher levels of trust between providers and the homeless to encourage vaccine acceptance.

Hyperactivation of TORC1 Drives Resistance to the Pan-HER Tyrosine Kinase Inhibitor Neratinib in HER2-Mutant Cancers

We developed neratinib-resistant HER2-mutant cancer cells by gradual dose escalation. RNA sequencing identified TORC1 signaling as an actionable mechanism of drug resistance. Primary and acquired neratinib resistance in HER2-mutant breast cancer patient-derived xenografts (PDXs) was also associated with TORC1 hyperactivity. Genetic suppression of RAPTOR or RHEB ablated P-S6 and restored sensitivity to the tyrosine kinase inhibitor. The combination of the TORC1 inhibitor everolimus and neratinib potently arrested the growth of neratinib-resistant xenografts and organoids established from neratinib-resistant PDXs. RNA and whole-exome sequencing revealed RAS-mediated TORC1 activation in a subset of neratinib-resistant models. DNA sequencing of HER2-mutant tumors clinically refractory to neratinib, as well as circulating tumor DNA profiling of patients who progressed on neratinib, showed enrichment of genomic alterations that converge to activate the mTOR pathway.

Impact of FDG PET Imaging for Expanding Patient Eligibility and Measuring Treatment Response in a Genome-Driven Basket Trial of the Pan-HER Kinase Inhibitor, Neratinib

PURPOSE

To determine whether FDG PET can expand eligibility in biomarker-selected clinical trials by providing a means to quantitate response in patients with non-assessable disease by RECIST.

EXPERIMENTAL DESIGN

SUMMIT (NCT01953926) is a multicenter phase II "basket" trial of the Pan-HER kinase inhibitor, neratinib. Patients had advanced ERBB2 (HER2)-mutant solid tumors, ≥1 measurable lesion, preferably defined unidimensionally by RECIST v1.1, or alternatively metabolically by PET Response Criteria (PRC). The primary aim was to determine the proportion of additional breast cancer patients accrued using PRC who would have otherwise been ineligible based on RECIST criteria alone. The secondary aim was to determine the concordance of response versus non-response between RECIST and PRC.

RESULTS

Eighty-one patients with HER2-mutant metastatic breast cancer were accrued; 77 were evaluable for response by RECIST and/or PRC. 63 (82%) were RECIST-evaluable and 14 (18%) were accrued using PRC alone. Bone-only disease (n = 11; 79%) was the most common reason for classification as non-measurable by RECIST. Twenty-nine patients were accrued and followed using both criteria, of which 25 (86%; 95% confidence interval, 68%-96%) were concordant for response versus non-response as defined by RECIST and PRC.

CONCLUSIONS

PRC allowed patients with non-RECIST measurable disease access to therapy and facilitated more rapid accrual of patients to this trial of a rare biomarker. PRC and RECIST both provided methods of response assessment and were generally concordant. Thus, PRC was useful as a supplement to RECIST criteria. This provides a rationale for including FDG PET measurements in future clinical trials involving rare tumors or rare genomically defined subpopulations of more common cancers.

Efficacy and Determinants of Response to HER Kinase Inhibition in HER2-Mutant Metastatic Breast Cancer

HER2 mutations define a subset of metastatic breast cancers with a unique mechanism of oncogenic addiction to HER2 signaling. We explored activity of the irreversible pan-HER kinase inhibitor neratinib, alone or with fulvestrant, in 81 patients with HER2-mutant metastatic breast cancer. Overall response rate was similar with or without estrogen receptor (ER) blockade. By comparison, progression-free survival and duration of response appeared longer in ER⁺ patients receiving combination therapy, although the study was not designed for direct comparison. Preexistent concurrent activating HER2 or HER3 alterations were associated with poor treatment outcome. Similarly, acquisition of multiple HER2-activating events, as well as gatekeeper alterations, were observed at disease progression in a high proportion of patients deriving clinical benefit from neratinib. Collectively, these data define HER2 mutations as a therapeutic target in breast cancer and suggest that coexistence of additional HER signaling alterations may promote both de novo and acquired resistance to neratinib. SIGNIFICANCE: HER2 mutations define a targetable breast cancer subset, although sensitivity to irreversible HER kinase inhibition appears to be modified by the presence of concurrent activating genomic events in the pathway. These findings have implications for potential future combinatorial approaches and broader therapeutic development for this genomically defined subset of breast cancer.This article is highlighted in the In This Issue feature, p. 161.

Neratinib-based therapy in patients with metastatic HER2-positive breast cancer from Asia

Aim: To evaluate the safety and efficacy of neratinib-based therapy in Asian patients with HER2-positive metastatic breast cancer (MBC). Patients & methods: We performed a pooled analysis of seven early-phase studies of neratinib given either as monotherapy or in combination with chemotherapeutic agents or trastuzumab in patients with advanced solid tumors. Results: A total of 793 patients with HER2-positive MBC were included in the efficacy analysis (Asia: 271 patients; other regions: 522 patients). The overall response rate in patients from Asia was 66.4% (180/271) and the median progression-free survival was 55.6 weeks. The most common adverse event in patients from Asia was diarrhea (all-grade: 96.3%; grade 3: 27.4%). Conclusion: Neratinib-based therapy is safe and effective in patients with HER2-positive MBC from Asia.

A qualitative study on the impact of the 2016 US election on the health of immigrant families in Southeast Michigan

BACKGROUND

Given the anti-immigrant rhetoric and policy proposals by President Donald Trump during the 2016 presidential campaign and afterwards, his election to president in November 2016 and subsequent policy changes has affected immigrant families. In this study, we aim to better understand how post-election policy change may have impacted the health and well-being, including health and social service utilization, of Latino immigrants in Southeastern Michigan.

METHODS

We conducted 28 in-depth interviews with frontline staff at two Federally Qualified Health Centers and a non-profit agency. These staff had intimate knowledge of and insights into the lived experiences of the mixed-status immigrant families they serve. The interviews were audio recorded, transcribed, and analyzed thematically.

RESULTS

Our findings show three major themes: (1) An increased and pervasive fear of deportation and family separation among mixed-status immigrant clients, (2) The fear of deportation and family separation has resulted in fractures in community cohesion, and (3) Fear of deportation and family separation has had an impact on the healthcare utilization and health-related behaviors of mixed-status families. Staff members report that these three factors have had an impact on physical and mental health of these immigrant clients.

CONCLUSIONS

These results add to previous literature on the effect of immigration policies on the health and provide key insights for interventions to improve the health of immigrants within this socio-political environment.

Abstract 329: Hyperactivation of mTORC1 drives acquired resistance to the pan-HER tyrosine kinase inhibitor neratinib in HER2-mutant cancers

Background: The HER2 tyrosine kinase inhibitor (TKI) neratinib has exhibited clinical activity in patients with metastatic HER2-mutant cancers. However, responses are heterogeneous across tumor types and not generally prolonged, suggesting mechanisms of de novo and acquired drug resistance.

Methods: Neratinib-resistant 5637 (HER2S310F) bladder cancer and OVCAR8 (HER2G776V) ovarian cancer cells were developed after gradual dose escalation. Candidate pathways associated with drug resistance identified by RNA sequencing were validated in a panel of HER2-mutant cell lines and in the SUMMIT basket trial in patients with HER2-mutant cancers.

Results: Neratinib-resistant 5637 and OVCAR8 cells were cross-resistant to the HER2 TKIs afatinib and lapatinib. Immunoblot analysis showed that neratinib was still able to suppress HER2, EGFR and HER3 phosphorylation. Gene Set Enrichment and Connectivity Map analyses of RNA-seq data suggested mTORC1 signaling as a druggable pathway driving neratinib resistance. Immunoblot analysis of drug-resistant cells revealed a striking increase in S6K and S6 phosphorylation compared to parental cells. P-S6 levels and viability of drug resistant cells/tumors were ablated upon combining neratinib with the TORC1i everolimus both in vitro and in vivo. Similar results were obtained in cells transfected with Raptor or Rheb siRNAs. Further, neratinib resistance was induced by TSC2 knockdown and resultant TORC1 hyperactivation in parental 5637, OVCAR8, and MCF7 cells expressing L755S or V777L HER2 mutations. RNA-seq also revealed significant enrichment of RAS pathway in neratinib resistant cells which was confirmed by RAS-GTP pulldown. Pharmacological inhibition of RAS signaling using the PI3Ki buparlisib and the MEKi trametinib, or genetic suppression using H-, K-, and N-RAS isoform-specific siRNAs, ablated P-S6 and viability of neratinib resistant cells, suggesting RAS is causally associated with TORC1 hyperactivity and drug resistance. Further, intrinsically neratinib-resistant HER2-mutant cell lines with KRAS or PIK3CA co-mutations [DV90 (ERBB2V842I, KRASG13D), SNUC2A (ERBB2R678Q, KRASG12D, TSC2P1521T), MCF7 (HER2L755S/V777L, PIK3CAH1047R)] were sensitized to neratinib upon the addition of everolimus. Finally, DNA sequencing of tumors (MSK-IMPACT panel; 410 genes) from 141 patients enrolled in the SUMMIT trial showed enrichment of somatic alterations associated with aberrant activation of TORC1 pathway (KRAS, NRAS, NF1, PIK3CA, PIK3R1, AKT1/2, PTEN) in patients exhibiting primary resistance to neratinib.

Conclusions: These data suggest that hyperactivation of TORC1 pathway promotes de novo and acquired resistance to neratinib across histologically distinct HER2-mutant cancers. Thus, we propose the combination of neratinib with TORC1 inhibitors is worthy of investigation in patients with HER2-mutant cancers.

Citation Format: Dhivya R. Sudhan, Angel Guerrero-Zotano, Helen Won, Paula Gonzales Ericsson, Qi Liu, Teresa Dugger, James Koch, Alison Schram, Alberto Servetto, Richard Cutler, Alshad Lalani, Richard Bryce, Alan Auerbach, Ariella Hanker, Carlos L. Arteaga. Hyperactivation of mTORC1 drives acquired resistance to the pan-HER tyrosine kinase inhibitor neratinib in HER2-mutant cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 329.

Abstract 1264: Design, synthesis and biological evaluation of new phenothiazine derivatives as potential Tousled-like kinase 1 inhibitors in prostate cancer treatment

Introduction: The standard therapy for advanced Prostate Cancer (PCa) consists of anti-androgens which provide respite from the disease progression, yet ultimately fail and result in the incurable phase of the disease: mCRPC. Targeting PCa cells before their progression to mCRPC would significantly improve the outcome. Untoward toxicity limits the combination therapies targeting the DNA Damage Response (DDR), and hence the goal of clinical trials is to target the DDR more specifically. Androgen deprivation therapy (ADT) in LNCaP cells results in the increased expression of TLK1B, a critical kinase upstream of NEK1 and ATR, thereby mediating a DDR that typically causes a temporary cell cycle arrest of androgen-responsive PCa cells. Following the DNA damage, the addition of a TLK1 specific inhibitor, thioridazine (THD), impairs ATR and Chk1 activation, establishing the existence of an ADT>TLK1>NEK1>ATR>Chk1 DDR pathway, while its abrogation, leads to apoptosis. However, THD is a known anti-psychotic and has undesirable side-effects. Hence, there is a compelling need to design and develop next-generation TLK1 inhibitors to circumvent the adverse effects and advance them in the clinic.

Methods: We performed immunoblotting of the tumour tissue phosphoproteins (pATR, pChk1 and pNEK1) and immunohistochemistry analysis of the tissue sections from the LNCaP xenograft models. To identify and develop new potent inhibitors against TLK1, we employed an in-silico homology modelling and molecular docking approach. Based on the protein-ligand binding interactions and the docking score, a handful of compounds were shortlisted, synthesised and screened for the TLK1 inhibition potential in-vitro and using cell-based assays.

Results: Our experimental data revealed that the pATR, pChk1, pNEK1, Ki-67 and PCNA were remarkably inhibited when treated with THD in combination with an anti-androgen drug, Bicalutamide (BIC). Moreover, it also induced apoptosis and increased DNA damage as demonstrated by the cleaved PARP, Caspase 3 and γH2AX levels respectively. The new inhibitor screening assay showed J54 compound to be most potent and inhibitory with a logIC50 of 1.1µM. J54 binds to the protein’s allosteric site noncompetitively with ATP and interacts with His504 and Gly630 with a corresponding docking score of -6.736. J54 is found to be non-toxic to normal cells and also suppresses the growth of androgen-dependent colonies of LNCaP cells cultured with BIC.

Conclusion: Our preliminary work suggests that targeting the TLK1/NEK1 axis with specific TLK1 inhibitors might be an effective therapy for PCa in combination with standard care, ADT.

Citation Format: Siddhant Bhoir, Javeena Hussain, Vibha Singh, Rupesh Chikhale, Richard Bryce, Sivapriya Kirubakaran, Arrigo DeBenedetti. Design, synthesis and biological evaluation of new phenothiazine derivatives as potential Tousled-like kinase 1 inhibitors in prostate cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1264.

Neratinib after trastuzumab-based adjuvant therapy in patients from Asia with early stage HER2-positive breast cancer

Aim: To evaluate the efficacy and safety of neratinib as extended adjuvant therapy in patients from Asia based on exploratory analyses of the Phase III ExteNET trial. Patients & methods: A total of 2840 women with early stage HER2-positive breast cancer were randomly assigned to neratinib 240 mg/day or placebo for 1 year after trastuzumab-based adjuvant therapy. Results: A total of 341 patients were from Asia (neratinib, n = 165; placebo, n = 176). 2-year invasive disease-free survival rates were 92.8 and 90.8% with neratinib and placebo, respectively (HR: 0.70; 95% CI: 0.31-1.55), and 5-year rates were 91.9 and 87.2%, respectively (HR: 0.57; 95% CI: 0.27-1.13). Diarrhea was the most common adverse event with neratinib. Conclusion: Extended adjuvant therapy with neratinib reduces disease recurrences in Asian women with HER2-positive breast cancer. Trial registration: Clinicaltrials.gov NCT00878709.

The Neat-HER Virtual Registry: A novel registry following HER2+ ESBC patients receiving neratinib in the extended adjuvant setting

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Background: While data from traditional registries are limited to patients (pts) treated at study sites, virtual registries can enroll a more diverse real-world population. Neat-HER is a US-based, non-interventional pilot virtual registry through PicnicHealth that will enroll 100 pts with HER2+ BC receiving neratinib as extended adjuvant therapy. Methods: Neat-HER will evaluate the feasibility of enrolling pts & answering research questions using this novel methodology. Eligibility includes receipt of neratinib, signed informed consent for medical record retrieval/data abstraction & > 18 years age at study consent. Pts who fail to complete enrollment procedures, are participating in a clinical trial, have metastatic disease, or who lack adequate medical records will be excluded. For each pt discontinuing neratinib within 60 days of starting treatment, an additional pt will be recruited, but all pts will be included in the analysis. Pts are recruited through multiple mechanisms incl. private social media groups, treating clinicians & pts enrolled in the Puma texting program. PicnicHealth will collect & structure medical records from medical practices in the United States for ~7 years prior to enrolment up to 1 year after enrolment. Research questions focus on descriptive pt characteristics & demographics, breast cancer history [(neo)adjuvant treatment/outcomes], use of diarrhea prophylaxis, incidence of diarrhea & duration of neratinib. Results: Enrollment began in 12/2018 with target completion in 4/2019. As of 2/2019, 42 pts have initiated enrolment. Of these, 19 pts completed enrolment & 69,750 data points have been extracted from medical records. Descriptive statistics will be used to characterize the pt cohort. Duration of treatment, receipt & type of prophylaxis, incidence of diarrhea, treatment discontinuation & reasons for discontinuation will be summarized for all pts. Conclusions: A virtual registry allows assessment of medication use & outcomes in a diverse population in a rapid timeframe. Neat-HER will provide comprehensive information on clinical history & treatment patterns in a real-world cohort of pts receiving extended adjuvant neratinib.

Neratinib + capecitabine versus lapatinib + capecitabine in patients with HER2+ metastatic breast cancer previously treated with ≥ 2 HER2-directed regimens: Findings from the multinational, randomized, phase III NALA trial

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Background: NALA (ClinicalTrials.gov NCT01808573) is a multinational, randomized, open-label, phase III trial of neratinib (an irreversible pan-HER tyrosine kinase inhibitor [TKI]) + capecitabine (N+C) vs lapatinib (a reversible dual TKI) + capecitabine (L+C) in patients with stage IV HER2+ metastatic breast cancer (MBC) who had received ≥2 prior HER2-directed regimens for MBC. Methods: Patients were randomized 1:1 to N (240 mg qd po) + C (750 mg/m2 bid po) or L (1250 mg qd po) + C (1000 mg/m2 bid po). Co-primary endpoints were centrally assessed progression-free survival (PFS) and overall survival (OS). Secondary endpoints were investigator-assessed PFS; objective response rate (ORR); duration of response (DoR); clinical benefit rate (CBR); time to intervention for symptomatic metastatic central nervous system (CNS) disease; safety; and patient-reported health outcomes. Results: 621 patients were randomized (307 to N+C; 314 to L+C). The risk of disease progression or death was reduced by 24% with N+C vs L+C (HR = 0.76; 95% CI 0.63–0.93; p = 0.006); 6- and 12-month PFS rates were 47.2% vs 37.8% and 28.8% vs 14.8% for N+C vs L+C, respectively. OS rates at 6 and 12 months were 90.2% vs 87.5% and 72.5% vs 66.7% for N+C vs L+C, respectively (HR = 0.88; 95% CI 0.72–1.07; p = 0.2086). ORR in patients with measurable disease at screening was improved with N+C vs L+C (32.8% vs 26.7%; p = 0.1201), as was CBR (44.5% vs 35.6%; p = 0.0328) and DoR (HR = 0.50; 95% CI 0.33–0.74; p = 0.0004). Time to intervention for symptomatic CNS disease (overall cumulative incidence 22.8% vs 29.2%; p = 0.043) was delayed with N+C vs L+C. Treatment-emergent adverse events (TEAEs) were similar between arms, but there was a higher rate of grade 3 diarrhea with N+C vs L+C (24.4% vs 12.5%). TEAEs leading to neratinib/lapatinib discontinuation were lower with neratinib (10.9%) than with lapatinib (14.5%). Conclusions: N+C significantly improved PFS with a trend towards improved OS vs L+C. N+C also resulted in a delayed time to intervention for symptomatic CNS disease. Tolerability was similar between the two arms, with no new safety signals observed. Clinical trial information: NCT01808573.

Modeling the consequences of recurrences after trastuzumab treatment of HER2+ early-stage breast cancer

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Background: The study objective was to estimate the long-term consequences of recurrences following treatment with trastuzumab (TRA) among women with HER2+ early stage breast cancer (BC) in the United States (US). Methods: A simulation model was constructed to estimate the following outcomes for each combination of hormone receptor (+/-) and nodal (+/-) status: number of recurrences, direct medical cost and indirect cost attributed to recurrences. The number of women aged ≥18 years with newly diagnosed HER2+ BC between 2018 and 2037 was estimated using SEER incidence rates (assumed constant over time) and from US Census data and accounted for the proportion of women utilizing adjuvant TRA by nodal status and age (assumed constant over time). The recurrence rate to any regional, distant or contralateral site was based on the long-term follow-up of the HERceptin Adjuvant (HERA) trial (expected 20-year recurrence proportions of 27.6% for TRA and 36.7% without TRA). Medical and pharmacy costs due to a recurrence were based on a 3-year study of metastatic BC patients treated with HER2 targeted agents. Beyond year 3, cost increased by 4.5% per year. The indirect costs of recurrences included loss of income from early retirement valued at the mean hourly wage, work absenteeism ($6,960/year), and reduced productivity while at work ($3,456/year). Non-cancer related mortality was estimated using SEER data. Results: We estimated that there would be 411,373 incident cases of early stage BC who would receive adjuvant TRA treatment from 2018 to 2037. Following each annual cohort for 20 years, we estimated that there would be 112,700 recurrences after TRA treatment and 149,674 recurrences without TRA treatment. The 20-year direct medical costs of recurrences were estimated to be $28.2 and $37.5 billion with and without TRA, respectively and the indirect costs were estimated to be $4.1 and $5.6 billion with and without TRA, respectively. Conclusions: Although TRA reduced recurrences by 25% in our 20-year model, there was a substantial number of recurrences. Future research will assess the clinical and economic impact of newer HER2 directed therapies in the adjuvant (pertuzumab, T-DM1) and extended adjuvant (neratinib) setting.

Effects of neratinib on health-related quality of life in women with HER2-positive early-stage breast cancer: longitudinal analyses from the randomized phase III ExteNET trial

BACKGROUND

We report longitudinal health-related quality-of-life (HRQoL) data from the international, randomized, double-blind, placebo-controlled phase III ExteNET study, which demonstrated an invasive disease-free survival benefit of extended adjuvant therapy with neratinib over placebo in human epidermal growth factor receptor-2-positive early-stage breast cancer.

PATIENTS AND METHODS

Women (N  = 2840) with early-stage HER2-positive breast cancer who had completed trastuzumab-based adjuvant therapy were randomly assigned to neratinib 240  mg/day or placebo for 12  months. HRQoL was an exploratory end point. Patients completed the Functional Assessment of Cancer Therapy-Breast (FACT-B) and EuroQol 5-Dimensions (EQ-5D) questionnaires at baseline and months 1, 3, 6, 9, and 12. Changes from baseline were compared using analysis of covariance with no imputation for missing values. Sensitivity analyses used alternative methods. Changes in HRQoL scores were regarded as clinically meaningful if they exceeded previously reported important differences (IDs).

RESULTS

Of the 2840 patients (intention-to-treat population), 2407 patients were evaluable for FACT-B (neratinib, N  = 1171; placebo, N  = 1236) and 2427 patients for EQ-5D (neratinib, N  = 1186; placebo, N  = 1241). Questionnaire completion rates exceeded 85%. Neratinib was associated with a decrease in global HRQoL scores at month 1 compared with placebo (adjusted mean differences: FACT-B total, -2.9 points; EQ-5D index, -0.02), after which between-group differences diminished at later time-points. Except for the FACT-B physical well-being (PWB) subscale at month 1; all between-group differences were less than reported IDs. The FACT-B breast cancer-specific subscale showed small improvements with neratinib at months 3-9, but all were less than IDs. Sensitivity analyses exploring missing data did not change the results.

CONCLUSIONS

Extended adjuvant neratinib was associated with a transient, reversible decrease in HRQoL during the first month of treatment, possibly linked to treatment-related diarrhea. With the exception of the PWB subscale at month 1, all neratinib-related HRQoL changes did not reach clinically meaningful thresholds. ClinicalTrials.gov: NCT00878709.

Abstract PD3-06: Neratinib + fulvestrant for HER2-mutant, HR-positive, metastatic breast cancer: Updated results from the phase 2 SUMMIT trial

Background: HER2 mutations define a rare subset of metastatic breast cancer (MBC) with a unique mechanism of oncogenic addiction to HER2 signaling. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has demonstrated single-agent clinical activity in HER2-mutant MBC. In HER2-mutant, HR+ MBC, neratinib + fulvestrant (N+F) appears synergistic vs single-agent neratinib, possibly due to more complete inhibition of bi-directional signaling between HER2 and estrogen receptors. Here we describe interim efficacy results of the expanded HER2-mutant, HR+ MBC cohort treated with N+F from SUMMIT (NCT01953926).

Methods: HR+ MBC patients (pts) with HER2 mutations documented by local testing received oral neratinib 240mg qd and intramuscular fulvestrant (labeled dose). Intensive loperamide prophylaxis was mandatory during cycle 1. Efficacy endpoints include objective response rate at week 8 (ORR8); confirmed objective response rate (ORR); clinical benefit rate (CBR); duration of response (DOR); progression-free survival (PFS); response was assessed by RECIST 1.1 and/or PET Response Criteria. Genomic profiling from fresh/archival tumor tissues and/or plasma cfDNA was performed retrospectively by next-generation sequencing (MSK-IMPACT).

Results: As of 18 May 2018, 46 HER2-mutant HR+ MBC pts have been treated with N+F. Most pts were pretreated, with 91% having received prior anti-cancer medication for MBC (range 0–10). ORR was 33% and median DOR in the 15 pts with a confirmed response was 9.2 months (95% CI 3.9–18.5). Twenty-four pts had prior fulvestrant exposure, and 19 had received prior CDK4/6i-based therapy. Clinical activity was observed with ORRs of 17% and 26% in prior fulvestrant-treated and prior CDK4/6i-treated pts, respectively. ORRs by HER2 mutation were: V777L 63% (5/8 pts); S310F/Y 67% (4/6 pts); G778_P780dup 50% (3/6 pts). Diarrhea was the most common adverse event (grade 3, 24%; grade 4, 0%). Median cumulative duration of grade 3 diarrhea was 3 days. There were no treatment discontinuations due to diarrhea.

 Neratinib + fulvestrantOutcomeaAll patients (N=46)Prior fulvestrant (N=24)Prior CDK4/6i-based therapy (N=19)ORR8 – n (%)19 (41.3)8 (33.3)7 (36.8)95% CI27.0–56.815.6–55.316.3–61.6ORR – n (%)15 (32.6)4 (16.7)5 (26.3)95% CI19.5–48.04.7–37.49.1–51.2DOR for each responder, months 5.6b; 9.2; 9.6b; 18.55.6b; 5.7b; 9.3; 9.6b; 12.9bCBR – n (%)27 (58.7)11 (45.8)9 (47.4)95% CI43.2–73.025.6–67.224.4–71.1Median (95% CI) time to event,c monthsPFS3.9 (3.6–5.7)3.7 (3.5–12.8)3.9 (1.9–NA)DOR9.2 (3.9–18.5)NANAaFor pts with both RECIST- and PET-evaluable lesions, the best of either RECIST or PET response was used to determine response; the earliest progression by RECIST or PET was used for progression; bPt has not progressed; cKaplan-Meier analysis; NA, not applicable

Conclusions: N+F demonstrates encouraging clinical activity with durable responses in heavily pretreated pts with HER2-mutant, HR+ MBC. Of note, responses were observed in pts who had received prior fulvestrant or CDK4/6 inhibitors. No new safety signals were identified; the rate of diarrhea was similar to single-agent neratinib and not dose limiting. Updated data after additional follow-up and genomic data will be presented.

Citation Format: Smyth LM, Piha-Paul SA, Saura C, Loi S, Lu J, Shapiro GI, Juric D, Mayer IA, Arteaga C, de la Fuente M, Brufksy AM, Mau-Sørensen M, Arnedos M, Moreno V, Sohn J-H, Schwartzberg L, Gonzàlez-Farré X, Cervantes A, Mann G, Shahin S, Cutler, Jr. RE, Eli LD, Xu F, Bagulho T, Lalani AS, Bryce R, Solit DB, Hyman DM, Meric-Bernstam F, Baselga J. Neratinib + fulvestrant for HER2-mutant, HR-positive, metastatic breast cancer: Updated results from the phase 2 SUMMIT trial [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 PD3-06.

The characterization, management, and future considerations for ErbB-family TKI-associated diarrhea

Purpose

Diarrhea is recognized as a common adverse event associated with tyrosine kinase inhibitors (TKIs), with those targeting the ErbB family of receptors being associated with the highest rate of diarrhea.

Methods

This paper reviews data on the incidence, timing, and duration of diarrhea associated with US Food and Drug Administration-approved ErbB family-targeted TKIs from the published literature, and sets forth recommendations for management.

Results

In the absence of anti-diarrheal prophylaxis the incidence of any-grade diarrhea varies and typically occurs early during the course of treatment. Although it is difficult to determine if the incidence and severity of diarrhea is related to inhibition of a particular kinase target because of the multi-targeted and overlapping activity of many agents, evidence suggests that second-generation TKIs with broader target profiles (i.e., afatinib, lapatinib, neratinib) result in a higher incidence of diarrhea compared with highly specific first- (erlotinib, gefitinib) or third- (osimertinib) generation agents. The mechanisms responsible for TKI-associated diarrhea are not fully understood and are likely multi-factorial, involving dysregulated ion transport, inflammation, and mucosal injury. Management strategies have been developed—and continue to be refined—to prevent and reduce the severity and duration of TKI-associated diarrhea. For agents associated with more significant symptoms, anti-diarrheal prophylaxis reduces the incidence and severity of diarrhea, and ongoing studies are evaluating specific strategies to further reduce incidence and duration of TKI-associated diarrhea.

Conclusions

Continued investigations into risk factors and pharmacogenomic markers for diarrhea may further improve management of this common toxicity.

Neratinib in Combination With Trastuzumab for the Treatment of Patients With Advanced HER2-positive Breast Cancer: A Phase I/II Study

BACKGROUND

Despite the availability of several human epidermal growth factor receptor 2 (HER2)-directed treatments, many HER2-positive (HER2⁺) breast cancers eventually progress because of primary or acquired resistance.

PATIENTS AND METHODS

A 2-part, open-label, multicenter phase I/II study was conducted to determine the recommended dose of neratinib when administered with trastuzumab (part I), and to assess the antitumor activity of this combination in women with locally advanced or metastatic HER2⁺ breast cancer previously treated with at least 1 prior trastuzumab-based regimen (part II). Patients received oral neratinib (160 or 240 mg/d) once daily plus intravenous trastuzumab 4 mg/kg (loading dose) then 2 mg/kg weekly. Diarrhea prophylaxis was not permitted. The primary endpoint in part II was investigator-assessed 16-week progression-free survival (PFS).

RESULTS

Forty-five patients received neratinib plus trastuzumab (part I: neratinib 160 mg/d, n = 4; neratinib 240 mg/d, n = 4; part II: neratinib 240 mg/d, n = 37). In part I, there were no dose-limiting toxicities and the recommended neratinib dose was 240 mg/d. In part II, the 16-week PFS rate was 44.8% (90% confidence interval, 28.8%-59.6%), and the median PFS was 15.9 weeks (95% confidence interval, 15.1-31.3 weeks) in 28 evaluable patients. Three patients had durable clinical benefit lasting 9.4 to 9.7 years. Diarrhea was the most common adverse event (grade 3, n = 7 [15.6%]; grade 4, n = 0). No clinically significant cardiac toxicity was seen.

CONCLUSIONS

Neratinib in combination with trastuzumab was well-tolerated and had encouraging antitumor activity in patients with advanced trastuzumab-pretreated HER2⁺ breast cancer. Durable responses can be achieved in some patients.

Extended Adjuvant Therapy with Neratinib Plus Fulvestrant Blocks ER/HER2 Crosstalk and Maintains Complete Responses of ER+/HER2+ Breast Cancers: Implications to the ExteNET Trial

PURPOSE

The phase III ExteNET trial showed improved invasive disease-free survival in patients with HER2⁺ breast cancer treated with neratinib versus placebo after trastuzumab-based adjuvant therapy. The benefit from neratinib appeared to be greater in patients with ER⁺/HER2⁺ tumors. We thus sought to discover mechanisms that may explain the benefit from extended adjuvant therapy with neratinib.Experimental Design: Mice with established ER⁺/HER2⁺ MDA-MB-361 tumors were treated with paclitaxel plus trastuzumab ± pertuzumab for 4 weeks, and then randomized to fulvestrant ± neratinib treatment. The benefit from neratinib was evaluated by performing gene expression analysis for 196 ER targets, ER transcriptional reporter assays, and cell-cycle analyses.

RESULTS

Mice receiving "extended adjuvant" therapy with fulvestrant/neratinib maintained a complete response, whereas those treated with fulvestrant relapsed rapidly. In three ER⁺/HER2⁺ cell lines (MDA-MB-361, BT-474, UACC-893) but not in ER⁺/HER2^- MCF7 cells, treatment with neratinib induced ER reporter transcriptional activity, whereas treatment with fulvestrant resulted in increased HER2 and EGFR phosphorylation, suggesting compensatory reciprocal crosstalk between the ER and ERBB RTK pathways. ER transcriptional reporter assays, gene expression, and immunoblot analyses showed that treatment with neratinib/fulvestrant, but not fulvestrant, potently inhibited growth and downregulated ER reporter activity, P-AKT, P-ERK, and cyclin D1 levels. Finally, similar to neratinib, genetic and pharmacologic inactivation of cyclin D1 enhanced fulvestrant action against ER⁺/HER2⁺ breast cancer cells.

CONCLUSIONS

These data suggest that ER blockade leads to reactivation of ERBB RTKs and thus extended ERBB blockade is necessary to achieve durable clinical outcomes in patients with ER⁺/HER2⁺ breast cancer.

Abstract 1828: Hyperactivation of mTORC1 drives acquired resistance to the pan HER tyrosine kinase inhibitor neratinib in HER2 mutant cancers

Background: Tumor genomic profiling has identified patients with cancers harboring activating ERBB2 (HER2) mutations that are sensitive to HER2 targeted therapies. In the SUMMIT phase II ‘basket' trial, a subset of patients with ERBB2 mutant cancers have exhibited significant clinical benefit from treatment with the pan-HER irreversible tyrosine kinase inhibitor (TKI) neratinib. However, durable responses to neratinib are few, suggesting mechanisms of de novo and acquired drug resistance. Thus, we sought to identify druggable mechanisms of resistance to neratinib.

Methods: We utilized 5637 bladder cancer (with HER2S310F) and OVCAR8 ovarian cancer (with HER2G776V) cells. Drug resistant cells were developed by exposing cells to increasing concentrations of neratinib over 6 months (5637, 600 nM; OVCAR8, 2 µM). Neratinib resistant H1781 lung cancer cells (with HER2G776>VC) and MCF7 breast cancer cells (with L755S or V777L) knock-in mutations are currently being developed. For immunoblot and drug sensitivity assays, neratinib resistant cells were maintained drug-free for 96 hours and then retreated with neratinib and other inhibitors. Candidate pathways/genes driving neratinib resistance were identified by performing RNA sequencing and whole exome sequencing in drug-resistant and -sensitive cells.

Results: Neratinib-resistant 5637 and OVCAR8 cells were cross-resistant to the HER2 TKIs afatinib and lapatinib. Immunoblot analysis of both cells treated with neratinib showed effective suppression of HER2, EGFR and HER3 phosphorylation. However, they exhibited a striking increase in S6 kinase (S6K) activity and S6 phosphorylation compared to drug-sensitive parental cells, which was maintained in the presence of supra-pharmacological levels of neratinib (1 µM). S6 phosphorylation and viability of drug resistant cells was completely ablated by the combination of neratinib and the mTORC1 inhibitor everolimus, but not with the PI3Kα inhibitor alpelisib, the pan-PI3K inhibitor buparlisib, or the AKT inhibitor MK-2206, suggesting PI3K- and AKT-independent activation of mTORC1. Gene set enrichment analysis (GSEA) of RNA seq data from the drug-resistant cells revealed significant enrichment of K-Ras pathway components in addition to mTORC1 pathway. Consistent with these results, whole exome sequencing revealed activating alterations of the Ras pathway including a truncating mutation in RASA2 and a P200L mutation in PIK3CA Ras binding domain; thereby suggesting potential Ras mediated mTOR activation driving neratinib resistance. Studies are underway to confirm the contribution of Ras pathway in mTOR mediated neratinib resistance.

Conclusions: These data suggest that hyperactivation of mTORC1 promotes acquired resistance to neratinib across histologically distinct ERBB2-mutant cancers.

Citation Format: Dhivya R. Sudhan, Ariella B. Hanker, Angel Guerrero-Zotano, Luigi Formisano, Yan Guo, Qi Liu, Francesca Avogadri-Connors, Richard E. Cutler, Alshad S. Lalani, Richard Bryce, Alan Auerbach, Carlos L. Arteaga. Hyperactivation of mTORC1 drives acquired resistance to the pan HER tyrosine kinase inhibitor neratinib in HER2 mutant cancers [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 1828.

Abstract 5468: Neratinib significantly inhibits responses to androgen in human prostate cancer cells

Background: Prostate cancer (PCa) is the most commonly diagnosed male cancer in the Western world. Tumor growth is initially androgen dependent - and driven by the androgen receptor (AR). The mainstays of prostate cancer treatment are androgen ablation and antiandrogen treatment, which block AR signalling. However, PCa often relapses to an androgen- independent disease. Androgens can transactivate genes directly via the AR-mediated transcription factor and indirectly via less well understood signal transduction pathways. These signal transduction pathways become increasingly relevant as prostate cancer cells progress to anti-androgen resistance, with HER2 being associated with higher relapse rates. Neratinib is an orally available tyrosine kinase inhibitor that irreversibly binds and inhibits EGFR, HER2 and HER4 receptor tyrosine kinases. This study aimed to examine the effect of neratinib on androgen signalling and on the expression of androgen-regulated genes in prostate cancer cells.

Methods: Changes in protein phosphorylation after androgen treatment of hormonally starved prostate cancer cells (LNCaP) was assessed using protein microarrays (Kinexus, Canada). Changes in gene expression after neratinib or androgen treatment were ascertained using AmpliSseq® technology or standard qPCR, and analysed via IPA Ingenuity software.

Results: Androgen treatment of hormonally starved prostate cancer cells (LNCaP) caused phosphorylation of several members of the signal transduction cascade including HER2 and Src within 2 hours, indicating a role for HER2 in rapid androgen signalling. Additionally, from over 1000 genes upregulated by androgen treatment (>2fold within 2 hours), 87% showed downregulation with neratinib treatment. Ingenuity pathway analysis indicated that STAT3, ETS-family and NF-κB transcription factors may be responsible for the rapid androgen-induced gene upregulation observed, and that these pathways were inhibited by neratinib treatment. Q-Quantitative PCR analysis of PSA expression in LNCaP cells stimulated with androgen in the presence of increasing concentrations of neratinib resulted in a dose-dependent inhibition of androgen activity.

Conclusions: These results show that neratinib is able to inhibit the responses of prostate cancer cells to androgens, and that a strong potential signaling cross-talk exists between the androgen receptor and the certain signal transduction pathways - pathways known to be involved in the progression of androgen-independent prostate cancer.

Citation Format: Dafydd A. Dart, Alshad S. Lalani, Francesca Avogadri-Connors, Richard Bryce, Wen G. Jiang. Neratinib significantly inhibits responses to androgen in human prostate cancer cells [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 5468.

Annually and monthly resolved solar irradiance and atmospheric temperature data across the Hawaiian archipelago from 1998 to 2015 with interannual summary statistics

This article contains data and summary statistics of solar irradiance and dry bulb temperature across the Hawaiian archipelago resolved on a monthly basis and spanning years 1998–2015. This data was derived in association with an article titled “Consequences of Neglecting the Interannual Variability of the Solar Resource: A Case Study of Photovoltaic Power Among the Hawaiian Islands” (Bryce et al., 2018 [7]). The solar irradiance data is presented in terms of Direct Normal Irradiance (DNI), Diffuse Horizontal Irradiance (DHI), and Global Horizontal Irradiance (GHI) and was obtained from the satellite-derived data contained in the National Solar Radiation Database (NSRDB). The temperature data is also obtained from this source. We have processed the NSRDB data and compiled these monthly resolved data sets, along with interannual summary statistics including the interannual coefficient of variability.