Efficacy and safety of tisotumab vedotin in previously treated recurrent or metastatic cervical cancer (innovaTV 204/GOG-3023/ENGOT-cx6): a multicentre, open-label, single-arm, phase 2 study.

BACKGROUND: Few effective second-line treatments exist for women with recurrent or metastatic cervical cancer. Accordingly, we aimed to evaluate the efficacy and safety of tisotumab vedotin, a tissue factor-directed antibody-drug conjugate, in this patient population. METHODS: This multicentre, open-label, single-arm, phase 2 study was done across 35 academic centres, hospitals, and community practices in Europe and the USA. The study included patients aged 18 years or older who had recurrent or metastatic squamous cell, adenocarcinoma, or adenosquamous cervical cancer; disease progression on or after doublet chemotherapy with bevacizumab (if eligible by local standards); who had received two or fewer previous systemic regimens for recurrent or metastatic disease; had measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1); and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received 2·0 mg/kg (up to a maximum of 200 mg) tisotumab vedotin intravenously once every 3 weeks until disease progression (determined by the independent review committee) or unacceptable toxicity. The primary endpoint was confirmed objective response rate based on RECIST (version 1.1), as assessed by the independent review committee. Activity and safety analyses were done in patients who received at least one dose of the drug. This study is ongoing with recruitment completed and is registered with ClinicalTrials.gov, NCT03438396. FINDINGS: 102 patients were enrolled between June 12, 2018, and April 11, 2019; 101 patients received at least one dose of tisotumab vedotin. Median follow-up at the time of analysis was 10·0 months (IQR 6·1-13·0). The confirmed objective response rate was 24% (95% CI 16-33), with seven (7%) complete responses and 17 (17%) partial responses. The most common treatment-related adverse events included alopecia (38 [38%] of 101 patients), epistaxis (30 [30%]), nausea (27 [27%]), conjunctivitis (26 [26%]), fatigue (26 [26%]), and dry eye (23 [23%]). Grade 3 or worse treatment-related adverse events were reported in 28 (28%) patients and included neutropenia (three [3%] patients), fatigue (two [2%]), ulcerative keratitis (two [2%]), and peripheral neuropathies (two [2%] each with sensory, motor, sensorimotor, and neuropathy peripheral). Serious treatment-related adverse events occurred in 13 (13%) patients, the most common of which included peripheral sensorimotor neuropathy (two [2%] patients) and pyrexia (two [2%]). One death due to septic shock was considered by the investigator to be related to therapy. Three deaths unrelated to treatment were reported, including one case of ileus and two unknown causes. INTERPRETATION: Tisotumab vedotin showed clinically meaningful and durable antitumour activity with a manageable and tolerable safety profile in women with previously treated recurrent or metastatic cervical cancer. Given the poor prognosis for this patient population and the low activity of current therapies in this setting, tisotumab vedotin, if approved, would represent a new treatment for women with recurrent or metastatic cervical cancer. FUNDING: Genmab, Seagen, Gynaecologic Oncology Group, and European Network of Gynaecological Oncological Trial Groups.

Phase 1b study of AVB-500 in combination with paclitaxel or pegylated liposomal doxorubicin platinum-resistant recurrent ovarian cancer.

OBJECTIVE: GAS6 and AXL are expressed in high-grade serous ovarian cancer but not in normal ovarian tissue. AVB-500, a novel high affinity Fc-sAXL fusion protein, binds GAS6 preventing AXL signaling. This Phase 1b study (NCT03639246) evaluated safety, efficacy, and exploratory predictive markers of AVB-500 combined with paclitaxel (PAC) or pegylated liposomal doxorubicin (PLD) in patients with platinum-resistant ovarian cancer (PROC), and used a model informed drug development (MIDD) approach for identification of the recommended phase 2 dose (RP2D). METHODS: Eligible patients received AVB-500 at 10, 15, or 20 mg/kg IV q2wk combined with PAC (n = 23) or PLD (n = 30). Patients were treated until progression or unacceptable toxicity. All were followed for survival. RESULTS: No dose limiting toxicities were observed and serum GAS6 was completely suppressed across the three dose levels evaluated. AVB-500 + PAC yielded better clinical activity than AVB-500 + PLD with an ORR of 34.8% (8/23, 2 complete responses) and median DoR, PFS, and OS of 7.0, 3.1, and 10.3 months, respectively. Subgroup analyses showed AVB-500 + PAC patients who had no prior bevacizumab or whose AVB-500 trough levels were >13.8 mg/L exhibited the best clinical response. The ORR and median PFS and OS in patients with these characteristics were ≥50%, ≥7.5 months, and ≥19 months, respectively. Given AVB-500 nor the combination with chemotherapy was expected to cause DLTs, the RP2D of AVB-500 was 15 mg/kg identified using an MIDD approach. CONCLUSION: AVB-500 was well-tolerated in combination with PAC or PLD and contributed to the clinical activity of PAC in PROC patients. Subgroup analyses identified a population of PROC patients who may benefit the most from AVB-500 treatment, which will be further assessed in an ongoing Phase 3 PROC trial.

Tisotumab vedotin in patients with advanced or metastatic solid tumours (InnovaTV 201): a first-in-human, multicentre, phase 1-2 trial.

BACKGROUND: Tisotumab vedotin is a first-in-human antibody-drug conjugate directed against tissue factor, which is expressed across multiple solid tumour types and is associated with poor clinical outcomes. We aimed to establish the safety, tolerability, pharmacokinetic profile, and antitumour activity of tisotumab vedotin in a mixed population of patients with locally advanced or metastatic (or both) solid tumours known to express tissue factor. METHODS: InnovaTV 201 is a phase 1-2, open-label, dose-escalation and dose-expansion study done at 21 centres in the USA and Europe. Patients (aged ≥18 years) had relapsed, advanced, or metastatic cancer of the ovary, cervix, endometrium, bladder, prostate, oesophagus, squamous cell carcinoma of the head and neck or non-small-cell lung cancer; an Eastern Cooperative Oncology Group performance status of 0-1; and had relapsed after or were not eligible to receive the available standard of care. No specific tissue factor expression level was required for inclusion. In the dose-escalation phase, patients were treated with tisotumab vedotin between 0·3 and 2·2 mg/kg intravenously once every 3 weeks in a traditional 3 + 3 design. In the dose-expansion phase, patients were treated at the recommended phase 2 dose. The primary endpoint was the incidence of adverse events, including serious adverse events, infusion-related, treatment-related and those of grade 3 or worse, and study drug-related adverse events, analysed in all patients who received at least one dose of tisotumab vedotin (full analysis population). This trial is registered with ClinicalTrials.gov, number NCT02001623, and is closed to new participants with follow-up ongoing. FINDINGS: Between Dec 9, 2013, and May 18, 2015, 27 eligible patients were enrolled to the dose-escalation phase. Dose-limiting toxicities, including grade 3 type 2 diabetes mellitus, mucositis, and neutropenic fever, were seen at the 2·2 mg/kg dose; therefore, 2·0 mg/kg of tisotumab vedotin intravenously once every 3 weeks was established as the recommended phase 2 dose. Between Oct 8, 2015, and April 26, 2018, 147 eligible patients were enrolled to the dose-expansion phase. The most common (in ≥20% of patients) treatment-emergent adverse events of any grade were epistaxis (102 [69%] of 147 patients), fatigue (82 [56%]), nausea (77 [52%]), alopecia (64 [44%]), conjunctivitis (63 [43%]), decreased appetite (53 [36%]), constipation (52 [35%]), diarrhoea (44 [30%]), vomiting (42 [29%]), peripheral neuropathy (33 [22%]), dry eye (32 [22%]), and abdominal pain (30 [20%]). The most common adverse events of grade 3 or worse were fatigue (14 [10%] of 147 patients), anaemia (eight [5%]), abdominal pain (six [4%]), hypokalaemia (six [4%]), conjunctivitis (five [3%]), hyponatraemia (five [3%]), and vomiting (five [3%]). 67 (46%) of 147 patients had a treatment-emergent serious adverse event. 39 (27%) of 147 patients had a treatment-emergent serious adverse event related to the study drug. Infusion-related reactions occurred in 17 (12%) of 147 patients. Across tumour types, the confirmed proportion of patients who achieved an objective response was 15·6% (95% CI 10·2-22·5; 23 of 147 patients). There were nine deaths across all study phases (three in the dose-escalation phase and six in the dose-expansion phase); only one case of pneumonia in the dose-expansion phase was considered possibly related to study treatment. INTERPRETATIONS: Tisotumab vedotin has a manageable safety profile with encouraging preliminary antitumour activity across multiple tumour types in heavily pretreated patients. Continued evaluation of tisotumab vedotin is warranted in solid tumours. FUNDING: Genmab A/S.

Pembrolizumab versus Chemotherapy for PD-L1-Positive Non-Small-Cell Lung Cancer.

BACKGROUND: Pembrolizumab is a humanized monoclonal antibody against programmed death 1 (PD-1) that has antitumor activity in advanced non-small-cell lung cancer (NSCLC), with increased activity in tumors that express programmed death ligand 1 (PD-L1). METHODS: In this open-label, phase 3 trial, we randomly assigned 305 patients who had previously untreated advanced NSCLC with PD-L1 expression on at least 50% of tumor cells and no sensitizing mutation of the epidermal growth factor receptor gene or translocation of the anaplastic lymphoma kinase gene to receive either pembrolizumab (at a fixed dose of 200 mg every 3 weeks) or the investigator's choice of platinum-based chemotherapy. Crossover from the chemotherapy group to the pembrolizumab group was permitted in the event of disease progression. The primary end point, progression-free survival, was assessed by means of blinded, independent, central radiologic review. Secondary end points were overall survival, objective response rate, and safety. RESULTS: Median progression-free survival was 10.3 months (95% confidence interval [CI], 6.7 to not reached) in the pembrolizumab group versus 6.0 months (95% CI, 4.2 to 6.2) in the chemotherapy group (hazard ratio for disease progression or death, 0.50; 95% CI, 0.37 to 0.68; P<0.001). The estimated rate of overall survival at 6 months was 80.2% in the pembrolizumab group versus 72.4% in the chemotherapy group (hazard ratio for death, 0.60; 95% CI, 0.41 to 0.89; P=0.005). The response rate was higher in the pembrolizumab group than in the chemotherapy group (44.8% vs. 27.8%), the median duration of response was longer (not reached [range, 1.9+ to 14.5+ months] vs. 6.3 months [range, 2.1+ to 12.6+]), and treatment-related adverse events of any grade were less frequent (occurring in 73.4% vs. 90.0% of patients), as were grade 3, 4, or 5 treatment-related adverse events (26.6% vs. 53.3%). CONCLUSIONS: In patients with advanced NSCLC and PD-L1 expression on at least 50% of tumor cells, pembrolizumab was associated with significantly longer progression-free and overall survival and with fewer adverse events than was platinum-based chemotherapy. (Funded by Merck; KEYNOTE-024 ClinicalTrials.gov number, NCT02142738 .).

Pembrolizumab for the treatment of non-small-cell lung cancer.

BACKGROUND: We assessed the efficacy and safety of programmed cell death 1 (PD-1) inhibition with pembrolizumab in patients with advanced non-small-cell lung cancer enrolled in a phase 1 study. We also sought to define and validate an expression level of the PD-1 ligand 1 (PD-L1) that is associated with the likelihood of clinical benefit. METHODS: We assigned 495 patients receiving pembrolizumab (at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks) to either a training group (182 patients) or a validation group (313 patients). We assessed PD-L1 expression in tumor samples using immunohistochemical analysis, with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 (proportion score). Response was assessed every 9 weeks by central review. RESULTS: Common side effects that were attributed to pembrolizumab were fatigue, pruritus, and decreased appetite, with no clear difference according to dose or schedule. Among all the patients, the objective response rate was 19.4%, and the median duration of response was 12.5 months. The median duration of progression-free survival was 3.7 months, and the median duration of overall survival was 12.0 months. PD-L1 expression in at least 50% of tumor cells was selected as the cutoff from the training group. Among patients with a proportion score of at least 50% in the validation group, the response rate was 45.2%. Among all the patients with a proportion score of at least 50%, median progression-free survival was 6.3 months; median overall survival was not reached. CONCLUSIONS: Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer. PD-L1 expression in at least 50% of tumor cells correlated with improved efficacy of pembrolizumab. (Funded by Merck; KEYNOTE-001 ClinicalTrials.gov number, NCT01295827.).

Health-related quality-of-life results for pembrolizumab versus chemotherapy in advanced, PD-L1-positive NSCLC (KEYNOTE-024): a multicentre, international, randomised, open-label phase 3 trial.

BACKGROUND: In the phase 3 KEYNOTE-024 trial, treatment with pembrolizumab conferred longer progression-free survival than did platinum-based therapy in patients with treatment-naive, advanced non-small-cell lung cancer (NSCLC) with a programmed cell death-ligand 1 (PD-L1) tumour proportion score of 50% or greater (PD-L1-positive). Here we report the prespecified exploratory endpoint of pembrolizumab versus chemotherapy on patient-reported outcomes (PROs). METHODS: In this multicentre, international, randomised, open-label, phase 3 trial, we recruited patients with treatment-naive, stage IV NSCLC in 102 sites in 16 countries. Eligible patients had measurable disease (per RECIST version 1.1) and an Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1. Patients were randomly assigned (1:1) via an interactive voice response system and integrated web response system to receive either pembrolizumab 200 mg every 3 weeks (35 cycles) or investigator-choice platinum-doublet chemotherapy (4-6 cycles or until documented disease progression or unacceptable toxicity). Randomisation was stratified according to geography, ECOG performance status, and histology. PROs were assessed at day 1 of cycles 1-3, every 9 weeks thereafter, at the treatment discontinuation visit, and at the 30-day safety assessment visit using the European Organisation for the Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 items (QLQ-C30), the EORTC Quality of Life Questionnaire Lung Cancer 13 items (QLQ-LC13), and the European Quality of Life 5 Dimensions-3 Level (EQ-5D-3L) questionnaire. The key exploratory PRO endpoints (analysed for all patients who received at least one dose of study treatment and completed at least one PRO instrument at at least one timepoint) were baseline-to-week-15 change in the QLQ-C30 global health status (GHS)/quality-of-life (QOL) score and time to deterioration of the composite of cough, chest pain, and dyspnoea in the QLQ-LC13. This study is registered with ClinicalTrials.gov, number NCT02142738, and is ongoing but no longer enrolling patients. FINDINGS: Between Sept 19, 2014, and Oct 29, 2015, 305 patients were randomly assigned to pembrolizumab (n=154) or chemotherapy (n=151). Three patients in each group did not complete any PRO instruments at any timepoints, and so 299 patients were included in the full analysis set. Of these patients, one in each group did not complete any PRO instruments before week 15, and so were not included in analyses of change from baseline to week 15. PRO compliance was greater than 90% at baseline and approximately 80% at week 15 for both groups. Least-squares mean baseline-to-week-15 change in QLQ-C30 GHS/QOL score was 6·9 (95% CI 3·3 to 10·6) for pembrolizumab and -0·9 (-4·8 to 3·0) for chemotherapy, for a difference of 7·8 (2·9 to 12·8; two-sided nominal p=0·0020). Fewer pembrolizumab-treated patients had deterioration in the QLQ-LC13 composite endpoint than did chemotherapy-treated patients (46 [31%] of 151 patients vs 58 [39%] of 148 patients). Time to deterioration was longer with pembrolizumab than with chemotherapy (median not reached [95% CI 8·5 to not reached] vs 5·0 months [3·6 to not reached]; hazard ratio 0·66, 95% CI 0·44-0·97; two-sided nominal p=0·029). INTERPRETATION: Pembrolizumab improves or maintains health-related QOL compared with that for chemotherapy, and might represent a new first-line standard of care for PD-L1-expressing, advanced NSCLC. FUNDING: Merck & Co.

Adverse Event Profile by Folate Receptor Status for Vintafolide and Pegylated Liposomal Doxorubicin in Combination, Versus Pegylated Liposomal Doxorubicin Alone, in Platinum-Resistant Ovarian Cancer: Exploratory Analysis of the Phase II PRECEDENT Trial.

OBJECTIVE: This exploratory analysis evaluated the incidence of adverse events (AEs) by folate receptor (FR) status in the randomized, multicenter, open-label PRECEDENT study in women with platinum-resistant ovarian cancer receiving pegylated liposomal doxorubicin (PLD) ± the small-molecule drug conjugate vintafolide. METHODS: Women 18 years or older with platinum-resistant ovarian cancer were randomized 2:1 to vintafolide (2.5 mg intravenously, 3 times per week, weeks 1 and 3, every 28 days) + PLD (50 mg/m intravenously, day 1, every 28 days) or PLD alone (same dose/schedule). The expression of functionally active FR was evaluated by single-photon emission computed tomography with etarfolatide. Patients were categorized according to FR positivity: patients with all target lesions positive for FR expression (FR 100%), patients with 1 or more but not all target lesions positive for FR expression (FR 10%-90%), and patients with all lesions negative for FR expression (FR 0%). RESULTS: Data on FR status were available for 94 patients: 38 were FR 100%, 36 were FR 10% to 90%, and 20 were FR 0%. Across all FR subgroups, the duration of treatment was longer, and the number of cycles was higher in combination-therapy arms than PLD-alone arms. Although the frequency of AEs was relatively consistent across subgroups, the FR 100% subgroup had a higher incidence of patients with at least 1 AE for combination therapy versus PLD alone. No surprising safety signals were shown according to FR status. The incidence of grade 3 or 4 treatment-emergent drug-related AEs was generally low across all FR subgroups and treatment arms. CONCLUSIONS: This exploratory analysis suggests that FR status does not influence the AE profile of vintafolide + PLD combination therapy or PLD alone in patients with platinum-resistant ovarian cancer. Future a priori analyses in larger populations are needed to confirm these findings.

Phase 1b study of batiraxcept in combination with durvalumab in patients with platinum-resistant ovarian cancer.

Combining an immune checkpoint inhibitor with batiraxcept (AVB-S6-500), an AXL inhibitor that acts via selective binding to growth arrest-specific protein 6 (GAS6), may improve anti-tumor immunity in platinum-resistant ovarian cancer (PROC). This phase 1b trial of durvalumab in combination with escalating doses of batiraxcept enrolled patients with recurrent PROC (NCT04019288). The primary objective was to determine the toxicity profile of the combination. Eleven patients were enrolled on the trial. No dose-limiting toxicities were observed, and no objective responses were noted. Median progression free survival (PFS) was 1.81 months (95% confidence interval (CI) 1.71-2.40), and median overall survival (OS) was 4.53 months (95% CI 2.10-24.74). Batiraxcept effectively reduced serum GAS6 levels at 1-h post-treatment, resulting in trough levels below the limit of detection in all cases but one. In conclusion, the combination of batiraxcept and durvalumab was safe and tolerable but did not demonstrate anti-tumor activity in a heterogenous population of patients with recurrent PROC.

Coordinate control of axon defasciculation and myelination by laminin-2 and -8.

Schwann cells form basal laminae (BLs) containing laminin-2 (Ln-2; heterotrimer alpha2beta1gamma1) and Ln-8 (alpha4beta1gamma1). Loss of Ln-2 in humans and mice carrying alpha2-chain mutations prevents developing Schwann cells from fully defasciculating axons, resulting in partial amyelination. The principal pathogenic mechanism is thought to derive from structural defects in Schwann cell BLs, which Ln-2 scaffolds. However, we found loss of Ln-8 caused partial amyelination in mice without affecting BL structure or Ln-2 levels. Combined Ln-2/Ln-8 deficiency caused nearly complete amyelination, revealing Ln-2 and -8 together have a dominant role in defasciculation, and that Ln-8 promotes myelination without BLs. Transgenic Ln-10 (alpha5beta1gamma1) expression also promoted myelination without BL formation. Rather than BL structure, we found Ln-2 and -8 were specifically required for the increased perinatal Schwann cell proliferation that attends myelination. Purified Ln-2 and -8 directly enhanced in vitro Schwann cell proliferation in collaboration with autocrine factors, suggesting Lns control the onset of myelination by modulating responses to mitogens in vivo.

Tisotumab Vedotin in Previously Treated Recurrent or Metastatic Cervical Cancer.

PURPOSE: Tissue factor (TF) is a potential target in cervical cancer, as it is frequently highly expressed and associated with poor prognosis. Tisotumab vedotin, a first-in-class investigational antibody-drug conjugate targeting TF, has demonstrated encouraging activity in solid tumors. Here we report data from the cervical cancer cohort of innovaTV 201 phase I/II study (NCT02001623). PATIENTS AND METHODS: Patients with recurrent or metastatic cervical cancer received tisotumab vedotin 2.0 mg/kg every 3 weeks until progressive disease, unacceptable toxicity, or consent withdrawal. The primary objective was safety and tolerability. Secondary objectives included antitumor activity. RESULTS: Of the 55 patients, 51% had received ≥2 prior lines of treatment in the recurrent or metastatic setting; 67% had prior bevacizumab + doublet chemotherapy. Fifty-one percent of patients had squamous cell carcinoma. The most common grade 3/4 treatment-emergent adverse events (AEs) were anemia (11%), fatigue (9%), and vomiting (7%). No grade 5 treatment-related AEs occurred. Investigator-assessed confirmed objective response rate (ORR) was 24% [95% confidence interval (CI): 13%-37%]. Median duration of response (DOR) was 4.2 months (range: 1.0+-9.7); four patients responded for >8 months. The 6-month progression-free survival (PFS) rate was 29% (95% CI: 17%-43%). Independent review outcomes were comparable, with confirmed ORR of 22% (95% CI: 12%-35%), median DOR of 6.0 months (range: 1.0+-9.7), and 6-month PFS rate of 40% (95% CI: 24%-55%). Tissue factor expression was confirmed in most patients; no significant association with response was observed. CONCLUSIONS: Tisotumab vedotin demonstrated a manageable safety profile and encouraging antitumor activity in patients with previously treated recurrent or metastatic cervical cancer.

Safety and Efficacy of Pembrolizumab in Advanced, Programmed Death Ligand 1-Positive Cervical Cancer: Results From the Phase Ib KEYNOTE-028 Trial.

Purpose The KEYNOTE-028 trial ( ClinicalTrials.gov identifier: NCT02054806) was designed to assess the safety and efficacy of pembrolizumab in 20 programmed death ligand 1-positive, advanced solid tumor cohorts. Here, we present the results from the cohort of patients with advanced cervical cancer. Methods Patients were treated with pembrolizumab 10 mg/kg every 2 weeks for up to 24 months. Response was assessed every 8 weeks for the first 6 months and every 12 weeks thereafter. The primary end point was overall response rate per Response Evaluation Criteria in Solid Tumors, version 1.1, by investigator review. Safety was a secondary end point. Results Twenty-four patients were enrolled in the cervical cancer cohort. The median age was 42 years (range, 26 to 62 years), 22 patients (92%) had received prior radiation therapy, and 15 patients (63%) had received two or more lines of therapy, including bevacizumab (10 of 24 patients), for advanced disease. At the data cutoff, median follow-up duration was 11.0 months (range, 1.3 to 32.2 months). Overall response rate was 17% (95% CI, 5% to 37%); four patients (17%) achieved a confirmed partial response, and three patients (13%) had stable disease. Median duration of response for the four patients who achieved a partial response was 5.4 months (4.1 to 7.5 months). Treatment related adverse events (AEs) were experienced by 18 patients (75%); only rash (n = 5; 21%) and pyrexia (n = 4; 17%) and occurred in ≥ 10% of patients. Five patients experienced grade 3 treatment-related AEs. No grade 4 treatment-related AEs or deaths were observed. Conclusion In patients with programmed death ligand 1-positive advanced cervical cancer, pembrolizumab demonstrated antitumor activity and exhibited a safety profile consistent with that seen in other tumor types.

CD44 associates with EGFR and erbB2 in metastasizing mammary carcinoma cells.

Type I receptor tyrosine kinases, including the epidermal growth factor receptor (EGFR) and erbB2, have been implicated in mammary carcinoma growth and metastasis. Recent evidence suggests that type I receptor signaling may be mediated by the CD44 family of transmembrane glycoproteins that also have been implicated in mammary tumor progression. Here, the authors tested whether CD44, EGFR, and erbB2 interacted and colocalized with one another in four mammary carcinoma cell lines (MCF-7, MDA-MB-231, MDA-MB-435, and MDA-MB-436) and in cytology samples obtained from patients with metastatic breast cancer. CD44 constitutively colocalized and coimmunoprecipitated with erbB2 and EGFR in all four mammary carcinoma cell lines. CD44 also colocalized with erbB2 and EGFR in all cytology samples expressing erbB2. CD44 colocalized with EGFR in cells from only 1 of 16 erbB2-negative cytology samples. These data indicate that CD44-EGFR-erbB2 protein complexes occur in a high proportion of metastatic mammary carcinomas and suggest that CD44-type I receptor colocalization may be a novel prognostic marker for aggressive mammary cancers.

Combined autophagy and proteasome inhibition: a phase 1 trial of hydroxychloroquine and bortezomib in patients with relapsed/refractory myeloma.

The efficacy of proteasome inhibition for myeloma is limited by therapeutic resistance, which may be mediated by activation of the autophagy pathway as an alternative mechanism of protein degradation. Preclinical studies demonstrate that autophagy inhibition with hydroxychloroquine augments the antimyeloma efficacy of the proteasome inhibitor bortezomib. We conducted a phase I trial combining bortezomib and hydroxychloroquine for relapsed or refractory myeloma. We enrolled 25 patients, including 11 (44%) refractory to prior bortezomib. No protocol-defined dose-limiting toxicities occurred, and we identified a recommended phase 2 dose of hydroxychloroquine 600 mg twice daily with standard doses of bortezomib, at which we observed dose-related gastrointestinal toxicity and cytopenias. Of 22 patients evaluable for response, 3 (14%) had very good partial responses, 3 (14%) had minor responses, and 10 (45%) had a period of stable disease. Electron micrographs of bone marrow plasma cells collected at baseline, after a hydroxychloroquine run-in, and after combined therapy showed therapy-associated increases in autophagic vacuoles, consistent with the combined effects of increased trafficking of misfolded proteins to autophagic vacuoles and inhibition of their degradative capacity. Combined targeting of proteasomal and autophagic protein degradation using bortezomib and hydroxychloroquine is therefore feasible and a potentially useful strategy for improving outcomes in myeloma therapy.

Combined MTOR and autophagy inhibition: phase I trial of hydroxychloroquine and temsirolimus in patients with advanced solid tumors and melanoma.

The combination of temsirolimus (TEM), an MTOR inhibitor, and hydroxychloroquine (HCQ), an autophagy inhibitor, augments cell death in preclinical models. This phase 1 dose-escalation study evaluated the maximum tolerated dose (MTD), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of HCQ in combination with TEM in cancer patients. In the dose escalation portion, 27 patients with advanced solid malignancies were enrolled, followed by a cohort expansion at the top dose level in 12 patients with metastatic melanoma. The combination of HCQ and TEM was well tolerated, and grade 3 or 4 toxicity was limited to anorexia (7%), fatigue (7%), and nausea (7%). An MTD was not reached for HCQ, and the recommended phase II dose was HCQ 600 mg twice daily in combination with TEM 25 mg weekly. Other common grade 1 or 2 toxicities included fatigue, anorexia, nausea, stomatitis, rash, and weight loss. No responses were observed; however, 14/21 (67%) patients in the dose escalation and 14/19 (74%) patients with melanoma achieved stable disease. The median progression-free survival in 13 melanoma patients treated with HCQ 1200mg/d in combination with TEM was 3.5 mo. Novel 18-fluorodeoxyglucose positron emission tomography (FDG-PET) measurements predicted clinical outcome and provided further evidence that the addition of HCQ to TEM produced metabolic stress on tumors in patients that experienced clinical benefit. Pharmacodynamic evidence of autophagy inhibition was evident in serial PBMC and tumor biopsies only in patients treated with 1200 mg daily HCQ. This study indicates that TEM and HCQ is safe and tolerable, modulates autophagy in patients, and has significant antitumor activity. Further studies combining MTOR and autophagy inhibitors in cancer patients are warranted.

Phase I trial of hydroxychloroquine with dose-intense temozolomide in patients with advanced solid tumors and melanoma.

Blocking autophagy with hydroxychloroquine (HCQ) augments cell death associated with alkylating chemotherapy in preclinical models. This phase I study evaluated the maximum tolerated dose (MTD), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of HCQ in combination with dose-intense temozolomide (TMZ) in patients with advanced solid malignancies. Forty patients (73% metastatic melanoma) were treated with oral HCQ 200 to 1200 mg daily with dose-intense oral TMZ 150 mg/m (2) daily for 7/14 d. This combination was well tolerated with no recurrent dose-limiting toxicities observed. An MTD was not reached for HCQ and the recommended phase II dose was HCQ 600 mg twice daily combined with dose-intense TMZ. Common toxicities included grade 2 fatigue (55%), anorexia (28%), nausea (48%), constipation (20%), and diarrhea (20%). Partial responses and stable disease were observed in 3/22 (14%) and 6/22 (27%) patients with metastatic melanoma. In the final dose cohort 2/6 patients with refractory BRAF wild-type melanoma had a near complete response, and prolonged stable disease, respectively. A significant accumulation in autophagic vacuoles (AV) in peripheral blood mononuclear cells was observed in response to combined therapy. Population pharmacokinetics (PK) modeling, individual PK simulations, and PK-pharmacodynamics (PD) analysis identified a threshold HCQ peak concentration that predicts therapy-associated AV accumulation. This study indicates that the combination of high-dose HCQ and dose-intense TMZ is safe and tolerable, and is associated with autophagy modulation in patients. Prolonged stable disease and responses suggest antitumor activity in melanoma patients, warranting further studies of this combination, or combinations of more potent autophagy inhibitors and chemotherapy in melanoma.

Erbin regulates mitogen-activated protein (MAP) kinase activation and MAP kinase-dependent interactions between Merlin and adherens junction protein complexes in Schwann cells.

Biallelic mutations in the neurofibromatosis 2 (NF2) gene are linked to schwannoma and meningioma tumorigenesis. Cells with NF2 mutations exhibit elevated levels of phosphorylated extracellular signal-regulated kinase (ERK) and aberrant cell-cell and cell-matrix contacts. The NF2 gene product, merlin, associates with adherens junction protein complexes, suggesting that part of its function as a tumor suppressor involves regulating cell junctions. Here, we find that a novel PDZ protein, called erbin, binds directly to the merlin-binding partner, EBP0, and regulates adherens junction dissociation through a MAP kinase-dependent mechanism. Reducing erbin expression using a targeted siRNA in primary cultures of Schwann cells results in altered cell-cell interactions, disruption of E-cadherin adherens junctions, increased cell proliferation, and elevated levels of phosphorylated ERK, all phenotypes observed in cells that lack merlin. Reduction of erbin expression also results in the dissociation of merlin from adherens junction proteins and an increase in the levels of phosphorylated merlin. These phenotypes can be rescued if cells with reduced levels of erbin are treated with a pharmacological inhibitor of ERK kinase. Collectively, these data indicate that erbin regulates MAP kinase activation in Schwann cells and suggest that erbin links merlin to both adherens junction protein complexes and the MAP kinase signaling pathway.

Regulation of immunoproteasome subunit expression in vivo following pathogenic fungal infection.

The proteasome catalytic beta subunits LMP2, LMP7, and MECL-1 and two proteasome activator proteins, PA28 alpha and beta, are induced following exposure to IFN-gamma in vitro. Induction of these immunosubunits and the PA28 alpha/beta hetero-oligomer alters proteasome catalytic functions and specificity and enhances production of certain MHC class I epitopes. We sought to determine whether and to what extent proteasome subunit composition is regulated in vivo and to elucidate the mechanisms of such regulation. We analyzed basal expression levels of these inducible genes in normal, IFN-gamma-deficient, and Stat-1-deficient mice. Mice of all three genotypes display constitutive expression of the immunosubunits and PA28, demonstrating that basal expression in vivo is independent of endogenous IFN-gamma production. However, basal expression levels are reduced in Stat-1(-/-) mice, demonstrating a role for Stat-1 independent of IFN-gamma signaling. To demonstrate that IFN-gamma can induce these genes in vivo, mice were infected with Histoplasma capsulatum. Elevated expression of these genes followed the same time course as IFN-gamma expression in infected mice. IFN-gamma-deficient mice did not display elevated protein expression following infection, suggesting that other inflammatory cytokines produced in infected mice are unable to influence proteasome expression. Cytokines other than IFN-gamma also failed to influence proteasome gene expression in vitro in cell lines that had no basal expression of LMP2, LMP7, or MECL-1. Thus, both in vitro and in vivo data demonstrate that IFN-gamma is essential for up-regulation, but not constitutive expression, of immunoproteasome subunits in mice.