Purpose: Histologic transformation from EGFR-mutant non-small cell lung cancer (NSCLC) to small-cell lung cancer (SCLC) is a key mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI). However, transcriptomic changes between NSCLC and transformed SCLC (t-SCLC) remain unexplored.
Experimental design: We conducted whole-transcriptome analysis of 59 regions of interest through the spatial profiling of formalin-fixed, paraffin-embedded tissues obtained from 10 patients (lung adenocarcinoma, 22; combined SCLC/NSCLC, 7; and t-SCLC, 30 regions of interests). Transcriptomic profiles and differentially expressed genes were compared between pre- and post-transformed tumors.
Results: Following EGFR-TKI treatment, 93.7% (15/16) of t-SCLC components evolved into neuroendocrine-high subtypes (SCLC-A or SCLC-N). The transition to t-SCLC occurred regardless of EGFR-TKI treatment and EGFR mutational status, with a notable decrease in EGFR expression (P < 0.001) at both mRNA and protein levels. Pathway analysis revealed that gene overexpression was related to epigenetic alterations in t-SCLC. Interestingly, histone deacetylase inhibitors restored EGFR expression in SNU-2962A cells and their organoid model. The synergistic effects of third-generation EGFR-TKI osimertinib and the histone deacetylase inhibitor fimepinostat were validated in both in vitro and in vivo models.
Conclusions: Our study demonstrated that most t-SCLC cases showed neuronal subtypes with low EGFR expression. Differentially expressed gene analysis and t-SCLC preclinical models identified an epigenetic modifier as a promising treatment strategy for t-SCLC.
Purpose: STAT3 is a key transcription factor that mediates cancer progression through phosphorylation or gain-of-function mutations. STAT3 activation in myeloid neoplasms (MN) is primarily mediated through phosphorylation. STAT3 mutation has only rarely been reported in MNs.
Experimental design: We assessed the clinicopathologic and molecular genetic features of 32 STAT3-mutated MNs.
Results: The frequency of STAT3 mutation in MNs was <0.5%. Twenty (62.5%) cases were classified as acute myeloid leukemia, 7 (21.9%) as myelodysplastic syndrome, and 5 (15.6%) as chronic myelomonocytic leukemia, but none as myeloproliferative neoplasms. STAT3 mutations occurred at initial diagnosis in 22 (88%) cases or at relapse or upon leukemic transformation. Clonal hierarchy analysis revealed that STAT3 mutations represented the dominant clone in 30% of acute myeloid leukemia cases but were subclonal in myelodysplastic syndrome and chronic myelomonocytic leukemia. Most were missense mutations located at the SH2 domain, Y640F being the most common. STAT3 mutation was accompanied by coexisting mutations in all cases, most frequently SRSF2, TET2, ASXL1, and SETBP1. STAT3 mutations were usually associated with morphologic dysplasia, increased blasts, and monosomy 7/del7q. With a median follow-up of 24.5 months, 21 patients died, 6 had persistent disease, and 5 achieved complete remission after stem cell transplantation.
Conclusions: STAT3 mutation is present in various MNs but not in myeloproliferative neoplasms. It is often an early event or occurs upon leukemic transformation, which suggests an important role in the pathogenesis and progression of MNs by activating the JAK-STAT pathway. It may help determine a subset of patients with MNs who may benefit from targeted therapy. See related commentary by Hochman and Frank, p. 4554.
Purpose: Pancreatic ductal adenocarcinoma upregulates CD73, potentially contributing to immune surveillance evasion. Combining oleclumab (CD73 inhibitor) and durvalumab with chemotherapy may identify an effective treatment option.
Patients and methods: We describe a multicenter phase Ib/II randomized clinical trial in patients with metastatic pancreatic ductal adenocarcinoma, untreated (cohort A) or previously received gemcitabine-based chemotherapy (cohort B; NCT03611556). During escalation, patients received oleclumab 1,500 or 3,000 mg, durvalumab 1,500 mg, and gemcitabine plus nab-paclitaxel (GnP; cohort A; n = 14) or modified FOLFOX (cohort B; n = 11). During expansion, cohort A patients (n = 170) were randomized to GnP (arm A1), oleclumab [recommended phase II dose (RP2D)] with GnP (arm A2), or oleclumab (RP2D) with durvalumab plus GnP (arm A3). Primary objectives were safety (escalation) and objective response rate (expansion). Secondary objectives included progression-free survival (PFS) and overall survival (OS).
Results: During escalation, 1/11 patients from cohort B (oleclumab 3,000 mg) experienced two dose-limiting toxicities. Oleclumab's RP2D was 3,000 mg. During expansion, grade ≥3 treatment-related adverse events occurred in 67.7% (42/62) of patients in A1, 73.7% (28/38) in A2, and 77.1% (54/70) in A3. The objective response rate was 29.0%, 21.1%, and 32.9% in A1, A2, and A3, respectively (A1 vs. A3; P = 0.650). PFS [HR = 0.72; 95% confidence interval (CI), 0.47, 1.11] and OS (HR = 0.75; 95% CI, 0.50-1.13) were similar for A3 versus A1. Patients with high CD73 expression had improved PFS and OS in A3 versus A1, although this should be interpreted with caution.
Conclusions: Although the safety profile was acceptable, this study did not meet its primary efficacy endpoint.
Purpose: This multicenter phase II basket trial investigated the efficacy, safety, and pharmacokinetics of Debio 1347, an investigational, oral, highly selective, ATP-competitive, small molecule inhibitor of FGFR1-3, in patients with solid tumors harboring a functional FGFR1-3 fusion.
Patients and methods: Eligible adults had a previously treated locally advanced (unresectable) or metastatic biliary tract (cohort 1), urothelial (cohort 2), or another histologic cancer type (cohort 3). Debio 1347 was administered at 80 mg once daily, continuously, in 28-day cycles. The primary endpoint was the objective response rate. Secondary endpoints included duration of response, progression-free survival, overall survival, pharmacokinetics, and incidence of adverse events.
Results: Between March 22, 2019, and January 8, 2020, 63 patients were enrolled and treated, 30 in cohort 1, 4 in cohort 2, and 29 in cohort 3. An unplanned preliminary statistical review showed that the efficacy of Debio 1347 was lower than predicted, and the trial was terminated. In total, 3 of 58 evaluable patients had partial responses, representing an objective response rate of 5%, with a further 26 (45%) having stable disease (≥6 weeks duration). Grade ≥3 treatment-related adverse events occurred in 22 (35%) of 63 patients, with the most common being hyperphosphatemia (13%) and stomatitis (5%). Two patients (3%) discontinued treatment due to adverse events.
Conclusions: Debio 1347 had manageable toxicity; however, the efficacy in patients with tumors harboring FGFR fusions did not support further clinical evaluation in this setting. Our transcriptomic-based analysis characterized in detail the incidence and nature of FGFR fusions across solid tumors. See related commentary by Hage Chehade et al., p. 4549.
Purpose: Epithelioid hemangioendothelioma (EHE) is a rare vascular cancer with pathogenic TAZ-CAMTA1 (calmodulinbinding transcription activator 1) operating as an oncogenic driver through activation of the MAPK pathway. Trametinib is an inhibitor of MEK, a critical kinase in the MAPK pathway. We sought to evaluate the effect of trametinib in patients with EHE.
Patients and methods: A phase 2 trial of trametinib was conducted in patients with locally advanced or metastatic EHE. Eligibility requirements included evidence of tumor progression or presence of EHE-related pain requiring opiates for management before enrollment. The primary endpoint was objective response rate (ORR) as per RECIST1.1 in cases with TAZ- CAMTA1 confirmed by fusion-FISH. Secondary objectives were to estimate ORR for all patients, median progression-free survival (PFS), 2-year overall survival (OS) rate, patient safety, and change in patient-reported global health and pain scores per PROMIS questionnaires.
Results: 44 patients enrolled and 42 started trametinib. TAZ- CAMTA1 was detected in 27 tumor samples. TheORRwas 3.7%[95% confidence interval (CI), 0.094-19.0], median PFS was 10.4 months (95%CI, 7.1-NA), and 2-year OS rate was 33.3%(95%CI, 19.1-58.2) in the target population. Median pain intensity and interference scores improved significantly after 4 weeks of trametinib in patients using opiates. Common adverse events related to trametinib were rash, fatigue, nausea/vomiting, diarrhea/constipation, alopecia, and edema; one grade 5 ARDS/pneumonitis was related to trametinib.
Conclusions: Trametinib was associated with reduction in EHE-related pain and median PFS of more than 6 months, providing palliative benefit in patients with advanced EHE, but the trial did not meet the ORR goal. See related commentary by Van Tine and Haarberg, p. 4552.