RB1 wild-type

SHAP analysis highlighted lower sphericity, higher flatness, and greater gray-level heterogeneity as predictive for MYCNampRB1+/+ status, yielding an AUC of 0.81 (SD 0.11). This study shows the potential of MRI-based radiomics to distinguish MYCNampRB1+/+ and RB1-/- retinoblastoma subtypes.

Overall, in our uLMS analysis, CDK4 and/or MDM2 amplification was identified in a small subset (2%) of uLMS, the majority of which are TP53/RB1-wildtype. This may suggest that CDK4/MDM2 amplification can be an alternative tumorigenic mechanism in this distinct class of uLMS, which may have therapeutic clinical implications, including possible use of specific cyclin-dependent kinase inhibitors.

Overall, in our uLMS analysis, CDK4 and/or MDM2 amplification was identified in a small subset (2%) of uLMS, the majority of which are TP53/RB1-wildtype. This may suggest that CDK4/MDM2 amplification can be an alternative tumorigenic mechanism in this distinct class of uLMS, which may have therapeutic clinical implications, including possible use of specific cyclin-dependent kinase inhibitors.

Patients with glioblastoma IDH-wildtype harboring 4q12 amplification rarely have restricting DWI patterns compared to their wildtype counterparts, in which this DWI pattern is present in ~ 50% of patients. This suggests that some phenotypic imaging characteristics can be identified among molecular subtypes of IDH-wildtype glioblastoma.

Adverse events include edema (composite term; any grade: 58.3%; grade 3: 12.5%) and constipation (any grade: 41.7%; grade 3: 4.2%). Tepotinib provides antitumor activity in high-level METamp NSCLC (ClinicalTrials.gov: NCT02864992).

Overall, biomarker-focused selection of models led to high efficacy of in vivo treatment. These data enable a paradigm shift to biomarker-driven trial designs for maximizing clinical benefit of ADC therapies.

And PDGFRA alteration correlated with multiple lesions. Our results suggest that clarifying the association between driver genes and tumor localization may be useful in clinical practice, including prognosis prediction.

P2; Trial completion date: Jun 2024 --> Jun 2025 | Trial primary completion date: Jun 2023 --> Jun 2024

Finally, profiling cases of SCLC containing oncogenic drivers typically associated with NSCLC demonstrates that SCLC transformation may occur across multiple distinct molecular cohorts of NSCLC. These novel and unsuspected genetic features of SCLC may help personalize treatment approaches for this fatal form of cancer.

© RSNA, 2023 Supplemental material is available for this article. See also the editorial by Rollins in this issue

Our work underscores the existence of genetic subtypes in SCLC, including rare subtypes with potential clinical utility. Findings from this study provide an improved understanding of genetic subtypes in SCLC and better inform mechanisms of transformation to SCLC from NSCLC, that may further guide the development of personalized therapies for subsets of patients with this fatal tumor.

P2; Recruiting --> Active, not recruiting

SCLC patients with RB1 WT status or lower RB1 LOF signature scores by transcriptomics have better outcomes with ICB monotherapy.

This is the largest study to-date to concurrently analyze Rb by NGS and immunohistochemistry in SCLC, identifying a 6% rate of Rb proficiency. Pathologic-genomic data implicate NSCLC-related progenitors as a putative source of Rb-proficient SCLC. Consistent upstream Rb inactivation via CDKN2A/p16↓ and CCND1/cyclinD1↑ suggests potential utility of CDK4/6 inhibitors in this aggressive SCLC subset. The study also clarifies technical aspects of Rb status determination in clinical practice, highlighting the limitations of exon-only sequencing for RB1 interrogation.

P2; Trial primary completion date: Jun 2022 --> Jun 2023

Tepotinib showed meaningful activity, especially in first line, in the first trial of a MET inhibitor in EGFR WT NSCLC with high-level METamp to enroll based on a convenient LBx assay. BL biomarker analyses indicated focal METamp, MYC/RB1 WT, and low ctDNA MAF were associated with improved outcomes. Serial LBx could monitor molecular response and evaluate resistance.

CDK4/6 inhibitor, abemaciclib, was used to reactivate the Rb pathway followed by treatment with gemcitabine or WEE1-kinase-inhibitor, to target the enriched S and G2/M phase cells post-abemaciclib removal. Our study presents an innovative treatment strategy inhibiting the Rb pathway followed by S or G2/M pathway sequentially resulting in synergistic cell killing in those cells/tumors with wild-type Rb. We also incorporate real-time PET imaging and serum TK1 as non-invasive indicators of response to the treatment strategy. The study with PDX models also identified biomarkers of cell proliferation to be used in conjunction with PET imaging to provide the pre-clinical rationale to translate our findings into clinical trials for this aggressive disease.

Overall, in our pan-LMS analysis, HPV reads were identified in a subset of TP53/RB1-wildtype LMS. For all HPV51-associated LMS, the striking absence of any detectable TP53 or RB1 mutations and predilection for the female lower reproductive tract supports our hypothesis that high-risk HPV can be an alternative tumorigenic mechanism in this distinct class of LMS.

P2; N=47 --> 0 | Suspended --> Withdrawn

P2; Trial completion date: Dec 2022 --> Dec 2024 | Trial primary completion date: Dec 2022 --> Dec 2023

P2; Trial completion date: Aug 2022 --> Dec 2022 | Trial primary completion date: Aug 2022 --> Dec 2022