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.

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

BACKGROUND

The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.

METHODS

ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.

RESULTS

The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.

CONCLUSIONS

This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.

CLINICAL TRIAL REGISTRATION

NCT03044899.

Severe acute respiratory infection in children in a densely populated urban slum in Kenya, 2007-2011

Background

Reducing acute respiratory infection burden in children in Africa remains a major priority and challenge. We analyzed data from population-based infectious disease surveillance for severe acute respiratory illness (SARI) among children <5 years of age in Kibera, a densely populated urban slum in Nairobi, Kenya.

Methods

Surveillance was conducted among a monthly mean of 5,874 (range = 5,778-6,411) children <5 years old in two contiguous villages in Kibera. Participants had free access to the study clinic and their health events and utilization were noted during biweekly home visits. Patients meeting criteria for SARI (WHO-defined severe or very severe pneumonia, or oxygen saturation <90%) from March 1, 2007-February 28, 2011 had blood cultures processed for bacteria, and naso- and oro- pharyngeal swabs collected for quantitative real-time reverse transcription polymerase chain reaction testing for influenza viruses, parainfluenza viruses (PIV), respiratory syncytial virus (RSV), adenovirus, and human metapneumovirus (hMPV). Swabs collected during January 1, 2009 – February 28, 2010 were also tested for rhinoviruses, enterovirus, parechovirus, Mycoplasma pneumoniae, and Legionella species. Swabs were collected for simultaneous testing from a selected group of control-children visiting the clinic without recent respiratory or diarrheal illnesses.

Results

SARI overall incidence was 12.4 cases/100 person-years of observation (PYO) and 30.4 cases/100 PYO in infants. When comparing detection frequency in swabs from 815 SARI cases and 115 healthy controls, only RSV and influenza A virus were significantly more frequently detected in cases, although similar trends neared statistical significance for PIV, adenovirus and hMPV. The incidence for RSV was 2.8 cases/100 PYO and for influenza A was 1.0 cases/100 PYO. When considering all PIV, the rate was 1.1 case/100 PYO and the rate per 100 PYO for SARI-associated disease was 1.5 for adenovirus and 0.9 for hMPV. RSV and influenza A and B viruses were estimated to account for 16.2% and 6.7% of SARI cases, respectively; when taken together, PIV, adenovirus, and hMPV may account for >20% additional cases.

Conclusions

Influenza viruses and RSV (and possibly PIV, hMPV and adenoviruses) are important pathogens to consider when developing technologies and formulating strategies to treat and prevent SARI in children.

Workload Indicators of Staffing Need method in determining optimal staffing levels at Moi Teaching and Referral Hospital

BACKGROUND

There is an increasing demand for quality healthcare in the face of limited resources. With the health personnel consuming up to three quarters of recurrent budgets, a need arises to ascertain that a workforce for any health facility is the optimal level needed to produce the desired product.

OBJECTIVE

To highlight the experience and findings of an attempt at establishing the optimal staffing levels for a tertiary health institution using the Workload Indicators of Staffing Need (WISN) method popularised by the World Health Organisation (WHO), Geneva, Switzerland.

DESIGN

A descriptive study that captures the activities of a taskforce appointed to establish optimal staffing levels.

SETTING

Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya, a tertiary hospital in the Rift Valley province of Kenya from September 2005 to May 2006.

MAIN OUTCOME MEASURES

The cadres of workers, working schedules, main activities, time taken to accomplish the activities, available working hours, category and individual allowances, annual workloads from the previous year's statistics and optimal departmental establishment of workers.

RESULTS

There was initial resentment to the exercise because of the notion that it was aimed at retrenching workers. The team was given autonomy by the hospital management to objectively establish the optimal staffing levels. Very few departments were optimally established with the majority either under or over staffed. There were intradepartmental discrepancies in optimal levels of cadres even though many of them had the right number of total workforce.

CONCLUSION

The WISN method is a very objective way of establishing staffing levels but requires a dedicated team with adequate expertise to make the raw data meaningful for calculations.