Plain language summary: tarlatamab for patients with previously treated small cell lung cancer

WHAT IS THIS SUMMARY ABOUT?

This is a summary of a phase 2 clinical study called DeLLphi-301. The study looked at how effective and safe a medicine called tarlatamab was in participants with small cell lung cancer (SCLC). Participants previously received at least two other treatments for their SCLC. Tarlatamab is a new medicine that locates a protein called DLL3 on the cancer, which allows T cells to attack the cancer. T cells belong to the body's natural defense system known as the immune system. The DeLLphi-301 study separated participants into two groups to receive tarlatamab 10 mg or 100 mg to determine which dose best shrank SCLC with minimal side effects. All participants received a small first dose (1 mg tarlatamab) to decrease the risk of an immune system reaction called cytokine release syndrome (CRS). Tarlatamab was given through the participant's vein once every 2 weeks. This method of administration is known as intravenous (IV) infusion.

WHAT WERE THE RESULTS OF THE DELLPHI-301 STUDY?

In the group given 10 mg tarlatamab, 40% of participants responded to treatment (cancer shrank). In the group given 100 mg tarlatamab, 32% of participants responded to treatment (cancer shrank). After taking tarlatamab at either dose, 59% of participants lived for at least 6 months without their cancer growing or getting worse.The most common side effect was CRS, which occurred in 51% of participants in the group given 10 mg tarlatamab and 61% of participants in the group given 100 mg tarlatamab. Other common side effects were decreased appetite, fever, constipation, and anemia. Some participants had a type of immune reaction called immune effector cell-associated neurotoxicity syndrome (ICANS). A small number of participants (3%) stopped taking tarlatamab because of side effects related to tarlatamab.

WHAT DO THE RESULTS FROM THE DELLPHI-301 STUDY MEAN?

The study found that tarlatamab given every 2 weeks shrank SCLC in participants with SCLC who received previous treatments. Participants given the 10 mg tarlatamab dose had fewer side effects than those given the 100 mg tarlatamab dose.Clinical Trial Registration: NCT05740566 (DeLLphi-304) (ClinicalTrials.gov).

Guide to Understanding and Supporting International Medical Graduates in Hematology/Oncology by the ASCO International Medical Graduates Community of Practice

PURPOSE

International medical graduates (IMGs) are an essential component of the oncology workforce in the United States, comprising a third of all practicing oncologists and almost half of hematology/oncology fellows. In this article, we discuss the contributions of IMGs in the US oncology workforce, review unique challenges faced by IMGs, and propose potential solutions to overcome these challenges.

METHODS

ASCO's IMG Community of Practice was established with the mission to connect, mentor, guide, raise awareness, and overcome the challenges unique to IMGs interested in pursuing medical oncology in the United States. The content of this article is based on discussions at the IMG Community of Practice meetings at ASCO's 2023 and 2024 Annual Meetings.

RESULTS

IMGs bring an inherent diversity of thought and experience to the oncology workforce. They provide high-quality, culture- and language-concordant care to a diverse population of patients with cancer. However, IMGs in oncology face significant hardships throughout their careers, including visa-related restrictions, psychosocial and cultural struggles, as well as differential treatment while applying for residency and fellowship training, and early career positions. Greater awareness of these challenges among the members of the hematology/oncology community, along with institutional and individual efforts to support IMGs, is warranted.

CONCLUSION

We encourage oncology professionals and institutions to join our efforts in recognizing the unique paths of IMGs and providing support and advocacy to maximize the potential of IMGs in the US oncology workforce.

Shifting Sociodemographic Characteristics of a Phase I Clinical Trial Population at an NCI-Designated Comprehensive Cancer Center in the Southeast

Racial and ethnic minority populations are consistently under-represented in oncology clinical trials despite comprising a disproportionate share of a cancer burden. Phase I oncology clinical trials pose a unique challenge and opportunity for minority inclusion. Here we compared the sociodemographic characteristics of patients participating in phase 1 clinical trials a National Cancer Institute ( NCI)-designated comprehensive center to all patients at the center, patients with new cancer diagnosis in metropolitan Atlanta and patients with new cancer diagnoses in the state of Georgia. From 2015 to 2020, 2325 patients (43.4% female, 56.6% male) consented to participate in a phase I trial. Grouped self-reported race distribution was 70.3% White, 26.2% Black, and 3.5% other. Of new patient registrations at Winship Cancer Institute (N = 107 497) (50% F, 50% M), grouped race distribution was 63.3% White, 32.0% Black, and 4.7% other. Patients with new cancer diagnoses in metro Atlanta from 2015 to 2016 (N = 31101) were 58.4% White, 37.2% Black, and 4.3% other. Race and sex distribution of phase I patients was significantly different than Winship patients (P < .001). Over time, percent of White patients decreased in both phase I and Winship groups (P = .009 and P < .001, respectively); percentage of females did not change in either group (P = .54 phase I, P = .063 Winship). Although phase I patients were more likely to be White, male, and privately ensured than the Winship cohort, from 2015 to 2020 the percentage of White patients in phase I trials and among all new patients treated at Winship decreased. The intent of characterizing existing disparities is to improve the representation of patients from racial and ethnic minority backgrounds in phase I clinical trials.

Tarlatamab for Patients with Previously Treated Small-Cell Lung Cancer

BACKGROUND

Tarlatamab, a bispecific T-cell engager immunotherapy targeting delta-like ligand 3 and CD3, showed promising antitumor activity in a phase 1 trial in patients with previously treated small-cell lung cancer.

METHODS

In this phase 2 trial, we evaluated the antitumor activity and safety of tarlatamab, administered intravenously every 2 weeks at a dose of 10 mg or 100 mg, in patients with previously treated small-cell lung cancer. The primary end point was objective response (complete or partial response), as assessed by blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

Overall, 220 patients received tarlatamab; patients had previously received a median of two lines of treatment. Among patients evaluated for antitumor activity and survival, the median follow-up was 10.6 months in the 10-mg group and 10.3 months in the 100-mg group. An objective response occurred in 40% (97.5% confidence interval [CI], 29 to 52) of the patients in the 10-mg group and in 32% (97.5% CI, 21 to 44) of those in the 100-mg group. Among patients with an objective response, the duration of response was at least 6 months in 59% (40 of 68 patients). Objective responses at the time of data cutoff were ongoing in 22 of 40 patients (55%) in the 10-mg group and in 16 of 28 patients (57%) in the 100-mg group. The median progression-free survival was 4.9 months (95% CI, 2.9 to 6.7) in the 10-mg group and 3.9 months (95% CI, 2.6 to 4.4) in the 100-mg group; the estimates of overall survival at 9 months were 68% and 66% of patients, respectively. The most common adverse events were cytokine-release syndrome (in 51% of the patients in the 10-mg group and in 61% of those in the 100-mg group), decreased appetite (in 29% and 44%, respectively), and pyrexia (in 35% and 33%). Cytokine-release syndrome occurred primarily during treatment cycle 1, and events in most of the patients were grade 1 or 2 in severity. Grade 3 cytokine-release syndrome occurred less frequently in the 10-mg group (in 1% of the patients) than in the 100-mg group (in 6%). A low percentage of patients (3%) discontinued tarlatamab because of treatment-related adverse events.

CONCLUSIONS

Tarlatamab, administered as a 10-mg dose every 2 weeks, showed antitumor activity with durable objective responses and promising survival outcomes in patients with previously treated small-cell lung cancer. No new safety signals were identified. (Funded by Amgen; DeLLphi-301 ClinicalTrials.gov number, NCT05060016.).

Tarlatamab, a First-in-Class DLL3-Targeted Bispecific T-Cell Engager, in Recurrent Small-Cell Lung Cancer: An Open-Label, Phase I Study

PURPOSE

Small-cell lung cancer (SCLC) is an aggressive malignancy with limited treatments. Delta-like ligand 3 (DLL3) is aberrantly expressed in most SCLC. Tarlatamab (AMG 757), a bispecific T-cell engager molecule, binds both DLL3 and CD3 leading to T-cellb-mediated tumor lysis. Herein, we report phase I results of tarlatamab in patients with SCLC.

PATIENTS AND METHODS

This study evaluated tarlatamab in patients with relapsed/refractory SCLC. The primary end point was safety. Secondary end points included antitumor activity by modified RECIST 1.1, overall survival, and pharmacokinetics.

RESULTS

By July 19, 2022, 107 patients received tarlatamab in dose exploration (0.003 to 100 mg; n = 73) and expansion (100 mg; n = 34) cohorts. Median prior lines of anticancer therapy were 2 (range, 1-6); 49.5% received antiprogrammed death-1/programmed death ligand-1 therapy. Any-grade treatment-related adverse events occurred in 97 patients (90.7%) and grade b % 3 in 33 patients (30.8%). One patient (1%) had grade 5 pneumonitis. Cytokine release syndrome was the most common treatment-related adverse event, occurring in 56 patients (52%) including grade 3 in one patient (1%). Maximum tolerated dose was not reached. Objective response rate was 23.4% (95% CI, 15.7 to 32.5) including two complete and 23 partial responses. The median duration of response was 12.3 months (95% CI, 6.6 to 14.9). The disease control rate was 51.4% (95% CI, 41.5 to 61.2). The median progression-free survival and overall survival were 3.7 months (95% CI, 2.1 to 5.4) and 13.2 months (95% CI, 10.5 to not reached), respectively. Exploratory analysis suggests that selecting for increased DLL3 expression can result in increased clinical benefit.

CONCLUSION

In patients with heavily pretreated SCLC, tarlatamab demonstrated manageable safety with encouraging response durability. Further evaluation of this promising molecule is ongoing.

Cisplatin-Induced Ototoxicity: A Concise Review of the Burden, Prevention, and Interception Strategies

Cisplatin is a bedrock of cancer management and one of the most used chemotherapeutic agents in the treatment of germ cell, lung, bladder, ovarian, and head and neck cancers. Approximately 500,000 patients diagnosed annually with these cancer types in the United States could be candidates for treatment with cisplatin. There is a 5-fold increase in the risk of hearing impairment or ototoxicity with cisplatin, which can manifest as ringing in the ear (tinnitus), high-frequency hearing loss, and at late stages, a decreased ability to hear normal conversation. More than half of adult and pediatric patients with cancer treated with cisplatin developed hearing impairment with major impact on patients' health-related quality of life. A considerable evidence gap persists regarding the burden and effective prevention and interception strategies for cisplatin-induced ototoxicity, especially in adult patients with cancer. We conducted a review of the published literature to provide an update on the status of this important clinical challenge. We also surveyed practicing oncologists within our network of academic and community practices to gain a better understanding of how the published literature compares with real-world practice. Our review of the literature showed a lack of standardized guidelines for monitoring and treatment of cisplatin-induced ototoxicity, especially in the adult cancer patient population. Our survey of practicing oncologists mirrored the findings from the published literature with a heterogeneity of practice, which highlights the need for standardization.

Abstract 4995: Targeting PLK1 effectively suppresses growth of small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor characterized by rapid disease progression and poor patient survival. Key transcription factors implicated as drivers of unique biological phenotypes of SCLC include ASCL1, NEUROD1, YAP1, and POU2F3. Strategies to exploit these phenotypes for innovative precision medicine approaches will be impactful. Using an unbiased agnostic preclinical drug screen to uncover therapeutic opportunities in SCLC, we identified a strong signal with PLK1 inhibitors (PLK1i) with low nanomolar IC50. We extended the in vitro findings by testing the efficacy of PLK1i in vivo using traditional xenograft of SCLC H526 cell line and patient derived xenografts (PDX). Volasertib achieved significant tumor growth inhibition relative to control in H526 xenografts. Also, onvansertib significantly inhibited growth of platinum-resistant and platinum-sensitive PDXs. The combination of PLK1i with standard chemotherapeutic agents identified promising synergy of the combination of onvansertib and paclitaxel. We further interrogated for predictive biomarkers of PLK1i sensitivity using gene expression profile comparing highly sensitive to less sensitive cell lines. High expression of C-MYC but not PLK1, TP53 or RB was associated with resistance to PLK1i. Conversely, while TP53 expression level did not correlate, TP53 gene mutation status (inactivating disruptive mutations) correlated with cell sensitivity to PLK1i. We queried the publicly available CCLE and the Cancer Therapeutics Response Portal to evaluate whether any of the SCLC subtypes have therapeutic vulnerability to PLK1i. In general, high expression of YAP1 in SCLC cell lines correlated with greater sensitivity to PLK1i. A YAP1 positive cell line, SW1271, with strong TP53 expression was particularly resistant to PLK1i. CRISPR knockout of YAP1 in this cell line enhanced SW1271 sensitivity to PLK1i suggesting that YAP1 expression as a marker of vulnerability to PLK1i could be context dependent especially when co-occurring with TP53 mutations. The mechanism of this interaction will be discussed.

Citation Format: John C. Schmitz, Guojing Zhang, Andrey A. Ivanov, Abbe Pannucci, Maya Ridinger, Taofeek K. Owonikoko. Targeting PLK1 effectively suppresses growth of small cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4995.

Serum glycomic profile as a predictive biomarker of recurrence in patients with differentiated thyroid cancer

PURPOSE

Thyroid cancer recurrence following curative thyroidectomy is associated with increased morbidity and mortality, but current surveillance strategies are inadequate for early detection. Prior studies indicate that tissue glycosylation is altered in thyroid cancer, but the utility of serum glycosylation in thyroid cancer surveillance remains unexplored. We therefore assessed the potential utility of altered serum glycomic profile as a tumor-specific target for disease surveillance in recurrent thyroid cancer.

EXPERIMENTAL DESIGN

We employed banked serum samples from patients with recurrent thyroid cancer post thyroidectomy and healthy controls. N-glycans were enzymatically released from serum glycoproteins, labeled via permethylation, and analyzed by MALDI-TOF mass spectrometry. Global level and specific subtypes of glycan structures were compared between patients and controls.

RESULTS

We evaluated 28 independent samples from 13 patients with cancer recurrence and 15 healthy controls. Global features of glycosylation, including N-glycan class and terminal glycan modifications were similar between groups, but three of 35 individual glycans showed significant differences. The three glycans were biosynthetically related biantennary core fucosylated N-glycans that only varied by the degree of galactosylation (G0F, G1F, and G2F; G: galactose, F: fucose). The ratio of G0F:G1F that captures reduced galactosylation was observed in patients samples but not in healthy controls (p = 0.004) and predicted thyroid cancer recurrence (AUC = 0.82, CI 95% = 0.64-0.99).

CONCLUSIONS

Altered N-glycomic profile was associated with thyroid cancer recurrence. This serum-based biomarker would be useful as an effective surveillance tool to improve the care and prognosis of thyroid cancer after prospective validation.

Clinical uptake of precision medicine advances in NSCLC: A case study in RET fusions

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Background: Precision medicine has revolutionized cancer care in advanced NSCLC and new actionable biomarkers and targeted therapies are emerging at an unprecedented pace, creating myriad opportunities to improve care and mitigate the often-dire sequelae of traditional cancer therapy. Delays in uptake of testing and biomarker-guided treatment for patients with NSCLC and EGFR activating mutations or ALK fusions are well documented despite clear evidence-based practice, guidelines, and expert recommendations. In this study, we analyze healthcare professionals (HCPs) awareness and application of RET fusion testing and integration of recently approved selective RET inhibitors into practice for appropriate patients with advanced NSCLC. Methods: From 1/2020-6/2022, multiple educational activities were developed to provide HCPs with evidence-based expert and guideline recommendations on assessment of and therapy selection for RET fusion–positive NSCLC. The activities comprised live symposia associated with 4 major oncology and pathology conferences (AMP, USCAP, ASCO, AACR), 3 regional live workshop series across the US, 3 live webinars, and 2 on-demand videos. Baseline polling questions designed to assess key aspects of HCP knowledge and practice patterns were repeated at each activity. Results: Across all activities at baseline, on average only 38% of responding HCPs correctly identified RNA NGS as the most sensitive testing assay for detection of RET fusions and 36% accurately selected the appropriate targeted therapy for patient case with a KIF5B-RET gene fusion. From 2020 through 2022, with each new group of learners across different scopes of practice, we found suboptimal awareness of optimal RET fusion testing methodology and choice of therapy for patients with RET fusion–positive NSCLC (table). Optimal responses were slightly higher among learners attending conference-associated symposia vs live workshop series and online education. Conclusions: The use of optimal testing assays for RET alterations across patients with NSCLC remains low and many HCPs continue to lack awareness of appropriate targeted therapy for patients with RET–fusion positive NSCLC > 2 years after the first approved indication for this biomarker. These results underscore a lag in adoption of optimal precision medicine approaches for NSCLC among oncology HCPs and the need for expert guidance and educational activities to optimize individualized, biomarker-driven treatment approaches. An analysis of patterns by HCP role (MD, NP/PA, RN, Pharmacist) will be presented.[Table: see text]

Phase I trial of the DLL3/CD3 bispecific T-cell engager BI 764532 in DLL3-positive small-cell lung cancer and neuroendocrine carcinomas

Poorly differentiated neuroendocrine carcinomas such as small-cell lung cancer (SCLC) have poor survival and high relapse rates. DLL3 is found on these carcinomas and has become a target of increasing interest in recent years. The bispecific DLL3/CD3 T-cell engager BI 764532 has been shown to induce complete tumor regression in a human T cell-engrafted mouse model. Here, we describe the study design of a first-in-human, phase I, multicenter, open-label, non-randomized, dose-escalation study in patients with SCLC or other DLL3-positive neuroendocrine carcinomas. The study will determine the maximum tolerated dose and evaluate safety, tolerability, pharmacokinetics and preliminary efficacy of BI 764532 monotherapy.

Pan-cancer analysis of YAP1 expression as a predictive biomarker for cancer immunotherapy

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Background: High YAP1 expression correlates with the ‘T-cell inflamed’ expression phenotype in small cell lung cancer (SCLC), but its association with other biomarkers of immune checkpoint vulnerability and in tumor types beyond SCLC is not known. We examined whether YAP1 expression correlates with other established markers of immune checkpoint blockade (ICB) efficacy (PDL1 expression and TMB) in a tumor agnostic manner to determine clinical relevance. Methods: Next-generation sequencing of DNA (592 gene panel or whole exome) and RNA (whole transcriptome) was performed for patient samples (n = 57,134), representing 13 cancer types, submitted to a CLIA-certified laboratory (Caris Life Sciences, Phoenix, AZ). The ‘T-cell inflamed’ signature (TIS) score was calculated as an 18-gene weighted coefficient composite value (Cristescu, 2018). PDL1 expression was assessed by immunohistochemistry (IHC) with cancer type-specific antibodies and thresholds, and high tumor mutational burden was defined as ≥10 mut/Mb. Patients were stratified into subgroups based on median YAP1 expression (YAP1-High/YAP-Low) within each cancer type. Significance was tested by Chi-square, Fisher’s exact test, or Mann-Whitney U test. Results: YAP1-High tumors were associated with significantly increased TIS scores compared to YAP1-Low across all 13 cancer types examined, with the largest fold increase observed in SCLC (1.33-fold, p < 0.0001), followed by pancreatic cancer (1.28-fold, p < 0.0001), while the smallest occurred in melanoma (1.13-fold, p < 0.0001). Spearman correlation strength (range 0.23-0.57) between YAP expression and TIS scores was consistent with increased TIS scores in YAP1-High samples. TMB-High rates were similar in YAP-High and YAP1-Low subgroups for most cancer types, with slightly lower rates in YAP1-High tumors observed for endometrial (23.0 vs 26.6%, p < 0.001) and esophageal (7.0 vs 9.5%, p < 0.05) cancers. YAP1 expression was not significantly increased in PDL1+ (IHC) tumors for most cancer types. However, significantly decreased YAP1 expression was associated with PDL1+ samples in RCC (Renal Cell Carcinoma) (0.91-fold change, P < 0.05), MM (0.90-fold change, P < 0.001), and ENCA (0.80-fold change, P < 0.0001) Conclusions: Our analyses provide confirmation that YAP1 expression positively correlates with the ‘T-cell inflamed’ phenotype across many cancer types, including those with approvals for (ICB) therapy. YAP1 expression was independent of established markers of ICB response, including TMB and PDL1. Further analysis of YAP1 expression as an additional tumor agnostic predictive biomarker is warranted.

Clinical application of precision medicine among oncologists: A case study in RET-targeted therapy

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Background: Precision medicine has revolutionized cancer care across multiple tumor types and new actionable biomarkers and targeted therapies are emerging at an unprecedented pace, creating myriad opportunities to optimize care and mitigate the often-dire sequelae of traditional cancer therapy. Many oncology healthcare professionals (HCPs) in practice are not employing optimal testing methodologies to detect biomarkers in patients who could benefit from novel targeted therapies. In this study, we analyze HCP awareness and application of RET alteration testing and integration of recently approved, new-generation selective RET inhibitors into practice for appropriate patients with NSCLC and thyroid cancer. Methods: In August 2020 HCPs were surveyed on RET alteration testing and use of RET-targeted therapeutics in their current practice. Study eligibility criteria included active HCPs in an oncology, pulmonology, or pathology practice. A curriculum of live and online educational activities was then developed for any interested oncologists and pathologists on RET alteration testing and/or targeted therapy for RET-altered lung and thyroid cancers. These activities included case studies, polling, and evaluations that provided additional insight on self-identified practice trends. In June 2021, at the completion of the educational program, eligible HCPs were surveyed again on RET alteration testing and selection of RET inhibitor therapy for appropriate patients. Results: In August 2020, 123 practicing HCPs completed the initial survey and 33% were testing patients for RET gene alterations and 18% were aware of the most sensitive testing assay for detection of RET fusions. 25% and 7%, respectively, were aware of the current indications for RET inhibitors in RET fusion–positive NSCLC and RET-altered thyroid cancer. Self-identified practice trends identified among the unselected cohort of 12,537 individual HPCs participating in the educational activities also demonstrated similar lack of appropriate testing for RET alterations and use of RET inhibitors. In June 2021, 60 practicing HCPs completed the follow-up survey and 40% were testing patients for RET gene alterations and 25% were aware of the most sensitive testing assay for detection of RET fusions. 52% and 22%, respectively, were aware of the current indications for RET inhibitors in RET fusion–positive NSCLC and RET-altered thyroid cancer. Conclusions: The rate of broad testing for RET alterations across patients with NSCLC and thyroid cancer remains low and many HCPs lack understanding of when to consider treating with a RET inhibitor. These results underscore the lag in adoption of optimal precision medicine approaches in oncology and the need for expert guidance and educational activities to optimize individualized, biomarker-driven treatment approaches for patients with cancer.

Surfaceome profiling to reveal unique therapeutic vulnerabilities in transcriptional subtypes of small cell lung cancer (SCLC)

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Background: Effective treatment options for SCLC remain limited and new treatment approaches are needed to improve outcome. We sought to validate the initial observation in cell lines and limited tissue samples of SCLC of a differential expression of cancer/testis (CT) antigens and TACSD2 gene that encodes surface protein, Trop2 across various subtypes of SCLC. We also tested whether overall surfaceome profile as previously described in other tumor types will show hierarchical priority of expression between transcriptionally defined SCLC subtypes. Methods: We conducted a comprehensive surfaceome profiling of SCLC samples using data generated by RNA sequencing (whole transcriptome) at Caris Life Sciences (Phoenix, AZ). SCLC tumors were stratified into 5 subgroups (SCLC-A/N/Y/P and -mixed) based on the relative expression of the four transcription factors. Expression values were converted to z-scores (the expression value for each gene is normalized to the average expression of that specific gene such that the z-score reflects the number of standard deviations above or below the average). The highest positive z-score among the 4 transcription factors determined subgroup. If all transcription factor z-scores for a given sample were negative, the sample was assigned to ‘Mixed’ subgroup. Significance was tested by Chi-square, Fisher’s exact test, or Mann-Whitney U test. Results: We employed data generated from 674 SCLC samples; median age of 66 years and male (48.7%). The SCLC subtype distribution was 241 (35.8%), 120 (17.8%), 40 (5.9%), 143 (21.2%), 130 (19.3%) for types A, N, P, Y and mixed respectively. Supervised analysis for TACSTD2 expression showed highest levels in YAP1 subtype and was overall significantly increased in SCLC-Y (̃3-fold) and SCLC-P (̃2-fold) subtypes compared to A, N and mixed subtypes. Similarly, SCLC-Y subtype showed the highest median expression as well as the strongest correlation with most TACSTD2-interacting and regulatory genes. A top 10 list of candidate surface protein gene out of 3699 surfaceome genes was defined for each subtype based on the strength of correlation. The top candidate surface protein gene and CT antigen gene respectively by subtype were: SCN3A (r = 0.7033, p = 1.08E-101) and NOL4, (r = 0.574, p = 2.46E-60) for SCLC-A; SSTR2, (r = 0.742, p = 8.18E-119) and TMEFF1, (r = 0.3601, p = 4.53E-22) for SCLC-N; TMPRSS13 (r = 0.5699, p = 2.64E-59) and LY6K (r = 0.4778, p = 9.80E-40) for SCLC-P; and CYBRD1 (r = 0.8559, p = 1.18E-194) and CTAGE5 (r = 0.5521, p = 4.95E-55) for SCLC-Y. Conclusions: SCLC-Y subtype showed the highest expression of TACSTD2 and its interacting and regulatory genes. This subtype could serve as an enrichment factor for antibody-drug-construct targeting TROP2. Several candidate CT antigens and surfaceome genes showing strong correlation with lineage-defining transcription factors offer additional therapeutic targets in SCLC.

Comparison of sociodemographic characteristics of a phase 1 clinical trial population at an NCI-designated comprehensive cancer center in the Southeast to catchment area

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Background: Racial and ethnic minority populations are consistently under-represented in oncology clinical trials despite comprising a disproportionate share of cancer burden. Due in part to difficulties associated with participation, phase 1 trials pose a unique challenge and opportunity for minority inclusion. Here we examine the sociodemographics of phase 1 clinical trial patients at an NCI-designated Comprehensive Cancer Center compared to all patients treated at the center, patients with new cancer diagnoses in metropolitan Atlanta, and the state of Georgia (GA). Methods: Patients enrolled on phase 1 trials at the Winship Cancer Institute (WCI) from 2015-2020, identified from a data warehouse, were compared to new patient registrations at WCI from 2015-2019. Patients with cancer in metro Atlanta and GA were identified from the Surveillance, Epidemiology, and End Results (SEER) Program: Nov 2018 Submission. Covariates for the phase 1 and institutional cohort included sex, race, ECOG PS, insurance, and age at consent. Covariates for SEER patients included sex, race, and age at diagnosis. Summary statistics are reported for categorical variables using frequencies and percentages, and for continuous variables using mean, median, standard deviation, and range. One-sample proportion tests were utilized to compare observed demographic proportions on phase 1 trials with proportions calculated from new patient registrations at WCI and from SEER case data. Results: From 2015-2020, 2325 patients (43.4% F, 56.6% M) signed consent for phase 1 trials. Grouped race distribution was 70.3% White, 26.2% Black, 3.5% Other. Insurance distribution was 42.9% private, 48% government, 9.1% uninsured/other. Mean age at consent was 61.7 years (MD 63, ran 19-92). Of new patient registrations at WCI in 2015 ( N= 12358) (49.7% F, 50.3% M), grouped race distribution was 64.0% W, 28.2% B, 8% O. Atlanta 2015 SEER patients ( N= 31101) (50.3%F, 49.7%M) showed grouped race distribution 58.4% W, 37.2% B, 4.3% O. Mean age at diagnosis was 62.9. GA 2015 SEER patients ( N= 99487) (48.6%F, 51.4%M) showed grouped race distribution 71.2% W, 26.7% B, 2.1% O. Mean age at diagnosis was 64.2. The race and sex distribution of phase 1 patients was significantly different than proportions calculated from new patient registrations at WCI and SEER data from patients in Atlanta ( p< 0.001). Sex distribution was significantly different than GA SEER patients. Conclusions: Phase 1 patients were significantly more likely to be white and male, compared with patients treated at the cancer center, as well as patients with cancer in Atlanta. Race distribution was not significantly different from patients with cancer in GA. Our intent is to characterize existing disparities in order to increase representation of patients from racial and ethnic minority backgrounds in phase 1 clinical trials.

A Multicenter Randomized Phase II Study of Single Agent Efficacy and Optimal Combination Sequence of Everolimus and Pasireotide LAR in Advanced Thyroid Cancer

PURPOSE

Aberrant mTOR pathway and somatostatin receptor signaling are implicated in thyroid cancer and offer potential therapeutic targets. We assessed the clinical efficacy of everolimus and Pasireotide long-acting release (LAR) in radioiodine-refractory differentiated thyroid cancer (DTC) and medullary thyroid cancer (MTC).

PATIENTS AND METHODS

Adults with progressive MTC and DTC untreated or treated with no more than one systemic agent were eligible. The trial was designed to establish the most promising regimen and the optimal combination sequence. Patients were randomized to start treatment with single agent everolimus (10 mg QD; Arm A), pasireotide-LAR (60 mg intramuscular injection, Q4 weeks; Arm B), or the combination (Arm C). At initial progression (PFS1), patients on Arm A or B switched to the combination and continued until progression (PFS2). Efficacy was measured by RECIST criteria.

RESULTS

Study enrolled 42 patients: median age 65 years; female 17 (40.5%); White 31 (73.8%), African American 6 (14.3%), others 5 (11.9); DTC 32 (76.2%); MTC 10 (23.8%). There was no objective response by RECIST criteria across the three arms. Median and 1-year PFS1 rates were 8.3, 1.8, 8.1 months and 49.9%, 36.4%, 25.0% for Arms A, B, C, respectively. Median and 1-year PFS2 rates were 26.3, 17.5, 8.1 months and 78.4%, 70.0%, 25% for Arms A, B, C, respectively. The most frequent adverse events were anemia, stomatitis, fatigue, hyperglycemia, and hypercholesterolemia.

CONCLUSIONS

The combination of everolimus and pasireotide-LAR showed promising efficacy over single agent. The delayed combination of everolimus and pasireotide-LAR following progression on single agent everolimus appeared intriguing as a combination strategy.

Systematic discovery of mutation-directed neo-protein-protein interactions in cancer

Comprehensive sequencing of patient tumors reveals genomic mutations across tumor types that enable tumorigenesis and progression. A subset of oncogenic driver mutations results in neomorphic activity where the mutant protein mediates functions not engaged by the parental molecule. Here, we identify prevalent variant-enabled neomorph-protein-protein interactions (neoPPI) with a quantitative high-throughput differential screening (qHT-dS) platform. The coupling of highly sensitive BRET biosensors with miniaturized coexpression in an ultra-HTS format allows large-scale monitoring of the interactions of wild-type and mutant variant counterparts with a library of cancer-associated proteins in live cells. The screening of 17,792 interactions with 2,172,864 data points revealed a landscape of gain of interactions encompassing both oncogenic and tumor suppressor mutations. For example, the recurrent BRAF V600E lesion mediates KEAP1 neoPPI, rewiring a BRAF^V600E/KEAP1 signaling axis and creating collateral vulnerability to NQO1 substrates, offering a combination therapeutic strategy. Thus, cancer genomic alterations can create neo-interactions, informing variant-directed therapeutic approaches for precision medicine.

Telaglenastat Plus Cabozantinib or Everolimus for Advanced or Metastatic Renal Cell Carcinoma: An Open-Label Phase I Trial

PURPOSE

Dual inhibition of glucose and glutamine metabolism results in synergistic anticancer effects in solid tumor models. Telaglenastat, an investigational, small-molecule, glutaminase inhibitor, exhibits modest single-agent activity in renal cell carcinoma (RCC) patients. This phase Ib trial evaluated telaglenastat plus cabozantinib or everolimus, agents known to impair glucose metabolism in patients with metastatic RCC (mRCC).

PATIENTS AND METHODS

mRCC patients received escalating doses of telaglenastat [400-800 mg per os (p.o.) twice daily] in a 3 + 3 design, plus either everolimus (10 mg daily p.o.; TelaE) or cabozantinib (60 mg daily p.o.; TelaC). Tumor response (RECISTv1.1) was assessed every 8 weeks. Endpoints included safety (primary) and antitumor activity.

RESULTS

Twenty-seven patients received TelaE, 13 received TelaC, with median 2 and 3 prior therapies, respectively. Treatment-related adverse events were mostly grades 1 to 2, most common including decreased appetite, anemia, elevated transaminases, and diarrhea with TelaE, and diarrhea, decreased appetite, elevated transaminases, and fatigue with TelaC. One dose-limiting toxicity occurred per cohort: grade 3 pruritic rash with TelaE and thrombocytopenia with TelaC. No maximum tolerated dose (MTD) was reached for either combination, leading to a recommended phase II dose of 800-mg telaglenastat twice daily with standard doses of E or C. TelaE disease control rate (DCR; response rate + stable disease) was 95.2% [20/21, including 1 partial response (PR)] among 21 patients with clear cell histology and 66.7% (2/3) for papillary. TelaC DCR was 100% (12/12) for both histologies [5/10 PRs as best response (3 confirmed) in clear cell].

CONCLUSIONS

TelaE and TelaC showed encouraging clinical activity and tolerability in heavily pretreated mRCC patients.

Assessment of hyperprogression versus the natural course of disease development with nivolumab with or without ipilimumab versus placebo in phase III, randomized, controlled trials

BACKGROUND

Retrospective studies have suggested a potential risk of hyperprogressive disease (HPD) in patients receiving immune checkpoint inhibitors (ICIs). We compared the incidence of HPD during treatment with nivolumab±ipilimumab versus natural tumor progression with placebo in post hoc analyses of two randomized, double-blind clinical trials.

METHODS

ATTRACTION-2 randomized patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC) and progression on ≥2 prior regimens to nivolumab 3 mg/kg Q2W or placebo. CheckMate 451 randomized patients with extensive-disease small cell lung cancer (ED SCLC) and ongoing complete/partial response or stable disease after first-line chemotherapy to nivolumab 240 mg Q2W, nivolumab 1 mg/kg+ipilimumab 3 mg/kg Q3W for four doses then nivolumab 240 mg Q2W, or placebo. Patients receiving ≥1 dose of study drug and with tumor scans at baseline and the first on-treatment evaluation were included in the HPD analyses. HPD definitions were ≥20%, ≥50%, and ≥100% increase in target lesion sum of the longest diameters (SLD) at the first on-treatment assessment.

RESULTS

In the ATTRACTION-2 HPD-evaluable population, 243 patients received nivolumab and 115 placebo. Fewer patients receiving nivolumab versus placebo had increases in SLD ≥20% (33.7% vs 46.1%) and ≥50% (6.2% vs 11.3%); similar proportions had increases in SLD ≥100% (1.6% vs 1.7%). In the CheckMate 451 HPD-evaluable population, 177 patients received nivolumab, 179 nivolumab+ipilimumab, and 175 placebo. Fewer patients receiving nivolumab or nivolumab+ipilimumab versus placebo had increases in SLD ≥20% (27.1%, 27.4% vs 45.7%), ≥50% (10.2%, 11.2% vs 22.3%), and ≥100% (2.8%, 2.8% vs 6.3%).

CONCLUSIONS

Nivolumab±ipilimumab was not associated with an increased rate of progression versus placebo in patients with GC, GEJC, or ED SCLC, suggesting that previous reports of HPD may reflect the natural disease course in some patients rather than ICI-mediated progression.

TRIAL REGISTRATION NUMBER

NCT02538666; NCT02267343.

Induction of SREBP1 degradation coupled with suppression of SREBP1-mediated lipogenesis impacts the response of EGFR mutant NSCLC cells to osimertinib

Emergence of acquired resistance to osimertinib (AZD9291), the first-approved third-generation EGFR inhibitor that selectively and irreversibly inhibits the activating EGFR mutations and the resistant T790M mutation, is a giant and urgent clinical challenge. Fully understanding the biology underlying the response of EGFR mutant non-small cell lung cancer (NSCLC) to osimertinib is the foundation for development of mechanism-driven strategies to overcome acquired resistance to osimertinib or other third-generation EGFR inhibitors. This study focused on tackling this important issue by elucidating the critical role of sterol regulatory element-binding protein 1 (SREBP1) degradation in conferring the response of EGFR mutant NSCLC cells to osimertinib and by validating the strategy via directly targeting SREBP1 for overcoming osimertinib acquired resistance. Osimertinib facilitated degradation of the mature form of SREBP1 (mSREBP1) in a GSK3/FBXW7-dependent manner and reduced protein levels of its regulated genes in EGFR-mutant NSCLC cells/tumors accompanied with suppression of lipogenesis. Once resistant, EGFR-mutant NSCLC cell lines possessed elevated levels of mSREBP1, which were resistant to osimertinib modulation. Both genetic and pharmacological inhibition of SREBP1 sensitized osimertinib-resistant cells and tumors to osimertinib primarily through enhancing Bim-dependent induction of apoptosis, whereas enforced expression of ectopic SREBP1 in sensitive EGFR-mutant NSCLC cells compromised osimertinib's cell-killing effects. Collectively, we have demonstrated a novel connection between osimertinib and SREBP1 degradation and its impact on the response of EGFR mutant NSCLC cells to osimertinib and suggested an effective strategy for overcoming acquired resistance to osimertinib, and possibly other EGFR inhibitors, via targeting SREBP1.

Advances in Treatment of Recurrent Small Cell Lung Cancer (SCLC): Insights for Optimizing Patient Outcomes from an Expert Roundtable Discussion

Second-line treatment options for patients with relapsed, extensive-stage small cell lung cancer (ES-SCLC) are limited, and even with currently available treatments, prognosis remains poor. Until recently, topotecan (a topoisomerase I inhibitor) was the only drug approved by the United States (US) Food and Drug Administration (FDA) for the management of ES-SCLC following progression after first-line treatment with etoposide plus a platinum derivative (EP; carboplatin preferred). With the most recent approval of EP plus a programmed death ligand 1 (PD-L1) inhibitor, there are now more therapeutic options for managing ES-SCLC. A number of novel agents have emerging data for activity in relapsed ES-SCLC, and single-agent lurbinectedin (an alkylating drug and selective inhibitor of oncogenic transcription and DNA repair machinery in tumor cells) has conditional FDA approval for use in this patient population. Trilaciclib, a short-acting cyclin-dependent kinase 4/6 (CDK 4/6) inhibitor, has also been recently approved as a supportive intervention for use prior to an EP or a topotecan-containing regimen to diminish the incidence of chemotherapy-induced myelosuppression. The current review is based on a recent expert roundtable discussion and summarizes current therapeutic agents and emerging data on newer agents and biomarkers. It also provides evidence-based clinical considerations and a treatment decision tool for oncologists treating patients with relapsed ES-SCLC. This paper discusses the importance of various factors to consider when selecting a second-line treatment option, including prior first-line treatment, available second-line treatment options, tumor platinum sensitivity, and patient characteristics (such as performance status, comorbidities, and patient-expressed and perceived values).

Expression of tdTomato and luciferase in a murine lung cancer alters the growth and immune microenvironment of the tumor

Imaging techniques based on fluorescence and bioluminescence have been important tools in visualizing tumor progression and studying the effect of drugs and immunotherapies on tumor immune microenvironment in animal models of cancer. However, transgenic expression of foreign proteins may induce immune responses in immunocompetent syngeneic tumor transplant models and augment the efficacy of experimental drugs. In this study, we show that the growth rate of Lewis lung carcinoma (LL/2) tumors was reduced after transduction of tdTomato and luciferase (tdTomato/Luc) compared to the parental cell line. tdTomato/Luc expression by LL/2 cells altered the tumor microenvironment by increasing tumor-infiltrating lymphocytes (TILs) while inhibiting tumor-induced myeloid-derived suppressor cells (MDSCs). Interestingly, tdTomato/Luc expression did not alter the response of LL/2 tumors to anti-PD-1 and anti-CTLA-4 antibodies. These results suggest that the use of tdTomato/Luc-transduced cancer cells to conduct studies in immune competent mice may lead to cell-extrinsic tdTomato/Luc-induced alterations in tumor growth and tumor immune microenvironment that need to be taken into consideration when evaluating the efficacy of anti-cancer drugs and vaccines in immunocompetent animal models.

Physician Communication and Patient Understanding of Molecular Testing Terminology

BACKGROUND

The use of molecular testing in oncology is rapidly expanding. The aim of this study was to determine how oncologists describe molecular testing and whether patients understand the terminology being used.

MATERIALS AND METHODS

Sixty conversations between oncologists and patients about molecular testing were observed, and the used technical terms were noted by the researcher. Patients were interviewed post-conversation to assess their understanding of the noted technical terms. A patient understanding score was calculated for each participant. Comparisons of the terms were conducted using χ² tests, Fisher's exact tests, or ANOVA when appropriate.

RESULTS

Sixty-one unique technical terms were used by oncologists, to describe seven topics. "Mutation" was a challenging term for patients to understand with 48.8% (21/43 mentions) of participants correctly defining the term. "Genetic testing" and "Gene" were understood a little more than half the time (53.3%; 8/15 and 56.4%; 22/39 respectively). "DNA" was well understood (80%; 12/15). There was no correlation between the terms being defined by the oncologist in the conversation, and the likelihood of the patient providing a correct definition. White participants were significantly more likely to understand both "mutation" and "genetic testing" than non-White participants. Forty-two percent (n = 25) of participants had an understanding score below 50%, and a higher family income was significantly correlated with a higher score.

CONCLUSION

Our results show that oncologists use variable terminology to describe molecular testing, which is often not understood. Because oncologists defining the terms did not correlate with understanding, it is imperative to develop new, improved methods to explain molecular testing.

IMPLICATIONS FOR PRACTICE

The use of molecular testing is expanding in oncology, yet little is known about how effectively clinicians are communicating information about molecular testing and whether patients understand the terminology used. The results of this study indicate that patients do not understand some of the terminology used by their clinicians and that clinicians tend to use highly variable terminology to describe molecular testing. These results highlight the need to develop and implement effective methods to explain molecular testing terminology to patients to ensure that patients have the tools to make autonomous and informed decisions about their treatment.

Discovery of Small Molecule Bak Activator for Lung Cancer Therapy

Rationale: Bak is a major proapoptotic Bcl2 family member and a required molecule for apoptotic cell death. High levels of endogenous Bak were observed in both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) cell lines. Increased Bak expression was correlated with poor prognosis of NSCLC patients, suggesting that Bak protein is an attractive target for lung cancer therapy. The BH3 domain functions as death domain and is required for Bak to initiate apoptotic cell death. Thus, the BH3 domain is attractive target for discovery of Bak agonist.

Methods: The BH3 death domain binding pocket (aa75-88) of Bak was chosen as a docking site for screening of small molecule Bak activators using the UCSF DOCK 6.1 program suite and the NCI chemical library (300,000 small molecules) database. The top 500 compounds determined to have the highest affinity for the BH3 domain were obtained from the NCI and tested for cytotoxicity for further screening. We identified a small molecule Bak activator BKA-073 as the lead compound. The binding affinity of BKA-073 with Bak protein was analyzed by isothermal titration calorimetry (ITC) assay. BKA-073-mediated Bak activation via oligomerization was analyzed by a cross-linking with Bis (maleimido) hexane (BMH). Sensitivity of BKA-073 to lung cancer cells in vitro was evaluated by dynamic BH3 profiling (DBP) and apoptotic cell death assay. The potency of BKA-073 alone or in combination with radiotherapy or Bcl2 inhibitor was evaluated in animal models.

Results: We found that BKA-073 binds Bak at BH3 domain with high affinity and selectivity. BKA-073/Bak binding promotes Bak oligomerization and mitochondrial priming that activates its proapoptotic function. BKA-073 potently suppresses tumor growth without significant normal tissue toxicity in small cell lung cancer (SCLC) and NSCLC xenografts, patient-derived xenografts, and genetically engineered mouse models of mutant KRAS-driven cancer. Bak accumulates in radioresistant lung cancer cells and BKA-073 reverses radioresistance. Combination of BKA-073 with Bcl-2 inhibitor venetoclax exhibits strong synergy against lung cancer in vivo.

Conclusions: Development of small molecule Bak activator may provide a new class of anticancer agents to treat lung cancer.

Targeting c-Myc to overcome acquired resistance of EGFR mutant NSCLC cells to the third generation EGFR tyrosine kinase inhibitor, osimertinib

Osimertinib (AZD9291 or TAGRISSOTM) is a promising and approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for treating patients with advanced non-small cell lung cancer (NSCLC) harboring EGFR-activating mutations or the resistant T790M mutation. However, the inevitable emergence of acquired resistance limits its long-term efficacy. A fuller understanding of the mechanism of action of osimertinib and its linkage to acquired resistance will enable the development of more efficacious therapeutic strategies. Consequently, we have identified a novel connection between osimertinib or other EGFR TKI and c-Myc. Osimertinib rapidly and sustainably decreased c-Myc levels primarily via enhancing protein degradation in EGFR-mutant (EGFRm) NSCLC cell lines and xenograft tumors. c-Myc levels were substantially elevated in different EGFRm NSCLC cell lines with acquired resistance to osimertinib in comparison with their corresponding parental cell lines and could not be reduced any further by osimertinib. Consistently, c-Myc levels were elevated in the majority of EGFRm NSCLC tissues relapsed from EGFR-TKI treatment compared to their corresponding untreated baseline c-Myc levels. Suppression of c-Myc through knockdown or pharmacological targeting with BET inhibitors restored the response of resistant cell lines to osimertinib. These findings indicate that c-Myc modulation mediates the therapeutic efficacy of osimertinib and the development of osimertinib-acquired resistance. Furthermore, they establish c-Myc as a potential therapeutic target and warrant clinical testing of BET inhibition as a potential strategy to overcome acquired resistance to osimertinib or other EGFR inhibitors.