Obinutuzumab Pretreatment as a Novel Approach to Mitigate Formation of Anti-Drug Antibodies Against Cergutuzumab Amunaleukin in Patients with Solid Tumors

PURPOSE

The immunocytokine cergutuzumab amunaleukin (CEA-IL2v) showed manageable safety and favorable pharmacodynamics in phase I/Ib trials in patients with advanced/metastatic carcinoembryonic antigen-positive (CEA+) solid tumors, but this was accompanied by a high incidence of anti-drug antibodies (ADA). We examined B-cell depletion with obinutuzumab as a potential mitigation strategy.

EXPERIMENTAL DESIGN

Preclinical data comparing B-cell depletion with rituximab versus obinutuzumab are summarized. Substudies of phase I/Ib trials investigated the effect of obinutuzumab pretreatment on ADA development, safety, pharmacodynamics, and antitumor activity of CEA-IL2v ± atezolizumab in patients with advanced/metastatic or unresectable CEA+ solid tumors who had progressed on standard of care.

RESULTS

Preclinical data showed superior B-cell depletion with obinutuzumab versus rituximab. In clinical studies, patients received CEA-IL2v monotherapy with (n = 16) or without (n = 6) obinutuzumab pretreatment (monotherapy study), or CEA-IL2v + atezolizumab + obinutuzumab pretreatment (n = 5; combination study). In the monotherapy study, after four cycles (every 2 weeks treatment), 0/15 evaluable patients administered obinutuzumab pretreatment had ADAs versus 4/6 patients without obinutuzumab. Obinutuzumab pretreatment with CEA-IL2v monotherapy showed no new safety signals and pharmacodynamic data suggested minimal impact on T cells and natural killer cells. Conversely, increased liver toxicity was observed in the combination study (CEA-IL2v + atezolizumab + obinutuzumab pretreatment).

CONCLUSIONS

These preliminary findings suggest that obinutuzumab pretreatment before CEA-IL2v administration in patients with CEA+ solid tumors may be a feasible and potent ADA mitigation strategy, with an acceptable safety profile, supporting broader investigation of obinutuzumab pretreatment for ADA mitigation in other settings.

Clinical implication of genetic intratumor heterogeneity for targeted therapy in head and neck cancer

BACKGROUND

Genomic profiling is increasingly used both in therapeutic decision-making and as inclusion criteria for trials testing targeted therapies. However, the mutational landscape may vary across different areas of a tumor and intratumor heterogeneity will challenge treatments or clinical decisions based on single tumor biopsies. The purpose of this study was to assess the clinical relevance of genetic intratumor heterogeneity in head and neck squamous cell carcinomas (HNSCC) using the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT).

MATERIALS AND METHODS

This prospective study included 33 whole tumor specimens from 28 patients with primary or recurrent HNSCC referred for surgery. Three tumor blocks were selected from central, semi-peripheral, and peripheral positions, mimicking biopsies in three different locations. Genetic analysis of somatic copy number alterations (SCNAs) was performed on the three biopsies using Oncoscan, focusing on 45 preselected HNSCC genes of interest. Clinical relevance was assessed using the ESCAT score to investigate whether and how treatment decisions would change based on the three biopsies from the same tumor.

RESULTS

The SCNAs identified among 45 preselected genes within the three tumor biopsies derived from the same tumor revealed distinct variations. The detected discrepancies could potentially influence treatment approaches or clinical decisions in 36% of the patients if only one tumor biopsy was used. Recurrent tumors exhibited significantly higher variation in SCNAs than primary tumors (p = .024). No significant correlation between tumor size and heterogeneity (p = .7) was observed.

CONCLUSION

In 36% of patients diagnosed with HNSCC, clinically significant intratumor heterogeneity was observed which may have implications for patient management. This finding substantiates the need for future studies that specifically investigate the clinical implications associated with intratumor heterogeneity.

A first-in-human study of the fibroblast activation protein-targeted, 4-1BB agonist RO7122290 in patients with advanced solid tumors

This first-in-human study evaluated RO7122290, a bispecific fusion protein carrying a split trimeric 4-1BB (CD137) ligand and a fibroblast activation protein α (FAP) binding site that costimulates T cells for improved tumor cell killing in FAP-expressing tumors. Patients with advanced or metastatic solid tumors received escalating weekly intravenous doses of RO7122290 as a single agent (n = 65) or in combination with a 1200-milligram fixed dose of the anti-programmed death-ligand 1 (anti-PD-L1) antibody atezolizumab given every 3 weeks (n = 50), across a tested RO7122290 dose range of 5 to 2000 milligrams and 45 to 2000 milligrams, respectively. Three dose-limiting toxicities were reported, two at different RO7122290 single-agent doses (grade 3 febrile neutropenia and grade 3 cytokine release syndrome) and one for the combination (grade 3 pneumonitis). No maximum tolerated dose was identified. The pharmacokinetic profile of RO7122290 suggested nonlinearity in elimination. The observed changes in peripheral and tissue pharmacodynamic (PD) biomarkers were consistent with the postulated mechanism of action. Treatment-induced PD changes included an increase in proliferating and activated T cells in peripheral blood both in the single-agent and combination arms. Increased infiltration of intratumoral CD8⁺ and Ki67⁺CD8⁺ T cells was observed for both treatment regimens, accompanied by the up-regulation of T cell activation genes and gene signatures. Eleven patients experienced a complete or partial response, six of whom were confirmed to be immune checkpoint inhibitor naive. These results support further evaluation of RO7122290 in combination with atezolizumab or other immune-oncology agents for the treatment of solid tumors.

New pathogenic germline variants identified in mesothelioma

BACKGROUND

Mesothelioma (MM) is associated with asbestos exposure, tumor heterogeneity and aggressive clinical behavior. Identification of germline pathogenic variants (PVs) in mesothelioma is relevant for identifying potential actionable targets and genetic counseling.

METHODS

44 patients underwent whole exome sequencing (WES) or whole genome sequencing (WGS). Germline variants were selected according to association with inherited cancer using a 168-gene in silico panel, and variants classified according to ACMG/AMP classification as pathogenic (class 5) or likely pathogenic (class 4).

RESULTS

In total, 16 patients (36%) were found to carry pathogenic or likely pathogenic variants in 13 cancer associated genes (ATM, BAP1, BRCA2, CDKN2A, FANCA, FANCC, FANCD2, FANCM, MUTYH, NBN, RAD51B, SDHA and XPC). The germline PVs occurred in DNA repair pathways, including homologous recombination repair (HRR) (75%), nucleotide excision repair (6%), cell cycle regulatory (7%), base excision repair (6%), and hypoxic pathway (6%). Five (31%) patients with a germline PV had a first or second degree relative with mesothelioma compared to none for patients without a germline PV. Previously undiagnosed BRCA2 germline PVs were identified in two patients. Potential actionable targets based on the germline PVs were found in four patients (9%).

CONCLUSION

This study revealed a high frequency of germline PVs in patients with mesothelioma. Furthermore, we identified germline PVs in two genes (NBN & RAD51B) not previously associated with mesothelioma. The data support germline testing in mesothelioma and provide a rationale for additional investigation of the HRR pathway as a potential actionable target.

ProTarget: a Danish Nationwide Clinical Trial on Targeted Cancer Treatment based on genomic profiling - a national, phase 2, prospective, multi-drug, non-randomized, open-label basket trial

BACKGROUND

An increasing number of trials indicate that treatment outcomes in cancer patients with metastatic disease are improved when targeted treatments are matched with druggable genomic alterations in individual patients (pts). An estimated 30-80% of advanced solid tumors harbor actionable genomic alterations. However, the efficacy of personalized cancer treatment is still scarcely investigated in larger, controlled trials due to the low frequency and heterogenous distribution of druggable alterations among different histologic tumor types. Therefore, the overall effect of targeted cancer treatment on clinical outcomes still needs investigation.

STUDY DESIGN/METHODS

ProTarget is a national, non-randomized, multi-drug, open-label, pan-cancer phase 2 trial aiming to investigate the anti-tumor activity and toxicity of currently 13 commercially available, EMA-approved targeted therapies outside the labeled indication for treatment of advanced malignant diseases, harboring specific actionable genomic alterations. The trial involves the Danish National Molecular Tumor Board for confirmation of drug-variant matches. Key inclusion criteria include a) measurable disease (RECIST v.1.1), b) ECOG performance status 0-2, and c) an actionable genomic alteration matching one of the study drugs. Key exclusion criteria include a) cancer type within the EMA-approved label of the selected drug, and b) genomic alterations known to confer drug resistance. Initial drug dose, schedule and dose modifications are according to the EMA-approved label. The primary endpoint is objective response or stable disease at 16 weeks. Pts are assigned to cohorts defined by the selected drug, genomic alteration, and tumor histology type. Cohorts are monitored according to a Simon's two-stage-based design. Response is assessed every 8 weeks for the first 24 weeks, then every 12 weeks. The trial is designed similar to the Dutch DRUP and the ASCO TAPUR trials and is a partner in the Nordic Precision Cancer Medicine Trial Network. In ProTarget, serial fresh tumor and liquid biopsies are mandatory and collected for extensive translational research including whole genome sequencing, array analysis, and RNA sequencing.

DISCUSSION

The ProTarget trial will identify new predictive biomarkers for targeted treatments and provide new data and essential insights in molecular pathways involved in e.g., resistance mechanisms and thereby potentially evolve and expand the personalized cancer treatment strategy.

PROTOCOL VERSION

16, 09-MAY-2022.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04341181. Secondary Identifying No: ML41742. EudraCT No: 2019-004771-40.

Avelumab Plus Talazoparib in Patients With Advanced Solid Tumors: The JAVELIN PARP Medley Nonrandomized Controlled Trial

Importance

Preclinical data suggest that poly(ADP-ribose) polymerase (PARP) inhibitors have synergistic activity when combined with immune checkpoint inhibitors (ICIs); however, it is unknown which tumor types or molecular subtypes may benefit from this combination.

Objective

To investigate responses associated with the combination of avelumab and talazoparib in different tumor types and/or molecular subtypes.

Design, Setting, and Participants

In this phase 1b and 2 basket nonrandomized controlled trial, patients with advanced solid tumors were enrolled in the following cohorts: non-small cell lung cancer (NSCLC); DNA damage response (DDR)-positive NSCLC; triple-negative breast cancer (TNBC); hormone receptor-positive, human epidermal growth factor receptor 2 (ERBB2)-negative, DDR-positive breast cancer; recurrent, platinum-sensitive ovarian cancer (OC); recurrent, platinum-sensitive, BRCA1/2-altered OC; urothelial cancer; metastatic castration-resistant prostate cancer (mCRPC); DDR-positive mCRPC; and BRCA1/2- or ATM-altered solid tumors. Data were analyzed between June 17, 2021, and August 6, 2021.

Interventions

All patients in phases 1b and 2 received avelumab plus talazoparib.

Main Outcomes and Measures

The phase 1b primary end point was dose-limiting toxic effects. The phase 2 primary end point was objective response, measured as objective response rate (ORR). Secondary end points included safety, time to response, duration of response (DOR), progression-free survival, time to prostate-specific antigen progression and PSA response of 50% or greater (for mCRPC), cancer antigen 125 response (for OC), pharmacokinetics, immunogenicity, and biomarkers.

Results

A total of 223 patients (mean [SD] age, 63.2 [11.0] years; 117 [52.5%] men) were treated, including 12 patients in phase 1b and 211 patients in phase 2. The recommended phase 2 dose was avelumab 800 mg every 2 weeks plus talazoparib 1 mg once daily. In phase 2, the ORR was 18.2% (95% CI, 5.2%-40.3%) in patients with TNBC; 34.8% (95% CI, 16.4%-57.3%) in patients with HR-positive, ERBB2-negative, and DDR-positive BC; and 63.6% (95% CI, 30.8%-89.1%) in patients with platinum-sensitive, BRCA1/2-altered OC. Responses occurred more frequently in patients with BRCA1/2-altered tumors. Durable responses were observed in patients with TNBC (median [range] DOR, 11.1 [3.4-20.4] months); HR-positive, ERBB2-negative, and DDR-positive BC (median [range] DOR, 15.7 [3.9 to ≥20.6] months); and BRCA1/2-altered OC (median DOR not reached; range, 5.6 to ≥18.4 months). The most common grade 3 or greater treatment-related adverse events were anemia (75 patients [33.6%]), thrombocytopenia (48 patients [21.5%]), and neutropenia (31 patients [13.9%]).

Conclusions and Relevance

This nonrandomized controlled trial found that ORRs for avelumab plus talazoparib were comparable with those with PARP inhibitor or ICI monotherapy. Prolonged DOR in patients with TNBC; HR-positive, ERBB2-negative, and DDR-positive BC; and BRCA1/2-altered OC warrant further investigation in randomized clinical trials. These data highlight the importance of prospective patient selection in future studies of ICI and PARP-inhibitor combinations.

Trial Registration

ClinicalTrials.gov Identifier: NCT03330405.

Abstract 2276: High frequency of pathogenic germline variants in patients with malignant mesothelioma

Background: Malignant mesothelioma (MM) is associated with asbestos exposure, tumor heterogeneity and aggressive clinical behavior. Identification and characterization of germline variants in malignant mesothelioma is relevant for identifying potential actionable targets and genetic counseling of family members.

Methods: Patients referred to the Phase I Unit at Rigshospitalet were prospectively enrolled into the Copenhagen Prospective Personalized Oncology trial and underwent whole exome sequencing for somatic and germline variants. Between January 2014 and September 2021, 45 patients with MM were identified and 40 patients underwent whole exome sequencing. Germline variants were selected according to association to inherited cancer using a 168-gene panel and variants were classified according to ACMG/AMP classification as pathological (class 5) or likely pathogenic (class 4).

Results: 34 males (85%) and 6 females (15%) with a median age of 64 years (range: 43-77) were available for analysis. The majority (85%) had malignant pleural mesothelioma whilst the rest (15%) had malignant peritoneal mesothelioma. Histological subtypes were distributed between epithelioid type (N=24, 60%), biphasic type (N=12, 30%) and the sarcomatoid type (N=4, 10%).

A pathogenic or likely pathogenic variant was found in 16 patients (40%). In total 13 different germline variants were identified (ATM, BAP1, BRCA2, CDKN2A, FANCA, FANCC, FANCD2, FANCM, MUTYH, NBN, RAD51B, SDHA and XPC). The variants included five frameshifts (33%), four missenses (25%), four nonsenses (25%), one splice site (6%), one start loss (6%) and one synonymous (6%).

The pathogenic germline variants were found in DNA repair pathways, including homologous recombination repair (69%), nucleotide excision repair (13%), cell cycle regulatory (6%), DNA damage checkpoint control (6%) and hypoxic pathway (6%). Three (19%) of the patients with a germline variant had a second cancer. A previously undiagnosed BRCA2 germline mutation was found in 2 patients. A potential treatment target based on the pathogenic germline variant could be suggested in four patients (10%).

Conclusion: The current analysis revealed a high frequency of pathogenic germline variants in patients with malignant mesothelioma. These data support germline testing in these patients and provide a rationale for additional investigation of the homologous recombination pathway as a potential target for precision medicine.

Citation Format: Laila Belcaid, Birgitte Bertelsen, Karin A. Wadt, Ida V. Tuxen, Iben Spanggaard, Martin Højgaard, Jens B. Sørensen, Ulrik Lassen, Finn C. Nielsen, Kristoffer Rohrberg, Christina W. Yde. High frequency of pathogenic germline variants in patients with malignant mesothelioma [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 2276.

Modeling Metastatic Colonization in a Decellularized Organ Scaffold-Based Perfusion Bioreactor

Metastatic cancer spread is responsible for most cancer-related deaths. To colonize a new organ, invading cells adapt to, and remodel, the local extracellular matrix (ECM), a network of proteins and proteoglycans underpinning all tissues, and a critical regulator of homeostasis and disease. However, there is a major lack in tools to study cancer cell behavior within native 3D ECM. Here, an in-house designed bioreactor, where mouse organ ECM scaffolds are perfused and populated with cells that are challenged to colonize it, is presented. Using a specialized bioreactor chamber, it is possible to monitor cell behavior microscopically (e.g., proliferation, migration) within the organ scaffold. Cancer cells in this system recapitulate cell signaling observed in vivo and remodel complex native ECM. Moreover, the bioreactors are compatible with co-culturing cell types of different genetic origin comprising the normal and tumor microenvironment. This degree of experimental flexibility in an organ-specific and 3D context, opens new possibilities to study cell-cell and cell-ECM interplay and to model diseases in a controllable organ-specific system ex vivo.

493 First-in-human phase 1/2 trial to evaluate the safety and initial clinical activity of DuoBody®-CD40×4–1BB (GEN1042) in patients with advanced solid tumors

Background

Despite the preclinical promise of CD40 and 4-1BB as immuno-oncologic targets, clinical efforts evaluating these agonists as monotherapy have had limited success due to minimal efficacy and/or severe toxicity. DuoBody-CD40×4-1BB (GEN1042) is a first-in-class, bispecific, agonistic antibody that combines targeting and conditional activation of CD40 and 4-1BB on immune cells, resulting in enhanced priming and (re-)activation of tumor-specific immunity. Furthermore, preclinical data suggest that combination with anti–PD-1 can enhance antitumor activity. We present preliminary data from the ongoing, first-in-human, open-label, phase 1/2 trial of DuoBody-CD40×4-1BB in advanced solid tumors (NCT04083599).

Methods

During dose escalation, patients with metastatic/unresectable non-CNS solid tumors who had exhausted standard therapies received flat-dose DuoBody-CD40×4-1BB (0.1–400 mg) intravenously every 3 weeks until disease progression or unacceptable toxicity. Primary endpoint was dose-limiting toxicity (DLT). Secondary endpoints included adverse events (AEs), pharmacokinetic parameters, and preliminary antitumor activity (RECIST v1.1). Pharmacodynamic biomarkers were assessed as exploratory endpoints.

Results

As of June 11, 2021, 50 patients were enrolled (median age, 57 years). The most common cancer types were colorectal (22%), melanoma (20%), and non–small-cell lung cancer (8%). Patients received a median (range) of 2.5 (1–21) treatment cycles; Cmax was observed shortly after end of infusion. Treatment-related AEs occurring in ≥10% of patients (all grades; grade ≥3) were fatigue (22%; 0%), pyrexia (16%; 0%), nausea (10%; 0%), and transaminase elevation (10%; 6%). Maximum tolerated dose was not reached. One DLT of elevated transaminases (grade 4) was observed at the 200-mg dose that resolved upon corticosteroid administration. No drug-related grade ≥3 thrombocytopenia events were reported. Disease control, defined as best overall response of complete/partial response and stable disease, was achieved in 51% of patients (25/49), including 2 confirmed partial responses per RECIST v1.1 in melanoma and neuroendocrine lung cancer. Modulation of pharmacodynamic endpoints was observed across dose levels, with more pronounced effects near the 100-mg dose. Increases in peripheral IFN-y, TARC (monocyte/DC chemokine), and proliferating CD8+ total and effector memory T cells were observed during cycle 1. Using physiologically based pharmacokinetic/pharmacodynamic modeling and available safety, efficacy, and pharmacodynamic data, 100 mg every 3 weeks was identified as the expansion dose for further evaluation.

Conclusions

DuoBody-CD40×4-1BB demonstrated biologic and early antitumor activity with a favorable safety profile in patients with advanced solid tumors. Expansion cohorts, including combination therapy with PD-1 inhibitors, are currently enrolling.

Acknowledgements

This trial was funded by Genmab A/S and BioNTech SE.

Trial Registration

NCT04083599

Ethics Approval

This trial is undertaken following full approval of the final protocol, amendments, informed consent form, applicable recruiting materials, and subject compensation programs by the Independent Ethics Committee/Institutional Review Board.

Immune Cell Profiling of Peripheral Blood as Signature for Response During Checkpoint Inhibition Across Cancer Types

Despite encouraging results with immune checkpoint inhibition (ICI), a large fraction of cancer patients still does not achieve clinical benefit. Finding predictive markers in the complexity of the tumor microenvironment is a challenging task and often requires invasive procedures. In our study, we looked for putative variables related to treatment benefit among immune cells in peripheral blood across different tumor types treated with ICIs. For that, we included 33 patients with different solid tumors referred to our clinical unit for ICI. Peripheral blood mononuclear cells were isolated at baseline, 6 and 20 weeks after treatment start. Characterization of immune cells was carried out by multi-color flow cytometry. Response to treatment was assessed radiologically by RECIST 1.1. Clinical outcome correlated with a shift towards an effector-like T cell phenotype, PD-1 expression by CD8+T cells, low levels of myeloid-derived suppressor cells and classical monocytes. Dendritic cells seemed also to play a role in terms of survival. From these findings, we hypothesized that patients responding to ICI had already at baseline an immune profile, here called ‘favorable immune periphery’, providing a higher chance of benefitting from ICI. We elaborated an index comprising cell types mentioned above. This signature correlated positively with the likelihood of benefiting from the treatment and ultimately with longer survival. Our study illustrates that patients responding to ICI seem to have a pre-existing immune profile in peripheral blood that favors good outcome. Exploring this signature can help to identify patients likely to achieve benefit from ICI.

Phase I Assessment of Safety and Therapeutic Activity of BAY1436032 in Patients with IDH1-Mutant Solid Tumors

PURPOSE

BAY1436032, an inhibitor of mutant isocitrate dehydrogenase 1 (mIDH1), was active against multiple IDH1-R132X solid tumors in preclinical models. This first-in-human study was designed to determine the safety and pharmacokinetics of BAY1436032, and to evaluate its potential pharmacodynamics and antitumor effects.

PATIENTS AND METHODS

The study comprised of dose escalation and dose expansion cohorts. BAY1436032 tablets were orally administered twice daily on a continuous basis in subjects with mIDH1 solid tumors.

RESULTS

In dose escalation, 29 subjects with various tumor types were administered BAY1436032 across five doses (150-1,500 mg twice daily). BAY1432032 exhibited a relatively short half-life. Most evaluable subjects experienced target inhibition as indicated by a median maximal reduction of plasma R-2-hydroxyglutarate levels of 76%. BAY1436032 was well tolerated and an MTD was not identified. A dose of 1,500 mg twice daily was selected for dose expansion, where 52 subjects were treated in cohorts representing four different tumor types [lower grade glioma (LGG), glioblastoma, intrahepatic cholangiocarcinoma, and a basket cohort of other tumor types]. The best clinical outcomes were in subjects with LGG (n = 35), with an objective response rate of 11% (one complete response and three partial responses) and stable disease in 43%. As of August 2020, four of these subjects were in treatment for >2 years and still ongoing. Objective responses were observed only in LGG.

CONCLUSIONS

BAY1436032 was well tolerated and showed evidence of target inhibition and durable objective responses in a small subset of subjects with LGG.

Common phenotypic dynamics of tumor-infiltrating lymphocytes across different histologies upon checkpoint inhibition: impact on clinical outcome

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the cancer therapeutic landscape and our perception of interactions between the immune system and tumor cells. Despite remarkable progress, disease relapse and primary resistance are not uncommon. Understanding the biological processes that tumor-infiltrating lymphocytes (TILs) undergo during ICI, how this affects the tumor microenvironment (TME) and, ultimately, clinical outcome is, therefore, necessary to further improve treatment efficacy.

AIM

In the current study, we sought to characterize TILs from patients with metastatic solid tumors undergoing ICI correlating flowcytometric findings with clinical outcome.

METHODS

In total, 20 patients with 10 different metastatic solid tumors treated with ICIs targeting programmed-cell death-1 (PD-1)/PD-L1 axis were included in this study. The phenotype of T cells deriving from biopsies obtained prior to treatment initiation and on-treatment was investigaded. Analyses were focused on T cells' degree of differentiation and activity and how they correlate with transcriptomic changes in the TME.

RESULTS

Data indicate that patients benefitting from ICIs accumulate CD8+central memory T cells. TILs developed an effector-like phenotype over time, which was also associated with a cytolytic gene signature. In terms of modulation of T-cell responses, we observed that high expression of checkpoint molecules pre-treatment (i.e., PD-1, lymphocyte activation gene-3 [LAG-3], B and T-lymphocyte attenuator [BTLA] and T-cell immunoglobulin and mucin domain containing-3 [TIM-3]) was associated with similar gene signature and correlated to treatment benefit. Increasing expression of LAG-3 and BTLA in the CD8 compartment and their co-expression with PD-1 during treatment were, however, a common feature for patients who failed to respond to ICIs.

CONCLUSIONS

Besides identifying immune profiles suggestive of response to ICI, our results provide a more nuanced picture regarding expression of checkpoint molecules that goes beyond T-cell anergy.

Nivolumab Alone and With Ipilimumab in Previously Treated Metastatic Urothelial Carcinoma: CheckMate 032 Nivolumab 1 mg/kg Plus Ipilimumab 3 mg/kg Expansion Cohort Results

PURPOSE

CheckMate 032 is an open-label, multicohort study that includes patients with unresectable locally advanced or metastatic urothelial carcinoma (mUC) treated with nivolumab 3 mg/kg monotherapy every 2 weeks (NIVO3), nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 weeks for four doses followed by nivolumab monotherapy 3 mg/kg every 2 weeks (NIVO3+IPI1), or nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for four doses followed by nivolumab monotherapy 3 mg/kg every 2 weeks (NIVO1+IPI3). We report on the expanded NIVO1+IPI3 cohort and extended follow-up for the NIVO3 and NIVO3+IPI1 cohorts.

METHODS

Patients with platinum-pretreated mUC were enrolled in this phase I/II multicenter study to receive NIVO3, NIVO3+IPI1, or NIVO1+IPI3 until disease progression or unacceptable toxicity. Primary end point was investigator-assessed objective response rate per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, including duration of response.

RESULTS

Seventy-eight patients were treated with NIVO3 (minimum follow-up, 37.7 months), 104 with NIVO3+IPI1 (minimum follow-up, 38.8 months), and 92 with NIVO1+IPI3 (minimum follow-up, 7.9 months). Objective response rate was 25.6%, 26.9%, and 38.0% in the NIVO3, NIVO3+IPI1, and NIVO1+IPI3 arms, respectively. Median duration of response was more than 22 months in all arms. Grade 3 or 4 treatment-related adverse events occurred in 21 (26.9%), 32 (30.8%), and 36 (39.1%) patients treated with NIVO3, NIVO3+IPI1, and NIVO1+IPI3, respectively. Grade 5 treatment-related pneumonitis occurred in one patient each in the NIVO3 and NIVO3+IPI1 arms.

CONCLUSION

With longer follow-up, NIVO3 demonstrated sustained antitumor activity alone and in combination with ipilimumab. NIVO1+IPI3 provided the greatest antitumor activity of all regimens, with a manageable safety profile. This result not only supports additional study of NIVO1+IPI3 in mUC, but demonstrates the potential benefit of immunotherapy combinations in this disease.

High frequency of pathogenic germline variants within homologous recombination repair in patients with advanced cancer

Genomic screening of cancer patients for predisposing variants is traditionally based on age at onset, family history and type of cancer. Whereas the clinical guidelines have proven efficient in identifying families exhibiting classical attributes of hereditary cancer, the frequency of patients with alternative presentations is unclear. We identified and characterized germline variants in 636 patients with advanced solid cancer using whole exome sequencing. Pathogenic and likely pathogenic germline variants among 168 genes associated with hereditary cancer were considered. These variants were identified in 17.8% of the patients and within a wide range of cancer types. In particular, patients with mesothelioma, ovarian cancer, cervical cancer, urothelial cancer, and cancer of unknown primary origin displayed high frequencies of pathogenic variants. Variants were predominantly found in DNA-repair pathways and about half were within genes involved in homologous recombination repair. Twenty-two BRCA1 and BRCA2 germline variants were identified in 12 different cancer types, of which 10 (45%) were not previously identified in these patients based on the current clinical guidelines. Loss of heterozygosity and somatic second hits were identified in several of the affected genes, supporting possible causality for cancer development. A potential treatment target based on the pathogenic germline variant could be suggested in 25 patients (4%). The study demonstrates a high frequency of pathogenic germline variants in the homologous recombination pathway in patients with advanced solid cancers. We infer that genetic screening in this group of patients may reveal high-risk families and identify patients with potential PARP inhibitor sensitive tumors.