2610 Background: This trial combines the novel adjuvant immunomodulator IP-001, a glycan polymer, with laser ablation in patients with relapsed solid tumors. Methods: This is a non-randomized, open-label multicenter phase Ib/IIa trial with a dose-finding part 1 and a dose expansion part 2 in advanced melanoma and soft tissue sarcoma (STS). Primary objectives include the safety and tolerability of up to six 4-weekly cycles of intratumoral IP-001 following laser ablation (TRANBERG Thermal Therapy System, Clinical Laserthermia System AB), and 12-week disease control rate (12w-DCR) according to RECIST v1.1 in advanced melanoma. The dose-finding part used 4 mL of IP-001 (10 mg/mL). The activity endpoint for advanced melanoma used the 1 st stage of a Simon 2-stage design, with 12w-DCR ≤20% (H0) vs. ≥40% (H1) (type-I error 0.05, power 80%). Results: We treated 15 melanoma and 10 STS patients, including 4 in part 1 (n=28). Median age was 62 years, 57% were male, all patients had metastatic disease, including 60% with liver metastases. Most patients (78%) had received ≥3 prior lines of systemic treatment, including 79% with prior immunotherapy. Treatment was well tolerated with no dose-limiting toxicity, and a recommended IP-001 dose of 4 mL. Patients received a median of 2 (range 1 to 6) cycles of study treatment. Reasons for treatment discontinuation included physician’s decision (39%) and disease progression (25%). 27 patients (96%) experienced treatment-emergent adverse events (TEAE). IP-001-related TEAE occurred in 16 (57%) patients, including 5 (17%) patients with severe IP-001-related TEAE. Severe TEAE occurred in 20 (71%) patients overall. Most frequent mild IP-001-related TEAE included fever (36%), fatigue (21%), rash (14%), hypotension (11%), injection site reactions (11%) and flu-like symptoms (7%); 2 cases (7%) of severe allergic reactions were reported, including one serious reaction. Allergic reactions occurred at cycle 3 in both patients and resolved without sequelae. Treatment discontinuation for TEAE occurred in a single patient (4%). 12w-DCR in advanced melanoma was 21% (3/14 evaluable patients) (2-sided 90% CI: 6%, 46%), with stable disease in 50% and partial remission (PR) in one (7%) melanoma patient. 15 (53%) patients had radiological tumor shrinkage in ≥1 untreated tumor lesion. Median progression-free survival (PFS) in advanced melanoma was 3 months, with a 12-month PFS rate of 33%, indicating preliminary evidence of disease control beyond the 12-week primary endpoint window. Conclusions: Intratumoral IP 001 at a dose of 4 mL following thermal ablation is well tolerated, with mainly mild, transient immune-related events. Although the pre-specified activity endpoint was not met, the observed DCR and PFS support further evaluation of this novel immuno-oncologic strategy. Clinical trial information: NCT03993678 .

PURPOSE:The DNA damage-activated G2/M and S phase cell cycle checkpoint regulator WEE1 kinase is an attractive therapeutic target for solid tumors. We report the results of the dose escalation part of a phase 1 trial assessing the WEE1 inhibitor Debio 0123. PATIENTS AND METHODS:The study enrolled patients with relapsed/refractory advanced solid tumors. Debio 0123 was given orally, once daily. Safety, preliminary antitumor activity, pharmacokinetics, and pharmacodynamics were assessed. RESULTS:Twenty-seven patients were treated with Debio 0123 at doses ranging from 30 to 350 mg. Any grade treatment-related adverse events (TRAEs) were experienced by 92.6% of patients. The most frequent events were increased blood creatinine and QT interval corrected using Fridericia's formula (QTcF) prolongation (37% each). Grade 3 TRAEs were experienced by 33.3% of patients; QTcF prolongation (11%, only observed at 350 mg) and fatigue (7%) were the most common. The maximum tolerated dose and recommended phase 2 dose of Debio 0123 was 260 mg once daily. Proportional pharmacokinetics were seen up to 350 mg, the highest dose level tested. In paired skin biopsies, decreased phosphorylation of the WEE1 target CDC2 was consistently observed at doses ≥200 mg. Exploratory analysis of efficacy showed eight patients (32%) with stable disease as best response, including 5 tumor regressions (up to 20%). CONCLUSIONS:Debio 0123 demonstrated a manageable toxicity profile, exhibited linear pharmacokinetics and showed target engagement at doses ≥200 mg. Given the response observed in a subset of this heavily pre-treated population, results support further investigation of Debio 0123 in selected indications.

Background: CXCR4 is a chemokine receptor implicated in B-cell lymphoma pathogenesis and therapeutic resistance. Targeting CXCR4 is under active investigation using small molecules, antibodies, and peptide antagonists. We evaluated the antitumor activity of the synthetic CXCR4 inhibitors SPX5551 and balixafortide, alone and in combination, across B-cell lymphoma models.Methods: Binding modes were analyzed by molecular docking and molecular dynamics simulations. In vitro assays assessed single-agent and combinatorial effects with BTK inhibitors, PI3K inhibitors, rituximab, and R-CHOP in 20 lymphoma cell lines, including models with acquired resistance. Primary chronic lymphocytic leukemia (CLL) samples were used for translational validation. Transcriptomic and signaling analyses investigated mechanisms of synergy.Results: Structural modeling revealed highly similar CXCR4 binding modes for SPX5551 and balixafortide. SPX5551 showed limited single-agent activity but restored sensitivity to BTK and PI3K inhibitors in resistant marginal zone lymphoma models. Across mantle cell lymphoma (MCL), CLL, and diffuse large B-cell lymphoma models, SPX5551 enhanced the efficacy and/or potency of ibrutinib, copanlisib, rituximab, and R-CHOP. In MCL, dual CXCR4 and BTK inhibition synergistically induced apoptosis, suppressed NF-κB, AKT, and ERK signaling, and repressed inflammatory and MYC-driven transcriptional programs. These effects were confirmed in primary CLL samples, where combined treatment increased cytotoxicity and more effectively inhibited survival signaling than single agents.Conclusions: Although CXCR4 inhibition alone has limited cytotoxicity, it potentiates targeted agents and chemo-immunotherapy, including in drug-resistant models and primary CLL cells. These findings support clinical evaluation of CXCR4 blockade as a combinatorial strategy in B-cell malignancies.

Docetaxel micellar (DM) is a novel polysorbate-free docetaxel formulation that does not require steroid premedication. The aim of this study was to define the safety, pharmacokinetics (PK) and preliminary activity of DM in patients with metastatic castration-resistant prostate cancer (mCRPC). DM was administered intravenously to chemotherapy-naïve patients with mCRPC every 3 weeks following a 3 + 3 design (75, 90, 100 mg/m2) until disease progression or unacceptable toxicity (maximum 10 cycles). A total of 11 patients were recruited from June 2021 to April 2023. No dose limiting toxicities (DLT) were observed at 75 or 90 mg/m2. Two out of 5 patients experienced DLT at 100 mg/m2 (grade 4 neutropenia ≥ 7 days and grade 2 nausea/fatigue/diarrhoea requiring dose reduction at cycle 2, respectively). Most frequent all-grades TRAE included fatigue (91

Abstract Background: IL-1 is a central inflammatory cytokine with context-dependent effects in B-cell lymphomas, capable of supporting anti-tumor immunity but also promoting a pro-tumorigenic microenvironment. Here, we investigated the role of IL-1 in driving resistance to PI3K and BCL2 inhibitors in B-cell lymphoma preclinical. Methods: Cell lines, including derivatives with acquired resistance to PI3K/BCL2 inhibitors obtained by long exposure to the PI3K inhibitor copanlisib in the marginal zone lymphoma (MZL) cell line VL51 (Arribas, ENA 2020), were analyzed using transcriptomics, proteomics, and immunoblotting. Functional assays assessed drug sensitivity, pathway activation, cytokine responses, and the impact of IL-1 stimulation and blockade. A 1,400-compound FDA-approved library was used in combination with copanlisib/venetoclax. Results: VL51 cells with acquired resistance to PI3K/BCL2 inhibitors were characterized by an upregulation of IL1α and IL1β, elevated ERK and STAT3 phosphorylation, and increased expression of pro-survival and cytokine-responsive proteins. Recombinant IL-1α and IL-1β activated NF-κB and Ox-Phos in parental cells. IL-1α induced MYC and SRC targets, while IL-1β activated PI3K and STAT signaling. Either IL-1α or IL-1β reduced sensitivity to PI3K and BCL2 inhibitors in models of MZL (VL51, ESKOL), mantle cell lymphoma (REC1), and diffuse large B-cell lymphoma (OCI-Ly10). IL-1R1 blockade restored drug response. Notably, the combination of both IL-1α and IL-1β further enhanced resistance to copanlisib and to the BCL2 inhibitor venetoclax in VL51 cells. IL-1R1 blockade restored drug response. Notably, the combination of both IL-1α and IL-1β further enhanced the resistance to copanlisib and venetoclax in VL51. The drug-screen identified compounds targeting WNT, CDK, HDAC, HSP, PLK, ALDH1, AURKA, proton pump function, and microtubule dynamics that improved treatment efficacy, particularly in resistant cells. Validation studies demonstrated that several inhibitors effectively counteracted IL-1-associated resistance. The ALDH1 inhibitor disulfiram strongly restored copanlisib/venetoclax sensitivity in resistant models. Additional combinations, including ganetespib, rigosertib, panobinostat, alisertib, and AZ6102, also enhanced responses, indicating that IL-1-responsive stress, epigenetic, and mitotic pathways represent actionable vulnerabilities. Conclusions: IL-1-driven reprogramming promotes resistance to PI3K and BCL2 inhibition in B-cell lymphoma via activation of NF-κB, STAT3, and metabolic survival pathways. Targeting IL-1 signaling or downstream effectors may overcome resistance and offer a promising therapeutic strategy for relapsed or refractory B-cell lymphomas. Citation Format: Alberto J. Arribas, Federica Fuzio, Eleonora Cannas, Michela Chiappa, Luciano Cascione, Giulio Sartori, FIlippo Spriano, Andrea Rinaldi, Georg Stussi, Emanuele Zucca, Davide Rossi, Anastasios Stathis, Andrea Alimonti, Giovanna Damia, Massimo Broggini, Francesco Bertoni. IL-1-driven signaling promotes resistance to PI3K and BCL2 inhibitors in B-cell lymphoma preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1848.

Levels of p-AKT (A, top) and p-ERK (B, bottom) were determined by phospho-flow cytometry upon 1µM of idelalisib. Density plots show the median MFI values of two replicates, negative control (dotted black), parental (grey), resistant (red). (B) Images on the left show the expression of pRELA by immunofluorescence upon 1µM of idelalisib (right) or control (DMSO, left) in parental and resistant (4hr exposure). Boxplot on the right represents the protein quantification from the immunofluorescence experiments. Data derived from two independent experiments. Three representative fields were evaluated from each independent experiment. P-values from Welch Two Sample test performed on mean MFI values.

(A) Multidimensional scaling plot showing a 2-dimensional projection of distances across parental and resistant clones for RNA (GEP, top left), methylation (top right) and miRNA (bottom left) profiles. Magenta dots for resistant and pink for parental. (B) Vulcano plots on methylation (top left), gene expression (RNA-seq, top right) and microRNA (RNA-seq, bottom left) profiles of Karpas1718 resistant compared to parental. GEP-miRNA profiles integration. Moderated t-test (limma R Package) was performed comparing resistant to parental: delta Beta-value (methylation), fold change (RNA-seq), adj.P-value for Bonferroni correction of the nominal p-value. Dots represents genes and triangles represent miRNAs. Red corresponds to higher values in resistant, and blue higher values in parental. The genes or miRNAs inversely correlated with methylation are highlighted in darker color: hypomethylated and overexpressed in dark red (neg-corr UP) and hypermethylated and repressed in dark blue (neg-corr DN).

Panel of antibodies used in flow cytometry experiments.

ABSTRACT:This study analyzed the genetics of classic Hodgkin lymphoma (cHL) by using circulating tumor DNA (ctDNA). Two genetic subtypes were identified, differing in genetic instability mechanisms: one subtype (64% of cases) showed a higher mutation load and a higher fraction of mutations associated with activation-induced cytidine deaminase and microsatellite instability signatures, whereas the other subtype (36% of cases) exhibited chromosomal instability with more somatic copy number alterations. Whole-genome duplication was more common in cHL compared with other B-cell tumors and emerged as a prognostic biomarker for patients undergoing Adriamycin (doxorubicin)-bleomycin-vinblastine-dacarbazine-based therapy. Noncoding regulatory mutations, similar to those in diffuse large B-cell lymphoma, were highly prevalent in 86% of cHL. A recurrent somatic expression quantitative trait locus (seQTL) involving the BCL6 gene was found in 30% of cases. The seQTL of BCL6 aligned with accessible chromatin and increased H3K27 acetylation in cHL, disrupted PRDM1 binding, and co-occurred with BCL6 expression in cHL cells. Weak to strong expression of BCL6 was observed in 68% of cases, and BCL6 expression associated with gene repression similarly in cHL and germinal center B cells. After BCL6 degradation, the core set of genes directly bound and regulated by BCL6 was derepressed in cHL, and proliferation was impaired. The number and clonality of neoantigens was associated with tumor microenvironment type and response to checkpoint blockade. Finally, ctDNA analysis was suggested as a tool to distinguish ambiguous positron emission tomography/computed tomography-positive lesions after treatment.

(A) Cell viability for the combination of idelalisib and the CD20 blocking antibody rituximab in parental and resistant by MTT assay (72h). Bars correspond to the mean of two independent experiments. Error bars represent standard deviation of the mean. Table contains p-values from a moderated t-test comparing each combination to idelalisib as single agent. The benefit of the combination was assessed both as synergism according to the Chou-Talalay combination index (CI, synergistic: CI<0.9, additive: CI~1, antagonistic: CI>1) (B) (2) and as potency (x-axis, synergistic: potency>0.5, additive: 01, additive: 0

Figure S8. Evaluation of benefit from elimusertib in patients with specific tumor-associated DDR alterations (A–D)

Figure S4. Patient enrollment and disposition in the alternative-schedule dose-escalation cohorts

Figure S6. Best response, earliest time point, duration of best response, previous PARPi exposure, platinum sensitivity, biomarker status, and duration of treatment in the prostate (A, B), colorectal (C, D), and breast (E, F) cancer dose-expansion cohorts, and best response, biomarker status, and duration of treatment in the alternative-schedule dose-escalation cohorts (G–J)

(A) Immunoblotting was performed to measure protein levels in parental and resistant clones for pAKT/AKT and pERK/ERK in three independent experiments. GAPDH was used as a loading control. (B) Protein quantification was done normalizing first to GAPDH and then to total protein. Barplot represents the quantification in each of the independent experiments, parental in grey, resistant in red. Median and standard error of the mean for parental and resistant levels in the three experiments. Moderated t-test was performed to determine statistically significance (p<0.05).

Table S3. Single- and multiple-dose pharmacokinetics from the dose-expansion and alternative-schedule dose-escalation cohorts (pharmacokinetic analysis set)

Karpas1718 parental (A-B), SP53 (C-D), OCILY10 (C, E) and JEKO1-Cas9-ERBB4 (F-G) cells were exposed with DMSO (grey), idelalisib (red) or idelalisib + lapatinib (yellow) for 2-weeks. Expression levels of let-7c and miR-29c miRNAs (real-time PCR); and surface ERBB4 and intracellular HBEGF (both by FACS), were evaluated. RQ values calculated by the DDCt method. MFI for median fluorescence intensity. Expression levels of let-7c and miR-29c miRNAs (A), and surface ERBB4 and intracellular HBEGF (B) in Karpas1718 parental cells exposed with DMSO (grey), idelalisib (red) or idelalisib + lapatinib (yellow). Expression levels of let-7c and miR-29c miRNAs (C), and surface ERBB4 and intracellular HBEGF in SP53 (D) and OCILY10 (E) cells exposed with DMSO (grey), idelalisib (red) or idelalisib + lapatinib (yellow). Expression levels of surface ERBB4 and intracellular HBEGF in JEKO1-CNT (scramble sgRNA, F) and JEKO1-ERBB4 (sgRNA-ERBB4, G) cells exposed with DMSO (grey), idelalisib (red) or idelalisib + lapatinib (yellow). Data derived from two independent experiments; error bars represent standard deviation of the mean. * for p<0.05 from a t-test.

Figure S3. Study design for the alternative-schedule dose-escalation cohorts

Figure S7. Serial computed tomography imaging at baseline and after elimusertib treatment in a patient with prostate cancer after six cycles of treatment (A) and a patient with ureteral cancer after two cycles of treatment (B)