Safety, Pharmacokinetics, Pharmacodynamics, and Antitumor Activity from a Phase I Study of Simlukafusp Alfa (FAP-IL2v) in Advanced/Metastatic Solid Tumors.

PURPOSE: Simlukafusp alfa (FAP-IL2v), a tumor-targeted immunocytokine, comprising an interleukin-2 variant moiety with abolished CD25 binding fused to human immunoglobulin G1, is directed against fibroblast activation protein-α. This phase I, open-label, multicenter, dose-escalation and extension study (NCT02627274) evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of FAP-IL2v in patients with advanced/metastatic solid tumors. METHODS: Participants received FAP-IL2v intravenously once weekly. Dose escalation started at 5 mg; flat dosing (≤25 mg) and intra-participant up-titration regimens (15/20 mg, 20/25 mg, 20/20/35 mg, 20/35/35 mg) were evaluated. Primary objectives were dose-limiting toxicities (DLT), maximum tolerated dose (MTD), recommended expansion dose, and pharmacokinetics. RESULTS: Sixty-one participants were enrolled. DLTs included fatigue (flat dose 20 mg: n = 1), asthenia (25 mg: n = 1), drug-induced liver injury (up-titration regimen 20/25 mg: n = 1), transaminase increase (20/25 mg: n = 1), and pneumonia (20/35/35 mg: n = 1). Up-titration regimen 15/20 mg was the MTD and was selected as the recommended expansion dose. Increases in peripheral blood absolute immune cell counts were seen for all tested doses (natural killer cells, 13-fold; CD4+ T cells [including Tregs], 2-fold; CD8+ T cells, 3.5-fold), but without any percentage change in Tregs. Clinical activity was observed from 5 mg (objective response rate, 5.1% [n = 3]; disease control rate, 27.1% [n = 16]). Responses were durable (n = 3; 2.8 [censored], 6.3, and 43.4 months). CONCLUSIONS: FAP-IL2v had a manageable safety profile and showed initial signs of antitumor activity in advanced/metastatic solid tumors.

Obinutuzumab Pretreatment as a Novel Approach to Mitigate Formation of Anti-Drug Antibodies Against Cergutuzumab Amunaleukin in Patients with Solid Tumors.

PURPOSE: The immunocytokine cergutuzumab amunaleukin (CEA-IL2v) showed manageable safety and favorable pharmacodynamics in phase I/Ib trials in patients with advanced/metastatic carcinoembryonic antigen-positive (CEA+) solid tumors, but this was accompanied by a high incidence of anti-drug antibodies (ADA). We examined B-cell depletion with obinutuzumab as a potential mitigation strategy. EXPERIMENTAL DESIGN: Preclinical data comparing B-cell depletion with rituximab versus obinutuzumab are summarized. Substudies of phase I/Ib trials investigated the effect of obinutuzumab pretreatment on ADA development, safety, pharmacodynamics, and antitumor activity of CEA-IL2v ± atezolizumab in patients with advanced/metastatic or unresectable CEA+ solid tumors who had progressed on standard of care. RESULTS: Preclinical data showed superior B-cell depletion with obinutuzumab versus rituximab. In clinical studies, patients received CEA-IL2v monotherapy with (n = 16) or without (n = 6) obinutuzumab pretreatment (monotherapy study), or CEA-IL2v + atezolizumab + obinutuzumab pretreatment (n = 5; combination study). In the monotherapy study, after four cycles (every 2 weeks treatment), 0/15 evaluable patients administered obinutuzumab pretreatment had ADAs versus 4/6 patients without obinutuzumab. Obinutuzumab pretreatment with CEA-IL2v monotherapy showed no new safety signals and pharmacodynamic data suggested minimal impact on T cells and natural killer cells. Conversely, increased liver toxicity was observed in the combination study (CEA-IL2v + atezolizumab + obinutuzumab pretreatment). CONCLUSIONS: These preliminary findings suggest that obinutuzumab pretreatment before CEA-IL2v administration in patients with CEA+ solid tumors may be a feasible and potent ADA mitigation strategy, with an acceptable safety profile, supporting broader investigation of obinutuzumab pretreatment for ADA mitigation in other settings.

Anti-CSF-1R emactuzumab in combination with anti-PD-L1 atezolizumab in advanced solid tumor patients naïve or experienced for immune checkpoint blockade.

BACKGROUND: This phase 1b study (NCT02323191) evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of colony-stimulating factor-1 receptor-blocking monoclonal antibody (mAb) emactuzumab in combination with the programmed cell death-1 ligand (PD-L1)-blocking mAb atezolizumab in patients with advanced solid tumors naïve or experienced for immune checkpoint blockers (ICBs). METHODS: Emactuzumab (500-1350 mg flat) and atezolizumab (1200 mg flat) were administered intravenously every 3 weeks. Dose escalation of emactuzumab was conducted using the 3+3 design up to the maximum tolerated dose (MTD) or optimal biological dose (OBD). Extension cohorts to evaluate pharmacodynamics and clinical activity were conducted in metastatic ICB-naive urothelial bladder cancer (UBC) and ICB-pretreated melanoma (MEL), non-small cell lung cancer (NSCLC) and UBC patients. RESULTS: Overall, 221 patients were treated. No MTD was reached and the OBD was determined at 1000 mg of emactuzumab in combination with 1200 mg of atezolizumab. Grade ≥3 treatment-related adverse events occurred in 25 (11.3%) patients of which fatigue and rash were the most common (14 patients (6.3%) each). The confirmed objective response rate (ORR) was 9.8% for ICB-naïve UBC, 12.5% for ICB-experienced NSCLC, 8.3% for ICB-experienced UBC and 5.6% for ICB-experienced MEL patients, respectively. Tumor biopsy analyses demonstrated increased activated CD8 +tumor infiltrating T lymphocytes (TILs) associated with clinical benefit in ICB-naïve UBC patients and less tumor-associated macrophage (TAM) reduction in ICB-experienced compared with ICB-naïve patients. CONCLUSION: Emactuzumab in combination with atezolizumab demonstrated a manageable safety profile with increased fatigue and skin rash over usual atezolizumab monotherapy. A considerable ORR was particularly seen in ICB-experienced NSCLC patients. Increase ofCD8 +TILs under therapy appeared to be associated with persistence of a TAM subpopulation.

Macrophage depletion induces edema through release of matrix-degrading proteases and proteoglycan deposition.

Colony-stimulating factor 1 receptor (CSF1R) blockade abates tumor-associated macrophage (TAM) infiltrates and provides marked clinical benefits in diffuse-type tenosynovial giant cell tumors. However, facial edema is a common adverse event associated with TAM elimination in patients. In this study, we examined molecular and cellular events associated with edema formation in mice and human patients with cancer treated with a CSF1R blocking antibody. Extended antibody treatment of mice caused marked body weight gain, an indicator of enhanced body fluid retention. This was associated with an increase of extracellular matrix-remodeling metalloproteinases (MMPs), namely MMP2 and MMP3, and enhanced deposition of hyaluronan (HA) and proteoglycans, leading to skin thickening. Discontinuation of anti-CSF1R treatment or blockade of MMP activity restored unaltered body weight and normal skin morphology in the mice. In patients, edema developed at doses well below the established optimal biological dose for emactuzumab, a CSF1R dimerization inhibitor. Patients who developed edema in response to emactuzumab had elevated HA in peripheral blood. Our findings indicate that an early increase of peripheral HA can serve as a pharmacodynamic marker for edema development and suggest potential interventions based on MMP inhibition for relieving periorbital edema in patients treated with CSF1R inhibitors.

Long-term clinical activity, safety and patient-reported quality of life for emactuzumab-treated patients with diffuse-type tenosynovial giant-cell tumour.

OBJECTIVES: This study investigated the safety, clinical activity and patient-reported outcomes of patients with diffuse-type tenosynovial giant-cell tumour (dTGCT) of the soft tissue who were treated with emactuzumab, a humanised anti-colony stimulating factor 1 receptor (CSF1R) monoclonal antibody and were followed up for up to 2 years after the start of treatment. METHODS: In this open-label phase 1 study (ClinicalTrials.govNCT01494688), patients received intravenous (IV) emactuzumab from 900 to 2000 mg every two weeks in the dose-escalation phase and at the optimal biological dose of 1000 mg with different schedules in the dose-expansion phase. Adverse event (AE) rates and biomarker assessments from tumour biopsies were analysed. Quality of life was assessed using a standard questionnaire (EuroQol-5D-3L) and the WOMAC® 3.1 Osteoarthritis Index. Tumour responses were determined with magnetic resonance imaging. RESULTS: Altogether, 63 patients were enrolled into the study. The most frequently reported AEs were pruritus, asthenia and oedema. In 36 patients for whom biopsy tissue was available a substantial decrease of CSF1R-positive and CD68/CD163-positive macrophages was detected. The independently reviewed best overall objective response rate (ORR) (Response Evaluation Criteria in Solid Tumors version 1.1) was 71%. Responses were durable, and an ORR of 70% and 64% was determined after one or two years after enrolment into the study. Clinical activity was accompanied by an improvement in EuroQol-5D-3L and particularly the joint disorder-specific WOMAC score. CONCLUSIONS: Systemic therapy of dTGCT patients with emactuzumab resulted in pronounced and durable responses associated with symptomatic improvement and a manageable safety profile.

Phase Ib study of anti-CSF-1R antibody emactuzumab in combination with CD40 agonist selicrelumab in advanced solid tumor patients.

BACKGROUND: This phase Ib study evaluated the safety, clinical activity, pharmacokinetics, and pharmacodynamics (PD) of emactuzumab (anti-colony stimulating factor 1 receptor monoclonal antibody (mAb)) in combination with selicrelumab (agonistic cluster of differentiation 40 mAb) in patients with advanced solid tumors. METHODS: Both emactuzumab and selicrelumab were administered intravenously every 3 weeks and doses were concomitantly escalated (emactuzumab: 500 to 1000 mg flat; selicrelumab: 2 to 16 mg flat). Dose escalation was conducted using the product of independent beta probabilities dose-escalation design. PD analyzes were performed on peripheral blood samples and tumor/skin biopsies at baseline and on treatment. Clinical activity was evaluated using investigator-based and Response Evaluation Criteria In Solid Tumors V.1.1-based tumor assessments. RESULTS: Three dose-limiting toxicities (all infusion-related reactions (IRRs)) were observed at 8, 12 and 16 mg of selicrelumab together with 1000 mg of emactuzumab. The maximum tolerated dose was not reached at the predefined top doses of emactuzumab (1000 mg) and selicrelumab (16 mg). The most common adverse events were IRRs (75.7%), fatigue (54.1%), facial edema (37.8%), and increase in aspartate aminotransferase and creatinine phosphokinase (35.1% both). PD analyzes demonstrated an increase of Ki67+-activated CD8+ T cells accompanied by a decrease of B cells and the reduction of CD14Dim CD16bright monocytes in peripheral blood. The best objective clinical response was stable disease in 40.5% of patients. CONCLUSION: Emactuzumab in combination with selicrelumab demonstrated a manageable safety profile and evidence of PD activity but did not translate into objective clinical responses. TRIALREGISTRATION NUMBER: NCT02760797.

Recurrence rate of cholesteatoma with autoclaved incus autograft.

OBJECTIVE: To study the long-term recurrence rate of cholesteatoma with autoclaved incus autograft. STUDY DESIGN: Prospective observational study between 1994 and 2009. The incus remnants were autoclaved at 134°C for 24 minutes at 205 kPa. The mean follow-up duration was 65.5 months, with a minimum follow-up duration of 31 months and a maximum follow-up duration of 186 months. SETTING: Secondary referral center in a district general hospital. PATIENTS: Thirty-seven cases of cholesteatoma treated with canal wall down mastoidectomy with primary ossicular reconstruction with autoclaved incus autograft were included. The age range of the patients was from 11 years to 67 years. The mean age was 38 years. Fifty-four percent was male, and 46% was female. INTERVENTIONS: Therapeutic and rehabilitative--to treat and improve the patients' hearing loss secondary to cholesteatoma by using autoclaved autologous incus. MAIN OUTCOME MEASURES: Primary end point is the recurrence rate of cholesteatoma with a mean follow-up period of more than 5 years. Secondary end point is the audiometric outcome with air-bone gap (ABG) and air conduction improvement. RESULTS: No recurrence of cholesteatoma was observed. No graft extrusion was seen. Preoperative mean ABG was 29.8 dB. Postoperative mean ABG was 25.6 dB at the final review, with the air conduction improvement at final review at 4.2 dB. CONCLUSION: Autoclaving the incus remnant harvested from cholesteatomatous middle ear cleft is a safe and effective method to prepare an incus autograft for primary ossicular reconstruction.

Recommendations and best practices for reference standards and reagents used in bioanalytical method validation.

The continued globalization of pharmaceutics has increased the demand for companies to know and understand the regulations that exist across the globe. One hurdle facing pharmaceutical and biotechnology companies developing new drug candidates is interpreting the current regulatory guidance documents and industry publications associated with bioanalytical method validation (BMV) from each of the different agencies throughout the world. The objective of this commentary is to provide our opinions on the best practices for reference standards and key reagents, such as metabolites and internal standards used in the support of regulated bioanalysis based on a review of current regulatory guidance documents and industry white papers for BMV.

Objective assessment of the perineural vascular plexus as a landmark for the horizontal part of the facial nerve in middle ear and mastoid surgery.

OBJECTIVE: To objectively evaluate the usefulness and the reliability of the perineural vascular plexus as a landmark for identification of the facial nerve in surgery for chronic squamous otitis media. STUDY DESIGN: Prospective case series. SETTING: Tertiary otologic center. PATIENTS: Seventy consecutive patients requiring surgery for cholesteatomatous otitis media. INTERVENTION: Use of a semiquantitative grading system intraoperatively to assess the utility and ease of using the perineural facial plexus as the pointer to the facial nerve. MAIN OUTCOME MEASURES: Description of the perineural vascular plexus and assessment of the reproducibility of the grading system. RESULTS: In 82.5% of patients, the plexus was used as the sole pointer to the level of the facial nerve, with other landmarks being used in the remaining 17.5%. A very prominent vessel was used to identify the nerve in 82.5%, therefore being classified as Grade 1. Multiple small vessels were seen in 15.8% (Grade 2), and in 1.5% the vessel plexus was thin and difficult to identify. The average measure intraclass correlation was 0.75 (95% confidence interval, 0.57-0.85), indicating excellent reproducibility of the system. CONCLUSION: We believe that the perineural vascular plexus is a dependable and reliable landmark for the level of the facial nerve in surgery for chronic otitis media.