This Phase 2 study tests whether adding two immune therapies - nogapendekin alfa-inbakicept (NAI) and off-the-shelf iNKT cell infusions - to standard care can safely help critically ill adults with severe community-acquired pneumonia (CAP) (with or without sepsis/ARDS) recover. The study will give NAI by subcutaneous injection (Days 1 and 10) and one IV dose of iNKT cells (Day 3), then follow participants for 90 days.
Phase 2, single-arm study in up to 20 critically ill adults with severe community-acquired pneumonia (CAP) (with or without sepsis/ARDS) and lymphopenia (ALC \<1,500/µL). The study evaluates the safety, tolerability, and preliminary efficacy of combining an IL-15 superagonist (nogapendekin alfa-inbakicept, NAI) with an allogeneic invariant natural killer T cell product (iNKT cells) added to standard ICU care. Key elements Population: Adults (≥18) admitted to ICU for severe CAP within 72 hours, meeting IDSA/ATS severe CAP criteria (≥1 major or ≥3 minor) and on antibiotics. Planned enrollment: up to 20 participants (≈40 screened). Intervention schedule: Day 1: NAI subcutaneous (≤50 kg → 15 µg/kg; \>50 kg → fixed 1 mg). Day 3: Single IV infusion of iNKT cells (1 × 10\^9 cells). Day 10: Second NAI subcutaneous dose (same dosing as Day 1). Concomitant care: all participants receive guideline-based standard of care for CAP/sepsis/ARDS (antibiotics, organ support, lung-protective ventilation, vasopressors, low-dose steroids as indicated, etc.). Safety oversight: continuous ICU monitoring; Sponsor Drug Safety review of SAEs; Safety Review Committee (SRC) reviews safety after first 5 participants and oversees stopping rules. Predefined toxicity rules and management algorithms for infusion reactions, CRS, and ICANS are specified. Primary endpoints: safety/tolerability (TEAEs, SAEs, grade ≥3 AEs) and 28-day all-cause mortality. Secondary endpoints: absolute lymphocyte count recovery, ventilator-free days, ICU-free days, antibiotic-free days, days free from organ support, time to ICU/hospital discharge, incidence of secondary infections through Day 28, and 90-day mortality. Exploratory endpoints: serum cytokines, NK and T-cell expansion and activation/exhaustion markers, monocyte HLA-DR, quantification and persistence of donor iNKT cells (Days 1, 7, 14, 28). Duration per participant: treatment up to 10 days; follow-up to 90 days after first dose. Stopping/discontinuation: specified criteria for permanent discontinuation (e.g., drug-related Grade ≥3 organ toxicity, Grade ≥3 CRS/ICANS, intolerable infusion reactions), SRC stopping rules (including treatment-related death or clustered severe toxicities). Objective: determine whether the NAI + iNKT combination can be given safely in this population and provide signals of reduced 28-day mortality and immune recovery (reversal of lymphopenia) to justify further study. Sites will collect clinical outcomes, safety data, laboratory panels (CBC/CMP/coagulation), and samples for immune monitoring per protocol schedule.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
20
Nogapendekin alfa-inbakicept (NAI) - a recombinant IL-15 superagonist complex (IL-15N72D:IL-15RαSu/IgG1 Fc) administered subcutaneously (Day 1 and Day 10; weight-based 15 µg/kg if ≤50 kg or fixed 1 mg if \>50 kg) to stimulate NK and CD8+ T-cell proliferation and function.
Allogeneic invariant Natural Killer T (iNKT) Cells (AgenT-797) - cryopreserved, GMP-manufactured off-the-shelf donor iNKT cell product administered as a single intravenous infusion (1 × 10\^9 cells on Day 3) intended to provide immediate effector function and immunomodulation; cell product thawed and infused per cell-therapy procedures with premedication as indicated.
28-day all-cause mortality
Proportion of participants who die from any cause within 28 days of first study drug administration.
Time frame: Day 28 (28 days after first dose)
Treatment Emergent Adverse Events (TEAEs)
Any new or worsening medical event beginning after the first dose through 30 days post-last dose, collected to characterize overall tolerability.
Time frame: From first study treatment to 30 days after the participant's last study dose.
Severe Adverse Events (SAEs)
Events meeting regulatory seriousness criteria (death, life-threatening, hospitalization, disability, congenital anomaly or other medically important events) reported to evaluate major safety risks.
Time frame: From first study treatment to 30 days after the participant's last study dose (SAEs related to study product reported regardless of last dose date).
Grade ≥3 TEAEs
Adverse events of CTCAE severity grade 3 or higher that emerge after first dose, used to quantify severe toxicity burden.
Time frame: From first study treatment to 30 days after the participant's last study dose.
Safety laboratory tests
Routine clinical labs (CBC, chemistry, coagulation, etc.) collected serially to detect clinically meaningful laboratory abnormalities attributable to treatment.
Time frame: From baseline (pre-dose) through 30 days after the participant's last study dose.
Temperature
Serial core body temperature measured in degrees Celsius. Report baseline, maximum post-dose within 24 hours, and incidence of fever \>39.0°C.
Time frame: Baseline (pre-dose) through End of ICU stay; intensified monitoring for 24 hours after iNKT infusion (vitals every ≥4 hours; continuous telemetry as indicated).
Heart rate
Serial heart rate (bpm). Report baseline, peak within 24 hours post-infusion, and incidence of new clinically significant tachycardia (\>120 bpm) requiring intervention.
Time frame: Baseline (pre-dose); maximum post-dose within 24 hours after iNKT infusion (intensified monitoring during this 24-hour window); overall reporting through End of ICU stay (up to 28 days).
Blood pressure
Serial systolic/diastolic blood pressure (mmHg). Report baseline, nadir within 24 hours post-infusion, and incidence of new hypotension (MAP \<65 mmHg or need for new/increased vasopressor) temporally related to infusion.
Time frame: Baseline (pre-dose); maximum post-dose within 24 hours after iNKT infusion (intensified monitoring during this 24-hour window); overall reporting through End of ICU stay (up to 28 days).
Respiratory rate
Serial RR (breaths/min). Report baseline, worst value within 24 hours post-infusion, and incidence of clinically significant tachypnea (RR ≥30) or new respiratory deterioration requiring escalation.
Time frame: Baseline (pre-dose); maximum post-dose within 24 hours after iNKT infusion (intensified monitoring during this 24-hour window); overall reporting through End of ICU stay (up to 28 days).
Oxygen saturation
Serial peripheral oxygen saturation (%). Report baseline, nadir within 24 hours post-infusion, and incidence of new hypoxemia (SpO2 \<90% on prior baseline support or increase in FiO2/ventilatory support).
Time frame: Baseline through End of ICU stay; intensified monitoring for 24 hours after iNKT infusion.
Absolute Lymphocyte Count (ALC)
Peripheral ALC measured over time to evaluate reversal of lymphopenia and quantitative immune recovery after treatment.
Time frame: Assessed at baseline and summarized at Days 7, 14, 21, and 28 after first dose.
Ventilator-free days (VFD) through Day 28
From first study treatment through Day 28 after first dose.
Time frame: Number of days within the 28-day window the participant is alive and free from mechanical ventilation, with death or ventilator dependence to Day 28 scored as zero.
ICU-free days through Day 28
Number of days within 28 days the participant is alive and not in ICU, reflecting time free from intensive care support.
Time frame: From first study treatment through Day 28 after first dose.
Antibiotic-free days through Day 28
Number of days within 28 days the participant is alive and not receiving systemic antibiotics for respiratory infection, as a proxy for infection control and clinical recovery.
Time frame: From first study treatment through Day 28 after first dose.
Days alive and free of other organ support through Day 28
Count of days within 28 days the participant is alive and not requiring non-respiratory organ supports (eg, vasopressors, renal replacement therapy), reflecting multi-organ recovery.
Time frame: From first study treatment through Day 28 after first dose.
Time to ICU discharge
Interval from first dose to date/time participant leaves ICU, used to assess speed of clinical improvement sufficient for lower-level care.
Time frame: From first study treatment (Day 1) through Day 28 - time to ICU discharge will be reported as days from first dose to date/time of ICU discharge; participants not discharged by Day 28 will be censored at Day 28.
Time to hospital discharge
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From first study treatment until hospital discharge (if occurs).
Time frame: From first study treatment (Day 1) through Day 28 - time to hospital discharge will be reported as days from first dose to date of hospital discharge; participants not discharged by Day 28 will be censored at Day 28.
Number of secondary infections through Day 28
Incidence and timing of new clinically documented infections (eg, ventilator-associated pneumonia, bloodstream infection) occurring within 28 days, to evaluate infection risk post-treatment.
Time frame: From first study treatment through Day 28 after first dose.
Number of secondary infections through participant follow-up
From first study treatment through 90 days after first dose.
Time frame: Incidence of new clinically documented infections up to 90 days to capture later-onset infectious complications.
90-day all-cause mortality
Death from any cause occurring within 90 days of first treatment to evaluate longer-term survival.
Time frame: From first study treatment to Day 90 after first dose.