Abstract CT235: MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan versus trabectedin in patients with de-differentiated liposarcomas

Background: Murine double minute 2 (MDM2) is a negative regulator of tumor suppressor protein p53. MDM2 induces degradation of p53 and promotes tumorigenesis. MDM2 amplification occurs in many cancers but is documented in up to 100% of well-differentiated or de-differentiated liposarcomas (WD/DDLPS) [Cancer Genome Atlas Research Network. Cell 2017]. Inhibition of the MDM2-p53 interaction is a promising therapeutic approach to restore p53 tumor suppressor activity in WD/DDLPS. Milademetan (RAIN-32) is a small-molecule MDM2 inhibitor that inhibits the MDM2-p53 interaction and restores p53 function at nanomolar concentrations. In a phase 1 study, milademetan showed promising efficacy in 53 patients with WD/DDLPS when administered on an intermittent schedule (260 mg QD on Days 1-3 and 15-17 on a 28-day cycle), with a median progression-free survival (PFS) of 7.4 months [Gounder et al. AACR-NCI-EORTC 2020]. WD/DDLS are relatively resistant to chemotherapy, and systemic treatment options for patients with advanced disease are limited. MANTRA (RAIN-3201) is a randomized, multicenter, open-label, phase 3 registration study designed to evaluate the efficacy and safety of milademetan versus trabectedin in patients with unresectable or metastatic DDLPS with disease progression on ≥1 prior systemic therapies.

Methods: Eligible patients are ≥18 years of age with histologically confirmed unresectable and/or metastatic DDLPS, with or without a WD component, who have received ≥1 prior systemic therapies, including ≥1 anthracycline-based regimen, with radiographic evidence of progression by RECIST v1.1 within 6 months before study entry. Prior treatment with trabectedin or an MDM2 inhibitor is not permitted. Patients will be randomly assigned (1:1) to receive milademetan (260 mg once daily orally Days 1-3 and 15-17 on a 28-day cycle) or trabectedin (1.5 mg/m2 as a 24-hour intravenous infusion every 3 weeks). Randomization is stratified by Eastern Cooperative Oncology Group performance status (0 or 1) and number of prior treatments for WD/DDLPS (≤2 or >2). Tumor response will be evaluated by RECIST v1.1 at Weeks 8, 16, 24, and 32, and then every 12 weeks. Primary endpoint: PFS by blinded independent central review. Secondary endpoints: overall survival; disease control rate; objective response rate; duration of response; PFS by investigator assessment; safety; health-related quality of life. Exploratory endpoints: molecular markers in peripheral blood and/or tumor tissue; milademetan pharmacokinetics. To demonstrate a 3-month increase in PFS (from 3 to 6 months) corresponding to a hazard ratio of 0.5, approximately 160 patients will be required to observe 105 events with 93.9% power and 2-sided significance level of 5%. ClinicalTrials.gov: NCT04979442.

Citation Format: Mrinal M. Gounder, Gary K. Schwartz, Robin L. Jones, Sant P. Chawla, Victoria S. Chua-Alcala, Silvia Stacchiotti, Andrew J. Wagner, Gregory M. Cote, Robert G. Maki, Hanna Kosela-Paterczyk, Dale R. Shepard, Naisargee Shah, Richard Bryce, Robert C. Doebele, Shreyaskumar Patel. MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan versus trabectedin in patients with de-differentiated liposarcomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT235.

Using CDKN2A loss in the context of wildtype TP53 to predict sensitivity for the MDM2 inhibitor milademetan

3136

Background: MDM2 is an E3 ubiquitin ligase that plays a critical role in the degradation of the tumor suppressor p53. Milademetan (RAIN-32) is an orally available, small molecule inhibitor of MDM2 that disrupts the MDM2-p53 complex thereby restoring p53 activity. Approximately 50% of tumors harbor wildtype (WT) TP53 and thus may be susceptible to strategies that reactivate p53. The CDKN2A gene is altered in more than 15% of all tumors (TCGA PanCancer Atlas) and encodes two proteins, p14ARF and p16, which are inhibitors of p53 and cyclin dependent kinases, respectively. Given the role of p14ARF in regulating the MDM2-p53 pathway, we investigated the use of CDKN2A loss in the context of WT TP53 as a strategy for selection of patients who might benefit from milademetan. Methods: N/A. Results: We evaluated the sensitivity of 215 cancer cell lines to milademetan treatment (Ishizawa et al., 2018) by CDKN2A and TP53 status. The median IC50 of CDKN2A homozygous (HZ) loss vs. non-HZ loss was 8,620 vs. 10,000 nM. However, when we assessed CDKN2A HZ loss with WT TP53 versus mutant TP53 the median IC50 was 79.5 vs. 10,000 nM demonstrating that the use of both CDKN2A and TP53 was better able to discriminate sensitive vs. resistant cell lines. To validate these in vitro findings, we tested milademetan in 5 xenograft models with CDKN2A HZ loss and WT TP53, all of which demonstrated tumor growth inhibition with milademetan. As suppression of p53 activity by MDM2 amplification (Kato et al. 2017) or CDKN2A loss (Adib et al. 2021) has been associated with resistance to immune checkpoint inhibitors (ICI), we also tested the combination of anti-PD1 with milademetan in the colon-26 syngeneic model ( CDKN2A HZ loss) and observed a significant enhancement in tumor growth inhibition compared to milademetan or anti-PD1 alone. Based on the differential sensitivity to milademetan using both CDKN2A loss and WT TP53 status we evaluated TCGA Pan-Cancer Atlas data to estimate the frequency of these genetic co-alterations. Among solid tumors types the most frequent percentage of these co-alterations included glioblastoma, mesothelioma, melanoma, bladder, sarcoma, pancreatic and NSCLC. Overall, the percentage of all tumors with co-alteration of CDKN2A HZ loss and WT TP53 was 6.2%. Patients with CDKN2A HZ loss had a significantly worse overall survival than those without CDKN2A HZ loss (median OS of 29.7 vs. 97.4 months, p < 0.0001), and this was maintained when accounting for tumor type in multivariate analysis (p < 0.0001). Conclusions: Milademetan showed evidence of preclinical anti-tumor activity across multiple tumor types with CDKN2A loss and WT TP53. In vivo data supported potential synergy of milademetan with an ICI in this genetic subset. A clinical trial evaluating the safety and efficacy of milademetan plus atezolizumab in advanced solid tumors with CDKN2A HZ loss and WT TP53 (MANTRA-4) is planned.

MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan versus trabectedin in patients with de-differentiated liposarcomas

TPS11589

Background: Murine double minute 2 (MDM2) is a negative regulator of tumor suppressor protein p53. MDM2 induces degradation of p53 and promotes tumorigenesis. MDM2 amplification occurs in many cancers but is documented in up to 100% of well-differentiated or dedifferentiated liposarcomas (WD/DDLPS) [Cancer Genome Atlas Research Network. Cell 2017]. Inhibition of the MDM2-p53 interaction is a promising therapeutic approach to restore p53 tumor suppressor activity in WD/DDLPS. Milademetan (RAIN-32) is a small-molecule MDM2 inhibitor that inhibits the MDM2-p53 interaction and restores p53 function at nanomolar concentrations. In a phase 1 study, milademetan showed promising efficacy in 53 patients with WD/DDLPS when administered on an intermittent schedule (260 mg QD on Days 1–3 and 15–17 on a 28-day cycle), with a median progression-free survival (PFS) of 7.4 months [Gounder et al. AACR-NCI-EORTC 2020]. WD/DDLS are relatively resistant to chemotherapy, and systemic treatment options for patients with advanced disease are limited. MANTRA (RAIN-3201) is a randomized, multicenter, open-label, phase 3 registration study designed to evaluate the efficacy and safety of milademetan versus trabectedin in patients with unresectable or metastatic DDLPS with disease progression on ≥ 1 prior systemic therapies. Methods: Eligible patients are ≥ 18 years of age with histologically confirmed unresectable and/or metastatic DDLPS, with or without a WD component, who have received ≥ 1 prior systemic therapies, including ≥ 1 anthracycline-based regimen, with radiographic evidence of progression by RECIST v1.1 within 6 months before study entry. Prior treatment with trabectedin or an MDM2 inhibitor is not permitted. Patients will be randomly assigned (1:1) to receive milademetan (260 mg once daily orally Days 1–3 and 15–17 on a 28-day cycle) or trabectedin (1.5 mg/m2 as a 24-hour intravenous infusion every 3 weeks). Randomization is stratified by Eastern Cooperative Oncology Group performance status (0 or 1) and number of prior treatments for WD/DDLPS (≤ 2 or > 2). Tumor response will be evaluated by RECIST v1.1 at Weeks 8, 16, 24, and 32, and then every 12 weeks. Primary endpoint: PFS by blinded independent central review. Secondary endpoints: overall survival; disease control rate; objective response rate; duration of response; PFS by investigator assessment; safety; health-related quality of life. Exploratory endpoints: molecular markers in peripheral blood and/or tumor tissue; milademetan pharmacokinetics. To demonstrate a 3-month increase in PFS (from 3 to 6 months) corresponding to a hazard ratio of 0.5, approximately 160 patients will be required to observe 105 events with 93.9% power and 2-sided significance level of 5%. Clinical trial information: NCT04979442.

The phase II MutHER study of neratinib alone and in combination with fulvestrant in HER2 mutated, non-amplified metastatic breast cancer

PURPOSE

HER2 mutations (HER2^mut) induce endocrine resistance in estrogen receptor positive (ER+) breast cancer.

EXPERIMENTAL DESIGN

In this single arm multi-cohort phase II trial, we evaluated the efficacy of neratinib plus fulvestrant in patients with ER+/HER2^mut, HER2-non-amplified metastatic breast cancer (MBC) in the fulvestrant-treated (n=24) or fulvestrant-naïve cohort (n=11). Patients with ER-negative/HER2^mut MBC received neratinib monotherapy in an exploratory ER- cohort (n=5).

RESULTS

The clinical benefit rate (CBR: 95% CI) was 38% (18-62%), 30% (7-65%), and 25% (1-81%) in the fulvestrant-treated, fulvestrant-naïve, and ER- cohort, respectively. Adding trastuzumab at progression in 5 patients resulted in 3 partial responses and 1 stable disease {greater than or equal to}24 weeks. CBR appeared positively associated with lobular histology and negatively associated with HER2 L755 alterations. Acquired HER2^mut were detected in 5 of 23 patients at progression.

CONCLUSION

Neratinib and fulvestrant is active for ER+/HER2^mut MBC. Our data supports further evaluation of dual HER2 blockade for the treatment of HER2^mut MBC.

Abstract P031: MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan (RAIN-32) versus trabectedin in patients with de-differentiated liposarcoma

Background: p53 plays a central role in tumor suppression and maintenance of genome integrity. Murine double minute 2 (MDM2) is a ubiquitin ligase that inhibits p53 transcriptional activity and induces p53 degradation through ubiquitination. MDM2 amplification occurs in many cancers but is universal in well-differentiated (WD) or de-differentiated (DD) liposarcomas (100% of cases) [Cancer Genome Atlas Research Network. Cell 2017]. Current therapies for WD/DD liposarcomas include anthracycline-based chemotherapy, eribulin, and trabectedin. Inhibition of the MDM2-p53 interaction is a promising therapeutic approach to restore p53 tumor suppressor activity in liposarcomas. Milademetan (RAIN-32) is a small-molecule MDM2 inhibitor that inhibits the MDM2-p53 interaction and restores p53 function at nanomolar concentrations. In a phase 1 study, milademetan showed promising efficacy in patients with WD/DD liposarcoma when administered on an intermittent schedule (260 mg on Days 1–3 and 15–17 every 28 days), with a median progression-free survival (PFS) of 7.4 months [Gounder et al. AACR-NCI-EORTC 2020]. MANTRA (RAIN-3201) is a randomized, multicenter, open-label, phase 3 registration study designed to evaluate the efficacy and safety of milademetan versus trabectedin in patients with unresectable or metastatic DD liposarcoma with disease progression on ≥1 prior systemic therapies, including ≥1 anthracycline-based regimen (EudraCT: 2021-001394-23). Methods: Eligible patients are ≥18 years of age with histologically confirmed unresectable and/or metastatic DD liposarcoma, with or without a WD component, who have received ≥1 prior systemic therapies, including ≥1 anthracycline-based regimen, with radiographic evidence of progression within 6 months before study entry. Prior treatment with trabectedin or an MDM2 inhibitor is not permitted. Patients will be randomly assigned (1:1) to receive milademetan (260 mg once daily orally Days 1–3 and 15–17 on a 28-day cycle) or trabectedin (1.5 mg/m2 as a 24-hour intravenous infusion every 3 weeks). Randomization is stratified by Eastern Cooperative Oncology Group performance status (0 or 1) and number of prior treatments for liposarcoma (≤2 or &gt;2). Tumor response will be evaluated by RECIST v1.1 at Weeks 8, 16, 24, and 32, and then every 12 weeks. Primary endpoint: PFS by blinded independent central review. Secondary endpoints: overall survival; disease control rate; objective response rate; duration of response; PFS by investigator assessment; safety; health-related quality of life. Exploratory endpoints: molecular markers in peripheral blood and/or tumor tissue; milademetan pharmacokinetics. To demonstrate a 3-month increase in PFS (from 3 to 6 months) corresponding to a hazard ratio of 0.5, approximately 160 patients will be required to observe 105 events with 93.9% power and 2-sided significance level of 5%. MANTRA is currently open to enrollment.

Citation Format: Mrinal Gounder, Gary Schwartz, Robin Jones, Shreyaskumar Patel, Silvia Stacchiotti, Andrew Wagner, Vijaya Tirunagaru, Naisargee Shah, Richard Bryce, Robert Doebele. MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan (RAIN-32) versus trabectedin in patients with de-differentiated liposarcoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P031.

Biomarker Analysis of the Phase III NALA Study of Neratinib + Capecitabine versus Lapatinib + Capecitabine in Patients with Previously Treated Metastatic Breast Cancer

PURPOSE

Neratinib plus capecitabine (N+C) demonstrated significant progression-free survival (PFS) benefit in NALA (NCT01808573), a randomized phase III trial comparing N+C with lapatinib + capecitabine (L+C) in 621 patients with HER2-positive (HER2+) metastatic breast cancer (MBC) who had received ≥2 prior HER2-directed regimens in the metastatic setting. We evaluated correlations between exploratory biomarkers and PFS.

PATIENTS AND METHODS

Somatic mutations were evaluated by next-generation sequencing on primary or metastatic samples. HER2 protein expression was evaluated by central IHC, H-score, and VeraTag/HERmark. p95 expression (truncated HER2) was measured by VeraTag. HRs were estimated using unstratified Cox proportional hazards models.

RESULTS

Four hundred and twenty samples had successful sequencing: 34.0% had PIK3CA mutations and 5.5% had HER2 (ERBB2) mutations. In the combined patient populations, PIK3CA mutations trended toward shorter PFS [wild-type vs. mutant, HR = 0.81; 95% confidence interval (CI), 0.64-1.03], whereas HER2 mutations trended toward longer PFS [HR = 1.69 (95% CI, 0.97-3.29)]. Higher HER2 protein expression was associated with longer PFS [IHC 3+ vs. 2+, HR = 0.67 (0.54-0.82); H-score ≥240 versus <240, HR = 0.77 (0.63-0.93); HERmark positive vs. negative, HR = 0.76 (0.59-0.98)]. Patients whose tumors had higher HER2 protein expression (any method) derived an increased benefit from N+C compared with L+C [IHC 3+, HR = 0.64 (0.51-0.81); H-score ≥ 240, HR = 0.54 (0.41-0.72); HERmark positive, HR = 0.65 (0.50-0.84)], as did patients with high p95 [p95 ≥2.8 relative fluorescence (RF)/mm2, HR = 0.66 (0.50-0.86) vs. p95 < 2.8 RF/mm2, HR = 0.91 (0.61-1.36)].

CONCLUSIONS

PIK3CA mutations were associated with shorter PFS whereas higher HER2 expression was associated with longer PFS. Higher HER2 protein expression was also associated with a greater benefit for N+C compared with L+C.

Analysis of the pan-Asian subgroup of patients in the NALA Trial: a randomized phase III NALA Trial comparing neratinib+capecitabine (N+C) vs lapatinib+capecitabine (L+C) in patients with HER2+metastatic breast cancer (mBC) previously treated with two or more HER2-directed regimens

PURPOSE

Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has demonstrated systemic efficacy and intracranial activity in various stages of HER2+breast cancer. NALA was a phase III randomized trial that assessed the efficacy and safety of neratinib+capecitabine (N+C) against lapatinib+capecitabine (L+C) in HER2+ metastatic breast cancer (mBC) patients who had received ≥ 2 HER2-directed regimens. Descriptive analysis results of the Asian subgroup in the NALA study are reported herein.

METHODS

621 centrally assessed HER2+ mBC patients were enrolled, 202 of whom were Asian. Those with stable, asymptomatic brain metastases (BM) were eligible for study entry. Patients were randomized 1:1 to N (240 mg qd) + C (750 mg/m² bid, day 1-14) with loperamide prophylaxis or to L (1250 mg qd) + C (1000 mg/m² bid, day 1-14) in 21-day cycles. Co-primary endpoints were centrally assessed progression-free survival (PFS) and overall survival (OS). Secondary endpoints included time to intervention for central nervous system (CNS) disease, objective response rate, duration of response (DoR), clinical benefit rate, and safety.

RESULTS

104 and 98 Asian patients were randomly assigned to receive N+C or L+C, respectively. Median PFS of N+C and L+C was 7.0 and 5.4 months (P = 0.0011), respectively. Overall cumulative incidence of intervention for CNS disease was lower with N+C (27.9 versus 33.8%; P = 0.039). Both median OS (23.8 versus 18.7 months; P = 0.185) and DoR (11.1 versus 4.2 months; P < 0.0001) were extended with N+C, compared to L+C. The incidences of grade 3/4 treatment emergent adverse events (TEAEs) and TEAEs leading to treatment discontinuation were mostly comparable between the two arms. Diarrhea and palmar-plantar erythrodysesthesia were the most frequent TEAEs in both arms, similar to the overall population in incidence and severity.

CONCLUSION

Consistent with the efficacy profile observed in the overall study population, Asian patients with HER2+ mBC, who had received ≥ 2 HER2-directed regimens, may also benefit from N+C. No new safety signals were noted.

CLINICAL TRIAL REGISTRATION

NCT01808573.

Abstract CT026: A phase II trial of neratinib (NER) or NER plus fulvestrant (FUL) (N+F) in HER2 mutant, non-amplified (HER2mut) metastatic breast cancer (MBC): Part II of MutHER

Introduction: The irreversible pan-HER inhibitor NER showed modest single agent activity for HER2mut MBC in Part I of MutHER trial. In Part II, we hypothesized that (1) N+F would improve activity in estrogen receptor positive (ER+) HER2mut MBC due to ER-HER2 crosstalk and (2) dual HER2 blockade by adding trastuzumab at disease progression (PD) could overcome resistance.

Methods: Pts with ER+HER2mut MBC were enrolled to 2 cohorts (FUL treated or naive) to receive N+F with diarrhea prophylaxis. ER- pts received NER in an exploratory ER- cohort. Trastuzumab was added at PD if approved by insurance. Simon's Minimax 2-stage phase II design with the primary endpoint of clinical benefit rate (CBR: rates of complete/partial response [CR/PR] plus stable disease [SD] &gt;24 weeks [wks]), with anticipated vs null hypothesis being CBR of 55% vs 35% (FUL treated) or 65% vs 40% (FUL naïve) with 80% power, 1 sided 0.05 alpha, was used. Secondary endpoints included progression free survival (PFS) and adverse events (AEs). Serial blood samples were analyzed for circulating tumor DNA (ctDNA) by Guardant360 for concomitant mutations, HER2mut variant allele frequency (VAF) dynamics, and resistance mechanisms.

Results: Between Sep. 2015 and Oct. 2020, 40 pts with HER2mut MBC were enrolled, completing the 1st stage of each ER+ cohort. 35 pts (21 FUL treated, 10 FUL naïve, 4 ER-) were evaluable for response, with median age 63 (35-82) years, 3 (0-12) prior MBC regimen, lobular BC in 13 (37%) and visceral mets in 32 (91%) pts. 21 (68%) ER+ pts had prior CDK4/6 inhibitor. All but 1 pt has come off study due to PD. Table 1 shows the efficacy by cohort. Further enrollment is closed per protocol. Adding trastuzumab at PD induced CB in 4 (3 PR, 1 SD≥24 wks) of 5 pts (1 ER-, 4 ER+), with PFS 28 (95% CI 18~NA) wks. Common AEs across cohorts were diarrhea (G3 21%) and fatigue (G3 5%). No G4 AEs.

ctDNA HER2mut was detected in 72% (23/32) baseline (BL) samples tested. In pts with paired samples, HER2mut VAF decreased at C1D15/C2D1 from BL in 75% (15/20) and rose in 89% (16/18) at PD. Acquired HER2mut, including the T798I gatekeeper mutation, were detected in 2 pts at PD. Mutations in TP53 (53%), PIK3CA (43%), and CDH1 (35%) were common, but none significantly associated with PFS in all or ER+ pts.

Conclusions: NER, or N+F, is active for HER2mut MBC with good tolerability. Adding trastuzumab at PD induced further response, supporting dual HER2 blockade for HER2mut MBC.

Table 1.EfficacyCohortFUL treatedFUL naïveER-Best Response, n evaluablen = 21n = 10n = 4CR, n100PR, n431SD (≥ 24 wks), n300SD (&lt; 24 wks), n1030PD, n343CBR, n with CB/total n evaluable, % (95% CI)8 of 20*, 40% (19~64%)3 of 10, 30% (7~65%)1 of 4, 25% (0.6~81%)mPFS (95% CI), wks, ITT (n)24 (16~31) wks, (n = 24)20 (8~NA) wks, (n = 11)8.5 (8~NA) wks, (n = 5)*20 of 21 pts are evaluable for CBR in the FUL treated Cohort as 1 pt had SD as best response and treatment is still ongoing. ITT (intent to treat) population is used for mPFS estimate.

Citation Format: Cynthia X. Ma, Jingqin Luo, Rachel A. Freedman, Timothy Pluard, Julie Nangia, Janice Lu, Frances Valdez-Albini, Melody Cobleigh, Jason Jones, Nancy U. Lin, Eric Winer, P. Kelly Marcom, Shana Thomas, Jill Anderson, Brittney Haas, Kimberly M. Hamann, Richard Bryce, Alshad S. Lalani, Lisa Carey, Matthew Goetz, Feng Gao, Gretchen Kimmick, Mark Pegram, Matthew J. Ellis, Ron Bose. A phase II trial of neratinib (NER) or NER plus fulvestrant (FUL) (N+F) in HER2 mutant, non-amplified (HER2mut) metastatic breast cancer (MBC): Part II of MutHER [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT026.

Immigration law enforcement, social support, and health for Latino immigrant families in Southeastern Michigan

RATIONALE

Social support is a key determinant of physical and mental health outcomes. Implementation of restrictive immigration policies in the U.S. under the Trump administration impacted the way mixed-status Latino families (i.e., those with varying legal statuses, including undocumented) maintained social relationships and provided social support.

OBJECTIVE

This paper examines how federal immigration policies introduced after the 2016 U.S. presidential election impacted social networks and support related to health for undocumented and mixed-status Latino families.

METHODS

We interviewed 23 clients and 28 service providers at two Federally Qualified Health Centers and one non-profit organization in Southeast Michigan. The interviews were audio-recorded, transcribed, and analyzed thematically.

RESULTS

Policies introduced during the Trump administration increased opportunities for deportation and contributed to the isolation of mixed-status Latino families by transforming safe spaces of social interaction into prime locations for immigration enforcement activity. Despite the limitations created by these restrictive policies, mixed-status families employed alternative mechanisms to maintain access to vital informal and formal support systems while simultaneously navigating emerging immigration-related threats.

CONCLUSIONS

Elections have health consequences and immigration policies are needed that promote the health and well-being of Latino immigrant communities.

Efficacy of Neratinib Plus Capecitabine in the Subgroup of Patients with Central Nervous System Involvement from the NALA Trial

Background

Neratinib has efficacy in central nervous system (CNS) metastases from HER2‐positive metastatic breast cancer (MBC). We report outcomes among patients with CNS metastases at baseline from the phase III NALA trial of neratinib plus capecitabine (N + C) versus lapatinib plus capecitabine (L + C).

Materials and Methods

NALA was a randomized, active‐controlled trial in patients who received two or more previous HER2‐directed regimens for HER2‐positive MBC. Patients with asymptomatic/stable brain metastases (treated or untreated) were eligible. Patients were assigned to N + C (neratinib 240 mg per day, capecitabine 750 mg/m² twice daily) or L + C (lapatinib 1,250 mg per day, capecitabine 1,000 mg/m² twice daily) orally. Independently adjudicated progression‐free survival (PFS), overall survival (OS), and CNS endpoints were considered.

Results

Of 621 patients enrolled, 101 (16.3%) had known CNS metastases at baseline (N + C, n = 51; L + C, n = 50); 81 had received prior CNS‐directed radiotherapy and/or surgery. In the CNS subgroup, mean PFS through 24 months was 7.8 months with N + C versus 5.5 months with L + C (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.41–1.05), and mean OS through 48 months was 16.4 versus 15.4 months (HR, 0.90; 95% CI, 0.59–1.38). At 12 months, cumulative incidence of interventions for CNS disease was 25.5% for N + C versus 36.0% for L + C, and cumulative incidence of progressive CNS disease was 26.2% versus 41.6%, respectively. In patients with target CNS lesions at baseline (n = 32), confirmed intracranial objective response rates were 26.3% and 15.4%, respectively. No new safety signals were observed.

Conclusion

These analyses suggest improved PFS and CNS outcomes with N + C versus L + C in patients with CNS metastases from HER2‐positive MBC.

Implications for Practice

In a subgroup of patients with central nervous system (CNS) metastases from HER2‐positive breast cancer after two or more previous HER2‐directed regimens, the combination of neratinib plus capecitabine was associated with improved progression‐free survival and CNS outcomes compared with lapatinib plus capecitabine. These findings build on previous phase II and III studies describing efficacy of neratinib in the prevention and treatment of CNS metastases, and support a role for neratinib as a systemic treatment option in the management of patients with HER2‐positive brain metastases following antibody‐based HER2‐directed therapies.

This article reports outcomes among HER2‐positive breast cancer patients with central nervous system metastases at baseline from the phase III NALA trial of neratinib plus capecitabine versus lapatinib plus capecitabine.

A pilot randomized controlled trial of a fruit and vegetable prescription program at a federally qualified health center in low income uncontrolled diabetics

Eating a healthy diet is important for managing diabetes. Although there are high rates of diabetes in low-income urban areas, these patients often have limited access to fruits and vegetables. The 15-week Fresh Prescription (Fresh Rx) program was designed to improve access and consumption of fruits and vegetables among low-income patients with diabetes in Detroit, MI. The purpose of this study was to evaluate the effects of a fruit and vegetable prescription program on changes in hemoglobin A1C (HbA₁C), blood pressure (BP), and body mass index (BMI) in patients with diabetes in a randomized controlled trial at a federally qualified health center (FQHC). Patients randomized to the Fresh Rx group (n = 56) were allotted up to $80 ($10 for up to eight weeks) for purchase of produce from a farmers market based at the FQHC. The control group (n = 56) received standard treatment plus information on community resources to improve health. Outcomes were compared at baseline and within three months of program completion. There were no significant between-group differences for any of the outcomes at program completion (p > .05); however, there was a small effect size for HbA1c (partial η² = 0.02). Within the Fresh Rx group, HbA1c significantly decreased from 9.64% to 9.14% (p = 0.006). However, no changes were noted within the control group (9.38 to 9.41%, p = 0.89). BMI and BP did not change from pre- to post-study in either group (p > .05). Results from this study offer preliminary evidence that produce prescription programs may reduce HbA₁C in low-income patients with diabetes.

Neratinib efficacy in a subgroup of patients with EGFR exon 18-mutant non-small cell lung cancer (NSCLC) and central nervous system (CNS) involvement: Findings from the SUMMIT basket trial

9068

Background: The phase 2 SUMMIT basket trial (NCT01953926) demonstrated efficacy of neratinib in patients with EGFR exon 18-mutant NSCLC [Boni et al. WCLC 2020]. Neratinib also has documented activity in HER2+ metastatic breast cancer with CNS metastases [Saura et al. SABCS 2020 & J Clin Oncol 2020]. Here we report neratinib efficacy in a subgroup of patients with EGFR exon 18-mutant NSCLC and CNS involvement from SUMMIT. Methods: Patients with EGFR exon 18-mutant NSCLC were treated with single-agent neratinib (240 mg po daily). Prior EGFR tyrosine kinase inhibitors (TKIs), chemotherapy, and checkpoint inhibitors (IO) were allowed. Patients with stable, asymptomatic CNS metastasis were enrolled. Study endpoints: objective response rate (ORR) at week 8 (±1 week); ORR (RECIST 1.1 confirmed); duration of response (DOR); clinical benefit rate (CBR); progression-free survival (PFS); safety; biomarkers. Results: Baseline characteristics of 11 patients with EGFR exon 18-mutant NSCLC: median age 67 (range 56–83) years; ECOG PS 0/1 (45%/55%). Prior lines of therapies: 2 (range 1–3): EGFR TKIs (91%); chemotherapy (55%); IO (27%). 3/11 patients had baseline CNS metastasis and received radiation 8–22 months prior to study enrollment. Best CNS response in these 3 patients was stable disease with overall individual PFS of 1.9 (censored), 6.9 and 9.1 months and OS of 2.6 (censored), 17.7 (censored), and 17.9 months. Efficacy is summarized in Table. Efficacy summary: TKI-pretreated EGFR exon 18-mutant NSCLC cohort receiving neratinib monotherapy. Conclusions: Activity of single-agent neratinib was observed in prior TKI-exposed patients with EGFR exon 18-mutant NSCLC. Despite the small sample size of only 3 patients with baseline CNS metastases, findings suggest a potential role for neratinib as a systemic treatment option for patients with NSCLC and difficult-to-treat uncommon mutations with CNS involvement. The SUMMIT trial continues to enroll patients with EGFR exon 18-mutant NSCLC. Clinical trial information: NCT01953926. [Table: see text]

Neratinib + capecitabine sustains health-related quality of life in patients with HER2-positive metastatic breast cancer and ≥ 2 prior HER2-directed regimens

PURPOSE

To characterize health-related quality of life (HRQoL) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) from the NALA phase 3 study.

METHODS

In NALA (NCT01808573), patients were randomized 1:1 to neratinib + capecitabine (N + C) or lapatinib + capecitabine (L + C). HRQoL was assessed using seven prespecified scores from the European Organisation for Research and Treatment of Cancer Quality Of Life Questionnaire core module (QLQ-C30) and breast cancer-specific questionnaire (QLQ-BR23) at baseline and every 6 weeks. Descriptive statistics summarized scores over time, mixed models evaluated differences between treatment arms, and Kaplan-Meier methods were used to assess time to deterioration in HRQoL scores of ≥ 10 points.

RESULTS

Of the 621 patients randomized in NALA, patients were included in the HRQoL analysis if they completed baseline and at least one follow-up questionnaire. The summary, global health status, physical functioning, fatigue, constipation, and systemic therapy side effects scores were stable over time with no persistent differences between treatment groups. There were no differences in time to deterioration (TTD) for the QLQ-C30 summary score between treatment arms; the hazard ratio (HR) for N + C vs. L + C was 0.94 (95% CI 0.63-1.40). Only the diarrhea score worsened significantly more in the N + C arm as compared to the L + C arm, and this remained over time (HR for TTD for N + C vs. L + C was 1.71 [95% CI 1.32-2.23]).

CONCLUSION

In NALA, patients treated with N + C maintained their global HRQoL over time, despite a worsening of the diarrhea-related scores. These results may help guide optimal treatment selection for HER2-positive MBC.

Abstract PD13-09: Impact of neratinib on outcomes in HER2-positive metastatic breast cancer patients with central nervous system disease at baseline: Findings from the phase 3 NALA trial

Background: The development of central nervous system (CNS) metastases presents a considerable challenge in metastatic breast cancer (MBC) due to the limited availability of evidence-based treatments. Up to 50% of patients with HER2-positive (HER2+) MBC develop CNS metastases during the course of their disease. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has demonstrated activity against CNS metastases in HER2+ MBC in two phase 2 studies (NEfERT-T, TBCRC 022) and one phase 3 study (NALA); significant benefits for predefined CNS endpoints were reported in NEfERT-T and confirmed in NALA. Here we present an exploratory analysis of patients from NALA with CNS involvement at enrollment.

Methods: NALA was an international, randomized, open-label, active-controlled, phase 3 study in patients with HER2+ MBC who had received ≥2 lines of HER2-directed therapy in the metastatic setting (ClinicalTrials.gov: NCT01808573). Patients with asymptomatic metastatic brain disease managed with stable doses of corticosteroids for ≥14 days prior to randomization were eligible, whereas patients with symptomatic or unstable brain metastases were excluded. Patients were randomized (1:1 ratio) to neratinib (N; 240 mg qd po) + capecitabine (C; 750 mg/m2 bid po) or lapatinib (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). Intervention for symptomatic metastatic CNS disease was a secondary endpoint. CNS disease at baseline was defined as patients with treated or untreated disease in the ‘brain’ assessed by investigator at enrollment. CNS imaging was not mandatory at screening.

Results: Of the 621 patients enrolled in NALA, 101 (16%) had documented baseline CNS disease and 520 (74%) had no CNS disease at baseline. Patients with CNS disease had a lower performance status and were more likely to have hormone receptor-negative disease than those with no CNS disease; no major imbalances of baseline characteristics were noted between treatment arms. Overall, 78 (77%) patients had previously received CNS radiation [whole brain, n=59 (58%); stereotactic, n=17 (17%); unknown, n=2 (2%)], and 5 (5%) patients had undergone CNS surgery. Median treatment duration was 5.7 (IQR 2.8-8.5) months for N, and 3.5 (IQR 2.1-6.9) months for L. PFS, OS, and cumulative incidence of interventions for symptomatic CNS disease are summarized in the table. No new safety signals were detected.

Conclusions: Regardless of the status of CNS metastases at baseline, patients appeared to have better outcomes in the N+C arm compared with the L+C arm.

Table. Efficacy outcomes in patients with and without CNS disease at baselineIntention-to-treat (n=621)CNS metastases at baseline – Yes (n=101)CNS metastases at baseline – No (n=520)N+C (n=307)L+C (n=314)N+C (n=51)L+C (n=50)N+C (n=256)L+C (n=264)PFSaHazard ratio (95% CI)0.76 (0.63–0.93)0.66 (0.41–1.05)0.76 (0.62–0.94)P-value0.00590.07410.0099Restricted mean PFSb, months8.86.67.85.59.06.9Difference, months2.22.32.1OSHazard ratio (95% CI)0.88 (0.72–1.07)0.90 (0.59–1.38)0.85 (0.68–1.06)P-value0.20860.63520.1517Restricted mean OSb, months24.022.216.415.425.623.6Difference, months1.71.02.0Incidence of CNS interventionOverall cumulative incidencec, %22.7629.1940.1347.7919.1624.65P-value0.0430.4300.067aCentrally confirmed; bRestriction prespecified as 24 months for PFS, and 48 months for OS; c % requiring intervention for CNS disease (competing risk model)

Citation Format: Cristina Saura, Larisa Ryvo, Sara Hurvitz, William Gradishar, Beverly Moy, Suzette Delaloge, Sung-Bae Kim, Mafalda Oliveira, Maureen Trudeau, Ming-Shen Dai, Barbara Haley, Ron Bose, Luciana Landeiro, Judith Bebchuk, Aimee Frazier, Kiana Keyvanjah, Richard Bryce, Adam Brufsky. Impact of neratinib on outcomes in HER2-positive metastatic breast cancer patients with central nervous system disease at baseline: Findings from the phase 3 NALA trial [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 PD13-09.

Abstract PS9-02: Neratinib + capecitabine sustains health-related quality of life (HRQoL) while improving progression-free survival (PFS) in patients with HER2+ metastatic breast cancer and ≥2 prior HER2-directed regimens

Background: The FDA approved neratinib (N), an irreversible pan-HER tyrosine kinase inhibitor, in combination with capecitabine (C) for patients with HER2+ advanced or metastatic breast cancer who have received ≥2 prior HER2-directed regimens in the metastatic setting based on the NALA clinical study, where N+C significantly improved PFS vs. lapatinib (L)+C. Characterizing HRQoL associated with this regimen can help inform treatment decision-making for these patients. The objective of this analysis was to characterize HRQoL among patients with HER2+ metastatic breast cancer from the NALA clinical study.

Methods: NALA was a multinational, randomized, open-label, phase III clinical study of N+C vs. L+C in patients with HER2+ metastatic breast cancer and ≥2 prior HER2-directed regimens. From May 2013 to July 2017, patients were randomized 1:1 to N (240 mg qd) + C (750 mg/m2 bid 14d/21d) with loperamide prophylaxis during the first cycle, or to L (1250 mg qd) + C (1000 mg/m2 bid 14d/21d). HRQoL, a prespecified secondary endpoint of the NALA study, was measured using the EORTC QLQ-C30 and the breast cancer-specific QLQ-BR23 at baseline and every 6 weeks (±3 days) until the end of treatment (data collection through treatment cycle 19, 12.5 months). The QLQ-C30 summary and global health status scores range from 0 (worst) to 100 (best) and the systemic therapy side-effects scores range from 0 (best) to 100 (worst). Patients were included in the analysis for a particular scale if they had a baseline assessment and at least 1 follow-up assessment. For these analyses, a change of ≥10 points was considered to be clinically meaningful. Descriptive statistics summarized observed scores and changes from baseline, Kaplan-Meier and log-rank tests were used for time-to-deterioration (TTD) of ≥10 points and mixed models estimated the change over time for 7 prespecified scales: QLQ-C30 summary score, global health status, physical functioning, fatigue, constipation and diarrhea, and the EORTC QLQ-BR23 systemic therapy side effects subscale. No adjustments for multiplicity were performed.

Results: 621 patients from 28 countries were randomized (307 N+C; 314 L+C). The mean completion rate of the QLQ-C30 over the course of the study was 91% for both treatment arms. Discontinuation due to any treatment-emergent adverse event (TEAE) was lower in the N+C vs. L+C arm (14% vs. 18%). At baseline, the mean (SD) QLQ-C30 summary scores were 79.8 (14.1) for N+C and 79.9 (15.7) for L+C. After 19 treatment cycles, the mean (SD) QLQ-C30 summary scores were similar to baseline scores: 81.8 (16.7) for N+C and 81.3 (15.3) for L+C. There were no differences in TTD of ≥10 points for the QLQ-C30 summary score between treatment arms; the HR for N+C vs. L+C was 0.94 (95% CI 0.63-1.40). All prespecified HRQoL subscales had similar statistically non-significant results for TTD with the exception of diarrhea (HR=1.71; 95% CI 1.32-2.23). The mixed models analyzing change in HRQoL from baseline did not demonstrate persistent declines nor meaningful differences between the treatment arms.

Conclusion: In these results from the NALA study, among patients with HER2+ metastatic breast cancer, at study end and throughout most of the study, there were no differences observed between the two treatment arms in HRQoL scores. HRQoL was sustained over the study period despite the early transient presence of diarrhea in some patients. Discontinuation due to any TEAE was lower in the N+C vs. the L+C arm. These results may help guide healthcare providers, patients and carers in selection of optimal treatment for HER2+ metastatic breast cancer.

Citation Format: Beverly Moy, Mafalda Oliveira, Cristina Saura, William Gradishar, Sung-Bae Kim, Adam Brufsky, Sara Hurvitz, Larisa Ryvo, Daniele Fagnani, Nancy Chan, Sujith R Kalmadi, Paula Silverman, Suzette Delaloge, Richard Bryce, Kiana Keyvanjah, Judith Bebchuk, Bo Zhang, Nina Oestreicher, Ron Bose. Neratinib + capecitabine sustains health-related quality of life (HRQoL) while improving progression-free survival (PFS) in patients with HER2+ metastatic breast cancer and ≥2 prior HER2-directed regimens [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 PS9-02.

Abstract PD3-03: Continued efficacy of neratinib in patients with HER2-positive early-stage breast cancer: Final overall survival analysis from the randomized phase 3 ExteNET trial

Background: Neratinib (NERLYNX®) is an irreversible pan-HER inhibitor that significantly improves invasive disease-free survival (iDFS) compared with placebo when given as extended adjuvant therapy in patients with HER2-positive (HER2+) early breast cancer after trastuzumab-based adjuvant therapy. In the phase 3 ExteNET trial, an absolute iDFS benefit of 2.5% and distant disease-free survival (DDFS) benefit of 1.7% were observed with neratinib after 5 years’ follow-up. As reflected in the approved indication by the European Medicines Agency (EMA), patients with hormone receptor-positive (HR+) disease who initiated neratinib treatment within 1 year of completing trastuzumab (HR+/≤1 year) experienced an absolute iDFS benefit of 5.1% and DDFS benefit of 4.7% at 5 years. In HR+/≤1 year patients with residual disease after neoadjuvant therapy, absolute 5-year iDFS and DDFS benefits of 7.4% and 7.0%, respectively, were observed. Here we report the final protocol-defined, event-driven analysis of overall survival (OS) from ExteNET, and provide descriptive analyses of subgroups of primary interest according to the EU label and current clinical practice in early-stage HER2+ disease.

Methods: ExteNET was a multicenter, randomized, double-blind, placebo-controlled phase 3 trial of women with early-stage HER2+ breast cancer who had completed neoadjuvant or adjuvant trastuzumab plus chemotherapy (NCT00878709). Patients were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year. Hazard ratios (HR) for OS were estimated from Cox proportional hazards models, and survival rates by the Kaplan-Meier method. The OS analysis was event-driven and powered for the intention-to-treat (ITT) population with a target of 248 events. Descriptive analyses were performed in the HR+/≤1 year subgroup per the approved indication in the EU, and in higher-risk patients, i.e. HR+/≤1 year who have residual disease after neoadjuvant therapy [i.e. those who did not achieve a pathologic complete response (pCR)]. Cut-off date: July 2019.

Results: 2840 patients were randomized to study treatment (1420 per group). After a median follow-up of 8.1 years, 127 (8.9%) and 137 (9.6%) patients in the neratinib and placebo ITT groups had died, respectively. The 8-year OS rates were 90.1% (95% CI, 88.3–91.6) in the neratinib group and 90.2% (95% CI, 88.4–91.7) in the placebo group (absolute difference at 8 years -0.1%; stratified HR=0.95; 95% CI, 0.75–1.21; p=0.6914). A positive trend was seen in the prespecified HR+ subgroup (n=1631; absolute difference at 8 years 1.5%; HR=0.80; 95% CI, 0.58–1.12), and within this population, descriptive analyses suggested greater benefits with neratinib in the HR+/≤1 year subgroup (n=1334; absolute difference at 8 years 2.1%; HR=0.79; 95% CI, 0.55–1.13) and in the HR+/≤1 year subset with no pCR after neoadjuvant therapy (n=295; absolute difference at 8 years 9.1%; HR=0.47; 95% CI, 0.23–0.92). No new safety signals were reported with this long-term follow-up to 8 years.

Conclusions: In this final OS analysis of ExteNET, there were fewer deaths with neratinib than placebo in the ITT population, but the results did not reach statistical significance. Analyses showed greater OS improvements with neratinib in subgroups including HR+/≤1 year, and HR+/≤1 year with residual disease after neoadjuvant therapy. These findings are consistent with the results based on the primary endpoint of iDFS, and support the use of neratinib in clinical practice in these patients.

Citation Format: Frankie Ann Holmes, Beverly Moy, Suzette Delaloge, Stephen Chia, Bent Ejlertsen, Janine Mansi, Hiroji Iwata, Michael Gnant, Mark Buyse, Carlos Barrios, Tajana Silovski, Robert Separovic, Anna Bashford, Angel Guerrero-Zotano, Neelima Denduluri, Debra Patt, Erhan Gokmen, Ira Gore, John Smith, Richard Bryce, Feng Xu, Alvin Wong, Miguel Martin, Arlene Chan. Continued efficacy of neratinib in patients with HER2-positive early-stage breast cancer: Final overall survival analysis from the randomized phase 3 ExteNET trial [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 PD3-03.

Evaluation of neratinib (N), pembrolizumab (P), everolimus (E), and nivolumab (V) in patients (pts) with fibrolamellar carcinoma (FLC)

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Background: FLC, a rare liver cancer of young adults, has no effective systemic therapies. Surgical resection is used extensively with non-curative intent. FLC is associated with a DNAJB1- PRKACA chimeric transcript that produces a fusion protein with retained kinase activity and increased expression of several oncogenic signaling pathways including, but not limited to, HER2 ( ERBB2). Methods: N (240 mg oral daily) was studied in FLC pts in the SUMMIT study (NCT01953926); and later under compassionate use for N-based combinations (combo): P (2 mg/kg q3w), E (7.5 mg daily), and V (240 mg q2w) in doublet or triplet regimens. Eligible pts: ≥12y; histologically confirmed FLC; adequate organ function; any number of prior therapies. Primary endpoint: objective response rate (ORR; RECIST v1.1). Secondary endpoints: duration of response; clinical benefit rate (CBR); safety (CTCAE v4.0); somatic and germline sequencing (MSK IMPACT). Results: As of 03-Sep-2020, 15 pretreated pts received N in SUMMIT (confirmed ORR 0%; CBR 13%). Efficacy data for 5 pts from SUMMIT and 2 more pts receiving combo under compassionate use (4 male, 3 female, median age 26 years, median 0 [range 0–4] prior systemic therapies) are in shown in the table. The most common adverse events (AE) with single-agent N (n = 5) were diarrhea (grade 1 80%; grade 2 20%) and nausea (grade 1 60%); other AEs were grade ≤1 in ≤20% of pts. Conclusions: N monotherapy had limited benefit as a single agent in FLC pts. Several case studies evaluating N-based combo with checkpoint inhibitors administered under compassionate use demonstrated that NP led to 1 PR, and the triplet of NPE to prolonged SD. These are case-limited observations but are critical and worth evaluating further in upcoming clinical trials given the continued lack of a standard of care therapy for pts with FLC. Clinical trial information: NCT01953926. [Table: see text]

Application of the Minority Stress Theory: Understanding the Mental Health of Undocumented Latinx Immigrants

This paper applies the Minority Stress framework to data collected from an ongoing community-based participatory research project with health and social service agencies in Southeast Michigan. We examine the stressors and coping strategies employed by undocumented Latinx immigrants and their families to manage immigration-related stress. We conducted in-depth interviews with 23 immigrant clients at Federally Qualified Health Care Centers (FQHC) in Southeast Michigan and 28 in-depth interviews with staff at two FQHC's and a non-profit agency serving immigrants. Findings suggest that immigrants face heightened anxiety and adverse mental health outcomes because of unique minority identity-related stressors created by a growing anti-immigrant social environment. Chronic stress experienced stems from restrictive immigration policies, anti-immigrant rhetoric in the media and by political leaders, fear of deportation, discriminatory events, concealment, and internalized anti-immigrant sentiment. Though identity can be an important effect modifier in the stress process, social isolation in the immigrant community has heightened the impact of stress and impeded coping strategies. These stressors have resulted in distrust in community resources, uncertainty about future health benefits, delayed medical care, and adverse mental health outcomes. Findings provide a framework for understanding the unique stressors experienced by immigrants and strategies for interventions by social service agencies.

LRRC8A is essential for hypotonicity-, but not for DAMP-induced NLRP3 inflammasome activation

The NLRP3 inflammasome is a multi-molecular protein complex that converts inactive cytokine precursors into active forms of IL-1β and IL-18. The NLRP3 inflammasome is frequently associated with the damaging inflammation of non-communicable disease states and is considered an attractive therapeutic target. However, there is much regarding the mechanism of NLRP3 activation that remains unknown. Chloride efflux is suggested as an important step in NLRP3 activation, but which chloride channels are involved is still unknown. We used chemical, biochemical, and genetic approaches to establish the importance of chloride channels in the regulation of NLRP3 in murine macrophages. Specifically, we identify LRRC8A, an essential component of volume-regulated anion channels (VRAC), as a vital regulator of hypotonicity-induced, but not DAMP-induced, NLRP3 inflammasome activation. Although LRRC8A was dispensable for canonical DAMP-dependent NLRP3 activation, this was still sensitive to chloride channel inhibitors, suggesting there are additional and specific chloride sensing and regulating mechanisms controlling NLRP3.

Impact of anti-immigrant rhetoric and policies on frontline health and social service providers in Southeast Michigan, U.S.A

Rising hostility towards immigrants characterised the 2016 Presidential election in the United States (US) and subsequent policy priorities by the new presidential administration. The political shift towards aggressive policies targeting undocumented immigrants is far-reaching and extends into other communities that convive con-or coexist with-immigrant communities. Our study aims to examine the rippling effects of these anti-immigrant policies and rhetoric on health and social service providers in Southeast Michigan who predominantly serve Latino immigrants. Between April and August 2018, we conducted in-depth individual interviews in two Federally Qualified Health Centers and a non-profit social service agency at a county health department. We interviewed 28 frontline health and social service providers. After coding and thematic analyses, we found that staff members' experiences in supporting immigrant clients was congruent with definitions of secondary trauma stress and compassion fatigue, whereby exposure to clients' trauma combined with job burden subsequently impacted the mental health of providers. Major themes included: (a) frontline staff experienced a mental and emotional burden in providing services to immigrant clients given the restrictive anti-immigrant context; and (b) this burden was exacerbated by the increased difficulties in providing these services to their clients. Staff described psychological and emotional distress stemming from exposure to clients' immigration-related trauma and increased mental health needs. This distress was exacerbated by an increased demand to meet clients' needs, which involved explaining or translating documents into English, assisting with legal paperwork, referring clients to mental health resources, addressing increased transportation barriers, and reestablishing trust with the community. Our findings add qualitative data on the mental health implications for frontline providers who support Latino immigrant clients impacted by immigration and highlights the need for further research and resources that address the workplace-related stress generated by heightened immigration enforcement.

Improved tolerability of neratinib in patients with HER2-positive early-stage breast cancer: the CONTROL trial

BACKGROUND

Neratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for extended adjuvant treatment in early-stage HER2-positive breast cancer based on the phase III ExteNET study. In that trial, in which no antidiarrheal prophylaxis was mandated, grade 3 diarrhea was observed in 40% of patients and 17% discontinued due to diarrhea. The international, open-label, sequential-cohort, phase II CONTROL study is investigating several strategies to improve tolerability.

PATIENTS AND METHODS

Patients who completed trastuzumab-based adjuvant therapy received neratinib 240 mg/day for 1 year plus loperamide prophylaxis (days 1-28 or 1-56). Sequential cohorts evaluated additional budesonide or colestipol prophylaxis (days 1-28) and neratinib dose escalation (DE; ongoing). The primary end point was the incidence of grade ≥3 diarrhea.

RESULTS

Final data for loperamide (L; n = 137), budesonide + loperamide (BL; n = 64), colestipol + loperamide (CL; n = 136), and colestipol + as-needed loperamide (CL-PRN; n = 104) cohorts, and interim data for DE (n = 60; completed ≥six cycles or discontinued; median duration 11 months) are available. No grade 4 diarrhea was observed. Grade 3 diarrhea rates were lower than ExteNET in all cohorts and lowest in DE (L 31%, BL 28%, CL 21%, CL-PRN 32%, DE 15%). Median number of grade 3 diarrhea episodes was one; median duration per grade 3 episode was 1.0-2.0 days across cohorts. Most grade 3 diarrhea and diarrhea-related discontinuations occurred in month 1. Diarrhea-related discontinuations were lowest in DE (L 20%, BL 8%, CL 4%, CL-PRN 8%, DE 3%). Decreases in health-related quality of life did not cross the clinically important threshold.

CONCLUSIONS

Neratinib tolerability was improved with preemptive prophylaxis or DE, which reduced the rate, severity, and duration of neratinib-associated grade ≥3 diarrhea compared with ExteNET. Lower diarrhea-related treatment discontinuations in multiple cohorts indicate that proactive management can allow patients to stay on neratinib for the recommended time period. CLINICALTRIALS.GOV: NCT02400476.

Neratinib Plus Capecitabine Versus Lapatinib Plus Capecitabine in HER2-Positive Metastatic Breast Cancer Previously Treated With ≥ 2 HER2-Directed Regimens: Phase III NALA Trial

PURPOSE

NALA (ClinicalTrials.gov identifier: NCT01808573) is a randomized, active-controlled, phase III trial comparing neratinib, an irreversible pan-HER tyrosine kinase inhibitor (TKI), plus capecitabine (N+C) against lapatinib, a reversible dual TKI, plus capecitabine (L+C) in patients with centrally confirmed HER2-positive, metastatic breast cancer (MBC) with ≥ 2 previous HER2-directed MBC regimens.

METHODS

Patients, including those with stable, asymptomatic CNS disease, were randomly assigned 1:1 to neratinib (240 mg once every day) plus capecitabine (750 mg/m² twice a day 14 d/21 d) with loperamide prophylaxis, or to lapatinib (1,250 mg once every day) plus capecitabine (1,000 mg/m² twice a day 14 d/21 d). Coprimary end points were centrally confirmed progression-free survival (PFS) and overall survival (OS). NALA was considered positive if either primary end point was met (α split between end points). Secondary end points were time to CNS disease intervention, investigator-assessed PFS, objective response rate (ORR), duration of response (DoR), clinical benefit rate, safety, and health-related quality of life (HRQoL).

RESULTS

A total of 621 patients from 28 countries were randomly assigned (N+C, n = 307; L+C, n = 314). Centrally reviewed PFS was improved with N+C (hazard ratio [HR], 0.76; 95% CI, 0.63 to 0.93; stratified log-rank P = .0059). The OS HR was 0.88 (95% CI, 0.72 to 1.07; P = .2098). Fewer interventions for CNS disease occurred with N+C versus L+C (cumulative incidence, 22.8% v 29.2%; P = .043). ORRs were N+C 32.8% (95% CI, 27.1 to 38.9) and L+C 26.7% (95% CI, 21.5 to 32.4; P = .1201); median DoR was 8.5 versus 5.6 months, respectively (HR, 0.50; 95% CI, 0.33 to 0.74; P = .0004). The most common all-grade adverse events were diarrhea (N+C 83% v L+C 66%) and nausea (53% v 42%). Discontinuation rates and HRQoL were similar between groups.

CONCLUSION

N+C significantly improved PFS and time to intervention for CNS disease versus L+C. No new N+C safety signals were observed.

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 &lt; 0.45 and 16.1% had elevated TSH values (&gt; 4.5) at the time of their study visit, compared to 1.7% and 7.4% overall. 0.2% had TSH &gt; 10. Among those without a known history of thyroid disease, 1.3% had TSH &lt; 0.45 and 6.7% had TSH &gt; 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&gt;TLK1&gt;NEK1&gt;ATR&gt;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&gt;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 (&gt;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.