A phase 1/2a open label, multicenter study to assess the safety, tolerability, pharmacokinetics, and efficacy of AFM24 in patients with advanced solid cancers: Study design and rationale

TPS2672

Background: AFM24 is a first-in-class, tetravalent, bispecific, fragment crystallizable-silenced antibody that targets epidermal growth factor receptor-expressing (EGFR+) solid tumors. Of its 4 binding sites, 2 are specific for EGFR, and 2 are specific for CD16A, the Fcγ receptor expressed by natural killer (NK) cells and macrophages. The primary mode of action of AFM24 is not to inhibit EGFR signaling, but to redirect NK cells and macrophages to EGFR+ tumor cells to induce antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), respectively. Preclinical studies showed AFM24 induced killing of EGFR+ tumor cell lines, and the activity was independent of EGFR cell surface expression level. A favorable safety profile was also demonstrated in cynomolgus monkeys. Therefore, AFM24 may utilize the patients’ innate immunity to redirect and activate immune cells, overcoming resistance to current therapies and offering a favorable safety profile. An ongoing Phase 1/2a, first-in-human study (NCT04259450) is evaluating AFM24 in patients with locally advanced or metastatic, treatment refractory solid tumors that are known to express EGFR. The Phase 1 dose escalation study was designed to establish the maximum tolerated dose and/or the recommended Phase 2 dose (RP2D) of AFM24 and evaluated the safety, efficacy, immunogenicity, pharmacokinetic (PK) and pharmacodynamic (PD) responses. AFM24 was administered intravenously once weekly until disease progression, intolerable toxicity, patient withdrawal, or termination at the investigator’s discretion. AFM24 had a well-managed safety profile and the RP2D was established. Methods: In parallel to the continuing dose escalation phase, the Phase 2a dose expansion study was initiated, and the first patient was enrolled in January 2022. This study will assess AFM24 at the RP2D of 480 mg in patients with different EGFR-expressing tumors and will follow a Simon’s two-stage design; the trial will progress to the second stage unless the null hypothesis, that the true tumor response rate is below a specified value, is confirmed at the end of stage one. Eligible patients must have positive histological or cytological staining of EGFR in > 1% of tumor cells. The primary endpoint is to establish the overall response rate (assessed by the investigator per RECIST v1.1) in three disease-specific cohorts. These comprise patients with clear cell renal cell carcinoma (ccRCC), KRAS wild-type colorectal cancer (KRASwt CRC), and EGFR-mutant non-small cell lung cancer (EGFRmut NSCLC). Secondary endpoints include treatment-emergent adverse events, serious adverse events, PK, PD, and immunogenicity. Clinical trial information: NCT04259450.

AFM24 in combination with atezolizumab in patients with advanced EGFR-expressing solid tumors: Phase 1/2a study design and rationale

TPS2673

Background: Innate Cell Engagers (ICE) are bispecific molecules that bind both a tumor cell-surface antigen and to CD16A expressed on natural killer (NK) cells and macrophages, inducing antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), respectively. As epidermal growth factor receptor (EGFR) is often overexpressed in several types of solid tumors, this provides an ideal tumor-cell surface antigen which may be targeted using ICE molecules. AFM24 is a first in class, tetravalent, bispecific, novel ICE targeting EGFR. By binding to EGFR on tumor cells and CD16A on innate immune cells, AFM24 may utilize a patient’s innate immunity to induce ADCC/ADCP towards tumor cells. Anti-programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors, which enhance the anti-tumor activity of a patient’s adaptive immunity, have also demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatments. The combination of AFM24 and the PD-L1 inhibitor, atezolizumab, may therefore represent a rational new treatment modality, enhancing both the innate and adaptive immune responses to target EGFR+ tumor cells. Methods: An ongoing Phase 1/2a open-label, non-randomized, multicenter, dose escalation (Phase 1) and dose expansion (Phase 2a) study was initiated in November 2021 (NCT05109442) to evaluate the safety, tolerability and efficacy of AFM24 in combination with atezolizumab. The primary aim of the Phase 1 study is to determine the maximum tolerated dose and the recommended Phase 2 dose (RP2D) of AFM24. Eligible patients must have advanced histologically confirmed EGFR+ disease and confirmed disease progression after treatment with ≥1 prior therapy. Patients undergo a safety lead-in phase with AFM24 as a single agent 7 days before receiving the combination therapy. A standard 3+3 design will be used to determine the RP2D. Escalating doses of AFM24 will be given to each cohort as weekly intravenous (IV) infusions; the starting dose and at least two planned dose escalations are based on results from the ongoing AFM24 monotherapy trial (NCT04259450). Atezolizumab will be given at a fixed dose of 840 mg as a biweekly IV infusion. Patients will receive AFM24 and atezolizumab treatment until disease progression, intolerable toxicity, patient withdrawal, or termination at the investigator’s discretion. The Phase 2a study will then establish the overall response rate (as per RECIST v1.1) and safety of combination therapy in patients with advanced/ metastatic, or treatment refractory gastric, esophagogastric, hepatocellular, hepatobiliary, pancreatic, or non-small cell lung cancer. For both phases, secondary endpoints include treatment-emergent adverse events, serious adverse events, pharmacokinetics, pharmacodynamics, and immunogenicity. Clinical trial information: NCT05109442.

A phase I/II study of ANV419, a selective IL-2R-beta-gamma targeted antibody-IL-2 fusion protein, in patients with advanced solid tumors

e21552

Background: IL-2R agonists that are well tolerated and can selectively enhance immune activation may improve outcomes of patients with cancer. ANV419 is a potent and highly selective IL-2Rβγ binding agonist, consisting of an antibody specific for the IL-2Rα-binding domain of IL-2, fused to native hIL-2. It is currently being investigated in a phase I/II dose finding study in patients with relapsed/refractory advanced solid tumors (ANV419-001). The primary objective of ANV419-001 is to describe the safety and tolerability of ANV419. Methods: ANV419 is administered intravenously over 15 minutes every 2 weeks, without premedication. Thirteen patients with melanoma (cutaneous (n = 3), uveal (n = 2), mucosal (n = 2), choroidal (n = 1)), renal cell carcinoma (n = 1), hepatocellular carcinoma (n = 1), colorectal cancer (n = 1), esophageal adenocarcinoma (n = 1) and adenoid cystic carcinoma (n = 1) have been dosed in six cohorts. Patients received 3mcg/kg (n = 1), 6mcg/kg (n = 1), 12mcg/kg (n = 1), 24mcg/kg (n = 4), 48mcg/kg (n = 3) 72mcg/kg (n = 3) and 108 mcg/kg (ongoing) of ANV419. Results: ANV419 is well tolerated, all related AEs are Grade 1 or Grade 2 and no DLTs have been observed. Most patients experienced chills (G1), with or without low-grade fever (G1), 2-4 hours after post- infusion, which resolved with antipyretic treatment. Two G2 AEs related to ANV419 have been reported in two patients. One patient was reported to have G2 Cytokine Release Syndrome (hypotension (G2), fever (G1), chills (G1)) and one patient experienced transient, self-limiting G2 elevation of liver function tests. Four Serious Adverse Events were reported in three patients (urinary tract infection, lethargy, thoracic pain and abdominal pain), none of which were considered related to ANV419. Pharmacodynamic evaluation on day 4 post-dosing, showed an effector cell selective, dose dependent increase of Ki-67 positive CD8 T cells (2%, 14%, 37%, 62%, 62%, vs. baseline mean (BLM) 2%) and NK cells (30%, 62%, 75%, 85%, 80%, vs BLM 6%) with a dose independent frequency of Ki67+ Tregs ranging from 4% to 25% (BLM 7%) at 3, 6, 12, 24 and 48 mcg/kg doses respectively. At 72mcg/kg mean CD8 T cell and NK proliferation was 70% and 51% respectively, while the mean Treg proliferation increased to 48%. Pharmacokinetic data (including patients treated with up to 24 mcg/kg ANV419) show a dose proportional increase of the ANV419 plasma concentration. The estimated half-life at the 24mcg/kg dose is 17.6 hrs. Four patients continue to receive ANV419. Of the 11 patients who received at least two cycles of ANV419, 4 were assessed to have stable disease. One patient progressed after 24 weeks of confirmed stable disease. Conclusions: Overall, ANV419 is well tolerated and selectively induces expansion and proliferation of CD8 T cells and NK cells, but not Tregs up to a dose of at least 48mcg/kg. Updated data will be shared during the meeting. Clinical trial information: NCT04855929.

LEAP-005: A phase 2 multicohort study of lenvatinib plus pembrolizumab in patients with previously treated selected solid tumors—Results from the gastric cancer cohort

4030

Background: Lenvatinib, an anti-angiogenic multiple receptor tyrosine kinase inhibitor, in combination with the anti‒PD-1 antibody pembrolizumab, has demonstrated promising antitumor activity with manageable safety in the first- or second-line in a phase 2 trial of patients with advanced gastric cancer. LEAP-005 (NCT03797326) is a phase 2, multicohort, nonrandomized, open-label study evaluating efficacy and safety of lenvatinib plus pembrolizumab in patients with previously treated advanced solid tumors; here, we present findings from the gastric cancer cohort of LEAP-005. Methods: Eligible patients were aged ≥18 years with histologically or cytologically confirmed metastatic and/or unresectable gastric cancer, received at least 2 prior lines of therapy, had measurable disease per RECIST v1.1, ECOG PS of 0‒1, and provided a tissue sample evaluable for PD-L1 expression. Patients received lenvatinib 20 mg once daily plus pembrolizumab 200 mg Q3W for up to 35 cycles of pembrolizumab (approximately 2 years) or until confirmed disease progression, unacceptable toxicity, or withdrawal of consent. Treatment with lenvatinib could continue beyond 2 years in patients experiencing clinical benefit. Primary endpoints were ORR (per RECIST v1.1 by blinded independent central review) and safety. Secondary endpoints included disease control rate (DCR; comprising CR, PR, and SD), duration of response (DOR), PFS, and OS. Tumor imaging was performed Q9W from treatment initiation for 54 weeks, then Q12W to week 102, and Q24W thereafter. Results: 31 patients were enrolled in the gastric cancer cohort; 87% were male, 58% were aged < 65 years, and 71% had PD-L1 combined positive score (CPS) ≥1. Median time from first dose to data cutoff (April 10, 2020) was 7.0 months (range, 1.9‒11.9); 19 patients (61%) had discontinued treatment. ORR was 10% (95% CI, 2‒26); 1 patient had CR (3%), and 2 had a PR (6%). 12 patients (39%) had SD. Median DOR was not reached (range, 2.1+ to 2.3+ months). DCR was 48% (95% CI, 30‒67). Median PFS was 2.5 months (95% CI, 1.8‒4.2). Median OS was 5.9 months (95% CI, 2.6‒8.7). 28 patients (90%) had treatment-related AEs, including 13 patients (42%) with grade 3‒5 AEs. 1 patient had a treatment-related AE that led to death (hemorrhage). 8 patients (26%) had immune-mediated AEs: hypothyroidism (n = 5), hyperthyroidism (n = 2), and pneumonitis (n = 1). There were no infusion-related reactions. Conclusions: In patients with advanced gastric cancer who received 2 prior lines of therapy, lenvatinib plus pembrolizumab demonstrated promising antitumor activity and a manageable safety profile. Based on these data, enrollment in the gastric cancer cohort has been expanded to 100 patients. Clinical trial information: NCT03797326.

The potential utility of end-binding protein 1 (EB1) as response-predictive biomarker for lisavanbulin: A phase 2 study of lisavanbulin (BAL101553) in adult patients with recurrent glioblastoma

TPS2068

Background: Lisavanbulin (BAL101553, prodrug of BAL27862) is a novel tumor checkpoint controller that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule (MW 387) shown in rodents to penetrate the brain (1:1 plasma ratio) with promising antitumor activity in orthotopic models of glioblastoma (GB) as monotherapy or in combination with radiotherapy (RT) ± chemotherapy. In a completed phase 1 study (Lopez et al. ESMO 2020, NCT02490800) with daily oral lisavanbulin in patients with recurrent GB or high-grade glioma, the RP2D was determined at 25 mg/day. In this phase 1 study, two patients (out of 20 patients) with GB show a long-lasting (> 2 years) clinical benefit with improvement in clinical symptoms and in target and/or non-target GB lesions as per RANO criteria. Both patients show strong end-binding protein 1 (EB1) expression in their GB tissues as assessed by immunohistochemistry staining. EB1, a protein located on the plus-ends of microtubules, is involved in microtubule (MT) function and has been associated with stemness of glioma cells and a more aggressive disease. Data from GB mouse models suggest that EB1 is a predictive marker for response to lisavanbulin. The prevalence of EB1-positivity in GB is estimated at ̃5%. This ongoing phase 2 study is an extension of the completed Phase 1 study and is conducted to confirm prospectively whether EB1 is a response-predictive biomarker for lisavanbulin in GB. Methods: This is an ongoing multicenter, open-label, phase 2 study using a Simon Two-Stage design to assess the efficacy of lisavanbulin in patients with recurrent GB. The study is being performed in the UK, Switzerland and Germany. Patients with histologically-confirmed GB and recurrent disease after prior RT with alkylating chemotherapy (de-novo/primary GB) or after prior chemotherapy or RT (secondary GB), are eligible for enrollment if their GB archival tumor tissue is EB1-positive. EB1-positivity is defined as moderate to strong EB1-staining in at least 70% of GB tumor cells using a CE-marked immunohistochemistry Clinical Trial Assay (Targos Molecular Pathology GmbH). The primary study objective is the overall response rate by RANO, with MRI scans being performed every 8 weeks. Secondary endpoints include progression-free survival and overall survival. Adverse events are assessed using CTCAEv5. To develop a potential RNA-based response signature, molecular profiling of tumor tissue is performed using whole transcriptome sequencing (RNAseq) in each patient enrolled in the study to define the genomic expression profiles in patients with EB1-positive GB. Nine evaluable patients are to be enrolled in Stage 1, and an additional 10 patients will be enrolled in stage 2 if at least 2 objective responses per RANO criteria are observed in stage 1. Clinical trial information: 02490800.

LEAP-005: A phase 2 multicohort study of lenvatinib plus pembrolizumab in patients with previously treated selected solid tumors—Results from the colorectal cancer cohort

3564

Background: Pembrolizumab (pembro), an anti-PD-1 antibody, is approved for the treatment of patients (pts) with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair (MMR) deficient colorectal cancer, both as first-line treatment and after progression following treatment with fluoropyrimidine, oxaliplatin, and irinotecan. The combination of lenvatinib, a multiple receptor tyrosine kinase inhibitor, and anti-PD-1 treatment showed synergistic antitumor activity in preclinical models. LEAP-005 (NCT03797326) is evaluating the efficacy and safety of lenvatinib plus pembro in pts with previously treated advanced solid tumors. We present findings from the colorectal cancer cohort. Methods: In this nonrandomized, open-label, phase 2 study, adult pts (aged ≥18 y) with histologically/cytologically documented metastatic and/or unresectable colorectal cancer, non–MSI-H/pMMR tumor per local determination, previous treatment with oxaliplatin and irinotecan in separate lines of therapy, measurable disease per RECIST v1.1, ECOG PS of 0‒1, and a tissue sample evaluable for PD-L1 expression were eligible. Pts received lenvatinib 20 mg QD plus pembro 200 mg Q3W for up to 35 cycles of pembro (̃2 y) or until confirmed disease progression, unacceptable toxicity, or withdrawal of consent. Treatment with lenvatinib could continue beyond 2 y in pts with clinical benefit. Primary endpoints were ORR (per RECIST v1.1 by blinded independent central review) and safety. Secondary endpoints included disease control rate (DCR), duration of response (DOR), PFS, and OS. Tumor imaging was performed Q9W from treatment initiation for 54 wks, then Q12W to week 102, and Q24W thereafter. Results: 32 pts with colorectal cancer received treatment with lenvatinib plus pembro (median age, 56 y [range, 36-77]; male, 81%; 3L, 91%); median time from first dose to data cutoff (April 10, 2020) was 10.6 mo (range, 5.9-13.1). ORR was 22% (95% CI, 9–40; table). Grade 3–5 treatment-related AEs occurred in 16 (50%) pts. Treatment-related AEs led to treatment discontinuation in 3 pts (grade 2 ischemic stroke [n = 1], grade 3 increased liver transaminases [n = 1], grade 5 intestinal perforation [n = 1]). Conclusions: In pts with previously treated advanced non–MSI-H/pMMR colorectal cancer, lenvatinib plus pembro demonstrated promising antitumor activity and a manageable safety profile. Enrollment in the colorectal cohort was expanded to 100 pts. Clinical trial information: NCT03797326. [Table: see text]

A phase 1 study of SGN-B6A, an antibody-drug conjugate targeting integrin beta-6, in patients with advanced solid tumors (SGNB6A-001, Trial in Progress)

TPS3144

Background: The extracellular matrix (ECM) plays an important role in solid tumor pathogenesis and is a major focus of research and therapeutic targeting. Integrin beta-6 is a cell surface receptor that interacts with the ECM to mediate cellular adhesion. Integrin beta-6 is overexpressed in numerous solid tumors and its expression is a negative prognostic marker in cancers including colorectal, non-small cell lung, gastric, and cervical cancers. SGN-B6A is an investigational vedotin, an antibody-drug conjugate directed against integrin beta-6 to selectively deliver the cytotoxic agent monomethyl auristatin E, which binds tubulin and induces apoptosis. In multiple xenograft models, treatment with SGN-B6A resulted in tumor growth delay and regression in tumor volume when compared to non-binding control. Methods: SGNB6A-001 (NCT04389632) is a phase 1, first-in-human, open-label, multicenter study designed to evaluate the safety, tolerability, pharmacokinetics (PK), and antitumor activity of SGN-B6A in adults with select advanced solid tumors. Primary objectives are to evaluate the safety and tolerability of SGN-B6A in patients with advanced solid tumors, identify the maximum tolerated dose, and identify a recommended dose and schedule. The study has 2 parts: dose escalation (Part A) and dose expansion with multiple disease-specific cohorts and a biology cohort (Part B). SGN-B6A will initially be given by intravenous infusion on Days 1, 8, and 15 of 21-day cycles. The dose escalation (Part A) will be conducted using the modified toxicity probability interval method to determine a dose that demonstrates a dose-limiting toxicity rate of 25% with a 5% margin. The dose and schedule for Part B will be determined based on evaluation of safety, PK, and pharmacodynamic biomarkers. Response evaluations will be based on RECIST v1.1. Patients must be ≥18 years old and have histologically or cytologically confirmed metastatic or unresectable solid malignancy within one of the following tumor types: non-small cell lung cancer, head and neck squamous cell cancer, breast cancer, esophageal cancer, ovarian cancer, cutaneous squamous cell cancer, exocrine pancreatic adenocarcinoma, bladder cancer, cervical cancer, or gastric cancer. After an appropriate dose and schedule are determined in Part A, safety and preliminary antitumor efficacy of SGN-B6A will be evaluated in indication-specific cohorts (Part B). This study is ongoing in sites across North America and Europe. Clinical trial information: NCT04389632.

Expression of end-binding protein 1 (EB1), a potential response-predictive biomarker for lisavanbulin, in glioblastoma and various other solid tumor types

3118

Background: EB1, a protein located on the plus-ends of microtubules is involved in microtubule function and has been associated with glioblastoma (GBM) stem-cell-ness and more aggressive disease. Lisavanbulin (BAL101553) is a prodrug of the lipophilic small molecule BAL27862, that promotes tumor cell death by modulating the spindle assembly checkpoint and has been shown in rodents to efficiently penetrate the brain. Data from GBM mouse models and recent phase 1 clinical data (Lopez et al. ESMO 2020) suggest that EB1 is a response-predictive marker for lisavanbulin in GBM. A phase 2 study is ongoing to confirm this hypothesis (NCT02490800). A proof-of-concept in GBM would support an expansion of EB1-directed lisavanbulin clinical development in non-GBM tumors, which requires prevalence estimates of EB1-positivity in non-GBM tumor types. Methods: Tissue samples from GBM and other tumor types were stained for EB1 using a CE-marked immunohistochemistry Clinical Trial Assay (Targos Molecular Pathology GmbH, Kassel Germany). EB1-positivity was assessed by a board-certified pathologist based on the percentage of tumor cells showing moderate or strong staining for EB1, using thresholds of ≥50%, ≥60% and ≥70% of tumor cells with EB1 positivity. Whole transcriptome sequencing (WTS) using RNAseq was performed in a subset of tissue samples to develop a potential RNA-based predictive response signature for lisavanbulin. Results: 73 GBM tissue samples and 333 tissue samples from 13 other cancer types were stained for EB1. The strongest overall signal for EB1-positivity was obtained for medulloblastoma, neuroblastoma and GBM. In addition, moderate or strong EB1-staining in ≥50% of tumor cells was observed in samples from colorectal cancer (CRC), non small-cell lung cancer (NSCLC), metastatic melanoma, small-cell lung cancer (SCLC) and triple-negative breast cancer (TNBC). An expanded staining campaign is ongoing in these cancer types. Initial results from the ongoing WTS analyses show marked differences in gene expression profiles between EB1-positive and -negative cases. Conclusions: Strong EB1-positivity is infrequent but occurs in a variety of tumor types, with the strongest signals in medulloblastoma, neuroblastoma and GBM. A phase 2 study is ongoing to assess prospectively whether EB1 is a response-predictive biomarker for lisavanbulin in GBM.[Table: see text]

Correction to: Radiological evaluation of malignant pleural mesothelioma - defining distant metastatic disease

An amendment to this paper has been published and can be accessed via the original article.

LEAP-005: A phase II multicohort study of lenvatinib plus pembrolizumab in patients with previously treated selected solid tumors—Results from the gastric cancer cohort

230

Background: Lenvatinib, an anti-angiogenic multiple receptor tyrosine kinase inhibitor, in combination with the anti‒PD-1 antibody pembrolizumab, has demonstrated promising antitumor activity with manageable safety in the first- or second-line in a phase 2 trial of patients with advanced gastric cancer. LEAP-005 (NCT03797326) is a phase 2, multicohort, nonrandomized, open-label study evaluating efficacy and safety of lenvatinib plus pembrolizumab in patients with previously treated advanced solid tumors; here, we present findings from the gastric cancer cohort of LEAP-005. Methods: Eligible patients were aged ≥18 years with histologically or cytologically confirmed metastatic and/or unresectable gastric cancer, received at least 2 prior lines of therapy, had measurable disease per RECIST v1.1, ECOG PS of 0‒1, and provided a tissue sample evaluable for PD-L1 expression. Patients received lenvatinib 20 mg once daily plus pembrolizumab 200 mg Q3W for up to 35 cycles of pembrolizumab (approximately 2 years) or until confirmed disease progression, unacceptable toxicity, or withdrawal of consent. Treatment with lenvatinib could continue beyond 2 years in patients experiencing clinical benefit. Primary endpoints were ORR (per RECIST v1.1 by blinded independent central review) and safety. Secondary endpoints included disease control rate (DCR; comprising CR, PR, and SD), duration of response (DOR), PFS, and OS. Tumor imaging was performed Q9W from treatment initiation for 54 weeks, then Q12W to week 102, and Q24W thereafter. Results: 31 patients were enrolled in the gastric cancer cohort; 87% were male, 58% were aged < 65 years, and 71% had PD-L1 combined positive score (CPS) ≥1. Median time from first dose to data cutoff (April 10, 2020) was 7.0 months (range, 1.9‒11.9); 19 patients (61%) had discontinued treatment. ORR was 10% (95% CI, 2‒26); 1 patient had CR (3%), and 2 had a PR (6%). 12 patients (39%) had SD. Median DOR was not reached (range, 2.1+ to 2.3+ months). DCR was 48% (95% CI, 30‒67). Median PFS was 2.5 months (95% CI, 1.8‒4.2). Median OS was 5.9 months (95% CI, 2.6‒8.7). 28 patients (90%) had treatment-related AEs, including 13 patients (42%) with grade 3‒5 AEs. 1 patient had a treatment-related AE that led to death (hemorrhage). 8 patients (26%) had immune-mediated AEs: hypothyroidism (n = 5), hyperthyroidism (n = 2), and pneumonitis (n = 1). There were no infusion-related reactions. Conclusions: In patients with advanced gastric cancer who received 2 prior lines of therapy, lenvatinib plus pembrolizumab demonstrated promising antitumor activity and a manageable safety profile. Based on these data, enrollment in the gastric cancer cohort has been expanded to 100 patients. Clinical trial information: NCT03797326.

LEAP-005: A phase II multicohort study of lenvatinib plus pembrolizumab in patients with previously treated selected solid tumors—Results from the colorectal cancer cohort

94

Background: Pembrolizumab (pembro), an anti-PD-1 antibody, is approved for the treatment of patients (pts) with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair (MMR) deficient colorectal cancer, both as first-line treatment and after progression following treatment with fluoropyrimidine, oxaliplatin, and irinotecan. The combination of lenvatinib, a multiple receptor tyrosine kinase inhibitor, and anti-PD-1 treatment showed synergistic antitumor activity in preclinical models. LEAP-005 (NCT03797326) is evaluating the efficacy and safety of lenvatinib plus pembro in pts with previously treated advanced solid tumors. We present findings from the colorectal cancer cohort. Methods: In this nonrandomized, open-label, phase 2 study, adult pts (aged ≥18 y) with histologically/cytologically documented metastatic and/or unresectable colorectal cancer, non–MSI-H/pMMR tumor per local determination, previous treatment with oxaliplatin and irinotecan in separate lines of therapy, measurable disease per RECIST v1.1, ECOG PS of 0‒1, and a tissue sample evaluable for PD-L1 expression were eligible. Pts received lenvatinib 20 mg QD plus pembro 200 mg Q3W for up to 35 cycles of pembro (~2 y) or until confirmed disease progression, unacceptable toxicity, or withdrawal of consent. Treatment with lenvatinib could continue beyond 2 y in pts with clinical benefit. Primary endpoints were ORR (per RECIST v1.1 by blinded independent central review) and safety. Secondary endpoints included disease control rate (DCR), duration of response (DOR), PFS, and OS. Tumor imaging was performed Q9W from treatment initiation for 54 wks, then Q12W to week 102, and Q24W thereafter. Results: 32 pts with colorectal cancer received treatment with lenvatinib plus pembro (median age, 56 y [range, 36-77]; male, 81%; 3L, 91%); median time from first dose to data cutoff (April 10, 2020) was 10.6 mos (range, 5.9-13.1) ORR was 22% (95% CI, 9-40; Table). Grade 3-5 treatment-related AEs occurred in 16 (50%) pts. Treatment-related AEs led to treatment discontinuation in 3 pts (grade 2 ischemic stroke [n = 1], grade 3 increased liver transaminases [n = 1], grade 5 intestinal perforation [n = 1]). Efficacy Results. Clinical trial information: NCT03797326. NR, not reached aConfirmation was not required for best overall response of SD, but a final visit response of SD or better must have occurred ≥6 wks after starting study treatment Conclusions: In pts with previously treated advanced non–MSI-H/pMMR colorectal cancer, lenvatinib plus pembro demonstrated promising antitumor activity and a manageable safety profile. Enrollment in the colorectal cohort was expanded to 100 pts. [Table: see text]

Radiological evaluation of malignant pleural mesothelioma - defining distant metastatic disease

BACKGROUND

Malignant pleural mesothelioma (MPM) is traditionally characterized by local destructive spread of the pleura and surrounding tissues. Patient outcomes in MPM with distant metastatic dissemination are lacking.

METHODS

In this retrospective study, we reviewed a cohort of 164 MPM patients referred to a Phase I trials unit, aiming to describe identified metastatic sites, and correlate with clinical outcomes.

RESULTS

67% of patients were diagnosed with distant metastatic disease with a high incidence of bone (19%), visceral (14%), contralateral lung (35%) and peritoneal metastases (22%). Peritoneal metastases were more likely in epithelioid versus biphasic/ sarcomatoid MPM (p = 0.015). Overall survival was 23.8 months with no statistical difference in survival between those with distant metastases and those without.

CONCLUSIONS

This report highlights the frequency of distant metastases and encourages further radiological investigations in the presence of symptoms. In particular, given the relatively high incidence of bone metastases, bone imaging should be considered in advanced MPM clinical workflow and trial protocols. The presence of distant metastases does not appear to have prognostic implications under existing treatment paradigms. This cohort of MPM patients gives an indication of patterns of metastatic spread that are likely to become prevalent as prognosis improves with emerging treatment paradigms.

Intermittent schedules of the oral RAF-MEK inhibitor CH5126766/VS-6766 in patients with RAS/RAF-mutant solid tumours and multiple myeloma: a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study

BACKGROUND

CH5126766 (also known as VS-6766, and previously named RO5126766), a novel MEK-pan-RAF inhibitor, has shown antitumour activity across various solid tumours; however, its initial development was limited by toxicity. We aimed to investigate the safety and toxicity profile of intermittent dosing schedules of CH5126766, and the antitumour activity of this drug in patients with solid tumours and multiple myeloma harbouring RAS-RAF-MEK pathway mutations.

METHODS

We did a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study at the Royal Marsden National Health Service Foundation Trust (London, UK). Patients were eligible for the study if they were aged 18 years or older, had cancers that were refractory to conventional treatment or for which no conventional therapy existed, and if they had a WHO performance status score of 0 or 1. For the dose-escalation phase, eligible patients had histologically or cytologically confirmed advanced or metastatic solid tumours. For the basket dose-expansion phase, eligible patients had advanced or metastatic solid tumours or multiple myeloma harbouring RAS-RAF-MEK pathway mutations. During the dose-escalation phase, we evaluated three intermittent oral schedules (28-day cycles) in patients with solid tumours: (1) 4·0 mg or 3·2 mg CH5126766 three times per week; (2) 4·0 mg CH5126766 twice per week; and (3) toxicity-guided dose interruption schedule, in which treatment at the recommended phase 2 dose (4·0 mg CH5126766 twice per week) was de-escalated to 3 weeks on followed by 1 week off if patients had prespecified toxic effects (grade 2 or worse diarrhoea, rash, or creatinine phosphokinase elevation). In the basket dose-expansion phase, we evaluated antitumour activity at the recommended phase 2 dose, determined from the dose-escalation phase, in biomarker-selected patients. The primary endpoints were the recommended phase 2 dose at which no more than one out of six patients had a treatment-related dose-limiting toxicity, and the safety and toxicity profile of each dosing schedule. The key secondary endpoint was investigator-assessed response rate in the dose-expansion phase. Patients who received at least one dose of the study drug were evaluable for safety and patients who received one cycle of the study drug and underwent baseline disease assessment were evaluable for response. This trial is registered with ClinicalTrials.gov, NCT02407509.

FINDINGS

Between June 5, 2013, and Jan 10, 2019, 58 eligible patients were enrolled to the study: 29 patients with solid tumours were included in the dose-escalation cohort and 29 patients with solid tumours or multiple myeloma were included in the basket dose-expansion cohort (12 non-small-cell lung cancer, five gynaecological malignancy, four colorectal cancer, one melanoma, and seven multiple myeloma). Median follow-up at the time of data cutoff was 2·3 months (IQR 1·6-3·5). Dose-limiting toxicities included grade 3 bilateral retinal pigment epithelial detachment in one patient who received 4·0 mg CH5126766 three times per week, and grade 3 rash (in two patients) and grade 3 creatinine phosphokinase elevation (in one patient) in those who received 3·2 mg CH5126766 three times per week. 4·0 mg CH5126766 twice per week (on Monday and Thursday or Tuesday and Friday) was established as the recommended phase 2 dose. The most common grade 3-4 treatment-related adverse events were rash (11 [19%] patients), creatinine phosphokinase elevation (six [11%]), hypoalbuminaemia (six [11%]), and fatigue (four [7%]). Five (9%) patients had serious treatment-related adverse events. There were no treatment-related deaths. Eight (14%) of 57 patients died during the trial due to disease progression. Seven (27% [95% CI 11·6-47·8]) of 26 response-evaluable patients in the basket expansion achieved objective responses.

INTERPRETATION

To our knowledge, this is the first study to show that highly intermittent schedules of a RAF-MEK inhibitor has antitumour activity across various cancers with RAF-RAS-MEK pathway mutations, and that this inhibitor is tolerable. CH5126766 used as a monotherapy and in combination regimens warrants further evaluation.

FUNDING

Chugai Pharmaceutical.

A phase I trial a FR alpha targeted thymidylate synthase inhibitor CT900 exploring four schedules of treatment in expansion cohorts of patients with high-grade serous ovarian cancer

6043

Background: CT900 (BTG945/ONX-0801) is a novel small molecule that binds to folate receptor alpha (FRα), is internalized and causes cytotoxicity by thymidylate synthase inhibition. Methods: The aims of the expansion cohorts were to determine toxicity, response rates and correlation of the response to FRα expression in patients with HGSOC (NCT02360345). Four expansion cohorts were studied which included: schedule A (6 mg/m2/q every 2 weeks), schedule B (12 mg/m2/q every 2 weeks), schedule C (12 mg/m2/q every 2 weeks with 12 mg dexamethasone IV and 8 mg of dexamethasone for 2 days) and schedule D (12 mg/m2/q every 3 weeks). Response rates were assessed by RECIST V1.1 and GCIG CA125 response criteria. Patients who were withdrawn for reasons other than toxicity within 8 weeks (cohorts A, B, C) and 12 weeks (cohort D) were not assessable for efficacy. FRα expression was quantified using immunohistochemistry. Results: A total of 67 patients were treated in the 4 cohorts (14, 25, 15 and 13 for cohorts A, B, C and D). The median age was 62 (IQR 57 - 68) and the median lines of previous treatment was 5 (range 1 to 13). A majority of patients were platinum resistant. The most common toxicities across all expansion cohorts were: fatigue (51%), nausea (36%), anemia (27%), fever (25%), AST elevation (21%), most of which were grade 1 - 2. Toxicity of special interest included radiological changes of pneumonitis and was 15% in all cohorts (7%, 16%, 27% and 8% in cohorts A, B, C and D, respectively). These changes were grade 1 - 2 in all but one case. RECIST response rates in evaluable patients across the different cohorts were: A 1/8 (13%), B 6/21 (29%), C 5/12 (42%) and D 2/12 (17%). FRα expression in archival tumor tissue was measured in 59/67 patients. Expression was found to be high/medium in 43/59 (73%), low in 7/59 (12%) and negative/very low in 9/59 (15%). In patients with high/medium FRα expression, the RECIST response rates in different cohorts were: A 0/9 (0%), B 6/16 (38%), C 4/12 (33%) and D 1/6 (17%). The CA125 response rate in all patients within cohort B was 13/25 (52%) and 10/16 (63%) in patients with high/medium FRα expression. Conclusions: CT900 has shown clinical activity in patients with heavily pre-treated platinum-resistant, high/medium FRα expressing HGSOC. Based on toxicity and efficacy, the schedule of 12 mg/m2/q2 weekly (schedule B) is the recommended phase II dose for further evaluation in patients with relapsed high/medium FRα expressing HGSOC. Clinical trial information: NCT02360345.

Epcoritamab (GEN3013; DuoBody-CD3×CD20) to induce complete response in patients with relapsed/refractory B-cell non-Hodgkin lymphoma (B-NHL): Complete dose escalation data and efficacy results from a phase I/II trial

8009

Background: CD3×CD20 bispecific antibodies (bsAbs) have demonstrated promising results for the treatment of pts with R/R B-NHL. Epcoritamab is a novel subcutaneously administered bsAb with a favorable safety profile and encouraging preliminary anti-tumor activity at low doses in both aggressive and indolent B-NHL. Here we present updated safety and efficacy data from the ongoing trial (NCT03625037). Methods: Adults with R/R CD20+ B-NHL received a single SC injection of flat-dose epcoritamab in 28-day cycles (q1w: cycle 1–2; q2w: cycle 3–6; q4w thereafter) until disease progression or unacceptable toxicity. Primary objectives are determination of maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Secondary objectives include anti-tumor activity. Results: As of 8 Jan 2020, 41 pts with median age of 66 (range: 21–82) were enrolled. Most pts had DLBCL/HGBCL (73%) or FL (20%) and received a median (range) of 3 (1–6) and 5 (2–18) prior lines of treatment. No DLTs were observed (median follow-up: 4.7 mo; range: 3.7– 5.6). MTD has not been reached. Most common TEAEs (>35%) were pyrexia (71%), fatigue (46%), and injection site reaction (39%; all Gr 1). AEs of special interest included cytokine release syndrome (59%; all Gr 1/2; all resolved) and cytokine release-related decreased CARTOX-10 score (n=1). There was no clinical tumor lysis syndrome or treatment-related deaths. Treatment is ongoing in 13 pts. Anti-tumor activity was observed at minimal efficacy threshold (based on PK modelling) for DLBCL/HGBCL and FL (Table). Complete dose escalation data and RP2D will be presented. Conclusions: SC epcoritamab continues to demonstrate a favorable safety profile across all doses with no ≥Gr 3 CRS and no DLTs. Dose escalation data show improved efficacy as doses reach above the modeled predicted exposure threshold, inducing CRs in heavily pretreated DLBCL pts. All pts achieving CRs remain in remission. Clinical trial information: NCT03625037 . [Table: see text]

PIPA: A phase Ib study of β-isoform sparing phosphatidylinositol 3-kinase (PI3K) inhibitor taselisib (T) plus palbociclib (P) and fulvestrant (FUL) in PIK3CA-mutant (mt) ER-positive and taselisib (T) plus palbociclib (P) in PIK3CA-mutant (mt) ER-negative advanced breast cancer

1051

Background: PI3K and CDK4/6 inhibitors synergise in ER+ve and –ve PIK3CA-mt breast cancer (BC) models. Escalation phase of this study set recommended phase 2 dose (RP2D) at P 125mg on a 3/1 scheme plus T 2mg daily ( Lim, ASCO 2017). Here we present the results of expansion cohorts for PIK3CA-mt BC patients (pts). Methods: The primary objective was to assess the confirmed objective response rate (ORR) of the P + T + FUL triplet in pts with measurable PIK3CA-mt ER+ve HER2-ve advanced BC, with up to two prior lines of chemotherapy for advanced disease. PIK3CA mutation was assessed in tissue or plasma DNA analysis. Exploratory objectives included assessment of efficacy of P + T in a cohort of pts with PIK3CA-mt advanced ER-ve BC. Safety is reported overall for 44 patients including an additional cohort of 7 PIK3CA-unknown ER+ve BC pts treated with P + T + letrozole (LET). For the P + T + FUL triplet a Simon minmax design was used, with 6 responses in 25 patients required to declare efficacy. Results: We recruited 24 assessable patients with PIK3CA-mt ER+ve HER2-ve advanced BC, median age 57 (42-74), median 3 (1-9) prior therapy lines for advance disease, with 24 (100%) receiving prior endocrine therapy and 23 (96%) prior aromatase inhibitor. ORR was 33% (8/24, 95% CI 16-55%), with median progression free survival (PFS) 7.9m (95% CI 5.6-11.8). For the 11 assessable PIK3CA-mt ER-ve pts (8 HER2-ve, 3 HER2+ve) receiving P + T, ORR was 0% (0/11), clinical benefit rate (CBR) 27% (3/11) and median PFS 4.3m (95% CI 1.8-6.1). Most common AEs across all cohorts were neutropenia (80%), fatigue (50%), mucositis (50%) and thrombocytopenia (30%). Most common grade 3/4 AEs were neutropenia (57%) and rash (11%). Translational research is ongoing. Conclusions: The triplet of P + T + FUL has promising efficacy in pre-treated PIK3CA-mt ER+ve advanced BC. A subset of patients with PIK3CA-mt ER-ve advanced BC had clinical benefit from P + T. The combination of P + T +/- FUL/LET was well tolerated with anticipated AEs. Clinical trial information: NCT02389842.

Evaluation of Electronic Activity Monitors (EAMs) during phase I clinical trials

e18175

Background: EAMs are wearable devices that record aspects of activity, including heart rate and step count. Medical oncologists use performance status (PS) (such as ECOG and Karnofsky) to assess patient’s physical function and to aid treatment decisions. These are subject to patient and physician bias. Our study evaluated the use of EAMs (Fitbit ®) during phase I trials, correlating EAM indices with PS and patient outcomes. Methods: We recruited patients in an academic hospital Drug Development Unit. Patients participating in a phase I trial consented to wear an EAM prior to starting and during the first treatment cycle. Physicians assessed PS at 4 timepoints. Outcomes (progression free survival (PFS), overall survival (OS), adverse events) were recorded. Results: Twenty-five patients were enrolled. At the time of data analysis results were available for 16 patients. Patients wore the EAM for an average of 70.3% (standard deviation 21%) of their time on study, defined as time with recordable heart rate. Mean step count per day varied with ECOG PS although the correlation did not reach statistical significance (co-efficient -1611.1 steps for each change in ECOG PS, p = 0.07, mixed effect regression model). A higher mean step count/day correlated with longer OS (HR0.67, p = 0.01, Cox proportional hazard model). Physician-assessed PS did not correlate with OS (HR2.65, p = 0.37, Cox proportional hazard model). There was no correlation between mean step count and PFS (HR1.7, p = 0.39, Cox proportional hazard model). Conclusions: The use of EAMs is feasible in this patient group. A higher step count correlated with longer OS whereas physician-assessed PS did not. Further research into the potential of EAMs as a means of predicting patient survival to guide decisions on eligibility for phase I trials and the potential for devising a revised Royal Marsden prognostic score incorporating EAM indices is warranted. Clinical trial information: SE536. [Table: see text]

Phase 1/2a study of once daily oral BAL101553, a novel tumor checkpoint controller (TCC), in adult patients with progressive or recurrent glioblastoma (GBM) or high-grade glioma

2025

Background: BAL101553 (prodrug of BAL27862) is a novel TCC that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule shown in rodents to penetrate the brain (brain/plasma ratio around unity), with promising antitumor activity in orthotopic preclinical GBM models as monotherapy or in combination with radiotherapy (RT) with or without temozolomide. In this ongoing study (NCT02490800, CDI-CS-002), daily oral BAL101553 was initially examined in solid-tumor patients, with an MTD of 16 mg/d and DLTs of G4 hyponatremia and G2 hallucinations (Lopez 2018, JCO 36, 2018, suppl. A2530). Subsequently the study was expanded by including a separate cohort of patients with progressive or recurrent GBM or high-grade glioma (Ingles Garces 2017, JCO 35, 2018, suppl. TPS2601). Methods: Patients with histologically-confirmed GBM or high-grade glioma, with progressive or recurrent disease after prior RT with/without chemotherapy, received once-daily oral BAL101553 (28-day cycles) in a 3+3 dose-escalation design to determine the maximum tolerated dose (MTD). Adverse events were assessed by CTCAE v4.03 grade (G), and tumor response by RANO every two cycles. Pharmacokinetics (PK) were evaluated on Day 1 of Cycles 1 and 2. Results: In the ongoing study, 23 pts (13M/10F; median age 50 y), median (min–max) number of prior regimens = 2 (1–5), received doses of 8, 15, 20, 25 or 30 mg oral BAL101553 once daily. One DLT of reversible G2 depression and fatigue occurred at 20 mg. Both mean Cmax and AUC increased with dose between 8 and 30 mg. The PK exposure in GBM patients was lower than for solid tumor patients, in particular at 20 and 25 mg. At 25 mg/d (n = 3), one patient with IDH-mutated GBM had a partial response (63% area reduction per RANO) and continues on study > 8 months, and another patient had stable disease for 5 months. At 15–20 mg/d, stable disease was observed in 3/10 patients. Conclusions: The current data in patients with GBM or high-grade glioma suggest that BAL101553 is well tolerated at dose levels above the MTD established in patients with advanced solid tumors, and shows indications of clinical activity. Clinical trial information: 02490800.

First-in-human, dose-escalation, phase (ph) I trial to evaluate safety of anti-Axl antibody-drug conjugate (ADC) enapotamab vedotin (EnaV) in solid tumors

2525

Background: Axl, a transmembrane receptor tyrosine kinase, is aberrantly overexpressed in various human cancers and associated with poor prognosis and treatment resistance. EnaV, a novel ADC of anti-Axl human IgG1 and monomethyl auristatin E, demonstrated potent anti-tumor activity in xenograft models. Methods: In a ph1 trial (NCT02988817), patients (pts) with relapsed/refractory cancer received single agent EnaV, 0.3–2.8 mg/kg once every 3 wks (1Q3W) or 0.45–1.4 mg/kg 3 times over 4 wks (3Q4W). Endpoints included dose-limiting toxicities (DLTs), adverse events (AEs) and pharmacokinetics (PK). DLTs were classed as hematological (e.g. Grade [G] 3/4 febrile neutropenia; G4 neutropenia or anemia) or non-hematological (e.g. severe skin toxicities; G3/4 neuropathy or infusion reactions; ≥G3 treatment-related AEs in first treatment cycle). Upon determining maximum tolerated dose (MTD) per arm and recommended ph2 dose (RP2D), ph2a (dose expansion) will enroll ≤297 pre-treated pts with advanced/metastatic cancer in 7 cohorts. Results: 47 pts with NSCLC (n=8), melanoma (n=9), ovarian (n=22), cervical (n=3) and endometrial (n=5) cancer enrolled in ph1 (1Q3W n=32; 3Q4W n=15). Most pts were female (87%), White (94%) and aged <65 y (66%). MTD was 2.2 mg/kg in 1Q3W arm and 1.0 mg/kg in 3Q4W arm; RP2D was 2.2 mg/kg 1Q3W. EnaV median elimination half-life: 0.9–2.2 d across doses/schedules. In 47 enrolled pts, there were 6 DLTs (Table). Most common AEs (any G; ≥40% pts) were fatigue (64%), nausea (57%), constipation (57%), diarrhea (47%), vomiting (45%) and decreased appetite (43%). 3 pts (1Q3W arm) had partial response (1 NSCLC [2.2 mg/kg dose]; 2 ovarian [1.5 and 2.4 mg/kg dose levels]). Conclusions: The RP2D of single agent EnaV in pre-treated pts with solid tumors was 2.2 mg/kg 1Q3W. EnaV had encouraging preliminary anti-tumor activity and will be evaluated in 7 ph2a expansion cohorts to further assess safety, tolerability, PK, anti-tumor activity and Axl expression. Funding: Genmab A/S. Clinical trial information: NCT02988817. [Table: see text]

Distinct radiological patterns of drug-induced pneumonitis (R-DIP) in early-phase clinical trials and predictive factors affecting outcome: A 10-year systematic review from the Royal Marsden Hospital Phase I Drug Development Unit experience

3088

Background: We studied clinical and radiological parameters influencing DIP in patients (pts) participating in phase I clinical trials, aiming to investigate predictive factors affecting DIP, in particular those affecting outcome. Methods: 2439 consecutive stage IV cancer pts on phase I clinical trials from 2007 to 2017 were identified. Pts with respiratory symptoms or abnormal lung imaging were reviewed in detail, with longitudinal analysis of imaging by an experienced radiologist. R-DIP was categorized according to internationally recognized criteria. Results: 60 pts developed R-DIP (overall incidence 2.5%); most frequent in pts receiving drug conjugates (31.1%) followed by targeted therapies (8.3%). Hypersensitivity pneumonitis was most common (33.3%) followed by non-specific interstitial pneumonitis (30%) and cryptogenic organising pneumonitis (26.7%). 45% pts who developed R-DIP were clinically asymptomatic. The number of affected lobes (OR 1.47, 95% CI: 1.19-1.81, p < 0.001) and the pattern of R-DIP (OR 5.83 for ARDS, 95% CI: 0.38-90.26, p = 0.002) were significantly associated with a higher CTCAE pneumonitis grading. 23% pts (14/60) had investigational medicinal product (IMP) temporarily discontinued or had a dose reduction while 42% pts (25/60) had IMP permanently discontinued. 48% pts were treated with steroids. The number of affected lobes, pattern of R-DIP and steroid therapy did not influence an improvement in R-DIP (p = 0.65, 0.27 and 0.23 respectively). Continuation of treatment resulted in worsening of DIP in 42.9% of cases. The only predictive factor for an improvement in DIP was an interruption of treatment (OR 0.05, 95% CI: 0.01-0.35, p = 0.01). 14 pts were retreated with a reoccurrence of R-DIP in 4 pts (28.6%). Conclusions: R-DIP from novel agents in early phase clinical trials presents in varied radiological patterns, with findings often preceding clinical symptoms. Treatment interruption leads to improvement of DIP and should be considered early. Close clinical and radiological surveillance is recommended should IMP be restarted.

PIPA: A phase Ib study of selective ß-isoform sparing phosphatidylinositol 3-kinase (PI3K) inhibitor taselisib (T) plus palbociclib (P) in patients (pts) with advanced solid cancers—Safety, tolerability, pharmacokinetic (PK), and pharmacodynamic (PD) analysis of the doublet combination

3087

Background: Oncogenic hyperactivation of the PI3K pathway is common in multiple cancers, with preclinical data showing that CDK4/6 inhibitors sensitise PIK3CA mutant cancers to PI3K inhibitors. We report the activity of the P+T in solid tumors with PI3K pathway activation, along with the PD biomarker analysis. Methods: We previously reported the dose escalation phase identifying 125mg P given 3-weeks-on, 1-week-off in combination with T 2mg as the recommended phase 2 dose (R2PD, Lim, ASCO 2017). We report the results in solid tumors with confirmed activating mutations (mts) in the PI3K pathway, from dose escalation and expansion, with no prior exposure to CDK4/6 or PI3K pathway inhibitors. PD studies include analyses of platelet-rich plasma (PRP) and paired tumour biopsies. Results: 20 pts (median age 61, range 34-72) were treated at the doublet RP2D, M/F 7/13, with a median 4 prior treatments (range 2-11). Tumour types included colorectal, breast, lung, endometrial,oligodendroglioma and head and neck cancers. Durable disease control occurred in 3 patients with ER+ advanced breast cancer with responses lasting >6 months including 1 pt with a H1047R PIK3CAmt with an ongoing RECIST PR>36 cycles, 2 pts with PIK3CAmt colorectal cancer had RECIST SD for >5 months, and 1 patient with a PIK3CGmt anaplastic oligodendroglioma had clinical and radiological benefit lasting 5.5 months. Treatment was well tolerated with predictable G1-2 adverse events (AEs). G3 toxicities of neutropenia (n=6), thrombocytopenia (2), rash (2), mucositis (1) and raised transaminases (1 each) were all transient with no G4/5 AEs. Significant decreases in tumour pRb, and pAKT and pGSK3ß in PRP, confirmed modulation of both CDK4/6 and PI3K pathways at R2PD. Conclusions: Doublet P+T is well tolerated at the combination RP2D, with PD evidence of PI3K and CDK4/6 modulation in both plasma and tumor. Promising preliminary anti-tumor activity is seen in a mixed histology cohort selected for activating PIK3 mutations. Clinical trial information: NCT02389842.

Adherence to novel oral anticancer therapies in the phase I setting: The Royal Marsden experience

2542

Background: The use of oral anticancer therapies has increased substantially in recent years. Nonadherence can impair the efficacy of such therapies as well as confound the interpretation of toxicity and pharmacokinetic data in phase I trials. However, there is a paucity of data regarding adherence patterns and barriers in this specific setting. Methods: We included patients treated in Phase I trials involving oral investigational medicinal products (IMPs) in the Drug Development Unit, Royal Marsden Hospital, UK, between 2012 and 2014. Patient, disease and treatment characteristics as well as compliance data from prospectively collected trial diary cards and drug accountability were recorded. Relationships between adherence rate and other variables were explored using logistic regression. Results: We collected data for 2819 patient-weeks, pertaining to 169 patients treated on 18 different phase I trials. Median age was 61 years (range 18-79), females predominated (60%), median number of previous systemic therapy was 3 (0-12) and median time on trial was 9 weeks (0.3-212.4). Hundred-percent adherence rate was 88% in the first cycle and 79% overall. Nonadherence occurred in 83 of 2819 patient-weeks (3.0%); including 75 (2.7 %) missed doses and 8 (0.3 %) overdoses. In univariate analysis, longer time on trial and a continuous treatment schedule were associated with poorer adherence, whereas fasting requirements pre- or post-dosing was associated with improved adherence. Known intracranial metastases, number of concomitant medications and opiates or anti-emetics use were not significantly associated to adherence. In multivariate analysis, fasting requirements (OR 5.347, 95%CI : 1.443-20.019, p = 0.012) and longer time on trial (OR 0.98, 95%IC : 0.961-0.996, p = 0.017) were statistically significant. Conclusions: This is the first report on adherence rates to oral anticancer IMPs in a large phase I trial population. Our observed adherence rates are at the higher end of published data in the general cancer population. Factors influencing adherence in phase I trials appear to be distinct, with fasting requirements being a unique finding. These findings may impact future early-phase trial design and conduct.

Dose-exposure-response relationship between AZD6738 and peripheral monocytes

e14063

Background: AZD6738 is a potent, selective inhibitor of the ataxia telangiectasia and Rad3-related (ATR) serine/threonine-specific protein kinase with good selectivity against other phosphatidylinositol 3-kinase-related kinase (PIKK) family members. To support dose/schedule guidance through mathematical modelling of clinical pharmacokinetic/pharmacodynamic relationships, we sought to determine quantitative pharmacodynamic effects of AZD6738 in peripheral blood with respect to drug exposure. Methods: We assessed peripheral blood cell subpopulations in clinical studies of AZD6738 used either as a monotherapy, a combination with the PARP-1 inhibitor olaparib and in combination with the PD-L1 inhibitor durvalumab through both blood analyser and flow cytometry characterization. Peripheral pharmacokinetics of AZD6738 were also assessed. Results: Levels of peripheral monocytes were suppressed in a dose-dependent manner for the duration of AZD6738 dosing resulting in a decrease of up to 80% within the first 7 consecutive days of AZD6738 treatment; these results were consistent across studies. Upon cessation of an AZD6738 dosing interval monocyte levels return to baseline values within 14 days; in combination with durvalumab there is a trend for the rebound in monocyte counts to surpass baseline levels by up to 20%. Monocyte suppression is specific to AZD6738 and not found with either single agent olaparib or single agent durvalumab, possibly attributable to defective base excision repair in monocytes and lack of PARP-1. Monocytes were found to be the most sensitive cell type to AZD6738 treatment compared with neutrophils, platelets, haemoglobin or lymphocytes. Conclusions: This drug effect of AZD6738 is consistent with natural clearance of peripheral monocytes under suppression of monocyte precursor proliferation in the bone marrow, suggestive of a change in the equilibrium between production and elimination of peripheral monocytes. Used as a surrogate marker of target inhibition, a mathematical model of the AZD6738/monocyte dose-exposure-response relationship is described and has been used to inform AZD6738 Phase 2 dose and schedule.

Final report of a phase I study of 2-hydroxyoleic acid (2OHOA) a novel sphingomyelin synthase activator in patients (pt) with advanced solid tumors (AST) including recurrent high grade gliomas (rHGG)

2554

Background: 2OHOA is an orally bioavailable, first-in-class synthetic hydroxylated fatty acid, that activates SGMS1 and modulates the lipid content of cancer cell membranes. This regulates the localization of key signaling proteins, including Ras and PKC at the plasma membrane, leading to inactivation of Ras/MAPK, PI3K/Akt and PKC/cyclin/CDK signaling pathways. A dose escalation (DE) and partial expansion cohorts (EC) results of the phase 1 study have previously been reported. We now present the final results of the study. Methods: 2OHOA was evaluated in a 3+3 DE design (7 cohorts from 500mg/d to 16000mg/d) and 2 EC at 4000mg TID in 21 days cycles. PK profiles were determined after single dose (fasted [D-7] or fed [D1]) and multiple doses (fed [D21]) during DE phase and only on D1 throughout EC.Safety assessments were based on CTCAEv4.Tumor response was measured by RECIST and RANO every 6 weeks. Results: Overall 54 pt (DE: 32 pt; 21AST/11rHGG; EC: 22 pt; 12 AST/10 rHGG) were treated (median age 60, range 19-78 years). During the EC the most common treatment related G1-G2 toxicities were diarrhea (n = 13;11pt),nausea (n = 7;6pt), ALT increase (n = 6;4pt), pruritus in throat (4pt), fatigue (4pt) and vomiting (3pt). No G3-G4 toxicities or DLTs were reported confirming the MTD from the DE at 4g TID. Food intake did not alter oral 2OHOA bioavailability. Steady state was already achieved at D8. Power model showed dose proportionality in terms of AUC and Cmax, after single and multiple BID dosing. Average t1/2 ranged from1-2h to 8-12h with delayed Tmax and longer half-lives at higher doses. One glioblastoma (GBM) pt had sustained partial response ( > 2,5 years) and 4rHGG pt (3 GBM) achieved stable disease for at least 6 months. They had previously received 2 lines of treatment without bevacizumab. Tumor markers were measured and will be presented. Conclusions: 2OHOA is well tolerated at the P2RD of 4000mg TID PO daily. The preliminary antitumor activity including a sustained PR in heavy pretreated rHGG pt warrants further investigation in a Ph2 study Clinical trial information: NCT01792310.

GCT1021-01, a first-in-human, open-label, dose-escalation trial with expansion cohorts to evaluate safety of Axl-specific antibody-drug conjugate (HuMax-Axl-ADC) in patients with solid tumors (NCT02988817)

TPS2605

Background: HuMax-AXL-ADC is an antibody-drug conjugate (ADC) composed of an Axl-specific human monoclonal immunoglobulin G1 (IgG1κ) conjugated via a protease-cleavable valine-citrulline linker to the microtubule disrupting agent monomethyl auristatin E (MMAE). In vivo, HuMax-AXL-ADC demonstrated therapeutic anti-tumor efficacy in patient-derived xenograft models representing a variety of solid cancers, including pancreas, thyroid, lung, esophageal, cervical cancers and malignant melanoma. The non-clinical safety profile and pharmacokinetics (PK) of a once every 3 weeks (1Q3W) dosing schedule were established in cynomolgus monkeys. Methods: The primary objective of this trial is to determine the MTD and to establish the safety profile of HuMax-AXL-ADC in a mixed population of patients with specified solid tumors: ovarian, cervical, endometrial, thyroid cancer, NSCLC, and malignant melanoma. The trial consists of two parts, a phase I dose escalation part and a phase IIa expansion part. The dose escalation part explores two different dosing regimens: the first investigates doses from 0.3 up to 2.8 mg/kg to be administered 1Q3W. The second investigates doses in the range of 0.45 to 1.4 mg/kg to be administered weekly for 3 weeks followed by one treatment-free week (3Q4W dosing schedule). The second arm has a delayed start to inform a safe starting dose: when at least 8 patients have been evaluated for dose limiting toxicities, the 1.5 mg/kg cohort of the 1Q3W arm has been declared safe, and the predicted PK parameters of the starting dose in the 3Q4W arm are below pre-defined limits, the 3Q4W arm will be initiated. The 1Q3W arm follows a modified Bayesian Continuous Reassessment Method including escalation with overdose control in up to 41 patients on up to 7 main and 4 intermediate dose levels while the 3Q4W arm is run as a standard 3+3 trial design on up to 5-6 dose levels. In the phase IIa expansion part, further safety and biological activity data will be generated in selected indications using cohorts of 22 patients (11+11 patients in each cohort applying the Simon’s two-stage design). Clinical trial information: NCT 02988817.

A phase I trial of selective PI3K inhibitor taselisib (tas) plus palbociclib (palb) with and without endocrine therapy incorporating pharmacodynamic (PD) studies in patients (pts) with advanced cancers

2573

Background: The phosphatidylinositol 3-kinase (PI3K) pathway is commonly mutated in cancer. Tas is a selective β-isoform-sparing PI3K inhibitor with improved therapeutic index compared to pan-PI3K inhibitors. Palb is a CDK4/6 inhibitor now standard of care in combination with endocrine therapy (ET) in hormone receptor positive breast cancer. Combination of Tas, Palb and ET is synergistic in preclinical models. Methods: This investigator-initiated study investigated safety and tolerability, pharmacokinetics (PK), PD and antitumor activity of Tas+Palb, with addition of ET in dose expansion. Pts were enrolled in 3+3 dose escalation design. Tas was given continuously or 3-weeks-on, 1-week-off (3/1), Palb was given on 3/1 schedule. PD studies included analyses of platelet-rich plasma (PRP) (n = 20) and paired tumor biopsies (n = 5). Serial circulating tumor DNA was monitored in pts with PIK3CA mutations. Results: 24 pts were treated, 22 with Tas+Palb, 2 with Tas+Palb+fulvestrant(ful); M/F 11/13, median lines prior therapy 4. Treatment was well tolerated with mainly G1-2 toxicities. Most frequent G3 toxicities were neutropenia (5/24), thrombocytopenia (5/24) and rash (5/24), with no G4/5 toxicities. Two pts had dose-limiting toxicities (DLT) at DL2. No DLTs were observed at DL4, although pts experienced delayed neutrophil recovery. PK was linear and comparable with monotherapy. At 125mg Palb, significant decreases in pAKT and pGSK3β in PRP confirmed PI3K target inhibition. Two pts with PI3KCA H1047R mutant breast cancers have ongoing RECIST partial response; 1 pt with PIK3CA E542K colorectal cancer had stable disease for 20 weeks. Conclusions: Tas+Palb is well tolerated with evidence of PD and antitumor activity. Dose expansion including recruitment to triplet Tas+Palb+ful and Tas+Palb+letrozole is ongoing with continuous Tas 2mg QD, and Palb 100mg QD on 3/1 schedule, increasing to 125mg after cycle 1 in absence of myelosuppression. Clinical trial information: NCT02389842. [Table: see text]

Clinical outcomes of adolescents and young adults (AYA) with advanced solid tumors participating in phase I trials

10536

Background: AYA cancer patients are relatively under-represented in clinical trials, with no published data regarding their outcomes in phase I studies. Trials utilizing novel therapeutic agents are often considered in these patients, due to their tendency to have good organ reserve, and ability to tolerate additional lines of therapy. This study describes the experience of AYA patients with advanced solid tumors treated in a specialized drug development unit. Methods: Patient characteristics and clinical outcomes of AYA patients (defined as age 15 to 39 years at time of initial cancer diagnosis) treated at the Drug Development Unit, Royal Marsden Hospital, United Kingdom, between 2002 and 2016, were captured and analyzed from case and trial records. Results: From a database of 2631 patients treated on phase I trials, 219 AYA patients (8%) were identified. Major tumor types included gynaecological cancer (24%), sarcoma (18%), gastrointestinal (16%) and breast cancer (11%). Patients had a median of 3 previous lines of systemic chemotherapy (range 0 – 6), and 19% participated in 2 or more phase I studies. Twenty (9%) had a known hereditary cancer syndrome (most commonly BRCA), 27% had a family history (FH) of cancer, 15% no FH and 49% no FH documented. Molecular characterization of tumors (n = 45) identified mutations most commonly in p53 (33%) , PI3KCA (18%) and KRAS (9%) . Major trial categories included DNA damage repair (16%), PI3K (16%) and anti-angiogenesis (15%) agents. Grade 3/4 toxicities were experienced in 25% of patients (10% hematological). Of the 214 evaluable patients, objective response rate was 12%, with clinical benefit rate at 6 months of 22%. Median progression free survival was 2.3 months (95% CI: 1.9 to 2.8), median OS was 7.6 months (95% CI: 6.3 to 9.5), and 2-year OS was 11%. Of patients with responses, 35% were matched to phase I trials based on germline or somatic genetic aberrations. Conclusions: A sub-group of AYA patients with advanced solid tumors derive considerable benefit from participating in trials involving novel therapeutics. Future research must focus on predictive biomarkers and molecular profiling to identify those that would benefit from novel therapies.

Phase 1/2a trial of daily oral BAL101553, a novel tumor checkpoint controller (TCC), in advanced solid tumors

2532

Background: BAL101553 (prodrug of BAL27862) is a small molecule TCC that binds microtubules and promotes tumor cell death by activation of the spindle assembly checkpoint. In a previous study (NCT01397929, Lopez et al. JCO 34, 2016; abstr 2525), 2-h IV infusion on Days 1, 8, 15 (q28d) of BAL101553 up to 80 mg/m2 (maximum administered dose, MAD) showed vascular toxicities, including transient hypertension, which appeared to be Cmax related. The recommended Phase 2 dose (RP2D) was 30 mg/m2 weekly IV. Based on nonclinical models, antiproliferative effects of BAL27862 are driven by AUC. This trial explores whether once daily oral administration of BAL101553 reduces Cmax-related toxicity and improves the therapeutic window (NCT02490800). Methods: Patients (pts) with advanced solid tumors who failed standard therapy, received QD oral BAL101553 (28-d cycles) in a 3+3 dose-escalation design to determine the MTD. Adverse events were assessed by CTCAEv4 grade (G); tumor response by RECIST 1.1; serial PK on Day 1 of Cycles 1 and 2. Results: In the ongoing study, 19 pts (9M/10F; median age 67 y) received doses of 2, 4, 8, 16 or 30 mg oral BAL101553 QD. The MAD was 30 mg with DLTs of reversible G2 hallucination and asymptomatic, reversible G3 electrolyte imbalances. No DLTs were observed at ≤ 16 mg. Dosing is ongoing between 16 and 30 mg QD to determine the MTD. BAL27862 exposures after oral QD dosing of BAL101553 compared to weekly 2-h infusions suggested high relative oral bioavailability. The BAL27862 weekly AUC at the oral MAD (30 mg QD) compared to the RP2D of 30 mg/m2 for 2-h IV was more than 5-fold higher (19,656 vs 3,584 ng*h/mL) and Cmax was 1.5-fold lower (171 vs 266 ng/mL). Both Cmaxand AUC were dose-proportional, with low/moderate variability. Oral BAL101553 had no effects on blood pressure and showed no vascular toxicity. 5 pts had stable disease (2 pts [cholangiocarcinoma, neuroendocrine pancreatic cancer] > 4 cycles). Conclusions: Daily oral BAL101553 enables higher weekly exposures of BAL27862 with lower Cmax levels compared with a 2-h weekly infusion, due to the absence of Cmax related vascular toxicity. Doses up to 16 mg QD are well tolerated. The MAD has been identified as 30 mg QD; definition of the MTD is ongoing. Clinical trial information: NCT02490800.

A phase I study to assess the safety, pharmacokinetics (PK), pharmacodynamics (PD) and antitumor activities of daily oral BAL101553, a novel tumor checkpoint controller (TCC) in adult patients with progressive or recurrent glioblastoma (GBM) or high-grade glioma

TPS2601

Background: BAL101553 (prodrug of BAL27862) is a novel TCC that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule (MW 387) shown in rats to penetrate the brain (1:1 plasma ratio) and has shown promising antitumor activity in orthotopic preclinical models of GBM as monotherapy or in combination with radiotherapy (RT) with/without chemotherapy. In a completed Phase 1 study with 2-h IV infusions (Days 1, 8, 15, q28d, NCT01397929 , CDI-CS-001, Lopez et al. J Clin Oncol 34, 2016 suppl; 2525), dose-limiting vascular effects were observed and appeared Cmax related. Preclinical data suggest that antiproliferative effects of BAL101553/27862 are driven by exposure (AUC); thus vascular toxicity and antitumor activity are mediated by different PK drivers. In this ongoing study (NCT02490800, CDI-CS-002), daily oral BAL101553 was initially examined in solid-tumor patients; no vascular toxicities were observed at doses up to the MAD of 30 mg QD. Given this absence, the study was amended to enroll separate cohorts of patients with progressive or recurrent GBM or high-grade glioma. Methods: This is an ongoing multicenter, open-label, Phase 1 dose-escalation study using a 3+3 design to determine the MTD, characterize dose-limiting toxicities and assess the PK, PD and antitumor activities of daily oral administration of BAL101553 in consecutive 28-day cycles at a starting dose of 8 mg QD. Patients with histologically-confirmed GBM or high-grade glioma, with progressive or recurrent disease after prior RT with/without chemotherapy, are eligible for enrollment. This includes patients with histologically-confirmed low-grade glioma with unequivocal evidence by imaging of transformation to high-grade glioma. Adverse events are assessed using CTCAEv4; tumor response by RANO (every 2 cycles). The dose escalation allows for doubling of dose levels depending on observed toxicities. PD assessments include circulating tumor cells. PK profiles are assessed throughout the first two treatment cycles. Clinical trial information: NCT02490800.

Patterns of metastases in malignant pleural mesothelioma in the modern era: Redefining the spread of an old disease

8556

Background: Malignant pleural mesothelioma (MPM) has been historically documented as a locally infiltrative disease in large series from the early 1980s. With the changing landscape of cancer diagnosis and treatment, increased areas of unusual metastases have been published as case reports. With no standard second-line therapies for MPM, referral to early phase trial units is common. We report the metastatic patterns of a large cohort of MPM patients treated at the Royal Marsden Drug Development Unit (DDU). Methods: Clinical data was gathered for MPM patients referred to the DDU from 1992 to 2016. Radiographic details were collected from CT, bone scan and FDG PET imaging. Prior treatment, response, somatic mutations, clinical trial and survival data was obtained from medical records. Results: From the database, 165 evaluable patients with MPM were identified. Median age at diagnosis was 64 years (range 37–90) and 76% were male. Epithelioid MPM comprised 81% and 65% were right sided. Bone metastases were reported in 20%, with the majority lytic in nature ( Table). Peritoneal and omental disease was evident in 24% with ascites in 16%. In 11% of cases lung metastases presented as diffuse miliary-type pattern. Visceral metastases (15%) were predominantly liver (78%), but also occurred in adrenals, spleen and kidneys. Symptomatic brain metastases were recorded in 3%. Median overall survival was 24.2 months (95% CI: 20.8 - 29.2). Conclusions: This large study documents the metastatic patterns of advanced MPM in the 21st century and highlights an increased frequency of traditionally unexpected sites of metastases. Higher than expected incidence of lytic bone metastases (20%) suggests consideration of bone imaging in advanced MPM clinical workflow and trial protocols. [Table: see text]

Results from the biomarker-driven basket trial of RO5126766 (CH5127566), a potent RAF/MEK inhibitor, in RAS- or RAF-mutated malignancies including multiple myeloma

2506

Background: RO5126766 is a potent RAF and MEK inhibitor with activity in xenografts models of RAS and RAF-mutated cancers. We present data from the RAS/RAF-mutated advanced solid tumor cohort and the initial results for the multiple myeloma (MM) cohort. Methods: Patients with KRAS, NRAS or BRAF-mutant tumours were treated with RO5127566 using a novel schedule:4mg twice weekly in 4-week cycles. For MM patients, it was given 3 weeks out of 4 and co-administration of weekly dexamethasone was authorised. Response assessment was completed using RECIST 1.1 criteria for solid tumours and the International Myeloma Working Group (IMWG) criteria were used for MM. Results: A total of 20 patients with solid tumours (10 NSCLC, 5 gynaecological cancers and 5 miscellaneous cancers) and 1 MM patients were evaluable. Among the 10 KRAS-mutant NSCLC patients, tumour regression was seen in 6/10 (60 %), of which 3/10 (30 %) were partial responses. Two of these patients had maintained response for over 1 year and one patient is still on study after 30 cycles. Of the gynaecological cancers, 3/5 patients (60%) achieved a partial response ( KRAS-mutant endometrial and ovarian cancer and BRAF-mutant ovarian). Of these patients, 1 of the KRAS mutants had received 2 previous lines of MEK inhibitors and the BRAF mutant had previously received a BRAF inhibitor. In the miscellaneous group, 4 patients with colorectal cancer (2 BRAF and 2 NRAS) and 1 patient with NRAS-mutant melanoma were treated and none responded. Two patients with MM have been treated so far (1 KRAS, 1 KRAS+NRAS). The one evaluable patient has had an IMWG partial response (PR) after 1 cycle (FLC-λ from 324 mg/L to 161mg/L, ratio 0.03 to 0.08) without concomittant dexamethasone. This patient was previously treated with an immunomodulatory drug, a proteasome inhibitor and two ASCTs. Conclusions: RO5126766 has shown exciting preliminary activity across a wide range of RAS- and RAF-mutated malignancies, with significant response rates in lung and gynaecological cancers. To our knowledge, the PR seen in our MM patient represents one of the first responses to a single-agent RAF/MEK inhibitor in multiple myeloma in a trial context. Clinical trial information: NCT02407509.

Results of the OPARATIC trial: A phase I dose escalation study of olaparib in combination with temozolomide (TMZ) in patients with relapsed glioblastoma (GBM)

2022

Background: Olaparib, a small molecule inhibitor of poly (ADP-ribose) polymerase (PARP), may improve GBM outcomes by enhancing cytotoxic effects of ionising radiation and TMZ. Clinical development of PARP inhibitors has been restricted by exacerbation of hematological toxicity. We investigated tumor pharmacokinetics (PK) of olaparib and safety and tolerability of its combination with TMZ. Methods: Dose escalation explored different schedules of olaparib (tablet formulation) with 42 day cycles of daily low dose TMZ. A dose expansion cohort evaluated the maximum tolerated schedule. PK analysis was performed on tumor and blood samples from patients undergoing neurosurgical resection, who received 4 olaparib doses pre-operatively. Results: 48 patients were recruited (median age 51(18-68); 29 male, 19 female) of whom 27 underwent surgery and 35 received olaparib/TMZ and were evaluable. 13 evaluable patients received expansion dose schedule (median age 54(21-67); 9 male, 4 female). Olaparib was detected in 73 of 74 tumor core specimens from 27 patients; mean conc. 588nM (97-1374nM), and in 27 of 28 tumor margin specimens from 10 patients; mean conc. 500nM (97-1237nM). Margin: core ratios ranged from 0.2–3.9(mean 1.2); tumor: plasma ratios ranged from 0.01 to 0.9 (mean 0.25). Olaparib dosing on days 1-5 was hindered by myelosuppression. Expansion cohort dose was defined as TMZ 75 mg/m2daily plus olaparib 150 mg (OD) days 1-3 weekly. Of 13 evaluable patients receiving expansion dose-schedule, 9 completed cycle 1, 2 completed cycle 2 and 2 completed cycle 3. Currently 45% of the evaluable patients remain progression-free at 6 months, with 2 still on treatment (full data set May2017). Of 35 evaluable patients, 24 experienced AE Grade ≥3 (see Table). Conclusions: Olaparib penetrates both core and margins of recurrent GBM despite failing to penetrate the intact brain barrier in pre-clinical heathy rodent models. Combination with extended low dose TMZ is safe and well tolerated, yielding encouraging 6 month progression-free survival rates. Clinical trial information: NCT01390571. [Table: see text]

Identification of unknown ocular pathogens in clinically suspected eye infections using ribosomal RNA gene sequence analysis

DNA sequence-based identification of pathogens from ocular samples of patients with clinically suspected eye infections was accomplished using 16S and internal transcribed spacer (ITS) ribosomal RNA gene sequence analysis. PCR was positive for 24 of 99 samples tested. Both culture and 16S rDNA sequence analysis identified Pseudomonas aeruginosa, streptococci and Enterobacteriaceae. Isolates misidentified as Burkholderia cepacia by biochemical tests were identified as Ralstonia mannitolilytica by 16S rDNA sequence analysis. Sequence analysis identified the following microorganisms from 19 culture-negative samples: Haemophilus influenzae, Sphingomonas sp., Klebsiella pneumoniae, Staphylococcus haemolyticus, Morganella morganii, Mycobacterium sp., Chryseobacterium sp., Pseudomonas saccharophila (Xanthomonas) and the fungus, Phaeoacremonium inflatipes.

Regression of melanoma metastases following treatment with the n-bisphosphonate zoledronate and localised radiotherapy

We report a case of regression of pulmonary and bony metastases in a patient with malignant melanoma following palliative treatment with systemic zoledronate and localised radiotherapy to the bone. Zoledronate is a potent new bisphosphonate used for the treatment of metabolic bone diseases including bone metastases due to its inhibitory effect on osteoclasts. In the context of metastatic cancer zoledronate is routinely used to improve bone pain and reduce the frequency of skeletal events. There is also an increasing body of evidence suggesting that bisphosphonates exhibit anti-tumour properties. Bisphosphonates are able to activate Vgamma9Vdelta2 gamma-delta T cells which can be key players in the immune defence against malignant cells. Furthermore bisphosphonates have direct anti-proliferative, anti-metastatic and pro-apoptotic effects on tumour cells. These actions, together with their low side effect profile, may prove to be useful therapeutic tools in the treatment of cancer even in the absence of bone metastases. On the basis of this case report we here review the current literature on present preclinical and clinical studies using bisphosphonates for the treatment of cancer.

Semaphorin 3A elicits stage-dependent collapse, turning, and branching in Xenopus retinal growth cones

The semaphorin receptor, neuropilin-1 (NP-1), was first identified in Xenopus as the A5 antigen and is expressed abundantly in developing retinal ganglion cells (RGCs). Here we show that growth cones acquire responsiveness to semaphorin 3A (Sema 3A) with age and that the onset of responsiveness correlates with the appearance of NP-1 immunoreactivity. Growth cones from "old" (stage 35/36) retinal explants collapse rapidly (5-10 min) in response to Sema 3A and turn away from a gradient of Sema 3A, whereas "young" growth cones (stage 24) are insensitive to Sema 3A. Moreover, transfection of full-length NP-1 into young neurons confers premature Sema 3A sensitivity. When young neurons are aged in culture they develop Sema 3A sensitivity in parallel with those in vivo, suggesting that an intrinsic mechanism of NP-1 regulation mediates this age-dependent change. Sema 3A-induced collapse is transient, and after recovery approximately 30% of growth cones extend new branches within 1 hr, implicating Sema 3A as a branching factor. Pharmacological inhibitors were used to investigate whether these three Sema 3A-induced behaviors (collapse, turning, and branching) use distinct second messenger signaling pathways. All three behaviors were found to be mediated via cGMP. In situ hybridization shows that Sema 3A is expressed in the tectum and at the anterior boundary of the optic tract where axons bend caudally, suggesting that Sema 3A/NP-1 interactions play a role in guiding axons in the optic tract and in stimulating terminal branching in the tectum.

Use of topical FK506 in a corneal graft rejection model in Lewis rats

PURPOSE

To evaluate the immunosuppressive effect of topical FK506 on allograft corneal rejection in rats.

METHODS

Lewis rats were used as recipients and Fisher rats as corneal graft donors. In Experiment 1, all rats received intraperitoneally FK506 (0.3 mg/kg per day) for 7 days to ensure equal baseline parameters. The rats then were assigned randomly to treatment with topical 0.3% FK506 or vehicle alone. In another set of experiments, rats were treated only with topical treatment. The grafts were inspected by clinical evaluation. Corneas obtained at the time of maximum rejection were used for histology and immunohistochemistry.

RESULTS

The selected combination of rat strains caused 100% graft rejection in untreated animals within 2 weeks after the penetrating keratoplasty. In the treated animals, rejection was delayed until the end of topical therapy. One third of corneal grafts remained clear until day 30. Histologic and immunohistochemical studies confirmed the clinical evaluations. Untreated rat corneas had a large number of infiltrating helper-inducer T cells, macrophages, interleukin-2 receptor-expressing cells, and Ia-antigen-expressing cells. At the same timepoint, topically treated corneas showed a limited inflammatory response characterized by a 2/3 reduction in the number of infiltrating helper and cytotoxic cells, and a five-fold decrease in the expression of class I and class II major histocompatibility antigens.

CONCLUSIONS

Topical FK506 treatment is an effective way of preventing corneal graft rejection in the Lewis rat corneal graft model. It shows promise as a drug to prevent corneal graft rejection in humans.

Suppression of S-antigen-induced experimental autoimmune uveoretinitis in Lewis rats by oral administration with CGS-13080, a thromboxane synthetase inhibitor

Oral administration of CGS-13080 [imidazo (1, 5-alpha) pyridine-5-hexanoic acid], a thromboxane synthetase inhibitor, has been reported to cause a marked reduction in serum thromboxane B2 concentration in humans and animals. Since thromboxane metabolites play an important role in ocular inflammation, the effect of oral CGS-13080 in the development of experimental autoimmune uveoretinitis in Lewis rats has been investigated. Females were immunized with bovine S-antigen (S-Ag). Treatment was started on day 0 of immunization. Animals were divided into three groups. The control group was fed a standard pellet diet, while the treated groups were fed the standard diet supplemented with either a low dose (0.8 g per 10 kg pellet) or a high dose (1.6 g per 10 kg pellet) of CGS 13080. From day 10 after immunization, the eyes of these rats were examined daily for clinical evidence of experimental autoimmune uveoretinitis. On day 14, the eyes were collected for histologic study. The cellular immune responses were evaluated on the draining inguinal lymph nodes. Blood samples were also collected for the measurement of anti-S-Ag antibody production, thromboxane B2 and prostaglandin A2 levels. Clinical disease developed in 73.3% of the control rat group, 30.0% of the low-dose treated group and 17.6% of the high-dose group. The average histologic grade was 1.9 in the control group, 0.65 in low-dose group and 0.32 in high-dose group. Lymphocyte proliferation to S-Ag paralleled the clinical disease scores. Average stimulation indices were 10.9 in the controls, 7.5 in the low-dose group and 2.2 in the high-dose group.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined use of cyclosporine and ketoconazole in the treatment of endogenous uveitis

Ten patients with endogenous uveitis were in clinical remission attributable to treatment with cyclosporine and prednisone. After the cyclosporine dose was reduced by two thirds, these patients were randomly assigned to treatment with or without ketoconazole, a potent inhibitor of cytochrome P-450, in a double-masked placebo-controlled study. The dose was reduced over three days. During a three-month follow-up, no patients treated with ketoconazole had a relapse of uveitis, while four of six (66%) control subjects had a flare-up. Toxicity in the ketoconazole-treated group was limited to a transient decrease in glomerular filtration rate (20% from baseline) at one month in two of six (33%) patients. Renal function was stabilized by further reduction of the cyclosporine dose.

Retinal toxicity in human immunodeficiency virus-infected children treated with 2',3'-dideoxyinosine

To assess the safety and antiretroviral activity of 2',3'-dideoxyinosine, we enrolled 43 children with symptomatic (Centers for Disease Control class P-2) human immunodeficiency virus infection in a Phase I-II study and monitored them prospectively for the development of ocular complications secondary to HIV infection or drug toxicity. Follow-up ranged from 12 to 103 weeks with a median follow-up of 71 weeks. Three of 43 children (7.0%) developed peripheral atrophy of the retinal pigment epithelium during treatment with 2',3'-dideoxyinosine. The two children with the most severe retinal atrophy were enrolled in the study at the highest dosage studied (540 mg/m2/day). In contrast to findings in children, no retinal atrophy in HIV-infected adults treated with 2',3'-dideoxyinosine has been evident to date.

Ocular complications of Stevens-Johnson syndrome and toxic epidermal necrolysis in patients with AIDS

Recent reports suggest that acquired immunodeficiency syndrome (AIDS) patients are at higher risk of developing mucocutaneous reactions such as toxic epidermal necrolysis and Stevens-Johnson syndrome (SJS). Resultant dry eye may be further exacerbated by human immunodeficiency virus (HIV) related lacrimal gland dysfunction and lead to a chronic keratoconjunctivitis. We report one patient with AIDS and toxic epidermal necrolysis and two patients with AIDS and SJS who developed severe dry eye misdiagnosed as infectious keratoconjunctivitis. Cicatrizing mucocutaneous reactions should be suspected in AIDS patients and the dry eye treated to control symptoms and prevent complications.