Development of an orally bioavailable mSWI/SNF ATPase degrader and acquired mechanisms of resistance in prostate cancer

Mammalian switch/sucrose nonfermentable (mSWI/SNF) ATPase degraders have been shown to be effective in enhancer-driven cancers by functioning to impede oncogenic transcription factor chromatin accessibility. Here, we developed AU-24118, an orally bioavailable proteolysis-targeting chimera (PROTAC) degrader of mSWI/SNF ATPases (SMARCA2 and SMARCA4) and PBRM1. AU-24118 demonstrated tumor regression in a model of castration-resistant prostate cancer (CRPC) which was further enhanced with combination enzalutamide treatment, a standard of care androgen receptor (AR) antagonist used in CRPC patients. Importantly, AU-24118 exhibited favorable pharmacokinetic profiles in preclinical analyses in mice and rats, and further toxicity testing in mice showed a favorable safety profile. As acquired resistance is common with targeted cancer therapeutics, experiments were designed to explore potential mechanisms of resistance that may arise with long-term mSWI/SNF ATPase PROTAC treatment. Prostate cancer cell lines exposed to long-term treatment with high doses of a mSWI/SNF ATPase degrader developed SMARCA4 bromodomain mutations and ABCB1 (ATP binding cassette subfamily B member 1) overexpression as acquired mechanisms of resistance. Intriguingly, while SMARCA4 mutations provided specific resistance to mSWI/SNF degraders, ABCB1 overexpression provided broader resistance to other potent PROTAC degraders targeting bromodomain-containing protein 4 and AR. The ABCB1 inhibitor, zosuquidar, reversed resistance to all three PROTAC degraders tested. Combined, these findings position mSWI/SNF degraders for clinical translation for patients with enhancer-driven cancers and define strategies to overcome resistance mechanisms that may arise.

Characterization of Responses to Lenvatinib plus Pembrolizumab in Patients with Advanced Renal Cell Carcinoma at the Final Prespecified Survival Analysis of the Phase 3 CLEAR Study

In the phase 3 CLEAR trial, lenvatinib plus pembrolizumab (L + P) showed superior efficacy versus sunitinib in treatment-naïve patients with advanced renal cell carcinoma (aRCC). The combination treatment was associated with a robust objective response rate of 71%. Here we report tumor responses for patients in the L + P arm in CLEAR, with median follow-up of ∼4 yr at the final prespecified overall survival (OS) analysis. Tumor responses were assessed by independent review using Response Evaluation Criteria in Solid Tumors v1.1. Patients with a complete response (CR; n = 65), partial response (PR) with maximum tumor shrinkage ≥75% (near-CR; n = 59), or PR with maximum tumor shrinkage <75% (other PR; n = 129), were characterized in terms of their baseline characteristics. The median duration of response was 43.7 mo (95% confidence interval [CI] 39.2-not estimable) for the CR group, 30.5 mo (95% CI 22.4-not estimable) for the near-CR group, and 17.2 mo (95% CI 12.5-21.4) for the other PR group. The 36-mo OS rates were consistently high in the CR (97%), near-CR (86%), and other PR (62%) groups. Robust objective response rates were observed across International Metastatic RCC Database Consortium favorable-risk (69%, 95% CI 60-78%), intermediate-risk (73%, 95% CI 67-79%), and poor-risk (70%, 95% CI 54-85%) subgroups. The robust response to L + P supports this combination as a standard-of-care first-line treatment for patients with aRCC. PATIENT SUMMARY: The CLEAR trial enrolled patients with advanced kidney cancer who had not previously received any treatment for their cancer. Here we report results for tumor shrinkage observed in the group that received lenvatinib plus pembrolizumab combination treatment during the trial. Shrinkage of target tumors with this combination was long-lasting and was observed in patients irrespective of their disease severity. This trial is registered on ClinicalTrials.gov as NCT02811861.

p300/CBP degradation is required to disable the active AR enhanceosome in prostate cancer

Prostate cancer is an exemplar of an enhancer-binding transcription factor-driven disease. The androgen receptor (AR) enhanceosome complex comprised of chromatin and epigenetic coregulators assembles at enhancer elements to drive disease progression. The paralog lysine acetyltransferases p300 and CBP deposit histone marks that are associated with enhancer activation. Here, we demonstrate that p300/CBP are determinant cofactors of the active AR enhanceosome in prostate cancer. Histone H2B N-terminus multisite lysine acetylation (H2BNTac), which was exclusively reliant on p300/CBP catalytic function, marked active enhancers and was notably elevated in prostate cancer lesions relative to the adjacent benign epithelia. Degradation of p300/CBP rapidly depleted acetylation marks associated with the active AR enhanceosome, which was only partially phenocopied by inhibition of their reader bromodomains. Notably, H2BNTac was effectively abrogated only upon p300/CBP degradation, which led to a stronger suppression of p300/CBP-dependent oncogenic gene programs relative to bromodomain inhibition. In vivo experiments using a novel, orally active p300/CBP proteolysis targeting chimera (PROTAC) degrader (CBPD-409) showed that p300/CBP degradation potently inhibited tumor growth in preclinical models of castration-resistant prostate cancer and synergized with AR antagonists. While mouse p300/CBP orthologs were effectively degraded in host tissues, prolonged treatment with the PROTAC degrader was well tolerated with no significant signs of toxicity. Taken together, our study highlights the pivotal role of p300/CBP in maintaining the active AR enhanceosome and demonstrates how target degradation may have functionally distinct effects relative to target inhibition, thus supporting the development of p300/CBP degraders for the treatment of advanced prostate cancer.

A phase Ib study evaluating the recommended phase II dose, safety, tolerability, and efficacy of mivavotinib in combination with nivolumab in advanced solid tumors

Mivavotinib (TAK-659/CB-659), a dual SYK/FLT3 inhibitor, reduced immunosuppressive immune cell populations and suppressed tumor growth in combination with anti-PD-1 therapy in cancer models. This dose-escalation/expansion study investigated the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of mivavotinib plus nivolumab in patients with advanced solid tumors. Patients received oral mivavotinib 60-100 mg once-daily plus intravenous nivolumab 3 mg/kg on days 1 and 15 in 28-day cycles until disease progression or unacceptable toxicity. The dose-escalation phase evaluated the recommended phase II dose (RP2D; primary endpoint). The expansion phase evaluated overall response rate (primary end point) at the RP2D in patients with triple-negative breast cancer (TNBC). During dose-escalation (n = 24), two dose-limiting toxicities (grade 4 lipase increased and grade 3 pyrexia) occurred in patients who received mivavotinib 80 mg and 100 mg, respectively. The determined RP2D was once-daily mivavotinib 80 mg plus nivolumab 3 mg/kg. The expansion phase was terminated at ~50% enrollment (n = 17) after failing to meet an ad hoc efficacy futility threshold. Among all 41 patients, common treatment-emergent adverse events (TEAEs) included dyspnea (48.8%), aspartate aminotransferase increased, and pyrexia (46.3% each). Common grade ≥3 TEAEs were hypophosphatemia and anemia (26.8% each). Mivavotinib plasma exposure was generally dose-proportional (60-100 mg). One patient had a partial response. Mivavotinib 80 mg plus nivolumab 3 mg/kg was well tolerated with no new safety signals beyond those of single-agent mivavotinib or nivolumab. Low response rates highlight the challenges of treating unresponsive tumor types, such as TNBC, with this combination and immunotherapies in general. TRIAL REGISTRATION ID: NCT02834247.

Hybrid Oncocytic Tumors (HOTs) in Birt-Hogg-Dubé Syndrome Patients-A Tale of Two Cities: Sequencing Analysis Reveals Dual Lineage Markers Capturing the 2 Cellular Populations of HOT

Birt-Hogg-Dubé (BHD) syndrome is associated with an increased risk of multifocal renal tumors, including hybrid oncocytic tumor (HOT) and chromophobe renal cell carcinoma (chRCC). HOT exhibits heterogenous histologic features overlapping with chRCC and benign renal oncocytoma, posing challenges in diagnosis of HOT and renal tumor entities resembling HOT. In this study, we performed integrative analysis of bulk and single-cell RNA sequencing data from renal tumors and normal kidney tissues, and nominated candidate biomarkers of HOT, L1CAM, and LINC01187 , which are also lineage-specific markers labeling the principal cell and intercalated cell lineages of the distal nephron, respectively. Our findings indicate the principal cell lineage marker L1CAM and intercalated cell lineage marker LINC01187 to be expressed mutually exclusively in a unique checkered pattern in BHD-associated HOTs, and these 2 lineage markers collectively capture the 2 distinct tumor epithelial populations seen to co-exist morphologically in HOTs. We further confirmed that the unique checkered expression pattern of L1CAM and LINC01187 distinguished HOT from chRCC, renal oncocytoma, and other major and rare renal cell carcinoma subtypes. We also characterized the histopathologic features and immunophenotypic features of oncocytosis in the background kidney of patients with BHD, as well as the intertumor and intratumor heterogeneity seen within HOT. We suggest that L1CAM and LINC01187 can serve as stand-alone diagnostic markers or as a panel for the diagnosis of HOT. These lineage markers will inform future studies on the evolution and interaction between the 2 transcriptionally distinct tumor epithelial populations in such tumors.

Immune Checkpoint Inhibitor Therapy Before Nephrectomy for Locally Advanced and Metastatic Renal Cell Carcinoma: A Review

Importance

The therapeutic landscape of advanced renal cell carcinoma (RCC) has rapidly evolved in the past 2 decades, with the advent of cytokines therapy followed by targeted therapies and novel immune checkpoint inhibitors (ICI). This article aims to review the current evidence and ongoing trials of neoadjuvant or prenephrectomy ICI therapy in patients with locally advanced and metastatic RCC.

Observations

A literature search was performed using the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and PubMed as well as relevant medical society meetings for English-language studies, articles, and abstracts published before January 31, 2023. Currently, level I evidence supports the use of ICI-based combination therapy as the first-line treatment of patients with metastatic RCC with the potential option of deferred nephrectomy in those who respond to treatment. Nevertheless, limited prospective data are available regarding the role and outcomes of nephrectomy (cytoreductive or consolidative) in conjunction with ICI therapy in both metastatic and locally advanced RCC. Although data from retrospective case series confirmed the feasibility and safety of deferred nephrectomy in this setting, the sequence of nephrectomy and whether it should be considered in patients with metastatic RCC is a common clinical dilemma. However, although neoadjuvant targeted therapy for nonmetastatic RCCs has been associated with some advantages yet not accepted as a standard, current data from a phase 3 randomized clinical trial failed to demonstrate the oncologic benefit of neoadjuvant nivolumab for locally advanced RCC.

Conclusion and Relevance

The findings of this review suggest that ICI-based combination therapy is the standard of care as the first-line treatment of patients with metastatic RCC. However, the role of neoadjuvant ICIs in locally advanced RCC is an active area of investigation. Deferred nephrectomy after ICI-based immunotherapy for metastatic RCC is feasible and safe yet should be performed in high-volume health centers by experienced surgeons. The multidisciplinary and careful approach is critical for treatment decisions.

Lessons from 801 clinical TFE3/TFEB fluorescence in situ hybridization assays performed on renal cell carcinoma suspicious for MiTF family aberrations

OBJECTIVES

Fluorescence in situ hybridization (FISH) assays for the detection of chromosomal rearrangements involving TFE3 and TFEB are considered the gold standard for the diagnosis of MiTF family altered renal cell carcinoma (MiTF-RCC). We reviewed 801 clinical TFE3/TFEB FISH assays performed at our tertiary-level institution between 2014 and 2023 on kidney tumors suspicious at the morphologic or biomarker level for MiTF aberrations.

METHODS

We summarized and analyzed clinical information, TFE3/TFEB FISH results, and available biomarker staining results in a cohort of 453 consecutive kidney tumor cases suspicious for MiTF-RCC.

RESULTS

In total, 61 of 434 (14%) kidney tumors were confirmed for TFE3 translocation; 10 of 367 cases (2.7%) were confirmed for TFEB translocation. Since TFEB amplification interpretation was implemented in our service line, 20 of 306 cases (6.5%) were diagnosed with TFEB amplification. Importantly, TFE3 and TFEB rearrangements were never co-detected within the same kidney tumor. Patients with TFEB amplification were significantly older (P < .001) than patients with TFE3 or TFEB translocation. Kidney tumors with TFEB amplification were seen to be at least 3 times as common as those with TFEB translocation.

CONCLUSIONS

Clinical TFE3/TFEB FISH assays successfully identified and confirmed rare MiTF-RCC with TFE3 and TFEB rearrangements. Although morphologic and biomarker features associated with a kidney tumor may be suggestive of MiTF-RCC, clinical TFE3/TFEB FISH assays are crucial for a confirmation and definitive subclassification of patients with MiTF-RCC.

Adaptor proteins mediate CXCR4 and PI4KA crosstalk in prostate cancer cells and the significance of PI4KA in bone tumor growth

The chemokine receptor, CXCR4 signaling regulates cell growth, invasion, and metastasis to the bone-marrow niche in prostate cancer (PCa). Previously, we established that CXCR4 interacts with phosphatidylinositol 4-kinase IIIα (PI4KIIIα encoded by PI4KA) through its adaptor proteins and PI4KA overexpressed in the PCa metastasis. To further characterize how the CXCR4-PI4KIIIα axis promotes PCa metastasis, here we identify CXCR4 binds to PI4KIIIα adaptor proteins TTC7 and this interaction induce plasma membrane PI4P production in prostate cancer cells. Inhibiting PI4KIIIα or TTC7 reduces plasma membrane PI4P production, cellular invasion, and bone tumor growth. Using metastatic biopsy sequencing, we found PI4KA expression in tumors correlated with overall survival and contributes to immunosuppressive bone tumor microenvironment through preferentially enriching non-activated and immunosuppressive macrophage populations. Altogether we have characterized the chemokine signaling axis through CXCR4-PI4KIIIα interaction contributing to the growth of prostate cancer bone metastasis.

Analysis of the Tumor Immune Microenvironment (TIME) in Clear Cell Renal Cell Carcinoma (ccRCC) Reveals an M0 Macrophage-Enriched Subtype: An Exploration of Prognostic and Biological Characteristics of This Immune Phenotype

There is a need to optimize the treatment of clear cell renal cell carcinoma (ccRCC) patients at high recurrence risk after nephrectomy. We sought to elucidate the tumor immune microenvironment (TIME) of localized ccRCC and understand the prognostic and predictive characteristics of certain features. The discovery cohort was clinically localized patients in the TCGA-Kidney Renal Clear Cell Carcinoma (KIRC) project (n = 382). We identified an M0 macrophage-enriched cluster (n = 25) in the TCGA-KIRC cohort. This cluster's median progression-free survival (PFS) and overall survival (OS) were 40.4 and 45.3 months, respectively, but this was not reached in the others (p = 0.0003 and <0.0001, respectively). Gene set enrichment (GSEA) analysis revealed an enrichment of epithelial to mesenchymal transition and cell cycle progression genes within this cluster, and these patients also had a lower predicted response to immune checkpoint blockade (ICB) (4% vs. 20-34%). An M0-enriched cluster (n = 9) with shorter PFS (p = 0.0006) was also identified in the Clinical Proteomics Tumor Analysis Consortium (CPTAC) cohort (n = 94). Through this characterization of the TIME in ccRCC, a cluster of patients defined by enrichment in M0 macrophages was identified that demonstrated poor prognosis and lower predicted ICB response. Pending further validation, this signature can identify localized ccRCC patients at high risk of recurrence after nephrectomy and who may require therapeutic approaches beyond ICB monotherapy.

Current Landscape of Genomic Biomarkers in Clear Cell Renal Cell Carcinoma

CONTEXT

Dramatic gains in our understanding of the molecular biology of clear cell renal cell carcinoma (ccRCC) have created a foundation for clinical translation to improve patient care.

OBJECTIVE

To review and contextualize clinically impactful data surrounding genomic biomarkers in ccRCC.

EVIDENCE ACQUISITION

A systematic literature search was conducted focusing on genomic-based biomarkers with an emphasis on studies assessing clinical outcomes.

EVIDENCE SYNTHESIS

The advancement of tumor sequencing techniques has led to a rapid increase in the knowledge of the molecular underpinnings of ccRCC and with that the discovery of multiple candidate genomic biomarkers. These include somatic gene mutations such as VHL, PBRM1, SETD2, and BAP1; copy number variations; transcriptomic multigene signatures; and specific immune cell populations. Many of these biomarkers have been assessed for their association with survival and a smaller number as potential predictors of a response to systemic therapy. In this scoping review, we discuss many of these biomarkers in detail. Further studies are needed to continue to refine and validate these molecular tools for risk stratification, with the ultimate goal of improving clinical decision-making and patient outcomes.

CONCLUSIONS

While no tissue or blood-based biomarkers for ccRCC have been incorporated into routine clinical practice to date, the field continues to expand rapidly. There remains a critical need to develop and validate these tools in order to improve the care for patients with kidney cancer.

PATIENT SUMMARY

Genomic biomarkers have the potential to better predict outcome and select the most appropriate treatment for patients with kidney cancer; however, further research is needed before any of these currently developed biomarkers are adopted into clinical practice.

Phase II Trial of Olaparib in Patients With Metastatic Urothelial Cancer Harboring DNA Damage Response Gene Alterations

PURPOSE

Poly (ADP-ribose) polymerase (PARP) inhibitors have demonstrated clinical benefit for patients with solid tumors bearing germline or somatic alterations in DNA damage response (DDR) genes. Somatic alterations in DDR genes are common in advanced urothelial cancer, raising the possibility that PARP inhibition may confer therapeutic benefit in a molecularly selected subgroup of patients with metastatic urothelial cancer (mUC).

METHODS

This single-arm, open-label, multi-institutional, investigator-initiated phase II study evaluated the antitumor activity of olaparib 300 mg twice a day in participants with mUC harboring somatic DDR alterations. Patients had progressed despite previous platinum-based chemotherapy, or were cisplatin-ineligible, and harbored somatic alterations in at least one of a prespecified list of DDR genes. The primary end point was objective response rate; secondary end points were safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

Overall, 19 patients with mUC were enrolled and received olaparib; the trial closed early before slow accrual. The median age was 66 years (range, 45-82). Nine patients (47.4%) had received previous cisplatin chemotherapy. Ten patients (52.6%) had alterations in homologous recombination (HR) genes: eight patients (42.1%) had pathogenic BRCA2 mutations and two patients carried alterations in other HR genes. No patients achieved a partial response although six patients achieved stable disease lasting 2.13-16.1 months (median, 7.69). The median PFS was 1.9 months (range, 0.8-16.1), and the median OS was 9.5 months (range, 1.5-22.1).

CONCLUSION

Single-agent olaparib showed limited antitumor activity in patients with mUC and DDR alterations, which may be related to poorly characterized functional implications of particular DDR alterations and/or cross-resistance with platinum-based chemotherapy in a disease where such therapy represents standard first-line treatment.

Metastatic renal cell carcinoma to the pancreas and other sites-a multicenter retrospective study

Background

Metastatic renal cell carcinoma (mRCC) is a heterogenous disease with poor 5-year overall survival (OS) at 14%. Patients with mRCC to endocrine organs historically have prolonged OS. Pancreatic metastases are uncommon overall, with mRCC being the most common etiology of pancreatic metastases. In this study, we report the long-term outcomes of patients with mRCC to the pancreas in two separate cohorts.

Methods

We performed a multicenter, international retrospective cohort study of patients with mRCC to the pancreas at 15 academic centers. Cohort 1 included 91 patients with oligometastatic disease to the pancreas. Cohort 2 included 229 patients with multiples organ sites of metastases including the pancreas. The primary endpoint for Cohorts 1 and 2 was median OS from time of metastatic disease in the pancreas until death or last follow up.

Findings

In Cohort 1, the median OS (mOS) was 121 months with a median follow up time of 42 months. Patients who underwent surgical resection of oligometastatic disease had mOS of 100 months with a median follow-up time of 52.5 months. The mOS for patients treated with systemic therapy was not reached. In Cohort 2, the mOS was 90.77 months. Patients treated with first-line (1L) VEGFR therapy had mOS of 90.77 months; patients treated with IL immunotherapy (IO) had mOS of 92 months; patients on 1L combination VEGFR/IO had mOS of 74.9 months.

Interpretations

This is the largest retrospective cohort of mRCC involving the pancreas. We confirmed the previously reported long-term outcomes in patients with oligometastatic pancreas disease and demonstrated prolonged survival in patients with multiple RCC metastases that included the pancreas. In this retrospective study with heterogeneous population treated over 2 decades, mOS was similar when stratified by first-line therapy. Future research will be needed to determine whether mRCC patients with pancreatic metastases require a different initial treatment strategy.

Funding

Statistical analyses for this study were supported in part by the University of Colorado Cancer Center Support Grant from the NIH/NCI, P30CA046934-30.

Radiogenomic associations clear cell renal cell carcinoma: an exploratory study

OBJECTIVES

This study investigates how quantitative texture analysis can be used to non-invasively identify novel radiogenomic correlations with Clear Cell Renal Cell Carcinoma (ccRCC) biomarkers.

METHODS

The Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) open-source database was used to identify 190 sets of patient genomic data that had corresponding multiphase contrast-enhanced CT images in The Cancer Imaging Archive (TCIA-KIRC). 2824 radiomic features spanning fifteen texture families were extracted from CT images using a custom-built MATLAB software package. Robust radiomic features with strong inter-scanner reproducibility were selected. Random Forest (RF), AdaBoost, and Elastic Net machine learning (ML) algorithms evaluated the ability of the selected radiomic features to predict the presence of 12 clinically relevant molecular biomarkers identified from literature. ML analysis was repeated with cases stratified by stage (I/II vs. III/IV) and grade (1/2 vs. 3/4). 10-fold cross validation was used to evaluate model performance.

RESULTS

Before stratification by tumor grade and stage, radiomics predicted the presence of several biomarkers with weak discrimination (AUC 0.60-0.68). Once stratified, radiomics predicted KDM5C, SETD2, PBRM1, and mTOR mutation status with acceptable to excellent predictive discrimination (AUC ranges from 0.70 to 0.86).

CONCLUSIONS

Radiomic texture analysis can potentially identify a variety of clinically relevant biomarkers in patients with ccRCC and may have a prognostic implication.

Abstract PD13-05: PD13-05 Updated results of a Phase 1b study of gedatolisib plus palbociclib and endocrine therapy in women with hormone receptor positive advanced breast cancer: Subgroup analysis by PIK3CA mutation status

Background: Addition of PI3K/mTOR inhibitor after progression on CDK4/6 inhibitor (CDK4/6i) and endocrine therapy (ET) can potentially restore sensitivity to CDK4/6i and prevent adaptive activation of the PI3K/mTOR pathway. To evaluate this hypothesis, we conducted a Phase Ib study of gedatolisib (G), a dual inhibitor of PI3K/mTOR, palbociclib (P) a CDK4/6i, and ET (with letrozole [LET] or fulvestrant [FUL]) in women with hormone receptor positive (HR+)/HER2- advanced breast cancer (ABC). Manageable toxicity and preliminary antitumor activity were observed in 35 patients(pts) enrolled in the dose escalation portion of the study (Forero-Torres, ASCO 2018) and 103 pts enrolled in the expansion portion of the study (Layman, SABCS 2021). Here, we report updated efficacy and safety data and sub-group analysis by PIK3CA mutation status in the four expansion study arms with a March 3, 2022, data cut-off.

Methods: Pts with HR+/HER2- ABC were treated in four expansion arms: A) G+P+LET as first-line treatment, B) G+P+FUL as 2nd line treatment in pts without prior CDK4/6i; C & D) G+P+FUL as 2nd or 3rd line therapy in pts with prior CDK4/6i. P, LET, and FUL were administered at standard doses. G 180 mg was intravenously administered weekly in Arms A, B, and C and three weeks on/one week off in Arm D. The primary endpoint was investigator assessed objective response rate (ORR). Secondary endpoints included safety, duration of response and progression free survival (PFS).

Results: Of the 103 pts treated with G+P+ ET in the expansion arms (A-D), 100% had measurable disease at baseline, 71% (73/103) lacked PIK3CA mutations (wild type; WT), 27% (28/103) had PIK3CA-mutations (MT), 70% (72/103) had evidence of bone metastases, and 59% (61/103) had liver metastases. The most frequent grade 3 and 4 treatment related AEs (TRAE) with G+P+ET included neutropenia (63%), stomatitis (27%), rash (20%), fatigue (11%) and hyperglycemia (7%). Treatment discontinuation due to TRAEs was 6.5% in Arm A, 15.4% in Arm B, 9.4% in Arm C and 3.7% in Arm D. Efficacy data for each arm is presented in Table 1. Promising ORR and PFS were seen in all arms regardless of PIK3CA mutation status. In Arm D, ORR was 63% overall, 73% in PIK3CA-MT pts, and 60% in PIK3CA-WT pts. Median PFS in Arm D was 12.9 months with a median follow up of 29 months. 60% and 48% of pts in the PIK3CA-MT and PIK3CA-WT Arm D sub-groups, respectively, were progression free at 12 months.

Conclusions: These preliminary data demonstrate promising activity of G+P+ET combination in pts who were CDK4/6i-naïve and in those whose disease progressed on or after CDK4/6i therapy regardless of PIK3CA mutation status. Encouraging results in CDK4/6i treatment naïve patients warrant further evaluation of gedatolisib in combination with CDK4/6i treatment in the front-line setting. Arm D results provide a strong basis for the initiated Phase 3 study (VIKTORIA-1) in pts whose disease progressed on or after CDK4/6i therapy.

Table 1. Efficacy Data by Expansion Arms

Citation Format: Robert Wesolowski, Hope Rugo, Erica Stringer-Reasor, Hyo S. Han, Jennifer M. Specht, E. Claire Dees, Peter Kabos, Ulka Vaishampayan, Seth A. Wander, Janice Lu, Keerthi Gogineni, Alexander I. Spira, Anne F. Schott, Maysa Abu-Khalaf, Pratima Nayak, Brian F. Sullivan, Igor Gorbatchevsky, AND Rachel M. Layman. PD13-05 Updated results of a Phase 1b study of gedatolisib plus palbociclib and endocrine therapy in women with hormone receptor positive advanced breast cancer: Subgroup analysis by PIK3CA mutation status [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD13-05.

Abstract OT3-18-02: Clinical validation of “TriNetra™-Breast” test for breast cancer screening in a prospective, observational, case-cohort study

Introduction The Standard of Care for early detection of breast cancer in asymptomatic women is screening mammography, which has limitations such as radiation exposure and lower sensitivity to detect cancer in women with high breast density or invasive carcinomas. TriNetra™-Breast is a blood test for the detection of breast cancer associated circulating tumor cells in blood. Previously, this test has been used in a study for breast cancer detection in India, where it has shown a sensitivity of 92.5%. It has since been granted the United States Food and Drug Administration (USFDA) Breakthrough Device Designation, attesting its potential to provide for improved detection of breast cancer. This prospective, observational, case-cohort study will confirm the clinical performance characteristics of the technology in the US population. Patients and Methods The primary endpoint of this study will be to determine the sensitivity and specificity of the test for breast cancer screening, using mammography and histopathology confirmed diagnosis (when relevant) as the reference methods. Women ≥40 years, with no prior diagnosis of any cancer and undergoing screening mammography for breast cancer will be eligible for participation in this study. 700 women, representing the diverse ethnic US population, will be enrolled. Cohort A will have 500 women with BI-RADS score of 1, 2, or 3. Among these 500 participants, the age categories of 40-49 years, 50-74 years and &gt;74 years will have 100, 300 and 100 women respectively. Cohort B will have 100 women with suspicion of DCIS (without a suspicion of simultaneous invasive carcinoma) and 50 women each with BI-RADS score of 4 or 5. These study population numbers will ensure optimal representation of in-situ carcinoma, malignant and benign cases. Blood samples will be collected from the enrolled women for TriNetra™-Breast, within sixty (60) days of the screening mammogram. If biopsy is indicated, sample collection will be required prior to the procedure. The lab investigators will be blinded to the clinical information of all participants, including mammography and histopathology results, while the participants and clinical investigators will be blinded to the TriNetra™-Breast test results. The results of TriNetra™-Breast will be compared with the results of mammography and/or histopathology for performance estimation of the test. Study participants will be followed for clinical outcomes for maximum duration of 2 years.

Citation Format: Ulka Vaishampayan, Darshana Patil, Wahida Rahman, Stephanie Patterson, Emilija Mitrikeska, Joe Dib. Clinical validation of “TriNetra™-Breast” test for breast cancer screening in a prospective, observational, case-cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-18-02.

Adaptor proteins mediate CXCR4 and PI4KA crosstalk in prostate cancer cells and the significance of PI4KA in bone tumor growth

The chemokine receptor, CXCR4 signaling regulates cell growth, invasion, and metastasis to the bone-marrow niche in prostate cancer (PCa). Previously, we established that CXCR4 interacts with phosphatidylinositol 4-kinase IIIα (PI4KIIIα encoded by PI4KA) through its adaptor proteins and PI4KA overexpressed in the PCa metastasis. To further characterize how the CXCR4-PI4KIIIα axis promotes PCa metastasis, here we identify CXCR4 binds to PI4KIIIα adaptor proteins TTC7 and this interaction induce plasma membrane PI4P production in prostate cancer cells. Inhibiting PI4KIIIα or TTC7 reduces plasma membrane PI4P production, cellular invasion, and bone tumor growth. Using metastatic biopsy sequencing, we found PI4KA expression in tumors correlated with overall survival and contributes to immunosuppressive bone tumor microenvironment through preferentially enriching non-activated and immunosuppressive macrophage populations. Altogether we have characterized the chemokine signaling axis through CXCR4-PI4KIIIα interaction contributing to the growth of prostate cancer bone metastasis.

Feasibility of using CT radiomic signatures for predicting CD8-T cell infiltration and PD-L1 expression in renal cell carcinoma

Objectives

To identify computed tomography (CT)-based radiomic signatures of cluster of differentiation 8 (CD8)-T cell infiltration and programmed cell death ligand 1 (PD-L1) expression levels in patients with clear-cell renal cell carcinoma (ccRCC).

Methods

Seventy-eight patients with pathologically confirmed localized ccRCC, preoperative multiphase CT and tumor resection specimens were enrolled in this retrospective study. Regions of interest (ROI) of the ccRCC volume were manually segmented from the CT images and processed using a radiomics panel comprising of 1708 metrics. The extracted metrics were used as inputs to three machine learning classifiers: Random Forest, AdaBoost, and ElasticNet to create radiomic signatures for CD8-T cell infiltration and PD-L1 expression, respectively.

Results

Using a cut-off of 80 lymphocytes per high power field, 59 % were classified to CD8 highly infiltrated tumors and 41 % were CD8 non highly infiltrated tumors, respectively. An ElasticNet classifier discriminated between these two groups of CD8-T cells with an AUC of 0.68 (95 % CI, 0.55-0.80). In addition, based on tumor proportion score with a cut-off of > 1 % tumor cells expressing PD-L1, 76 % were PD-L1 positive and 24 % were PD-L1 negative. An Adaboost classifier discriminated between PD-L1 positive and PD-L1 negative tumors with an AUC of 0.8 95 % CI: (0.66, 0.95). 3D radiomics metrics of graylevel co-occurrence matrix (GLCM) and graylevel run-length matrix (GLRLM) metrics drove the performance for CD8-Tcell and PD-L1 classification, respectively.

Conclusions

CT-radiomic signatures can differentiate tumors with high CD8-T cell infiltration with moderate accuracy and positive PD-L1 expression with good accuracy in ccRCC.

Telaglenastat plus Everolimus in Advanced Renal Cell Carcinoma: A Randomized, Double-Blinded, Placebo-Controlled, Phase II ENTRATA Trial

PURPOSE

Glutaminase is a key enzyme, which supports elevated dependency of tumors on glutamine-dependent biosynthesis of metabolic intermediates. Dual targeting of glucose and glutamine metabolism by the mTOR inhibitor everolimus plus the oral glutaminase inhibitor telaglenastat showed preclinical synergistic anticancer effects, which translated to encouraging safety and efficacy findings in a phase I trial of 2L+ renal cell carcinoma (RCC). This study evaluated telaglenastat plus everolimus (TelaE) versus placebo plus everolimus (PboE) in patients with advanced/metastatic RCC (mRCC) in the 3L+ setting (NCT03163667).

PATIENTS AND METHODS

Eligible patients with mRCC, previously treated with at least two prior lines of therapy [including ≥1 VEGFR-targeted tyrosine kinase inhibitor (TKI)] were randomized 2:1 to receive E, plus Tela or Pbo, until disease progression or unacceptable toxicity. Primary endpoint was investigator-assessed progression-free survival (PFS; one-sided α <0.2).

RESULTS

Sixty-nine patients were randomized (46 TelaE, 23 PboE). Patients had a median three prior lines of therapy, including TKIs (100%) and checkpoint inhibitors (88%). At median follow-up of 7.5 months, median PFS was 3.8 months for TelaE versus 1.9 months for PboE [HR, 0.64; 95% confidence interval (CI), 0.34-1.20; one-sided P = 0.079]. One TelaE patient had a partial response and 26 had stable disease (SD). Eleven patients on PboE had SD. Treatment-emergent adverse events included fatigue, anemia, cough, dyspnea, elevated serum creatinine, and diarrhea; grade 3 to 4 events occurred in 74% TelaE patients versus 61% PboE.

CONCLUSIONS

TelaE was well tolerated and improved PFS versus PboE in patients with mRCC previously treated with TKIs and checkpoint inhibitors.

Abstract 5469: Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer

The switch/sucrose non-fermentable (SWI/SNF) complex plays a crucial role in chromatin remodeling and is recurrently altered in over 20% of human cancers. Here, we developed a proteolysis targeting chimera (PROTAC) degrader of ATPase subunits of the SWI/SNF complex, SMARCA2 and SMARCA4. Intriguingly, we found androgen receptor (AR)/forkhead box A1 (FOXA1)-positive prostate cancer to be exquisitely sensitive to dual SMARCA2 and SMARCA4 degradation relative to benign prostate as well as other cancer cell lines, including those with inactivating SMARCA4 mutations. Mechanistically, SWI/SNF inhibition rapidly compacts the cis-regulatory elements that are bound and activated by transcription factors that drive cancer proliferation, namely AR, FOXA1, ERG, and MYC. This ensues in chromatin untethering of these oncogenic drivers, chemical decommissioning of their core enhancer circuitry, and attenuation of downstream gene programs. Furthermore, we found SWI/SNF inhibition to disrupt super-enhancer and promoter DNA looping interactions that wire supra-physiologic expression of the AR, FOXA1, and MYC oncogenes, thereby tempering their expression in cancer cells. Monotherapy with the SMARCA2/4 degrader induced potent inhibition of tumor growth in cell line-derived xenograft models of prostate cancer and remarkably synergized with AR antagonists, inducing disease remission in models of castration-resistant prostate cancer. We also found the combinatorial treatment to significantly inhibit the growth of enzalutamide resistant disease using in vitro as well as patient-derived xenograft models. Notably, no major toxicities were seen in mice upon prolonged treatment with the SMARCA2/4 degrader, including no indications of thrombocytopenia, gastrointestinal goblet cell depletion, or germ cell degeneration. Taken together, these results suggest that impeding enhancer accessibility through SWI/SNF ATPase inactivation represents a novel therapeutic approach in enhancer addicted human cancers.

Citation Format: Lanbo Xiao, Abhijit Parolia, Yuanyuan Qiao, Pushpinder Bawa Pushpinder, Sanjana Eyunni, Rahul Mannan, Sandra E. Carson, Yu Chang, Xiaoju Wang, Yuping Zhang, Josh Vo, Steven Kregel, Stephanie A. Simko, Andrew D. Delekta, Mustapha Jaber, Heng Zheng, Ingrid Apel, Lisa McMurry, Fengyun Su, Rui Wang, Sylvia Wang, Sanjita Sasmal, Leena K. Satyam, Subhendu Mukherjee, Chandrasekhar AbbinenI, Kiran Aithal, Mital S. Bhakta, Jay Ghurye, Xuhong Cao, Nora M. Navone, Alexey Nesvizhskii, Rohit Mehra, Ulka Vaishampayan, Marco Blanchette, Yuzhuo Wang, Susanta Samajdar, Murali Ramachandra, Arul M. Chinnaiyan. Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer [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 5469.

Predictive biomarkers for survival benefit with ramucirumab in urothelial cancer in the RANGE trial

The RANGE study (NCT02426125) evaluated ramucirumab (an anti-VEGFR2 monoclonal antibody) in patients with platinum-refractory advanced urothelial carcinoma (UC). Here, we use programmed cell death-ligand 1 (PD-L1) immunohistochemistry (IHC) and transcriptome analysis to evaluate the association of immune and angiogenesis pathways, and molecular subtypes, with overall survival (OS) in UC. Higher PD-L1 IHC and immune pathway scores, but not angiogenesis scores, are associated with greater ramucirumab OS benefit. Additionally, Basal subtypes, which have higher PD-L1 IHC and immune/angiogenesis pathway scores, show greater ramucirumab OS benefit compared to Luminal subtypes, which have relatively lower scores. Multivariable analysis suggests patients from East Asia as having lower immune/angiogenesis signature scores, which correlates with decreased ramucirumab OS benefit. Our data highlight the utility of multiple biomarkers including PD-L1, molecular subtype, and immune phenotype in identifying patients with UC who might derive the greatest benefit from treatment with ramucirumab.

Pathogenic ATM and BAP1 germline mutations in a case of early-onset, familial sarcomatoid renal cancer

Metastatic renal cell carcinoma (RCC) remains an incurable malignancy, despite recent advances in systemic therapies. Genetic syndromes associated with kidney cancer account for only 5%-8% of all diagnosed kidney malignancies, and genetic predispositions to kidney cancer predisposition are still being studied. Genomic testing for kidney cancer is useful for disease molecular subtyping but provides minimal therapeutic information. Understanding how aberrations drive RCC development and how their contextual influences, such as chromosome loss, genome instability, and DNA methylation changes, may alter therapeutic response is of importance. We report the case of a 36-yr-old female with aggressive, metastatic RCC and a significant family history of cancer, including RCC. This patient harbors a novel, pathogenic, germline ATM mutation along with a rare germline variant of unknown significance in the BAP1 gene. In addition, somatic loss of heterozygosity (LOH) in BAP1 and ATM genes, somatic mutation and LOH in the VHL gene, copy losses in Chromosomes 9p and 14, and genome instability are also noted in the tumor, potentially dictating this patient's aggressive clinical course. Further investigation is warranted to evaluate the association of ATM and BAP1 germline mutations with increased risk of RCC and if these mutations should lead to enhanced and early screening.

Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer

The switch/sucrose non-fermentable (SWI/SNF) complex has a crucial role in chromatin remodelling1 and is altered in over 20% of cancers2,3. Here we developed a proteolysis-targeting chimera (PROTAC) degrader of the SWI/SNF ATPase subunits, SMARCA2 and SMARCA4, called AU-15330. Androgen receptor (AR)+ forkhead box A1 (FOXA1)+ prostate cancer cells are exquisitely sensitive to dual SMARCA2 and SMARCA4 degradation relative to normal and other cancer cell lines. SWI/SNF ATPase degradation rapidly compacts cis-regulatory elements bound by transcription factors that drive prostate cancer cell proliferation, namely AR, FOXA1, ERG and MYC, which dislodges them from chromatin, disables their core enhancer circuitry, and abolishes the downstream oncogenic gene programs. SWI/SNF ATPase degradation also disrupts super-enhancer and promoter looping interactions that wire supra-physiologic expression of the AR, FOXA1 and MYC oncogenes themselves. AU-15330 induces potent inhibition of tumour growth in xenograft models of prostate cancer and synergizes with the AR antagonist enzalutamide, even inducing disease remission in castration-resistant prostate cancer (CRPC) models without toxicity. Thus, impeding SWI/SNF-mediated enhancer accessibility represents a promising therapeutic approach for enhancer-addicted cancers.

“PROBE”ing the Role of Cytoreductive Nephrectomy in Advanced Renal Cancer

The Southwest Oncology Group (SWOG)1931 trial, also known as PROBE (ClinicalTrials.gov Identifier: NCT04510597) is a phase III study evaluating the role of cytoreductive nephrectomy (CN) in metastatic renal cell cancer (RCC). Kidney cancer presenting with synchronous metastases has demonstrated shorter survival outcome compared to the patients relapsing with metastases after nephrectomy. Previously, CN has been associated with survival improvement when interferon-based systemic therapy was used. In the setting of antivascular therapy sunitinib, a prospective randomized clinical trial demonstrated no benefit of CN. Immune checkpoint-based combination therapy has now become the standard-of-care in the frontline setting for RCC. The role of nephrectomy or primary resection has not been evaluated in the setting of immune checkpoint-based systemic therapy. The sequence and optimal timing of nephrectomy is also not established. The PROBE study design attempts to answer the question whether CN has an impact on overall survival outcomes in RCC within the context of immune checkpoint-based combination regimens. The study requires starting with systemic therapy; any one of the FDA approved immunotherapy-based regimens at the time the study was activated are permitted. The disease status and response are evaluated at 9–12 weeks of therapy and then consented patients are randomized 1:1 to receive CN or to continue systemic therapy. The patients who have rapid disease progression are considered ineligible for randomization as they need a switch in systemic therapy. Both groups should continue systemic therapy as long as they are tolerating the treatment and continuing to derive clinical benefit. Quality-of-life, tumor genomic testing, microbiome, radiomics and circulating tumor DNA assessments as predictive biomarkers are planned as study correlatives. The study hypothesis is that CN will improved OS in synchronous metastatic RCC when surgery is performed after starting systemic immune checkpoint-based combination therapy. A potential mechanism leading to improved survival is the broader antigen spread and higher neoantigen load enabled by the primary tumor enhancing the efficacy of the immune therapy. CN after initial systemic therapy would help select the patient subset most likely to benefit and will potentially enable eradication of immune resistant clones within the primary tumor.

First-in-human phase 1 study of the anti-TIGIT antibody vibostolimab as monotherapy or with pembrolizumab for advanced solid tumors, including non-small cell lung cancer

BACKGROUND

In this first-in-human phase 1 study, we investigated the safety and efficacy of the anti-TIGIT antibody vibostolimab as monotherapy or in combination with pembrolizumab.

METHODS

Part A enrolled patients with advanced solid tumors and part B enrolled patients with non-small cell lung cancer (NSCLC). Patients received vibostolimab 2.1-700 mg alone or with pembrolizumab 200 mg in part A and vibostolimab 200 mg alone or with pembrolizumab 200 mg in part B. Primary end points were safety and tolerability. Secondary end points included pharmacokinetics and objective response rate (ORR) per RECIST v1.1.

RESULTS

Part A enrolled 76 patients (monotherapy, 34; combination therapy, 42). No dose-limiting toxicities were reported. Across doses, 56% of patients receiving monotherapy and 62% receiving combination therapy had treatment-related adverse events (TRAEs); grade 3-4 TRAEs occurred in 9% and 17% of patients, respectively. The most common TRAEs were fatigue (15%) and pruritus (15%) with monotherapy and pruritus (17%) and rash (14%) with combination therapy. Confirmed ORR was 0% with monotherapy and 7% with combination therapy. In part B, 39 patients had anti-PD-1/PD-L1-naïve NSCLC (all received combination therapy) and 67 had anti-PD-1/PD-L1-refractory NSCLC (monotherapy, 34; combination therapy, 33). In patients with anti-PD-1/PD-L1-naive NSCLC: 85% had TRAEs-the most common were pruritus (38%) and hypoalbuminemia (31%); confirmed ORR was 26%, with responses occurring in both PD-L1-positive and PD-L1-negative tumors. In patients with anti-PD-1/PD-L1‒refractory NSCLC: 56% receiving monotherapy and 70% receiving combination therapy had TRAEs-the most common were rash and fatigue (21% each) with monotherapy and pruritus (36%) and fatigue (24%) with combination therapy; confirmed ORR was 3% with monotherapy and 3% with combination therapy.

CONCLUSION

Vibostolimab plus pembrolizumab was well tolerated and demonstrated antitumor activity in patients with advanced solid tumors, including patients with advanced NSCLC.

476 First-in-human phase 1/2 study of the first-in-class SUMO-activating enzyme inhibitor TAK-981 in patients with advanced or metastatic solid tumors or relapsed/refractory lymphoma: phase 1 results

Background

SUMOylation is a post-translational modification that serves as an important modulator of immune responses via its role in constraining the type I interferon (IFN-1) response. TAK-981 is a small molecule that inhibits SUMOylation and increases IFN-1-dependent innate immune responses with the potential to enhance adaptive immunity. Here, we report dose-escalation data from a TAK-981 Phase 1/2 clinical study (NCT03648372), the first clinical data for a SUMOylation inhibitor.

Methods

Adults with advanced/metastatic solid tumors or relapsed/refractory lymphomas received TAK-981 IV twice-weekly (BIW; days 1, 4, 8, 11) or once-weekly (QW; days 1, 8) in 21-day cycles. Dose escalation was guided by a Bayesian Logistic Regression Model (BLRM) with overdose control, plus available pharmacokinetic/pharmacodynamic (PK/PD) data. Phase 1 objectives were to determine TAK-981 safety/tolerability and establish the recommended phase 2 dose (RP2D).

Results

Seventy-six patients received TAK-981 at 10 dose levels (3–40 mg BIW; 60–120 mg QW/BIW). Median age was 61 years (range, 38–79); 42 (55.3%) patients were female. Four dose-limiting toxicities were seen in 62 evaluable patients (transient grade 3 ALT/AST elevation, 60 mg BIW; grade 3 pneumonitis, 90 mg BIW; grade 3 stomatitis and grade 3 cognitive disturbance, 120 mg BIW). Per BLRM, 120 mg BIW was determined to be the maximum tolerated dose. At data cut-off, median treatment duration was 2 cycles (range, 1–12); 13 (17.1%) patients were ongoing. table 1 summarizes TAK-981 safety. The most common (≥20%) treatment-emergent adverse events (TEAEs) were fatigue (42.1%), nausea (39.5%), headache (31.6%), diarrhea (28.9%), pyrexia (27.6%), vomiting (23.7%), decreased appetite (22.4%). Common (≥5%) grade ≥3 TEAEs were hypokalemia (9.2%), anemia (7.9%), lymphocyte count decreased (6.6%), abdominal pain (5.3%). Grade 2 cytokine release syndrome was reported in 4 (5.2%) patients; symptoms resolved within 12–24 hours with supportive oxygen and/or IV fluids. One partial response was observed at 40 mg TAK-981 BIW in a patient with relapsed/refractory HER2-negative, hormone receptor-positive breast cancer. TAK-981 exhibited linear PK, with approximately dose-proportional exposure and a mean terminal half-life of 3.8–10.8 hours at ≥60 mg. Evidence of dose-dependent target engagement (figure 1), and PD (figures 2–4) in blood were observed. The single-agent TAK-981 RP2D was 90 mg BIW.

Abstract 476 Table 1

Summary of TAK-981 safety profile

Abstract 476 Figure 1

PD in patients receiving TAK-981 on the BIW schedule: target engagement.

Blood samples were collected on Cycle 1 Day 1 pre-dose and at multiple timepoints after TAK-981 administration. Target engagement in T cells was detected by flow cytometry with an antibody recognizing the TAK-981-SUMO adduct formed during the inhibition of the SUMO-activating enzyme by TAK-981; Cycle 1 Day 1 signal increased at 1 hour post-end-of-infusion compared to the background level observed pre-dose.

Abstract 476 Figure 2

PD in patients receiving TAK-981 on the BIW schedule: SUMOylation.

SUMOylation in T cells, detected by flow cytometry with an antibody recognizing SUMO2/3, decreased at 1 hour post-end-of-infusion on Cycle 1 Day 1 compared to pre-dose, indicating that fewer SUMO2/3 chains are formed when the SUMO-activating enzyme is inhibited.

Abstract 476 Figure 3

PD in patients receiving TAK-981 on the BIW schedule: upregulation of CXCL10 expression.

Upregulation of mRNA levels of CXCL10, an IFN-I-regulated gene, in peripheral blood. Gene expression was measured using Nanostring nCounter at Cycle 1 Day 1 pre-dose and at several timepoints post-dose. Data for maximum increase at 8 or 24 hours, relative to pre-dose, is shown.

Abstract 476 Figure 4

PD in patients receiving TAK-981 on the BIW schedule: NK cell activation.

NK cell activation in peripheral blood measured by flow cytometry. Percentage of CD69-positive NK cells at Cycle 1 Day 1 pre-dose and at 24 hours post-end-of-infusion is shown by patient for each dose.

Conclusions

The data generated in this study support continued TAK-981 development for treatment of solid tumors and lymphoma. The Phase 2 study expansion is ongoing in patients with advanced/metastatic non-small-cell lung, cervical, and colorectal cancer, and in relapsed/refractory non-Hodgkin lymphoma.

Trial Registration

Clinical Trial identification:

ClinicalTrials.gov. Identifier: NCT03648372

Ethics Approval

The study was approved by the Institutional Review Board or Institutional Ethics Committee of all participating institutions

524 A phase 2, multi-arm study of anti-CD47 antibody, magrolimab, in combination with docetaxel in patients with locally advanced or metastatic solid tumors

Background

Patients with solid tumors who progress on standard chemotherapy and/or immune checkpoint inhibitors, have limited efficacy with existing standard of care chemotherapy options (objective response rates [ORR] ~10%). These patients have a significant unmet medical need. Novel agents that can safely enhance treatment efficacy are urgently needed. Magrolimab is a first-in-class monoclonal antibody that blocks the macrophage inhibitory immune checkpoint CD47, a ”do not eat me” signal overexpressed on tumor cells. Pre-clinical studies provide compelling evidence that magrolimab triggers phagocytosis and eliminates cancer cells from human solid tumors and hematologic malignancies. Magrolimab has demonstrated clinical activity in both hematologic and solid tumor malignancies. Chemotherapeutic agents, including taxanes, enhance prophagocytic signals on tumor cells, leading to synergistic antitumor activity when combined with magrolimab. This study (NCT04827576) is evaluating the safety, tolerability, and efficacy of magrolimab with docetaxel in relapsed/refractory (R/R) metastatic non-small cell lung cancer (mNSCLC), urothelial cancer (mUC), and small cell lung cancer (mSCLC).

Methods

This phase 2, open-label, multi-arm study consists of a safety run-in cohort and a phase 2 cohort. Eligible patients are ≥18 years old with chemotherapy and/or immunotherapy refractory mNSCLC, mSCLC, or mUC. Magrolimab is administered intravenously (IV) with an initial 1 mg/kg priming dose to mitigate on target anemia, followed by 30 mg/kg dose during cycle 1 (cycles are 21 days) in the safety run-in to identify any dose-limiting toxicities (DLTs) and determine a recommended phase 2 dose (RP2D). De-escalation may occur for DLTs per protocol. In phase 2, following the priming dose on day 1, magrolimab RP2D will be administered on days 8 and 15 of cycle 1; days 1, 8, 15 of cycle 2; and day 1 for cycles 3 and beyond. Docetaxel 75 mg/m2 (IV) is administered on day 1 of each cycle for all study participants. Patients may continue treatment until unacceptable toxicity, progressive disease by RECIST 1.1, or patient/investigator choice to discontinue. The primary endpoints are incidence of adverse events (safety and phase 2 cohorts) and ORR (phase 2). Secondary endpoints (phase 2) are progression-free survival, duration of response, and overall survival. Exploratory endpoints are to evaluate the pharmacodynamic, mechanism of action, and/or therapeutic response of biomarkers in blood and tumor biopsy samples and to explore biomarkers that may predict response to therapy. Planned enrollment is approximately 116 patients, and recruitment is ongoing.

Acknowledgements

Funding provided by Gilead Sciences, Inc.

Trial Registration

NCT04827576

Ethics Approval

The study protocol was approved by an institutional review board before enrollment of patients.

Consent

Patients provided written informed consent based on Declaration of Helsinki principles.

Infigratinib in Early-Line and Salvage Therapy for FGFR3-Altered Metastatic Urothelial Carcinoma

The optimal sequencing of systemic treatments for metastatic urothelial cancer (mUC) is unknown. We assessed the efficacy of infigratinib, a fibroblast growth factor receptor (FGFR) 1 to 3 inhibitor, in 67 patients with FGFR3-altered mUC by line of therapy. Objective response rates were 31% (early-line setting) and 24% (≥2nd-line setting). Infigratinib has notable activity in mUC regardless of line of therapy.

Phase Ia dose escalation study of OBP-801, a cyclic depsipeptide class I histone deacetylase inhibitor, in patients with advanced solid tumors

Background Dysregulation of histone deacetylases (HDACs) is common in cancer and is critical to the development and progression of the majority of tumors. This first-in-human Phase Ia study assessed the safety, efficacy, and pharmacokinetics (PK) of OBP-801, a cyclic depsipeptide class I HDAC inhibitor. Methods Adult patients with advanced solid tumors were treated in 3 dose cohorts (1.0 mg/m², 2.0 mg/m² or 2.8 mg/m²) of OBP-801 that was administered via intravenous infusion weekly. Initially, an accelerated titration design was used that was followed by a 3 + 3 dose escalation strategy. Primary objective was assessment of safety. Secondary objectives included determination of PK and objective response rate. Results Seventeen patients were enrolled, of which 8 patients were evaluable for efficacy. Drug-related ≥ Grade 3 treatment-emergent adverse events included abdominal pain, anemia, fatigue, gamma glutamyl-transferase increase, hypertriglyceridemia and vomiting. No dose-limiting toxicity was observed in the 1.0 mg/m² cohort. The PK data showed that OBP-801 and its active metabolite OBP-801-SH exposure increased proportionally and more than proportionally, respectively. No accumulation of either agent was noticed after repeat administration. Best response was stable disease (37.5%), with one patient each in the three cohorts. Conclusion Further investigations of the OBP-801 1.0 mg/m² dose will be needed to better understand the efficacy of the agent, either alone or in combination. Trial registration: NCT02414516 (ClinicalTrials.gov) registered on April 10, 2015.

Effect of Cisplatin and Gemcitabine With or Without Berzosertib in Patients With Advanced Urothelial Carcinoma: A Phase 2 Randomized Clinical Trial

IMPORTANCE

Preclinical studies suggest that inhibition of single-stranded DNA repair by ataxia telangiectasia and Rad3 (ATR) may enhance the cytotoxicity of cisplatin, gemcitabine, and other chemotherapeutic agents. Cisplatin with gemcitabine remains the standard up-front therapy for treatment in patients with metastatic urothelial cancer.

OBJECTIVE

To determine whether the use of the selective ATR inhibitor, berzosertib, could augment the activity of cisplatin with gemcitabine.

DESIGN, SETTING, AND PARTICIPANTS

In a phase 2 randomized clinical trial, 87 patients across 23 centers in the National Cancer Institute Experimental Therapeutics Clinical Trials Network were randomized to receive either cisplatin with gemcitabine alone (control arm) or cisplatin with gemcitabine plus berzosertib (experimental arm). Key eligibility criteria included confirmed metastatic urothelial cancer, no prior cytotoxic therapy for metastatic disease, 12 months or more since perioperative therapy, and eligibility for cisplatin receipt based on standard criteria. The study was conducted from January 27, 2017, to December 15, 2020.

INTERVENTIONS

In the control arm, cisplatin, 70 mg/m2, was given on day 1 and gemcitabine, 1000 mg/m2, was given on days 1 and 8 of a 21-day cycle. In the experimental arm, cisplatin, 60 mg/m2, was given on day 1; gemcitabine, 875 mg/m2, on days 1 and 8; and berzosertib, 90 mg/m2, on days 2 and 9 of a 21-day cycle.

MAIN OUTCOMES AND MEASURES

The primary end point of the study was progression-free survival. The analysis was on all patients who started therapy.

RESULTS

Of the total of 87 patients randomized, 41 patients received cisplatin with gemcitabine alone and 46 received cisplatin with gemcitabine plus berzosertib. Median age was 67 (range, 32-84) years, and 68 patients (78%) were men. Median progression-free survival was 8.0 months for both arms (Bajorin risk-adjusted hazard ratio, 1.22; 95% CI, 0.72-2.08). Median overall survival was shorter with cisplatin with gemcitabine plus berzosertib compared with cisplatin with gemcitabine alone (14.4 vs 19.8 months; Bajorin risk-adjusted hazard ratio, 1.42; 95% CI, 0.76-2.68). Higher rates of grade 3 vs grade 4 thrombocytopenia (59% vs 39%) and neutropenia (37% vs 27%) were observed with cisplatin with gemcitabine and berzosertib compared with cisplatin with gemcitabine alone; consequently, more dose reductions were needed in the experimental arm. Patients in the experimental arm received a median cisplatin dose of 250 mg/m2, which was significantly lower than the median dose of 370 mg/m2 in the control arm (P < .001).

CONCLUSIONS AND RELEVANCE

The addition of berzosertib to cisplatin with gemcitabine did not prolong progression-free survival relative to cisplatin with gemcitabine alone in patients with metastatic urothelial cancer, and a trend toward inferior survival was observed with this combination. Berzosertib plus cisplatin with gemcitabine was associated with significantly higher hematologic toxicities despite attenuated dosing of cisplatin with gemcitabine.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02567409.

Cabozantinib in Combination With Atezolizumab for Advanced Renal Cell Carcinoma: Results From the COSMIC-021 Study

[Figure: see text].

Genetic risk assessment for hereditary renal cell carcinoma: Clinical consensus statement

BACKGROUND

Although renal cell carcinoma (RCC) is believed to have a strong hereditary component, there is a paucity of published guidelines for genetic risk assessment. A panel of experts was convened to gauge current opinions.

METHODS

A North American multidisciplinary panel with expertise in hereditary RCC, including urologists, medical oncologists, clinical geneticists, genetic counselors, and patient advocates, was convened. Before the summit, a modified Delphi methodology was used to generate, review, and curate a set of consensus questions regarding RCC genetic risk assessment. Uniform consensus was defined as ≥85% agreement on particular questions.

RESULTS

Thirty-three panelists, including urologists (n = 13), medical oncologists (n = 12), genetic counselors and clinical geneticists (n = 6), and patient advocates (n = 2), reviewed 53 curated consensus questions. Uniform consensus was achieved on 30 statements in specific areas that addressed for whom, what, when, and how genetic testing should be performed. Topics of consensus included the family history criteria, which should trigger further assessment, the need for risk assessment in those with bilateral or multifocal disease and/or specific histology, the utility of multigene panel testing, and acceptance of clinician-based counseling and testing by those who have experience with hereditary RCC.

CONCLUSIONS

In the first ever consensus panel on RCC genetic risk assessment, 30 consensus statements were reached. Areas that require further research and discussion were also identified, with a second future meeting planned. This consensus statement may provide further guidance for clinicians when considering RCC genetic risk assessment.

LAY SUMMARY

The contribution of germline genetics to the development of renal cell carcinoma (RCC) has long been recognized. However, there is a paucity of guidelines to define how and when genetic risk assessment should be performed for patients with known or suspected hereditary RCC. Without guidelines, clinicians struggle to define who requires further evaluation, when risk assessment or testing should be done, which genes should be considered, and how counseling and/or testing should be performed. To this end, a multidisciplinary panel of national experts was convened to gauge current opinion on genetic risk assessment in RCC and to enumerate a set of recommendations to guide clinicians when evaluating individuals with suspected hereditary kidney cancer.

A Prospective Multicenter Evaluation of Initial Treatment Choice in Metastatic Renal Cell Carcinoma Prior to the Immunotherapy Era: The MaRCC Registry Experience

INTRODUCTION

The Metastatic Renal Cell Carcinoma (MaRCC) Registry provides prospective data on real-world treatment patterns and outcomes in patients with metastatic renal cell carcinoma (mRCC).

METHODS AND MATERIALS

Patients with mRCC and no prior systemic therapy were enrolled at academic and community sites. End of study data collection was in March 2019. Outcomes included overall survival (OS). A survey of treating physicians assessed reasons for treatment initiations and discontinuations.

RESULTS

Overall, 376 patients with mRCC initiated first-line therapy; 171 (45.5%) received pazopanib, 75 (19.9%) sunitinib, and 74 (19.7%) participated in a clinical trial. Median (95% confidence interval) OS was longest in the clinical trial group (50.3 [35.8-not reached] months) versus pazopanib (39.0 [29.7-50.9] months) and sunitinib 26.2 [19.9-61.5] months). Non-clear cell RCC (21.5% of patients) was associated with worse median OS than clear cell RCC (18.0 vs. 47.3 months). Differences in baseline characteristics, treatment starting dose, and relative dose exposure among treatment groups suggest selection bias. Survey results revealed a de-emphasis on quality of life, toxicity, and patient preference compared with efficacy in treatment selection.

CONCLUSION

The MaRCC Registry gives insights into real-world first-line treatment selection, outcomes, and physician rationale regarding initial treatment selection prior to the immunotherapy era. Differences in outcomes between clinical trial and off-study patients reflect the difficulty in translating trial results to real-world patients, and emphasize the need to broaden clinical trial eligibility. Physician emphasis on efficacy over quality of life and toxicity suggests more data and education are needed regarding these endpoints.

Phase 1 study of single-agent WNT974, a first-in-class Porcupine inhibitor, in patients with advanced solid tumours

BACKGROUND

This Phase 1 study assessed the safety and efficacy of the Porcupine inhibitor, WNT974, in patients with advanced solid tumours.

METHODS

Patients (n = 94) received oral WNT974 at doses of 5-30 mg once-daily, plus additional dosing schedules.

RESULTS

The maximum tolerated dose was not established; the recommended dose for expansion was 10 mg once-daily. Dysgeusia was the most common adverse event (50% of patients), likely resulting from on-target Wnt pathway inhibition. No responses were seen by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1; 16% of patients had stable disease (median duration 19.9 weeks). AXIN2 expression by RT-PCR was reduced in 94% of paired skin biopsies (n = 52) and 74% of paired tumour biopsies (n = 35), confirming inhibition of the Wnt pathway. In an exploratory analysis, an inverse association was observed between AXIN2 change and immune signature change in paired tumour samples (n = 8).

CONCLUSIONS

Single-agent WNT974 treatment was generally well tolerated. Biomarker analyses suggest that WNT974 may influence immune cell recruitment to tumours, and may enhance checkpoint inhibitor activity.

CLINICAL TRIAL REGISTRATION

NCT01351103.

Active surveillance of metastatic renal cell carcinoma: Results from a prospective observational study (MaRCC)

BACKGROUND

Systemic therapy (ST) can be deferred in patients who have metastatic renal cell carcinoma (mRCC) and slow-growing metastases. Currently, this subset of patients managed with active surveillance (AS) is not well described in the literature.

METHODS

This was a prospective observational study of patients with mRCC across 46 US community and academic centers. The objective was to describe baseline characteristics and demographics of patients with mRCC initially managed by AS, reasons for AS, and patient outcomes. Descriptive statistics were used to characterize demographics, baseline characteristics, and patient-related outcomes. Wilcoxon 2-sample rank-sum tests and χ² tests were used to assess differences between ST and AS cohorts in continuous and categorical variables, respectively. Kaplan-Meier survival curves were used to assess survival.

RESULTS

Of 504 patients, mRCC was initially managed by AS (n = 143) or ST (n = 305); 56 patients were excluded from the analysis. Disease was present in 69% of patients who received AS, whereas the remaining 31% had no evidence of disease. At data cutoff, 72 of 143 patients (50%) in the AS cohort had not received ST. The median overall survival was not reached (95% CI, 122 months to not estimable) in patients who received AS versus 30 months (95% CI, 25-44 months) in those who received ST. Quality of life at baseline was significantly better in patients who were managed with AS versus ST.

CONCLUSIONS

AS occurs frequently (32%) in real-world clinical practice and appears to be a safe and appropriate alternative to immediate ST in selected patients.

A Phase Ib Study of Atezolizumab with Radium-223 Dichloride in Men with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

Men with metastatic castration-resistant prostate cancer (mCRPC) have limited treatment options after progressing on hormonal therapy and chemotherapy. Here, we evaluate the safety and efficacy of atezolizumab (anti-PD-L1) + radium-223 dichloride (radium-223) in men with mCRPC.

PATIENTS AND METHODS

This phase Ib study evaluated atezolizumab + radium-223 in men with mCRPC and bone and lymph node and/or visceral metastases that progressed after androgen pathway inhibitor treatment. Following safety assessment of concurrent dosing, 45 men were randomized 1:1:1 to concurrent or one of two staggered dosing schedules with either agent introduced one cycle before the other. This was followed by a safety-efficacy expansion cohort (randomized 1:1:1). The primary endpoints were safety and objective response rate (ORR) by RECIST 1.1. Secondary endpoints included radiographic progression-free survival (rPFS), PSA responses, and overall survival (OS).

RESULTS

As of October 4, 2019, 44 of 45 men were evaluable. All 44 had ≥1 all-cause adverse event (AE); 23 (52.3%) had a grade 3/4 AE. Fifteen (34.1%) grade 3/4 and 3 (6.8%) grade 5 AEs were related to atezolizumab; none were related to radium-223. Confirmed ORR was 6.8% [95% confidence interval (CI), 1.4-18.7], median rPFS was 3.0 months (95% CI, 2.8-4.6), median PSA progression was 3.0 months (95% CI, 2.8-3.3), and median OS was 16.3 months (95% CI, 10.9-22.3).

CONCLUSIONS

This phase Ib study demonstrated that atezolizumab + radium-223, regardless of administration schedule, had greater toxicity than either drug alone, with no clear evidence of additional clinical benefit for patients with mCRPC and bone and lymph node and/or visceral metastases.

A comparison of sunitinib with cabozantinib, crizotinib, and savolitinib for treatment of advanced papillary renal cell carcinoma: a randomised, open-label, phase 2 trial

BACKGROUND

MET (also known as hepatocyte growth factor receptor) signalling is a key driver of papillary renal cell carcinoma (PRCC). Given that no optimal therapy for metastatic PRCC exists, we aimed to compare an existing standard of care, sunitinib, with the MET kinase inhibitors cabozantinib, crizotinib, and savolitinib for treatment of patients with PRCC.

METHODS

We did a randomised, open-label, phase 2 trial done in 65 centres in the USA and Canada. Eligible patients were aged 18 years or older with metastatic PRCC who had received up to one previous therapy (excluding vascular endothelial growth factor-directed and MET-directed agents). Patients were randomly assigned to receive sunitinib, cabozantinib, crizotinib, or savolitinib, with stratification by receipt of previous therapy and PRCC subtype. All drug doses were administered orally: sunitinib 50 mg, 4 weeks on and 2 weeks off (dose reductions to 37·5 mg and 25 mg allowed); cabozantinib 60 mg daily (reductions to 40 mg and 20 mg allowed); crizotinib 250 mg twice daily (reductions to 200 mg twice daily and 250 mg once daily allowed); and savolitinib 600 mg daily (reductions to 400 mg and 200 mg allowed). Progression-free survival (PFS) was the primary endpoint. Analyses were done in an intention-to-treat population, with patients who did not receive protocol therapy excluded from safety analyses. This trial is registered with ClinicalTrials.gov, NCT02761057.

FINDINGS

Between April 5, 2016, and Dec 15, 2019, 152 patients were randomly assigned to one of four study groups. Five patients were identified as ineligible post-randomisation and were excluded from these analyses, resulting in 147 eligible patients. Assignment to the savolitinib (29 patients) and crizotinib (28 patients) groups was halted after a prespecified futility analysis; planned accrual was completed for both sunitinib (46 patients) and cabozantinib (44 patients) groups. PFS was longer in patients in the cabozantinib group (median 9·0 months, 95% CI 6-12) than in the sunitinib group (5·6 months, 3-7; hazard ratio for progression or death 0·60, 0·37-0·97, one-sided p=0·019). Response rate for cabozantinib was 23% versus 4% for sunitinib (two-sided p=0·010). Savolitinib and crizotinib did not improve PFS compared with sunitinib. Grade 3 or 4 adverse events occurred in 31 (69%) of 45 patients receiving sunitinib, 32 (74%) of 43 receiving cabozantinib, ten (37%) of 27 receiving crizotinib, and 11 (39%) of 28 receiving savolitinib; one grade 5 thromboembolic event was recorded in the cabozantinib group.

INTERPRETATION

Cabozantinib treatment resulted in significantly longer PFS compared with sunitinib in patients with metastatic PRCC.

FUNDING

National Institutes of Health and National Cancer Institute.

Long-term progression-free survival of patients with metastatic melanoma or renal cell carcinoma following high-dose interleukin-2

High-dose interleukin-2 (HD IL-2) was approved in the 1990s after demonstrating durable complete responses (CRs) in some patients with metastatic melanoma (mM) and metastatic renal cell carcinoma (mRCC). Patients who achieve this level of disease control have also demonstrated improved survival compared with patients who progress, but limited data are available describing the long-term course. The aim of this study was to better characterize long-term survival following successful HD IL-2 treatment in patients with no subsequent systemic therapy. Eleven HD IL-2 treatment centers identified patients with survival ≥5 years after HD IL-2, with no subsequent systemic therapy. Survival was evaluated from the date of IL-2 treatment to June 2017. Treatment courses consisted of 2 1-week cycles of HD IL-2. Patients were treated with HD IL-2 alone, or HD IL-2 followed by local therapy to achieve maximal response. 100 patients are reported: 54 patients with mM and 46 patients with mRCC. Progression-free survival (PFS) after HD IL-2 ranges from 5+ years to 30+ years, with a median follow-up of 10+ years. 27 mRCC and 32 mM are alive ≥10 years after IL-2. Thus, a small subset of patients with mM and mRCC achieve long-term PFS (≥5 years) after treatment with HD IL-2 as their only systemic therapy. The ability of HD IL-2 therapy to induce prolonged PFS should be a major consideration in studies of new immunotherapy combinations for mM and mRCC.

Axitinib plus pembrolizumab in patients with advanced renal-cell carcinoma: Long-term efficacy and safety from a phase Ib trial

BACKGROUND

Axitinib plus pembrolizumab showed superior overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) versus sunitinib in a randomised phase III trial in patients with advanced renal-cell carcinoma (RCC). We report long-term efficacy and safety of the axitinib/pembrolizumab from the phase I trial (NCT02133742), after 46-55 months from study initiation (data cut-off date, 23rd July 2019).

METHODS

Fifty-two treatment-naïve patients with advanced RCC were treated with oral axitinib 5 mg twice daily and intravenous pembrolizumab 2 mg/kg every 3 weeks. PFS, duration of response (DoR) and OS were summarised using the Kaplan-Meier method.

RESULTS

At a median follow-up of 42.7 months (95% confidence interval [CI]: 41.1-44.1), median OS was not reached; 38 (73.1%) patients were alive. The probability of being alive at 4 years was 66.8% (95% CI: 49.1-79.5). Median PFS in the overall population was 23.5 months (95% CI: 15.4-30.4). ORR was 73.1%; five patients had complete response. Median DoR was 22.1 months (95% CI: 15.1-34.5). Grade III/IV adverse events (AEs) were reported in 38 (73.1%) patients and 20 (38.5%) discontinued treatment because of AEs: 17 (32.7%) discontinued axitinib, 13 (25.0%) discontinued pembrolizumab, and 10 (19.2%) discontinued both drugs. Common AEs included diarrhoea (84.6%), fatigue (80.8%), hypertension (53.8%), cough (48.1%) and dysphonia (48.1%). There were no new AE terms reported and no treatment-related deaths.

CONCLUSIONS

In patients with advanced RCC with ~4 years of follow-up, combination axitinib/pembrolizumab continued to demonstrate clinical benefit, with no new safety signals.

A Phase 1 study of RO6870810, a novel bromodomain and extra-terminal protein inhibitor, in patients with NUT carcinoma, other solid tumours, or diffuse large B-cell lymphoma

Background

Bromodomain and extra-terminal (BET) proteins are epigenetic readers that can drive carcinogenesis and therapy resistance. RO6870810 is a novel, small-molecule BET inhibitor.

Methods

We conducted a Phase 1 study of RO6870810 administered subcutaneously for 21 or 14 days of 28- or 21-day cycles, respectively, in patients with the nuclear protein of the testis carcinoma (NC), other solid tumours, or diffuse large B-cell lymphoma (DLBCL) with MYC deregulation.

Results

Fatigue (42%), decreased appetite (35%) and injection-site erythema (35%) were the most common treatment-related adverse events. Pharmacokinetic parameters demonstrated linearity over the dose range tested and support once-daily dosing. Pharmacodynamic assessments demonstrated sustained decreases in CD11b levels in peripheral blood mononuclear cells. Objective response rates were 25% (2/8), 2% (1/47) and 11% (2/19) for patients with NC, other solid tumours and DLBCL, respectively. Responding tumours had evidence of deregulated MYC expression.

Conclusions

This trial establishes the safety, favourable pharmacokinetics, evidence of target engagement and preliminary single-agent activity of RO6870810. Responses in patients with NC, other solid tumours and DLBCL provide proof-of-principle for BET inhibition in MYC-driven cancers. The results support further exploration of RO6870810 as monotherapy and in combinations.

Clinical trials registration

NCT01987362.

Angiogenic and Immune-Related Biomarkers and Outcomes Following Axitinib/Pembrolizumab Treatment in Patients with Advanced Renal Cell Carcinoma

PURPOSE

Combined axitinib/pembrolizumab is approved for advanced renal cell carcinoma (aRCC). This exploratory analysis examined associations between angiogenic and immune-related biomarkers and outcomes following axitinib/pembrolizumab treatment.

PATIENTS AND METHODS

Prospectively defined retrospective correlative exploratory analyses tested biospecimens from 52 treatment-naïve patients receiving axitinib and pembrolizumab (starting doses 5 mg twice daily and 2 mg/kg respectively, every 3 weeks). Tumor tissue, serum, and whole blood samples were collected at baseline, at cycle 2 day 1 (C2D1), and end of treatment (EOT) for blood-based samples. Clinical outcomes were objective response rate (ORR) and progression-free survival (PFS).

RESULTS

Higher baseline tumor levels of CD8 showed a trend toward longer PFS (HR 0.4; P = 0.091). Higher baseline serum levels of CXCL10 (P = 0.0197) and CEACAM1 (P = 0.085) showed a trend toward better ORR and longer PFS, respectively. Patients for whom IL6 was not detected at baseline had longer PFS versus patients for whom it was detected (HR 0.4; P = 0.028). At C2D1 and/or EOT, mainly immune-related biomarkers showed any association with better outcomes. The genes CA9 (P = 0.084), HIF1A (P = 0.064), and IFNG (P = 0.073) showed trending associations with ORR, and AKT3 (P = 0.0145), DDX58 (P = 0.0726), GZMA (P = 0.0666), LCN2 (NGAL; P = 0.0267), and PTPN11 (P = 0.0287) with PFS.

CONCLUSIONS

With combined axitinib/pembrolizumab treatment in patients with aRCC, mostly immune-related biomarkers are associated with better treatment outcomes. This exploratory analysis has identified some candidate biomarkers to consider in future prospective testing.

Phase I and Pharmacokinetic Study of Romidepsin in Patients with Cancer and Hepatic Dysfunction: A National Cancer Institute Organ Dysfunction Working Group Study

PURPOSE

Romidepsin dosing recommendations for patients with malignancy and varying degrees of hepatic dysfunction was lacking at the time of regulatory approval for T-cell lymphoma. We conducted a multicenter phase I clinical trial (ETCTN-9008) via the NCI Organ Dysfunction Working Group to investigate safety, first cycle MTD, and pharmacokinetic profile of romidepsin in this setting.

PATIENTS AND METHODS

Patients with select advanced solid tumors or hematologic malignancies were stratified according to hepatic function. Romidepsin was administered intravenously on days 1, 8, and 15 of a 28-day cycle and escalation followed a 3 + 3 design in moderate and severe impairment cohorts. Blood samples for detailed pharmacokinetic analyses were collected after the first dose.

RESULTS

Thirty-one patients received one dose of romidepsin and were evaluable for pharmacokinetic analyses in normal (n = 12), mild (n = 8), moderate (n = 5), and severe (n = 6) cohorts. Adverse events across cohorts were similar, and dose-limiting toxicity occurred in two patients (mild and severe impairment cohorts). The MTD was not determined because the geometric mean AUC values of romidepsin in moderate (7 mg/m²) and severe (5 mg/m²) impairment cohort were 114% and 116% of the normal cohort (14 mg/m²).

CONCLUSIONS

Data from the ETCTN-9008 trial led to changes in the romidepsin labeling to reflect starting dose adjustment for patients with cancer and moderate and severe hepatic impairment, with no adjustment for mild hepatic impairment.

Discrepancies between genitourinary cancer patients' and clinicians' characterization of the Eastern Cooperative Oncology Group performance status

BACKGROUND

Patient-reported outcomes have been used to assess treatment effectiveness and actively engage patients in their disease management. This study was designed to describe the patient-reported performance status (PS) and the provider-reported PS.

METHODS

Patients with metastatic genitourinary cancers were recruited from a single cancer center before the initiation of a new line of treatment. PS (Eastern Cooperative Oncology Group [ECOG]), quality of life (Functional Assessment of Chronic Illness Therapy-General), and distress (Patient-Reported Outcomes Measurement Information System Anxiety and Depression) were self-reported by patients. Clinical data (eg, age, sex, diagnosis, and physician-reported ECOG PS) were extracted from medical records. Multivariate analysis was used to determine the association between PS, quality of life, and psychological symptoms.

RESULTS

One hundred forty-five patients were enrolled (76.6% male, 70.3% White, 81.4% married, and 76.6% well educated). The median age was 67 years; 66.9% were diagnosed with renal cell carcinoma, 20.0% were diagnosed with urothelial carcinoma, and 13.1% were diagnosed with prostate cancer. Clinicians more frequently classified patients' ECOG PS as 0 in comparison with the patients themselves (92.4% vs 64.1%; P = .001). Higher clinician-reported ECOG PS was associated with poorer physical and functional well-being and higher rates of depression (P < .01), whereas higher patient-reported ECOG PS was associated with worse psychosocial outcomes (P < .01).

CONCLUSIONS

Discrepancies were noted between the patient- and provider-reported ECOG PS, with clinicians overestimating the ECOG PS in comparison with the patients themselves. This study's findings suggest that patients incorporate their social and emotional well-being into their PS score in addition to their physical well-being. This information is not immediately accessible to most clinicians from just a standard patient interview and likely accounts for the overestimation of the patients' ECOG PS by the clinicians.

Hyperphosphatemia Secondary to the Selective Fibroblast Growth Factor Receptor 1-3 Inhibitor Infigratinib (BGJ398) Is Associated with Antitumor Efficacy in Fibroblast Growth Factor Receptor 3-altered Advanced/Metastatic Urothelial Carcinoma

BACKGROUND

Infigratinib (BGJ398) is a potent, selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor with significant activity in metastatic urothelial carcinoma (mUC) bearing FGFR3 alterations. It can cause hyperphosphatemia due to the "on-target" class effect of FGFR1 inhibition.

OBJECTIVE

To investigate the relationship between hyperphosphatemia and treatment response in patients with mUC.

INTERVENTION

Oral infigratinib 125 mg/d for 21 d every 28 d.

DESIGN, SETTING, AND PARTICIPANTS

Data from patients treated with infigratinib in a phase I trial with platinum-refractory mUC and activating FGFR3 alterations were retrospectively analyzed for clinical efficacy in relation to serum hyperphosphatemia. The relationship between plasma infigratinib concentration and phosphorous levels was also assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical outcomes were compared in groups with/without hyperphosphatemia.

RESULTS AND LIMITATIONS

Of the 67 patients enrolled, 48 (71.6%) had hyperphosphatemia on one or more laboratory tests. Findings in patients with versus without hyperphosphatemia were the following: overall response rate 33.3% (95% confidence interval [CI] 20.4-48.4) versus 5.3% (95% CI 0.1-26.0); disease control rate 75.0% (95% CI 60.4-86.4) versus 36.8% (95% CI 16.3-61.6). This trend was maintained in a 1-mo landmark analysis. Pharmacokinetic/pharmacodynamic analysis showed that serum phosphorus levels and physiologic infigratinib concentrations were correlated positively. Key limitations include retrospective design, lack of comparator, and limited sample size.

CONCLUSIONS

This is the first published study to suggest that hyperphosphatemia caused by FGFR inhibitors, such as infigratinib, can be a surrogate biomarker for treatment response. These findings are consistent with other reported observations and will need to be validated further in a larger prospective trial.

PATIENT SUMMARY

Targeted therapy is a new paradigm in treating bladder cancer. In a study using infigratinib, a drug that targets mutations in a gene called fibroblast growth factor receptor 3 (FGFR3), we found that elevated levels of phosphorous were associated with greater clinical benefit. In the future, these data may help inform treatment strategies.

The effect of sonidegib (LDE225) on the pharmacokinetics of bupropion and warfarin in patients with advanced solid tumours

AIMS

We evaluated the potential effect of sonidegib at an oral dose of 800 mg once daily (QD) on the pharmacokinetics (PK) of the probe drugs warfarin (CYP2C9) and bupropion (CYP2B6).

METHODS

This was a multicentre, open-label study to evaluate the effect of sonidegib on the PK of the probe drugs warfarin and bupropion in patients with advanced solid tumours. Cohort 1 patients received a single warfarin 15-mg dose on Day 1 of the run-in period and on Cycle 2 Day 22 (C2D22) of sonidegib administration. Cohort 2 patients received a single bupropion 75-mg dose on Day 1 of run-in period and on C2D22 of sonidegib administration. Sonidegib 800 mg QD oral dosing began on Cycle 1 Day 1 of a 28-day cycle after the run-in period in both cohorts.

RESULTS

The geometric means ratios [90% confidence interval] for (S)-warfarin with and without sonidegib were: area under the concentration-time curve from time 0 to infinity (AUC_inf ) 1.15 [1.07, 1.24] and maximum plasma concentration (C_max ) 0.88 [0.81, 0.97]; and for (R)-warfarin were: AUC_inf 1.10 [0.98, 1.24] and C_max 0.93 [0.87, 1.0]. The geometric means ratios [90% confidence interval] of bupropion with and without sonidegib were: AUC_inf 1.10 [0.99, 1.23] and C_max 1.16 [0.95, 1.42]. Sonidegib 800 mg had a safety profile that was similar to that of lower dose sonidegib 200 mg and was unaffected by single doses of the probe drugs.

CONCLUSIONS

Sonidegib dosed orally at 800 mg QD (higher than the Food and Drug Administration-approved dose) did not impact the PK or pharmacodynamics of warfarin (CYP2C9 probe substrate) or the PK of bupropion (CYP2B6 probe substrate).