Efficacy and safety of lucitanib + nivolumab in patients with advanced gynecologic malignancies: Phase 2 results from the LIO-1 study (NCT04042116; ENGOT-GYN3/AGO/LIO)

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Background: LIO-1 is assessing the oral antiangiogenic, multikinase inhibitor lucitanib in combination with the programmed cell death receptor 1 (PD-1) inhibitor nivolumab. Individualized lucitanib dose titration is being explored to maximize lucitanib exposure and potential clinical benefit of the combination. Here, we present data from stage 1 of a Simon 2-stage design across 4 different types of advanced gynecologic cancers from the phase 2 part of LIO-1. Methods: Patients (pts) with advanced, recurrent, or metastatic endometrial cancer (EC, who received ≥1 prior platinum-based chemotherapy); cervical cancer (CC, who received ≥1 prior platinum-based chemotherapy ± bevacizumab); high-grade ovarian cancer (OC, who received ≥2 prior chemotherapies); or EC/OC with clear-cell histology (EOCC, who received ≥1 prior platinum-based chemotherapy + taxane) were enrolled. Prior PD-1 or programmed cell death ligand 1 (PD-L1) inhibitor treatment was excluded, except for up to 10 pts in the EC cohort. Pts received lucitanib at a starting dose of 6 mg once daily (QD), escalating to 8 mg QD and then 10 mg QD if safety-based titration criteria were met, plus intravenous nivolumab 480 mg every 28 days. The data cutoff was Jan 10, 2022. Results: Across cohorts, 100 pts were enrolled to stage 1; 27 (27%) remain on treatment. To date, 28 (28%) have escalated to lucitanib 8 mg, and 17 (17%) have escalated to the maximum dose of 10 mg. Confirmed responses per RECIST v1.1 have been reported in 5/22 (22.7%; 5 partial responses [PRs]) EC pts, 7/22 (31.8%; 2 complete responses [CRs], 5 PRs) CC pts, 4/33 (12.1%; 4 PRs) OC pts, and 5/23 (21.7%; 1 CR, 4 PRs) EOCC pts. Response duration ranges from 1.9+ to 13.1+ months. Of 5 pts with EC who received prior PD-1 inhibitor, there were 2 PRs, and 1 pt with ongoing stable disease of 7+ months. Grade ≥3 treatment-emergent adverse events (TEAEs) considered related to study treatment were reported in 43 (43%) pts, with hypertension the most frequent (n = 25 [25%]). Forty-six (46%) pts had a lucitanib-related TEAE that led to lucitanib interruption and 12 (12%) had one that led to lucitanib dose reduction. Eleven (11%) and 8 (8%) pts discontinued lucitanib and nivolumab, respectively, due to a treatment-related TEAE. Safety results were generally consistent across tumor cohorts. Conclusions: The combination of lucitanib + nivolumab is active in the treatment of advanced gynecological malignancies and has a manageable safety profile through effective dose titration. Stage 2 enrollment has continued in the CC cohort. Biomarker analysis is ongoing, and more mature efficacy and safety data will be presented at the meeting. Clinical trial information: NCT04042116.

LIO-1: Lucitanib + nivolumab in patients with advanced solid tumors—Updated phase 1b results and initial experience in phase 2 ovarian cancer cohort

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Background: The phase (Ph) 1b part of LIO-1 (NCT04042116; ENGOT-GYN3/AGO/LIO) assessed the oral antiangiogenic, multikinase inhibitor lucitanib + immune checkpoint inhibitor nivolumab, confirming the recommended Ph2 dose (RP2D) of lucitanib as 6 mg QD + nivolumab (480 mg IV every 28 days). To maximize lucitanib exposure and potential clinical benefit of the combination, individualized lucitanib dose titration is being explored in a Ph2 part, across 4 recurrent gynecologic malignancies (endometrial, cervical, ovarian, and ovarian/endometrial clear-cell cancers) using a Simon 2-stage design. We present updated Ph1b data and describe initial experience for the first 24 patients (pts) enrolled in the Ph2 ovarian cancer (OC) cohort. Methods: In Ph1b, pts with advanced, metastatic solid tumors received lucitanib at 6, 8, and 10 mg QD + nivolumab (in a 4+3 dose escalation). In the Ph2 OC cohort, pts with recurrent high-grade epithelial ovarian, fallopian tube, or primary peritoneal cancer (excluding clear-cell histology) with ≥2 prior chemotherapy regimens (including ≥1 platinum doublet) received the combination at RP2D; lucitanib dose was escalated from 6 mg to 8 mg and then to 10 mg QD for pts who met safety-based titration criteria. Visit cutoff was Feb 1, 2021. Results: In the Ph1b part (N = 17), median treatment duration was 109 days (range 14–505+). There has been 1 confirmed complete response (CR; anal cancer) and 1 confirmed partial response (PR; cervical cancer) per RECIST v1.1 with durations of 7.1 and 12.8 months, respectively. Ten pts had stable disease (SD), 3 had progressive disease, and 2 were nonevaluable; 3 pts remain on treatment. Overall disease control rate (CR + PR + SD ≥16 wk) was 47.1%. One dose-limiting toxicity (DLT; grade [G] 3 proteinuria) was observed in a pt receiving lucitanib 6 mg, leading to lucitanib discontinuation; no DLTs were seen at 8 or 10 mg. G ≥3 treatment-emergent adverse events (TEAEs) reported in ≥2 pts included hypertension (HTN; n = 4), fatigue (n = 2), and proteinuria (n = 2). Of the first 24 pts enrolled in the Ph2 OC cohort, 13 (54%) remain on treatment (median duration 59 [2–167+] days). Most frequent any-grade TEAEs were HTN (n = 10), fatigue (n = 8), nausea (n = 7), and proteinuria (n = 6). The only G ≥3 TEAE experienced in ≥2 pts was HTN (n = 4); 1 pt discontinued due to G4 HTN/G2 angina pectoris and 1 pt to G2 colonic perforation. To date, 21 pts have completed ≥1 cycle; 11 met safety-based dose-titration criteria, 10 of whom escalated to the 8 mg lucitanib dose. Of these, 5 pts subsequently escalated to 10 mg. One pt required dose reduction from 6 mg to 4 mg lucitanib. Conclusions: Ph1b data suggest that lucitanib + nivolumab has promising signs of antitumor activity. A safety-based dose-titration strategy appears feasible with manageable toxicity, based on experience from the Ph2 OC cohort to date; efficacy data from this cohort will also be presented. Clinical trial information: NCT04042116.

Phase 1b/2 SEASTAR trial: Safety, pharmacokinetics, and preliminary efficacy of the poly(ADP)-ribose polymerase (PARP) inhibitor rucaparib and angiogenesis inhibitor lucitanib in patients with advanced solid tumors

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Background: Lucitanib is an oral, potent tyrosine kinase inhibitor that selectively inhibits VEGFR1–3, PDGFRα/β, and FGFR1–3. In preclinical studies, antitumor activity of rucaparib is enhanced by lucitanib through antiproliferative, antiangiogenic, and immunological mechanisms. We hypothesize that combining lucitanib and rucaparib is tolerable and can induce a higher hypoxic state and homologous recombination repair deficiency that may lead to greater sensitivity to PARP inhibition. Methods: Patients with advanced solid tumors who had ≥1 prior line of therapy were eligible. Patients with BRCA1/2-mutated ovarian cancer must have received prior PARP inhibitor. Rucaparib and lucitanib were escalated using a 3+3 phase 1b dose-escalation design from starting doses of 300 mg BID and 4 mg QD, respectively. Dose-limiting toxicities (DLTs) were assessed during the first 28 days of treatment. Plasma samples were collected for pharmacokinetic analyses. Genomic alterations were identified by local testing, or through central testing of plasma or tumor tissue. Results: As of February 1, 2021, 16 patients were treated with rucaparib + lucitanib and included in the analyses (Table). Patients had a median of 4 prior therapies; 1 patient had prior PARP inhibitor (olaparib) treatment. Median time on treatment was 58.5 days, with 2 patients ongoing as of the data cutoff date. A DLT of grade 3 proteinuria was seen in Cohort 1; no other DLTs have been reported. Across all cohorts, the most common any-grade treatment-emergent adverse events were nausea (n=9; grade ≥3, n=1), hypertension (n=8; grade ≥3, n=2) and ALT/AST increased (n=7; grade ≥3, n=3). Initial pharmacokinetic data indicated no drug interactions between the 2 agents. To date, 1 patient in Cohort 1 with PALB2-mutated advanced endometrial cancer had a confirmed partial response per RECIST v1.1, lasting 30 weeks; 6 patients had RECIST v1.1 stable disease (SD), including 1 patient each in Cohorts 1 and 3 with SD for ≥16 weeks. In addition, 1 patient in Cohort 2 with BRCA2-mutated castration-resistant prostate cancer continued to receive treatment despite initial progressing bone metastases, resulting in a prostate-specific antigen response (≥50% change) lasting 16 weeks and a best change in sum of target lesions of −46.3%. Conclusions: Initial findings suggest that rucaparib + lucitanib has an acceptable safety profile. The safety and efficacy of the combination are being further evaluated. Clinical trial information: NCT03992131. [Table: see text]

Early effects of tocilizumab in the treatment of moderate to severe active rheumatoid arthritis: a one-week sub-study of a randomised controlled trial (Rapid Onset and Systemic Efficacy [ROSE] Study)

OBJECTIVES

Tocilizumab has demonstrated efficacy in managing rheumatoid arthritis (RA) from week 2 onward. This sub-study assessed effects of tocilizumab plus disease-modifying anti-rheumatic drugs (DMARDs) during the first week of therapy.

METHODS

Rapid Onset and Systemic Efficacy was a 24-week, randomised, double-blind, placebo-controlled, parallel-group trial. Adults with moderate to severe active RA taking DMARDs received tocilizumab 8 mg/kg (or placebo) plus DMARDs every 4 weeks. Data were analysed from the first 62 patients at designated study sites who agreed to clinical evaluation and blood sampling at days 3 and 7 and had C-reactive protein levels ≥1 mg/dl. Outcomes included American College of Rheumatology core data set measures, disease activity score using 28 joints (DAS28) and routine assessment of patient index data 3 (RAPID3) scores.

RESULTS

Baseline evaluations were similar between groups (tocilizumab, n=40; placebo, n=22). Patient global assessments of disease activity and pain improved significantly in favour of tocilizumab (mean change from baseline to day 7: -16.2 [tocilizumab], 0.8 [placebo] [p=0.005] and -12.2 [tocilizumab], 1.4 [placebo] [p=0.01], respectively). Physician global assessment of disease activity also improved more with tocilizumab (-15.4 [tocilizumab], -5.6 [placebo] [p=0.05]). Changes from baseline in tender/swollen joint counts, physical function and RAPID3 scores were not significantly different between groups. DAS28 significantly improved with tocilizumab versus placebo at day 7 (-1.16 [tocilizumab], -0.27 [placebo] [p=0.007]).

CONCLUSIONS

Tocilizumab showed significant improvement in patient-reported disease activity, pain and DAS28 score as early as day 7 after first infusion, earlier than physician-reported measures, which may take longer to manifest.

Sequence and expression patterns of a human EMAP-related protein-2 (HuEMAP-2)

Until recently, the microtubule-associated protein, EMAP, was identified only in echinoderms such as sea urchin, starfish and sand dollar. Sea urchin EMAP localizes to the mitotic apparatus in vivo and modifies the assembly dynamics of microtubules in vitro. To identify domains important for EMAP function, we cloned and sequenced cDNAs for an EMAP-related protein in human. The nucleotide sequence of a human EMAP-related protein-2 (HuEMAP-2) encodes a protein of 649 amino acids in length. The translated polypeptide sequence and domain structure of sea urchin EMAP and HuEMAP-2 are highly conserved, with greater than 57% identity and 77% similarity at the translated amino acid level. Southern blot analysis is consistent with the presence of a single HuEMAP-2 gene in the human genome. Moreover, HuEMAP-2 is a member of a larger protein family with at least four HuEMAP sequences in the NCBI databases. One of these, HuEMAP-1, is identified as the candidate gene for the Usher syndrome 1 a locus (Genomics 43:104-106, 1997). Northern blot analysis indicates that HuEMAP-1, and HuEMAP-2 are expressed in different human tissues. In addition, these RNA blots indicate that HuEMAP-2 transcripts may be differentially spliced in neuronal tissues.

Induction of p21/WAF1 and G1 cell-cycle arrest by the chemopreventive agent apigenin

Apigenin is a plant flavonoid that has been shown to significantly inhibit ultraviolet-induced mouse skin tumorigenesis when applied topically and may be an alternative sunscreen agent for humans. A long-term goal of our laboratory is to elucidate the molecular mechanism or mechanism by which apigenin inhibits skin tumorigenesis. In a previous publication, we characterized the mechanism by which apigenin induced G2/M arrest in keratinocytes. More recent studies in our laboratory have provided evidence that apigenin can induce G1 arrest in addition to arresting cells at G2/M. Here we describe the mechanism of the apigenin-induced G1 arrest in human diploid fibroblasts (HDF). Treatment of asynchronous HDF for 24 h with 10-50 microM apigenin resulted in dose-dependent cell-cycle arrest at both the G0/G1 and G2/M phases as measured by flow cytometry. The G0/G1 arrest was more clearly defined by using HDF that were synchronized in G0 and then released from quiescence by replating at subconfluent densities in medium containing 10-70 microM apigenin. The cells were analyzed for cell-cycle progression or cyclin D1 expression 24 h later. A dose of apigenin as low as 10 microM reduced the percentage of cells in S phase by 20% compared with control cultures treated with solvent alone. Western blot analysis of apigenin-treated HDF indicated that cyclin D1 was expressed at higher levels than in untreated cells, which signifies that they were arrested in G1 phase rather than in a G0 quiescent state. The G1 arrest was further studied by cyclin-dependent kinase 2 (cdk2) immune complex-kinase assays of apigenin-treated asynchronous HDF, which demonstrated a dose-dependent inhibition of cdk2 by apigenin. Inhibition of cdk2 kinase activity in apigenin-treated cells was associated with the accumulation of the hypophosphorylated form of the retinoblastoma (Rb) protein as measured by western blot analysis. The cdk inhibitor p21/WAF1 was also induced in a dose-dependent manner, with a 22-fold induction of p21/WAF1 in 70 microM apigenin-treated cells. In conclusion, apigenin treatment produced a G1 cell-cycle arrest by inhibiting cdk2 kinase activity and the phosphorylation of Rb and inducing the cdk inhibitor p21/WAF1, all of which may mediate its chemopreventive activities in vivo. To our knowledge this is the first report of a chemopreventive agent inducing p21/WAF1, a known downstream effector of the p53 tumor suppressor protein.

Biochemical and functional characterization of soluble multivalent MHC L(d)/Fc gamma 1 and L(d)/Fc mu chimeric proteins loaded with specific peptides

Central to the specificity of the immune system is the interaction between the T cell receptor and the major histocompatibility complex (MHC)-peptide ligand complex. To better understand the nature of this interaction, and to investigate possible avenues for specific therapeutic intervention, we have produced soluble recombinant molecules that can modulate antigen-specific T cells. Our approach involved the construction of recombinant murine genes composed of the MHC class I gene H-2L(d) and the Fc portion of immunoglobulin (Ig) heavy chain genes mu or gamma1. Stable transfectants of these L(d)/Fc gamma1 and L(d)/Fc mu genes generated correctly spliced transcripts and were capable of secreting chimeric protein. Immunoprecipitation analyses demonstrated the presence of chimeric L(d)/ Fc gamma1 and L(d)/Fc mu monomers of approximately 69 kDa and 90 kDa, respectively, as well as chimeric dimers under nonreducing conditions. The capacity of L(d)/Ig molecules to bind specific peptide ligands was demonstrated using radiolabeled peptides or with monoclonal reagents that specifically identify peptide-induced conformational changes in the L(d) ligand binding site. Soluble divalent L(d)/Fc gamma1 molecules were loaded with the murine cytomegalovirus-derived peptide and other L(d)-specific peptide ligands and subsequently isolated and purified. Peptide-loaded L(d)/Fc gamma1 molecules were capable of inhibiting the response of class I-restricted T cells in vitro in a peptide-specific fashion. The development of soluble multivalent chimeric proteins that possess unique properties of both the MHC class I and Ig molecules provides a valuable reagent for the study of potential mechanisms of in vitro and in vivo immune modulation.

The chemopreventive flavonoid apigenin induces G2/M arrest in keratinocytes

Apigenin is a plant flavonoid which has been shown to significantly inhibit UV-induced mouse skin tumorigenesis when applied topically, and may represent an alternative sunscreen agent in humans. We have investigated the molecular mechanism(s) by which apigenin inhibits skin tumorigenesis. Initial studies examined the effects of apigenin on the cell cycle. DNA flow cytometric analysis indicated that culturing cells for 24 h in medium containing apigenin induced a G2/M arrest in two mouse skin derived cell lines, C50 and 308, as well as in human HL-60 cells. The G2/M arrest was fully reversible after an additional 24 h in medium without apigenin. We investigated the effects of apigenin on cyclin B1 and p34cdc2, since cyclin B1/p34cdc2 complexes regulate G2/M progression. Western blot and immune complex kinase assays using whole cell lysates from 308 and C50 cells treated for 24 h with 0-70 microM doses of apigenin demonstrated that apigenin treatment did not change the steady-state level of p34cdc2 protein, but did inhibit p34cdc2 H1 kinase activity in 308 cells. Western blot analysis showed that apigenin treatment of C50 cells and 308 cells inhibited the accumulation of cyclin B1 protein in a dose-dependent manner. The apigenin levels detected in cultured keratinocytes were relevant to those detected in epidermal cells of Sencar mice treated with tumor inhibitory doses of apigenin. In conclusion, we present evidence that apigenin induces a reversible G2/M arrest in cultured keratinocytes, the mechanism of which is in part due to inhibition of the mitotic kinase activity of p34cd2, and perturbation of cyclin B1 levels.