AB0358 SAFETY, TOLERABILITY, PHARMACOKINETICS, RECEPTOR OCCUPANCY, AND SUPPRESSION OF T-CELL-DEPENDENT ANTIBODY RESPONSE IN A PHASE 1 STUDY WITH KPL-404, AN ANTI-CD40 MONOCLONAL ANTIBODY

Background

T-cell priming and T-cell-dependent B-cell responses require an intact cluster of differentiation (CD)40/CD40L pathway. CD40 is expressed on the surface of B-cells, dendritic cells, antigen-presenting cells, and non-immune cell types; its ligand, CD40L (CD154), is expressed on the surface of activated T-cells, platelets, and other cell types. Blockade of CD40/CD40L interaction has been shown to ablate primary and secondary T-cell dependent antibody response (TDAR).

Objectives

We hypothesized that KPL-404, an anti-CD40 monoclonal antibody which inhibits interaction between CD40 and CD40L, would block T-cell dependent, B-cell-mediated autoimmunity in this Phase 1 study in healthy participants.

Methods

This randomized, double-blind, placebo-controlled, first-in-human study of KPL-404 in healthy participants was designed with two single-ascending-dose arms: single intravenous (IV) doses of 0.03 mg/kg, 0.3 mg/kg, 1 mg/kg, 3 mg/kg, or 10 mg/kg and single subcutaneous (SC) doses of 1 mg/kg or 5 mg/kg. The primary objective was safety and tolerability of KPL-404; secondary and exploratory objectives included pharmacokinetic (PK) parameters, TDAR inhibition, and receptor occupancy (RO). To evaluate TDAR inhibition, participants post-KPL-404 administration were immunized with 1 mg intramuscular injection of the test antigen Keyhole Limpet Hemocyanin (KLH) on day 4 and day 29 to elicit a primary and secondary Immunoglobulin (Ig) response, respectively. To evaluate RO, free and total CD40 receptor levels (percent change from baseline) on B-cells (whole blood) were measured using flow cytometry.

Results

There were no dose-limiting or dose-related safety findings in healthy participants after KPL-404 administration. One unrelated serious adverse event (patella fracture following a fall) occurred in the 10 mg/kg IV arm. The PK profile of KPL-404 in serum after IV or SC administration had low to moderate variability between individuals; elimination was dose-dependent and consistent with target-mediated drug disposition (TMDD) (Figure 1a). For participants receiving 10 mg/kg IV, full receptor occupancy was observed through day 71 (Figure 1b), complete TDAR suppression was observed through Day 57 (Figure 1c), and anti-drug antibodies to KPL-404 were suppressed for at least 57 days; the suppression of antibody responses to the drug itself is an independent indicator of target engagement and pharmacodynamic effect. For participants receiving 5 mg/kg SC, full receptor occupancy was observed through day 43 (Figure 1b), and complete TDAR suppression was observed through Day 29 (Figure 1c). The TDAR response to KLH antigen correlated with the observed full RO.

Conclusion

The safety and tolerability data and the PK/PD profile of KPL-404 support further investigation of KPL-404 in a broad range of autoimmune diseases, including rheumatoid arthritis. These data support the optionality for studying chronic KPL-404 dosing in patients with subcutaneous and/or intravenous administration.

Disclosure of Interests

Manoj Samant Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Alistair Wheeler Consultant of: Kiniksa Pharmaceuticals Corp., Guang-Liang Jiang Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Moses Njenga Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Madeline Spiers Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Arian Pano Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., John F. Paolini Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp.

AB0379 DOSE-DEPENDENT SUPPRESSION OF T CELL-DEPENDENT ANTIBODY RESPONSE IN HEALTHY VOLUNTEERS BY KPL-404, AN ANTI-CD40 MONOCLONAL ANTIBODY, SUPPORTS CHRONIC DOSING STUDY IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background

An unmet need remains in patients with failure and/or inadequate response (IR) to biological disease-modifying antirheumatic drugs (bDMARD-IR) and/or Janus kinase inhibitors (JAKi-IR). The CD40/CD40L (CD154) costimulatory pathway is linked to inflammation and joint destruction in RA via production of autoantibodies and inflammatory mediators. KPL-404 is a humanized IgG4 antibody engineered to bind CD40 without triggering Fc effector functions (Muralidharan, 2019), which are known to have been associated with thromboembolic events seen in the first generation of CD40L-targeting therapies.

In a first-in-human Phase 1 single ascending dose study, 52 healthy volunteers received single doses of KPL-404 administered either subcutaneously (SC) or intravenously (IV) with no dose-limiting safety findings, infectious episodes, or toxicities (Samant, 2021). The study demonstrated that with 10 mg/kg IV, full receptor occupancy (RO) was observed through day 71, and there was complete suppression of T-cell dependent antibody response (TDAR) to keyhole limpet hemocyanin challenge on day 1 and re-challenge on day 29 through day 57. With 5 mg/kg SC, full RO was observed through day 43, and there was complete suppression of TDAR through at least day 29. Complete suppression of ADA to KPL-404, an independent indicator of target engagement, was also observed while KPL-404 serum concentrations were above approximately 0.1 to 0.2 µg/mL and continued for at least 50 days and 57 days after 5 mg/kg SC and 10 mg/kg IV administration, respectively.

Objectives

Using Phase 1 and nonclinical data, identify chronic dosing regimens anticipated to yield PK in the sub-therapeutic, therapeutic, and supra-therapeutic ranges to be utilized in a Multiple Ascending Dose Phase 2 Study.

Methods

A PK model was used to simulate multiple dosing scenarios, including: 2.5, 5, and 10 mg/kg SC qwk, q2wk, and q4wk, as well as 10 mg/kg IV q4wk. The model was used to identify optimal Phase 2 dosing schedules by generating 1000 virtual subjects using the typical parameter estimates with between-subject variability included.

Results

Following SC administration, all subjects were predicted to achieve complete ADA suppression for the full dosing interval at/above 2.5 mg/kg SC q2wk. At 2 mg/kg SC q2wk (starting dose level), simulated steady-state 8-week data predicted PK in a sub-therapeutic range for most subjects and an approximately 31- and 18-fold safety margin relative to preclinical NOAEL dose. At 5 mg/kg SC q2wk, 100% of patients were predicted to be in a therapeutic range, indicating a potential practical efficacious dose level. At 10 mg/kg SC q2wk, 100% of patients were predicted to be in the supratherapeutic range.

These results support a Multiple Ascending Dose (MAD) Phase 2 study design, with PK lead-in comprised of 3 Cohorts at 2, 5, or 10 mg/kg SC q2wk (each randomized 6:2) and Proof-of-Concept phase (Cohort 4) comprised of 48-60 subjects randomized 1:1:1 to 10 mg/kg, 5 mg/kg, and placebo SC q2wk. The ongoing study will evaluate efficacy (Disease Activity of 28 joints using C-reactive protein [DAS28-CRP]), safety, PK, and pharmacodynamics (PD) of escalating doses levels of KPL-404 compared with placebo in patients with moderate to severe RA (bDMARD-IR or JAKi-IR). The study also allows the flexibility of optional cohorts including additional dosing regimens and/or subpopulations identified based on clinical response and biomarkers.

Conclusion

Inhibition of the CD40-CD154 co-stimulatory interaction holds promise for the management of a spectrum of autoimmune diseases. KPL-404 demonstrated prolonged absorption/excretion capable of suppressing TDAR for extended periods allowing for use of extended dosing intervals irrespective of IV or SC dosing. These analyses supported the design of the ongoing Phase 2 study assessing the efficacy and safety KPL-404 in RA.

References

[1]Muralidharan S et al. 2019. Poster at Keystone Symposia

[2]Samant M et al. Arthritis Rheumatol. 2021; 73(suppl 10)

Disclosure of Interests

Anastassia Papandrikopoulou Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Gerd Rüdiger Burmester Speakers bureau: Abbvie, Amgen, BMS, Lilly, MSD, Pfizer, Roche, Sanofi, Consultant of: Abbvie, Amgen, BMS, Kiniksa, Lilly, MSD, Pfizer, Roche, Sanofi, Fang Fang Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Alan Kivitz Shareholder of: Amgen, Gilead Sciences, Inc., GlaxoSmithKline, Novartis, Pfizer, Sanofi,, Speakers bureau: AbbVie, Celgene, Flexion, Genzyme, GlaxoSmithKline, Lilly, Merck, Novartis, Pfizer, Sanofi, UCB, Horizon, Consultant of: AbbVie, Boehringer Ingelheim, Flexion, Gilead Sciences, Inc., Janssen, Pfizer, Sanofi, SUN Pharma Advanced Research, Moses Njenga Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Arian Pano Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Costantino Pitzalis Speakers bureau: Abbott/AbbVie, Astra-

Zeneca/MedImmune, BMS, Janssen/J&J, MSD, Pfizer, Roche/Genentech/Chugai, UCB.,, Consultant of: Abbott/AbbVie, Astellas, Astra-Zeneca/MedImmune, BMS, CelGene, Grunenthal, GSK,

Janssen/J&J, Kiniksa, MSD, Pfizer, Sanofi, Roche / Genentech / Chugai, UCB., Grant/research support from: Abbott/AbbVie, Astellas, Astra-Zeneca/MedImmune, BMS, Janssen/J&J, MSD, Pfizer, Roche/Genentech/Chugai, UCB., Manoj Samant Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Steve Schmitz Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Madeline Spiers Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., Eben Tessari Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp., John Ziemniak Consultant of: Kiniksa Pharmaceuticals, Ltd., John F. Paolini Shareholder of: Kiniksa Pharmaceuticals Corp., Employee of: Kiniksa Pharmaceuticals Corp.

AB0370 UTILITY OF CRP AND ESR IN THE DIAGNOSIS OF GIANT CELL ARTERITIS RELAPSE IN A PHASE 2 TRIAL OF MAVRILIMUMAB

Background:

No universally accepted definition of flare currently exists in giant cell arteritis (GCA). Although relapses are defined mostly on clinical grounds (recurrence of GCA-related signs/symptoms), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) help clinicians assess disease activity. In fact, >70% of patients on glucocorticoids (GCs) alone have increased CRP or ESR when the disease is active. In contrast, tocilizumab, given its IL-6-blockade effect in the liver, rapidly reduces CRP and ESR levels, rendering them unreliable for disease activity monitoring. Mavrilimumab – a GM-CSF receptor α inhibitor with demonstrated efficacy in a Phase 2 GCA trial1 – downregulates inflammation upstream of IL-6. We hypothesized that mavrilimumab would not interfere with the utility of CRP and ESR in monitoring disease activity and in identifying GCA relapse.

Objectives:

To analyze the relationship between CRP/ESR and clinical disease activity in GCA patients treated with mavrilimumab.

Methods:

New-onset and relapsing GCA patients with active disease were recruited. GC-induced remission (no GCA symptoms and CRP <1 mg/dL or ESR <20 mm/hr) was required by baseline. Patients were randomized 3:2 to mavrilimumab 150 mg or placebo subcutaneously every 2 weeks plus a protocol-defined 26-week prednisone taper. The primary efficacy endpoint was time to relapse by Week 26. Relapse (adjudicated) was defined as recurrent GCA-related signs/symptoms, including new/worsening vasculitis on imaging, concurrent with CRP ≥1 mg/dL and/or ESR ≥30 mm/hr. CRP and ESR were also measured periodically during the trial.

This post hoc analysis assessed the association of recurrent GCA-related signs/symptoms with concurrent CRP or ESR elevation post-randomization by treatment arm. We also assessed the proportion of patients with CRP or ESR elevation without GCA-related signs/symptoms up to Week 26.

Results:

Seventy patients were enrolled (mavrilimumab, N=42; placebo, N=28). The association of CRP or ESR elevation with unequivocal GCA-related signs/symptoms post-randomization was consistent regardless of treatment arm: 8/8 in the mavrilimumab group and 13/13 in the placebo group (Table 1). During relapse, median (range) CRP was 1.8 (1.4 – 8.4) mg/dL (mavrilimumab group) and 1.8 (1.1 – 9.0) mg/dL (placebo group). Corresponding ESR values were 39.5 (30 – 102) mm/hr (mavrilimumab group) and 49 (31 – 101) mm/hr (placebo group). Four mavrilimumab recipients had self-limited, equivocal GCA-related signs/symptoms without concurrent CRP or ESR elevation; all 4 completed the prespecified GC taper by Week 26 without need for rescue GCs, so relapse was not confirmed. At least 1 elevated CRP or ESR value in the absence of GCA-related signs/symptoms was observed in 58.8% of mavrilimumab recipients and 93.3% of placebo recipients by Week 26.

Conclusion:

The observed association of CRP or ESR elevation with GCA-related signs/symptoms is consistent with the upstream mechanism and supports the utility of the stringent protocol definition of relapse. The frequency and magnitude of CRP and ESR elevations at relapse were similar in both treatment groups, suggesting that CRP and ESR remain useful in assessments of disease activity in mavrilimumab-treated patients. CRP and ESR elevations without GCA-related signs/symptoms occurred more often in placebo recipients.

References:

[1]Cid, Unizony et al. Arthritis Rheumatol. 2020; 72 (suppl 10)

Table 1.

CRP and ESR levels in patients with or without GCA relapse

Assessment§MavrilimumabPlaceboMavrilimumabPlaceboN=42N=28N=42N=28With RelapseWithout Relapse# of patients8 (19.1)13 (46.4)34 (81.0)15 (53.6) Elevated CRP* or ESR†8 (100.0)13 (100.0)20 (58.8)14 (93.3)  Elevated CRP*7 (87.5)10 (76.9)10 (29.4)11 (73.3)   Median (range) mg/dL1.8 (1.4 - 8.4)1.8 (1.1 - 9.0)2.6 (1.3 – 7.0)2.0 (1.0 – 6.6) Elevated ESR†6 (75.0)9 (69.2)16 (47.1)10 (66.7)  Median (range) mm/hr39.5 (30 - 102)49.0 (31 - 101)41.5 (30 - 110)53.5 (30 - 82)

§# (%), except where indicated otherwise.

*CRP ≥ 1 mg/dL

†ESR ≥ 30 mm/hr

Disclosure of Interests:

Sebastian Unizony Consultant of: Janssen and Kiniksa, Grant/research support from: Genentech, Maria C. Cid Speakers bureau: Roche and Kiniksa, Paid instructor for: GSK and Vifor, Consultant of: Janssen, GSK, and Abbvie, Grant/research support from: Kiniksa, Elisabeth Brouwer Speakers bureau: Dr. E.Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017 2018 which were paid to the UMCG., Consultant of: Dr. E.Brouwer as an employee of the UMCG received speaker fees and consulting fees from Roche in 2017 2018 which were paid to the UMCG., Lorenzo Dagna Speakers bureau: Abbvie, Amgen, Biogen, BMS, Celltrion, Galapagos, Glaxo SmithKline, Novartis, Pfizer, Roche, Sanofi-Genzyme, SOBI, Consultant of: Abbvie, Amgen, Biogen, BMS, Celltrion, Galapagos, Glaxo SmithKline, Novartis, Pfizer, Roche, Sanofi-Genzyme, SOBI; clinical trial for Kiniksa, Grant/research support from: Abbvie, Amgen, BMS, Celltrion, Galapagos, Novartis, Pfizer, Roche, Sanofi-Genzyme, SOBI, Merk Sharp &Dohme, Janssen, Kiniksa, Bhaskar Dasgupta Paid instructor for: Educational grant symposium/workshop for Roche-chugai, Sanofi, and Abbvie, Consultant of: CI UK for the Kiniksa trial, Grant/research support from: Educational grant symposium/workshop for Roche-chugai, Sanofi, and Abbvie, Bernhard Hellmich Consultant of: Honoraria paid to the institution for participation in the clinical trial, Eamonn Molloy: None declared, Carlo Salvarani: None declared, Bruce C. Trapnell Consultant of: Consultant member of DSMB for Kiniksa., Kenneth J Warrington Consultant of: Clinical trial support from Eli Lilly and Kiniksa, Ian Wicks: None declared, Manoj Samant Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Teresa Zhou Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Lara Pupim Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, John F. Paolini Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals

LB0001 MAVRILIMUMAB IMPROVES OUTCOMES IN PHASE 2 TRIAL IN NON-MECHANICALLY-VENTILATED PATIENTS WITH SEVERE COVID-19 PNEUMONIA AND SYSTEMIC HYPERINFLAMMATION

Background:

Granulocyte/macrophage-colony stimulating factor (GM-CSF) is a cytokine both vital to lung homeostasis and important in regulating inflammation and autoimmunity1,2,3 that has been implicated in the pathogenesis of respiratory failure and death in patients with severe COVID-19 pneumonia and systemic hyperinflammation.4-6 Mavrilimumab is a human anti GM-CSF receptor α monoclonal antibody capable of blocking GM-CSF signaling and downregulating the inflammatory process.

Objectives:

To evaluate the effect of mavrilimumab on clinical outcomes in patients hospitalized with severe COVID-19 pneumonia and systemic hyperinflammation.

Methods:

This on-going, global, randomized, double-blind, placebo-controlled seamless transition Phase 2/3 trial was designed to evaluate the efficacy and safety of mavrilimumab in adults hospitalized with severe COVID-19 pneumonia and hyperinflammation. The Phase 2 portion comprised two groups: Cohort 1 patients requiring supplemental oxygen therapy without mechanical ventilation (to maintain SpO2 ≥92%) and Cohort 2 patients requiring mechanical ventilation, initiated ≤48 hours before randomization. Here, we report results for Phase 2, Cohort 1: 116 patients with severe COVID- 19 pneumonia and hyperinflammation from USA, Brazil, Chile, Peru, and South Africa; randomized 1:1:1 to receive a single intravenous administration of mavrilimumab (10 or 6 mg/kg) or placebo. The primary efficacy endpoint was proportion of patients alive and free of mechanical ventilation at Day 29. Secondary endpoints included [1] time to 2-point clinical improvement (National Institute of Allergy and Infectious Diseases COVID-19 ordinal scale), [2] time to return to room air, and [3] mortality, all measured through Day 29. The prespecified evidentiary standard was a 2-sided α of 0.2 (not adjusted for multiplicity).

Results:

Baseline demographics were balanced among the intervention groups; patients were racially diverse (43% non-white), had a mean age of 57 years, and 49% were obese (BMI ≥ 30). All patients received the local standard of care: 96% received corticosteroids (including dexamethasone) and 29% received remdesivir. No differences in outcomes were observed between the 10 mg/kg and 6 mg/kg mavrilimumab arms. Results for these groups are presented together. Mavrilimumab recipients had a reduced requirement for mechanical ventilation and improved survival: at day 29, the proportion of patients alive and free of mechanical ventilation was 12.3 percentage points higher with mavrilimumab (86.7% of patients) than placebo (74.4% of patients) (Primary endpoint; p=0.1224). Mavrilimumab recipients experienced a 65% reduction in the risk of mechanical ventilation or death through Day 29 (Hazard Ratio (HR) = 0.35; p=0.0175). Day 29 mortality was 12.5 percentage points lower in mavrilimumab recipients (8%) compared to placebo (20.5%) (p=0.0718). Mavrilimumab recipients had a 61% reduction in the risk of death through Day 29 (HR= 0.39; p=0.0726). Adverse events occurred less frequently in mavrilimumab recipients compared to placebo, including secondary infections and thrombotic events (known complications of COVID-19). Thrombotic events occurred only in the placebo arm (5/40 [12.5%]).

Conclusion:

In a global, diverse population of patients with severe COVID-19 pneumonia and hyperinflammation receiving supplemental oxygen therapy, corticosteroids, and remdesivir, a single infusion of mavrilimumab reduced progression to mechanical ventilation and improved survival. Results indicate mavrilimumab, a potent inhibitor of GM-CSF signaling, may have added clinical benefit on top of the current standard therapy for COVID-19. Of potential importance is that this treatment strategy is mechanistically independent of the specific virus or viral variant.

References:

[1]Trapnell, Nat Rev Dis Pri, 2019

[2]Wicks, Nat Rev Immunology, 2015

[3]Hamilton, Exp Rev Clin Immunol, 2015

[4]De Luca, Lancet Rheumatol, 2020

[5]Cremer, Lancet Rheumatol, 2021

[6]Zhou, Nature, 2020

Disclosure of Interests:

Lara Pupim Employee of: Kiniksa, Shareholder of: Kiniksa, Tisha S. Wang Consultant of: Partner Therapeutics; steering committee for Kinevant BREATHE clinical trial, Kristin Hudock: None declared, Joshua Denson: None declared, Nyda Fourie: None declared, Luis Hercilla Vasquez: None declared, Kleber Luz: None declared, Mohammad Madjid Grant/research support from: Kiniksa, Kirsten McHarry: None declared, José Francisco Saraiva: None declared, Eduardo Tobar: None declared, Teresa Zhou Employee of: Kiniksa, Shareholder of: Kiniksa, Manoj Samant Employee of: Kiniksa, Shareholder of: Kiniksa, Joseph Pirrello Employee of: Kiniksa, Shareholder of: Kiniksa, Fang Fang Employee of: Kiniksa, Shareholder of: Kiniksa, John F. Paolini Employee of: Kiniksa, Shareholder of: Kiniksa, Arian Pano Employee of: Kiniksa, Shareholder of: Kiniksa, Bruce C. Trapnell: None declared

OP0059 MAVRILIMUMAB (ANTI GM-CSF RECEPTOR Α MONOCLONAL ANTIBODY) REDUCES RISK OF FLARE AND INCREASES SUSTAINED REMISSION IN A PHASE 2 TRIAL OF PATIENTS WITH GIANT CELL ARTERITIS

Background:

T helper (Th)1 and Th17 lymphocytes play a role in the pathogenesis of giant cell arteritis (GCA). Current treatments primarily target the Th17 axis, possibly leaving residual Th1 activity. Granulocyte macrophage colony stimulating factor (GM-CSF), a mediator of Th1 and Th17 cells, is a pathogenic factor in GCA.

Objectives:

To evaluate the efficacy and safety of the GM-CSF inhibitor mavrilimumab in patients with GCA.

Methods:

Randomized, double-blind, placebo-controlled phase 2 trial enrolling patients with active, biopsy- or imaging-proven new onset (N/O) or relapsing refractory (R/R) GCA. Active disease: GCA symptoms and erythrocyte sedimentation rate (ESR) (>30 mm/hr) and/or C-reactive protein (CRP) (≥1 mg/dL) elevation within 6 weeks from randomization. Corticosteroid-induced remission (resolution of GCA symptoms and CRP <1 mg/dL or ESR <20 mm/hr) was required by baseline. 3:2 randomization to mavrilimumab 150 mg or placebo subcutaneously every 2 weeks and protocol-defined 26-week prednisone taper starting at 20-60 mg/day.

Primary efficacy endpoint: time to first adjudicated flare (ESR ≥30 mm/hr and/or CRP ≥1 mg/dL and GCA symptoms or new/worsening vasculitis on imaging) by Week 26 in all treated patients. Key secondary endpoint: sustained remission through Week 26. Safety up to Week 38 was assessed.

Results:

70 patients (35 N/O, 35 R/R) were enrolled (mavrilimumab [N=42] or placebo [N=28]). Mean (SD) age was 69.7 (7.48) years and 71.4% were female. Flare by Week 26 occurred in 8 (19%) and 13 (46.4%) patients receiving mavrilimumab and placebo, respectively (27.4 percentage points reduction). Median time to flare by Week 26 could not be estimated in the mavrilimumab group due to too few events (Not Estimable) and was 25.1 weeks [95% CI: (16.0, NE)] in the placebo group (HR [95% CI] 0.38 [0.15, 0.92]; p=0.0263) (Figure). Sustained remission at Week 26 occurred in 83.2% of patients receiving mavrilimumab and 49.9% of those receiving placebo (33.4 percentage points increase; p=0.0038). Results were consistent across disease type subgroups (HR for flare: N/O 0.29 [95% CI: 0.06, 1.31; nominal p= 0.0873]; R/R 0.43 [95% CI: 0.14, 1.30]; nominal p=0.1231), although not powered for significance (Table). Adverse events (AEs), mostly mild to moderate, were comparable between groups. There were 5 serious AEs (mavrilimumab 2 [4.8%], placebo 3 [10.7%]), none drug-related. No deaths or vision loss occurred. No adjudicated cases of pulmonary alveolar proteinosis were observed.

Table 1.

Efficacy at Week 26

All Patients [1]SubgroupsN/OR/RMavrilimu-mab (N=42)Placebo (N=28)Mavrilimu-mab (N=24)Placebo (N=11)Mavrilimu-mab (N=18)Placebo (N=17)Patients with Flare, n (%)8 (19.0)13 (46.4)3 (12.5)4 (36.4)5 (27.8)9 (52.9)Time to Flare (weeks) [2]Median, 95% CINE (NE, NE)25.1 (16.0, NE)NE (NE, NE)NE (11.7, NE)NE (16.4, NE)22.6 (16.0, NE)HR (Mavrilimumab vs Placebo), 95% CI [3]0.38 (0.15, 0.92)0.29 (0.06, 1.31)0.43 (0.14, 1.30)P-value [4] [5]0.02630.08730.1231Sustained Remission (%), 95% CI [6]83.2 (67.9, 91.6)49.9 (29.6, 67.3)91.3 (69.3, 97.7)62.3 (27.7, 84.0)72.2 (45.6, 87.4)41.7 (17.4, 64.5)Difference in Proportions (95% CI) [7]33.3 (10.7, 55.8)28.9 (-2.7, 60.5)30.6 (-2.1, 63.2)P-value [5] [7]0.00380.07270.0668

NE = Not estimable. [1] Total mITT population. Stratified by randomization strata. [2] Kaplan-Meier. [3] Cox proportional-hazards model; treatment as covariate. [4] Log-rank test. [5] N/O and R/R subgroups not powered for significance; nominal p values reported. [6] Kaplan-Meier Survival Estimates with standard error. [7] Two-sided p-value for the difference in sustained remission between 2 arms using normal approximation. Placebo arm is reference.

Conclusion:

Mavrilimumab was superior to placebo on the primary and secondary efficacy endpoints of time to flare and sustained remission at week 26 in patients with GCA. Mavrilimumab was well tolerated, and no new safety signals were observed.

Disclosure of Interests:

Maria C. Cid Speakers bureau: meeting attendance support from Roche and Kiniksa, Paid instructor for: educational from GSK and Vifor, Consultant of: consulting for Janssen, GSK, and Abbvie, Grant/research support from: research grant from Kiniksa, Sebastian Unizony Consultant of: consulting for Janssen and Kiniksa, Grant/research support from: research support from Genentech, Lara Pupim Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Fang Fang Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Joseph Pirrello Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Ai Ren Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Manoj Samant Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, Teresa Zhou Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals, John F. Paolini Shareholder of: Kiniksa Pharmaceuticals, Employee of: Kiniksa Pharmaceuticals

Gene Therapy of Dominant CRX-Leber Congenital Amaurosis using Patient Stem Cell-Derived Retinal Organoids

Mutations in the photoreceptor transcription factor gene cone-rod homeobox (CRX) lead to distinct retinopathy phenotypes, including early-onset vision impairment in dominant Leber congenital amaurosis (LCA). Using induced pluripotent stem cells (iPSCs) from a patient with CRX-I138fs48 mutation, we established an in vitro model of CRX-LCA in retinal organoids that showed defective photoreceptor maturation by histology and gene profiling, with diminished expression of visual opsins. Adeno-associated virus (AAV)-mediated CRX gene augmentation therapy partially restored photoreceptor phenotype and expression of phototransduction-related genes as determined by single-cell RNA-sequencing. Retinal organoids derived from iPSCs of a second dominant CRX-LCA patient carrying K88N mutation revealed the loss of opsin expression as a common phenotype, which was alleviated by AAV-mediated augmentation of CRX. Our studies provide a proof-of-concept for developing gene therapy of dominant CRX-LCA and other CRX retinopathies.

•

Leber congenital amaurosis caused by CRX mutations is modeled in retinal organoids

•

Patient iPSCs-derived organoids show impaired expression of visual opsins

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AAV-mediated CRX delivery partially restores expression of phototransduction genes

•

Gene therapy is applicable to mutations in DNA-binding and transactivation domains

Immunostimulatory potential and proteome profiling of Leishmania donovani soluble exogenous antigens

Isolation of the soluble exogenous antigens (SEAgs), its immune response study and proteome profiling is an essential prerequisite for understanding the molecular pathogenesis of Leishmania donovani. The immunostimulatory potential of L. donovani SEAgs, purified from culture of L. donovani clinical isolate, was evaluated for their ability to induce cellular responses in treated/cured hamsters. SEAgs induced significant proliferative responses in lymphocytes (SI 5.6 ± 2.3; P < 0.01) isolated from cured hamster. In addition, significant NO production in response to SEAgs was also noticed in macrophages of hamsters, mouse and human cell lines (J774A-1 and THP1). Western blot analyses with antibodies against proteophosphoglycan (PPG; surface-expressed and secreted molecule) of L. donovani revealed that PPG molecules are also present in L. donovani SEAgs. Mass spectrometry (MS)-based proteome analysis of 12 protein bands of SEAgs through MALDI-TOF/TOF endorsed the identification of some Th1-stimulatory immunogenic proteins. These immunogenic proteins may offer increased hope for the discovery of new promising vaccine candidates against visceral leishmaniasis (VL). The overall results suggest that immunostimulatory molecules are present in the SEAgs, which may be further exploited, for developing a subunit vaccine against VL a fatal human disease.

Trastuzumab emtansine (T-DM1) versus lapatinib plus capecitabine in patients with HER2-positive metastatic breast cancer and central nervous system metastases: a retrospective, exploratory analysis in EMILIA

BACKGROUND

We characterized the incidence of central nervous system (CNS) metastases after treatment with trastuzumab emtansine (T-DM1) versus capecitabine-lapatinib (XL), and treatment efficacy among patients with pre-existing CNS metastases in the phase III EMILIA study.

PATIENTS AND METHODS

In EMILIA, patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer previously treated with trastuzumab and a taxane were randomized to T-DM1 or XL until disease progression. Patients with treated, asymptomatic CNS metastases at baseline and patients developing postbaseline CNS metastases were identified retrospectively by independent review; exploratory analyses were carried out.

RESULTS

Among 991 randomized patients (T-DM1 = 495; XL = 496), 95 (T-DM1 = 45; XL = 50) had CNS metastases at baseline. CNS progression occurred in 9 of 450 (2.0%) and 3 of 446 (0.7%) patients without CNS metastases at baseline in the T-DM1 and XL arms, respectively, and in 10 of 45 (22.2%) and 8 of 50 (16.0%) patients with CNS metastases at baseline. Among patients with CNS metastases at baseline, a significant improvement in overall survival (OS) was observed in the T-DM1 arm compared with the XL arm [hazard ratio (HR) = 0.38; P = 0.008; median, 26.8 versus 12.9 months]. Progression-free survival by independent review was similar in the two treatment arms (HR = 1.00; P = 1.000; median, 5.9 versus 5.7 months). Multivariate analyses demonstrated similar results. Grade ≥3 adverse events were reported in 48.8% and 63.3% of patients with CNS metastases at baseline administered T-DM1 and XL, respectively; no new safety signals were observed.

CONCLUSION

In this retrospective, exploratory analysis, the rate of CNS progression in patients with HER2-positive advanced breast cancer was similar for T-DM1 and for XL, and higher overall in patients with CNS metastases at baseline compared with those without CNS metastases at baseline. In patients with treated, asymptomatic CNS metastases at baseline, T-DM1 was associated with significantly improved OS compared with XL.

Synergistic metabolic benefits of an exenatide analogue and cholecystokinin in diet-induced obese and leptin-deficient rodents

AIM

To test the impact of cholecystokinin (CCK) plus either amylin or a glucagon-like peptide-1 receptor (GLP-1R) agonist on metabolic variables in diet-induced obese (DIO) rodents.

METHODS

A stabilized acetylated version of CCK-8 (Ac-Y*-CCK-8), selective CCK1 receptor (CCK1R) or CCK2 receptor (CCK2R) agonists, amylin or the GLP-1R agonist and exenatide analogue AC3174 were administered in select combinations via continuous subcutaneous infusion to DIO rats for 14 days, or Lep(ob) /Lep(ob) mice for 28 days, and metabolic variables were assessed.

RESULTS

Combined administration of Ac-Y*-CCK-8 with either amylin or AC3174 induced greater than additive weight loss in DIO rats, with the overall magnitude of effect being greater with AC3174 + Ac-Y*-CCK-8 treatment. Co-infusion of AC3174 with a specific CCK1R agonist, but not a CCK2R agonist, recapitulated the weight loss mediated by AC3174 + Ac-Y*-CCK-8 in DIO rats, suggesting that synergy is mediated by CCK1R activation. In a 4 × 4 full-factorial response surface methodology study in DIO rats, a synergistic interaction between AC3174 and the CCK1R-selective agonist on body weight and food intake was noted. Co-administration of AC3174 and the CCK1R-selective agonist to obese diabetic Lep(ob) /Lep(ob) mice elicited a significantly greater reduction in percentage of glycated haemoglobin and food intake relative to the sum effects of monotherapy groups.

CONCLUSIONS

The anti-obesity and antidiabetic potential of combined GLP-1R and CCK1R agonism is an approach that warrants further investigation.

Abstract P4-12-27: Efficacy and safety of trastuzumab emtansine (T-DM1) vs lapatinib plus capecitabine (XL) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and central nervous system (CNS) metastases: Results from a retrospective exploratory analysis of EMILIA

Introduction

T-DM1 is an antibody–drug conjugate that was recently approved by the FDA for patients with HER2-positive MBC who have received prior treatment with trastuzumab and a taxane. In the phase 3 EMILIA trial, T-DM1 significantly prolonged progression-free survival (PFS) and overall survival (OS) compared with XL in patients with previously treated HER2-positive MBC (Verma 2012). Because the CNS is a common site of progression in HER2-positive MBC, it is of interest to characterize the incidence of CNS metastases in patients treated with TDM1 vs XL and the efficacy of T-DM1 in patients with pre-existing CNS metastases.

Methods

EMILIA is a multicenter, randomized, open-label trial in which patients with HER2-positive, unresectable, locally advanced or MBC previously treated with trastuzumab and a taxane were randomized (1:1) to T-DM1 (3.6 mg/kg every 21 days) or XL (X: 1000 mg/m2 bid on days 1–14 of each 21-day cycle; L: 1250 mg/day on days 1–21). Treatment continued until disease progression or unacceptable toxicity. All patients underwent brain magnetic resonance imaging or computed tomography at screening, and follow-up scans were performed as clinically indicated. Those with untreated or symptomatic brain metastases and those who required therapy for symptom control ≤2 months before randomization were excluded from the trial. Patients with CNS metastases at baseline or who developed CNS metastases on study were retrospectively identified using independent review committee data, and exploratory analyses were performed on data from these patients.

Results

Of the 896 patients without CNS metastases at baseline (T-DM1 = 450; XL = 446), 9 (1.8%) and 3 (0.6%), respectively, developed CNS progression on study. Of the 95 patients with CNS metastases at baseline (T-DM1 = 45; XL = 50), 10 (2.0%) and 8 (1.6%), respectively, developed CNS progression on study. Median PFS in patients with CNS metastases at baseline was 5.9 months in the T-DM1 arm and 5.7 months in the XL arm (HR = 1.000; 95% CI: 0.542–1.844; P = 0.9998). Median OS was 26.8 months and 12.9 months in the T-DM1 and XL arms, respectively (HR = 0.382; CI: 0.184–0.795; P = 0.0081). Multivariate analysis adjusting for baseline risk factors produced similar results. Safety profiles of T-DM1 and XL in patients with CNS metastases at baseline (T-DM1 = 43; XL = 49) were consistent with those for the overall study population. Grade ≥3 adverse events (AEs) were reported in 17 (39.5%) patients in the T-DM1 arm and 29 (59.2%) patients in the XL arm. Serious AEs were reported in 5 (11.6%) and 11 (22.4%) patients in the T-DM1 and XL arms, respectively. No new safety signals were identified.

Conclusions

In this retrospective exploratory analysis of data from EMILIA, the rate of CNS progression in patients with or without baseline CNS metastases was low in both treatment arms. In the subset of patients with brain metastases at baseline, similar to the intent-to-treat population, T-DM1 was associated with significantly improved OS compared with XL. Prospective phase 3 trials are necessary to confirm these results.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-27.

Abstract P5-18-24: Population pharmacokinetics of trastuzumab emtansine, a HER2-targeted antibody-drug conjugate, in patients with HER2-positive metastatic breast cancer: clinical implications of the effect of various covariates

Background: Trastuzumab emtansine (T-DM1) is a HER2-targeted antibody-drug conjugate composed of the humanized monoclonal antibody trastuzumab, the potent cytotoxic agent DM1 (a microtubule inhibitor), and a stable thioether linker. To estimate typical pharmacokinetic (PK) parameter values and interpatient variability, a population PK model for T-DM1 was previously developed from 1 phase 1 (0.3 to 4.8 mg/kg in qw or q3w regimens) and 2 phase 2 (3.6 mg/kg q3w) trials (Gupta, J Clin Pharmacol 2012). The model reported here has been updated with additional data from 2 randomized trials (phase 2 TDM4450g and phase 3 EMILIA, 3.6 mg/kg q3w). Another phase 2 trial (TDM4688g) was used for external validation of the model. The effect of demographic and pathophysiological covariates on the PK of T-DM1 was explored to better understand the clinical factors that might affect exposure and clinical outcome for individual patients.

Methods: For the current analysis, 9934 T-DM1 serum concentration-time data points from 671 patients were simultaneously fitted using NONMEM® software. T-DM1 concentration-time data to date are best described using a 2-compartment linear model. All relevant and plausible covariates likely to have an effect on T-DM1 systemic exposure, or likely to have clinical relevance, were explored for possible correlation with the key T-DM1 PK parameters of clearance (CL) and central volume of distribution (Vc). These covariates include those related to demographics, renal and hepatic function, disease status, and treatment history.

Results: The estimated CL for T-DM1 is 0.68 L/day, Vc is 3.13 L, and the terminal half-life is 3.94 days. Interindividual variability (IIV) of the base model is 25.6% and 17.5% for CL and Vc, respectively. Patients with greater body weight, sum of longest dimension of target lesions, serum concentration of shed HER2 extracellular domain, and aspartate aminotransferase concentrations, as well as patients with lower serum albumin and baseline trastuzumab concentrations, have statistically faster CL. Patients with greater body weight also have statistically larger Vc. Incorporation of these covariates (P&lt;0.001 by likelihood ratio test) decreased IIV of CL and Vc to 19.1% and 11.7%, respectively. All covariates together explain 44.4% and 55.8% of IIV in CL and Vc, respectively. The model sensitivity analysis suggests that a patient with a statistically significant PK covariate value at the 5th or 95th percentile of the population will have a &lt;20% difference in cumulative exposure (as represented by area under the T-DM1 concentration-time curve) compared with a typical patient with a median covariate value.

Conclusions: A relatively small IIV for the estimated T-DM1 PK parameters of CL and Vc was observed. None of the evaluated covariates had a clinically meaningful magnitude of effect on T-DM1 exposure (&lt;20% difference for patients with 5th and 95th percentiles vs patients with median value of covariates) that would justify a further dose adjustment. The body weight–based dose of 3.6 mg/kg q3w without further correction for other factors is considered appropriate in ongoing clinical trials.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-24.

SABRE-B: an evaluation of paclitaxel and bevacizumab with or without sunitinib as first-line treatment of metastatic breast cancer

BACKGROUND

The vascular endothelial growth factor (VEGF) pathway can be targeted through VEGF neutralization or VEGF receptor (VEGFR) blockade using tyrosine kinase inhibition. Because laboratory models suggest that combining these approaches might be synergistic, we sought to evaluate the feasibility and efficacy of combining sunitinib with paclitaxel + bevacizumab (PB).

METHODS

Patients with human epidermal growth factor receptor 2 (HER2)-negative, metastatic breast cancer receiving first-line chemotherapy were randomized to PB or PB with sunitinib (PBS), with planned escalation of the sunitinib dose.

RESULTS

Forty-six patients were randomized to PB or PBS with sunitinib dosed at 25 mg p.o. daily. Patients receiving PBS encountered substantial toxicity that precluded adequate treatment. The percentage of patients with grade ≥3 adverse events was greater in the PBS arm than the PB arm (83% versus 57%), and sunitinib dosing was modified in 78% of patients, most often due to neutropenia, febrile neutropenia, and fatigue. In addition, 44% of patients had sunitinib dose reduction to 12.5 mg, and 39% required discontinuation. Patients receiving PBS had more bevacizumab treatment interruptions and discontinuations because of toxicity. Median treatment duration was longer in the PB arm compared with the PBS arm (14.1 versus 11.1 weeks), reflecting early treatment discontinuation of PBS. Because of poor tolerability of the addition of sunitinib to PB, the planned sunitinib dose escalation was halted and the study accrual was terminated.

CONCLUSION

Adding sunitinib to standard doses of bevacizumab plus paclitaxel for metastatic breast cancer is not feasible. Different strategies will be required to evaluate whether there is additional clinical benefit to combining VEGF/VEGFR-targeted agents.

Proteophosphoglycan is differentially expressed in sodium stibogluconate-sensitive and resistant Indian clinical isolates of Leishmania donovani

Leishmania produce several types of mucin-like glycoproteins called proteophosphoglycans (PPGs) some of which are secreted while others are found on the surface of promastigotes and amastigotes. These proteins are thought to be important in the transmission, invasion and subsequent intracellular survival of parasites. The structure and function of PPGs are species and stage-specific in the case of L. major and L. mexicana, but no such information has hitherto been available for L. donovani. This study presents, for the first time, an initial characterization (localization) of PPG in sodium stibogluconate (SSG)-resistant and sensitive clinical isolates of L. donovani from Bihar (India) by confocal microscopy, flow cytometry and Western blotting using antibodies to L. major PPG. Confocal microscopy analysis revealed that both promastigotes and amastigotes possess PPG on their cell membrane and flagellar pocket membrane but its expression was variable in different isolates. The quantitative analysis by FACS and Western blotting showed that the expression and intensity of PPG bands was higher in SSG-resistant isolates. This study suggests the possibilities of involvement of PPG in drug-resistant mechanisms and of using PPG abundance as a marker for identifying drug-resistant clinical isolates in Indian kala azar.

In vitro and in vivo leishmanicidal activity of Dysoxylum binectariferum and its fractions against Leishmania donovani

The leishmanicidal effect of crude ethanolic extract of stem bark of Dysoxylum binectariferum and its fractions has been investigated against Leishmania donovani, the causative agent of visceral leishmaniasis. Ethanolic extract was lethal to promastigotes as well as amastigote forms in macrophage system at the concentration of 100 microg/ml. Chloroform fraction significantly inhibited promastigote multiplication and was also active against amastigotes in infected J774A.1 macrophages at 100 microg/ml. Hexane fraction was moderately active and the other fractions were inactive against both the forms. When tested in vivo in hamsters, ethanolic extract was toxic at 500 mg/kg whereas exhibited marginal activity (67.7+/-5.3%) at 250 mg/kg x 5, p.o. on day 7 post treatment (p.t.) which increases slightly (69+/-4.7) by day 30 p.t. Chloroform and n-hexane fractions exhibited 64.3+/-4% and 47.8+/-4.6% parasite inhibition at the dose of 100 mg/kg x 5 p.o., respectively. The pure compound, rohitukine, obtained from chloroform fraction showed weaker in vitro activity and was ineffective in infected hamsters. The lead potential of this plant need further investigations.

Atomic-beam alignment of inorganic materials for liquid-crystal displays

The technique used to align liquid crystals-rubbing the surface of a substrate on which a liquid crystal is subsequently deposited-has been perfected by the multibillion-dollar liquid-crystal display industry. However, it is widely recognized that a non-contact alignment technique would be highly desirable for future generations of large, high-resolution liquid-crystal displays. A number of alternative alignment techniques have been reported, but none of these have so far been implemented in large-scale manufacturing. Here, we report a non-contact alignment process, which uses low-energy ion beams impinging at a glancing angle on amorphous inorganic films, such as diamond-like carbon. Using this approach, we have produced both laptop and desktop displays in pilot-line manufacturing, and found that displays of higher quality and reliability could be made at a lower cost than the rubbing technique. The mechanism of alignment is explained by adopting a random network model of atomic arrangement in the inorganic films. Order is induced by exposure to an ion beam because unfavourably oriented rings of atoms are selectively destroyed. The planes of the remaining rings are predominantly parallel to the direction of the ion beam.