A phase I study evaluating subcutaneous administration of the monoclonal antibody programmed cell death protein-1 (PD-1) inhibitor cetrelimab (JNJ-63723283) in patients with advanced solid malignancies

Abstract

Purpose

Pharmacokinetics, pharmacodynamics, safety, and efficacy of subcutaneous cetrelimab were assessed in Parts (P)3 and 4 of the phase I LUC1001 study in patients with advanced/refractory solid tumors who progressed on or wereineligible for standard treatment and had no prior PD-1/PD-L1/PD-L2 treatment.

Methods

In P3, low-concentration cetrelimab (30 mg/mL) was administered subcutaneously at 600 mg with a 6-week interval between doses 1 and 2, then every 3 weeks (Q3W). Based on P3 pharmacokinetic and safety findings, high-concentration cetrelimab (150 mg/mL) was administered subcutaneously at a 900 mg loading dose followed by 600 mg Q3W in P4.

Results

Among 30 enrolled patients (P3, n = 11; P4, n = 19), median age was 54.5y; 76.7% received ≥ 3 prior lines of therapy. Median duration of treatment was 2.1mo. Treatment-related adverse events (AEs) occurred in 70% of patients, including 23.3% with grade ≥ 3 treatment-related AEs and 30.0% immune-related AEs; no treatment-related serious AEs or systemic infusion-related reactions occurred. After 3.7mo median follow-up, 2 patients (6.7%) achieved durable responses and 4 patients (13.3%) had stable disease for ≥ 24 weeks. Pharmacokinetic data showed that adding a 900 mg loading dose to the 600 mg Q3W subcutaneous regimen shortened the time to reach target recommended phase 2 dose (RP2D) exposures, making it a suitable intravenous alternative. Maximum PD-1 receptor occupancy was achieved with both formulations. Anti-cetrelimab antibodies were detected in 4 patients (13.3%); none were neutralizing.

Conclusions

RP2D of subcutaneous cetrelimab was established as a loading dose of 900 mg followed by 600 mg Q3W. Subcutaneous cetrelimab demonstrated characteristics consistent with prior characterization of intravenous cetrelimab.

Trial registration NCT02908906 at ClinicalTrials.gov, September 21, 2016; EudraCT 2016–002,017-22 at clinicaltrialsregister.eu, Jan 11, 2017.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1007/s00262-026-04457-1.

Introduction

Programmed cell death protein (PD)-1 is an immune checkpoint receptor that regulates adaptive immunity in the tumor microenvironment [1]. The introduction of PD-(L)1 inhibitors revolutionized the field of cancer immunotherapy. Anti-PD-(L)1 inhibitors are now a standard of care across many tumor types as monotherapy or in combination with other anticancer treatments including immunotherapy, chemotherapy, and targeted agents.

Cetrelimab (JNJ-63723283) is a fully human immunoglobulin G4 kappa monoclonal antibody that binds to PD-1 with high affinity and specificity [2]. The first-in-human, phase I/II, LUC1001 study evaluated cetrelimab for the treatment of solid tumors in 4 Parts. Parts 1 and 2 evaluated safety, efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity of intravenous cetrelimab in 204 patients with advanced/refractory solid tumors. Two intravenous recommended phase 2 doses (RP2Ds), 240 mg every 2 weeks (Q2W) and 480 mg Q4W, were established [3]. At the primary analysis of Parts 1 and 2 (clinical cutoff of July 1, 2019), grade ≥ 3 treatment-emergent adverse events (TEAEs) with intravenous cetrelimab occurred in 53.9% of patients and immune-related TEAEs occurred in 35.3%. Treatment-related AEs occurred in 67.2% of patients, including grade ≥ 3 in 13.7% and serious treatment-related AEs in 10.8% of patients. Objective response rate (ORR) was 18.6% across tumor types (non-small cell lung cancer [NSCLC], 34.3%; PD-L1 high [≥ 50% PD-L1+ on tumor cells by immunohistochemistry in NSCLC], 52.6%; melanoma, 28.0%; centrally confirmed microsatellite instability high-colorectal cancer [MSI-H CRC], 23.8%). After the first dose, mean maximum serum concentrations (C_max) ranged from 24.7 to 227.0 µg/mL; median time to C_max ranged from 2.0 to 3.2 h. Pharmacodynamic effect was maintained throughout the dosing period across intravenous doses [3].

Subcutaneous administration of monoclonal antibodies offers several advantages compared with intravenous administration, including convenience of shorter administration time, improved patient experience, reduced treatment burden, the possibility of extended interval between doses, and lower healthcare costs [4–6]. Here, we report the results of LUC1001 Parts 3 and 4, which evaluated safety, pharmacokinetics, pharmacodynamics, and efficacy of two different formulations of subcutaneous cetrelimab. First, the pharmacokinetics and safety of a low-concentration formulation (30 mg/mL) were assessed in Part 3 with a dosing schedule of 600 mg every 3 weeks (Q3W) and a dosing interval of 6 weeks between the first 2 doses. Next, based on the safety and pharmacokinetics of Part 3, a high-concentration formulation (150 mg/mL) was evaluated for subcutaneous delivery with an adjusted dosing schedule in Part 4 (900 mg loading dose followed by 600 mg Q3W). This manuscript also reports updated efficacy results from the long-term follow up of Parts 1 and 2 with intravenous cetrelimab.

Methods

Study design

LUC1001 (NCT02908906) is a first-in-human, phase I/II, open-label, multicenter study of cetrelimab in patients with advanced cancers. This study was conducted in accordance with the International Council for Harmonisation, Good Clinical Practice Standards, and the Declaration of Helsinki. The protocol was approved by institutional review boards and ethics committees. All patients provided written informed consent.

Patients

All eligible patients were ≥ 18 years old with an Eastern Cooperative Oncology Group performance status of 0 or 1, and metastatic or unresectable, advanced or refractory solid tumor malignancy (except lymphoma). Patients must have previously received or were ineligible for standard treatment options including appropriate molecularly targeted therapies. Key exclusion criteria included prior treatment with PD-1/PD-L1/PD-L2 antibodies, grade ≥ 3 adverse events from previous immunotherapy, and an active history of autoimmune disease that required systemic corticosteroids or immunosuppressive agents.

Study treatment

Part 3 was initiated on August 31, 2021, and the cutoff for data analysis was January 30, 2023.

In Part 3, low-concentration (30 mg/mL) cetrelimab was delivered by subcutaneous infusion via infusion pump at alternating locations on the abdomen in the periumbilical area. A dose of 600 mg (20 mL infusion volume) was administered simultaneously at 2 infusion sites (10 mL per infusion site) on the abdomen. Infusion was performed at a speed of 0.25 mL/min for approximately 40 min per infusion site. A 6-week interval was implemented between the first and second dose to fully characterize the cetrelimab pharmacokinetic profile after first dose. From the second dose onwards, patients were treated with 600 mg Q3W. In Part 3, initially eight patients were planned to be enrolled and dosed. Replacement patients could be added if fewer than 8 patients were evaluable for toxicity or pharmacokinetics due to reasons unrelated to toxicity. An additional cohort (n ≈ 8) could be enrolled at a lower dose level if the subcutaneous 600 mg Q3W schedule was deemed too toxic.

Next, the Part 4 dosing schedule was selected based on safety and pharmacokinetic results established in Part 3, with 8 patients planned for Part 4 enrollment and dosing. Part 4 was initiated on July 27, 2022, and the cutoff for data analysis was November 7, 2023.

In Part 4, high-concentration (150 mg/mL) cetrelimab was administered subcutaneously by manual push using a prefilled 2-mL syringe (300 mg), allowing for rapid injection. A loading dose of 900 mg was administered at 3 different locations (3 × 2 mL injections) in the periumbilical area. Subsequent doses of 600 mg (2 × 2 mL injections) were administered at 2 different locations on a Q3W schedule from Week 4 onwards. After confirmation of adequate pharmacokinetics, pharmacodynamics, and safety, an additional 12 patients were planned to be enrolled in Part 4 at the same dose level and schedule, with additional cohorts possible to evaluate other dose levels or modifications of the treatment schedule (eg, wider dosing interval).

Patients received cetrelimab until radiologic disease progression, clinical progression, investigator discretion, or until the patient experienced unacceptable toxicity or withdrew from the study. Patients were allowed to continue treatment with cetrelimab beyond initial radiologic progression at the discretion of the treating physician if the patient was clinically stable (eg, no signs, symptoms, decline in ECOG performance status, or requirement for therapeutic/medical intervention) due to the potential for transient tumor flare (“pseudo-progression”) in the first few months after the start of immunotherapy before subsequent response. Per protocol, detailed toxicity management guidelines were provided for immune-related adverse events (irAEs) including gastrointestinal, hepatic, endocrine, dermatologic, renal, neurologic, pulmonary, ophthalmic, and cardiovascular events. Management of hepatic toxicities comprised frequent monitoring of liver function tests, the use of corticosteroids or immunosuppressants, and dose delays or permanent discontinuation of cetrelimab. End of data collection for Parts 3 and 4 was defined as when the last patient enrolled in Part 4 reached study dose 7.

Study endpoints

The primary endpoints were safety and tolerability, pharmacokinetics, and to define a subcutaneous cetrelimab RP2D achieving exposure comparable to the previously established intravenous RP2Ds. Secondary objectives were to characterize the immunogenicity and antitumor activity of subcutaneous cetrelimab.

Pharmacokinetics

Blood samples for pharmacokinetic analyses were taken within 2 h before the start of subcutaneous dosing on Day 1 of each dose (for up to 18 cycles, then every 9 cycles for up to 3 years) until end of treatment. Additional sampling in Part 3 occurred at 2 and 6 h post-infusion on Day 1 (first and third dose); Days 2, 4, 8, 15, 22, 29, and 36 post-infusion after the first dose; and Days 2, 4, 8, and 15 post-infusion after the third dose. For Part 4, additional sampling for the first and fourth dose occurred at 2 and 6 h post-injection on Day 1 and on Days 2, 4, 8, and 15 post-injection. Serum cetrelimab concentrations were measured using a validated electrochemiluminescence immunoassay method. Pharmacokinetic parameters were compared after the first dose in Part 3 and the fourth dose in Part 4.

Pharmacodynamics

Sample collection for pharmacodynamic and biomarker analyses occurred within 2 h before the start of subcutaneous dosing on Day 1 of the first 5 doses (and every 3 doses thereafter), and at the end of treatment for both Parts 3 and 4. Additional sampling in Part 3 occurred 2 h post-infusion on Day 1; on Days 4, 8, 15, 22, and 36 after the first dose; and on Days 2 and 8 after the third dose. Additional sampling for Part 4 occurred 2 and 6 h post-injection of Day 1 as well as Days 4, 8, and 15 after the first dose and on Days 2 and 8 after the fourth dose.

Ex vivo staphylococcal enterotoxin B (SEB) stimulation of interleukin(IL)-2 production by peripheral blood mononuclear cells in whole blood samples that were diluted 1:10 in RPMI 1640 medium (Catalog #111,875,093, ThermoFisher Scientific, Waltham, MA) and incubated for 4 days with 100 ng/mL SEB in the presence of either 10 µg/mL cetrelimab or isotype control [3]. The ratio of IL-2 release levels between the isotype control antibody and cetrelimab ex vivo treated blood samples was then calculated to assess the degree of pharmacodynamic modulation with a ratio of 1 indicating maximum T cell activation. Serum concentrations of interferon-γ-inducible protein 10 (IP10) and IL-2 receptor alpha chain (IL2Rα) were assessed using MesoScale Discovery in patients with at least one pretreatment and more than one collection post-treatment [3].

PD-1 receptor occupancy on circulating CD3+ T cells was assessed by flow cytometry [3].

Immunogenicity

Immunogenicity assessments for anti-drug antibodies were performed using whole blood samples. Samples were taken within 2 h before the start of subcutaneous infusion on Day 1 for the first 5 doses (then every 3 cycles up to 18 cycles and every 9 cycles thereafter) until end of treatment. Additional samples were taken for Part 3 on Days 8 and 29 after the first dose and on Day 8 after the third dose. For Part 4, additional samples were taken on Day 8 after the first and fourth doses. Samples were screened for anti-drug antibodies binding to cetrelimab, and the titers of confirmed positive samples were reported.

Safety

Safety assessments included frequency and severity of AEs, irAEs, local infusion or injection site reactions, systemic infusion- or injection-related reactions, clinical laboratory tests, and vital signs. AE severity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4. All irAEs of an inflammatory nature in the absence of a clear alternative etiology were considered irAEs per investigator.

Efficacy

Tumor response was assessed by investigators per Response Evaluation Criteria in Solid Tumors version 1.1 [7]. Tumor assessments by computed tomography or magnetic resonance imaging were performed at baseline and then every 9 weeks until Week 27, after which assessments were made every 12 weeks. Efficacy endpoints assessed included objective response defined as complete response (CR) or partial response (PR); duration of response (DOR) defined as time from the initial response of CR or PR to progressive disease or death due to underlying disease, whichever comes first; and clinical benefit defined as CR, PR, or stable disease (SD) for ≥ 24 weeks from first dose of study drug. Due to the short follow-up time in Parts 3 and 4, progression-free survival could not be determined. Per protocol, overall survival data were not collected in Parts 3 and 4.

Statistical analysis

Continuous variables were summarized using descriptive statistics such as mean, standard deviation, median, and range. Categorical variables were summarized using frequency and percentage. Data were summarized by study part. Safety, pharmacokinetics, pharmacodynamics, and efficacy endpoints were summarized using the all-treated analysis set (patients who received ≥ 1 dose of study drug) unless otherwise specified. Parts 3 and 4 were designed to generate preliminary data for the subcutaneous delivery of cetrelimab; sample size was not based on formal hypothesis testing.

Results

Patients

Thirty patients with solid tumors were enrolled in Parts 3 and 4 at 7 sites across 4 countries (Moldova, Poland, Spain, and the United Kingdom). Eleven patients were enrolled in Part 3 (low-concentration [30 mg/mL] cetrelimab); 19 patients were enrolled in Part 4 (high-concentration [150 mg/mL] cetrelimab). In the combined Parts 3 and 4 population, patients had a median age of 54.5 (range, 26–78) years, 56.7% were male, and 96.7% were White. The most common tumor types were CRC (n = 6, 20.0%), breast cancer (n = 4, 13.3%), cholangiocarcinoma (n = 3, 10.0%), and NSCLC, n = 3, 10.0%). Most patients (n = 23, 76.7%) received ≥ 3 prior treatments; the median number of prior lines of systemic therapy was 3 (range, 1–8; Supplementary Table 1).

Exposure

The median duration of treatment with low-concentration cetrelimab was 2.1 (range 0–13.6) months, and the median number of doses received was 3 (range 1–17). The median duration of treatment with high-concentration cetrelimab was 2.1 (range 0–13.8) months, and the median number of doses received was 4 (range 1–20).

The median duration of follow-up was 3.7 (range, 1.3–15.2) months for Part 3 and 4.2 (range, 0.6–14.5) months for Part 4. At the time of data cutoff, 25 patients discontinued study treatment. Of the 25 patients who discontinued treatment, 19 (63.3%) patients had discontinued treatment due to progressive disease (Part 3, n = 8; Part 4, n = 11). In Part 3, 1 patient discontinued treatment due to physician decision. In Part 4, 5 patients continued high-concentration cetrelimab in the long-term extension portion of the study initiated in June 2023, which allowed those deriving benefit to remain on treatment.

Pharmacokinetics

Following a single subcutaneous dose of 600 mg cetrelimab in Part 3, the mean C_max was 43.3 µg/mL. Mean bioavailability was 44.3% but should be interpreted with caution because only 3 patients could be included from the intravenous RP2D in Part 1 of the study (Table 1). Following a single subcutaneous dose of 900 mg cetrelimab in Part 4, the mean C_max and AUC_0-3 weeks were 67.3 µg/mL and 24,840 µg*h/mL, respectively. Mean dose-normalized C_max (Part 3, 0.0722 µg/mL/mg; Part 4, 0.0748 µg/mL/mg), AUC_0-3 weeks (Part 3, 29.1 µg*h/mL/mg; Part 4, 27.6 µg*h/mL/mg), C_3weeks (Part 3, 0.0474 µg/mL/mg; Part 4, 0.0418 µg/mL/mg), and mean t_max (Part 3, 167.67 h; Part 4, 167.41 h) were comparable. Mean C_max following a single subcutaneous dose of low- or high-concentration cetrelimab was observed 1 week after dosing, gradually declining thereafter (Fig. 1).

Table 1.

Pharmacokinetics parameters of cetrelimab

Pharmacokinetics following a single subcutaneous cetrelimab dose
	Part 3: Low-concentration 600 mg SC Q3W dose 1 (n = 11)a	Part 4: High-concentration 900/600 mg SC Q3W dose 1 (n = 18)b
Cmax, μg/mL	43.3 (12.0)	67.3 (30.6)
tmax, h	167.67 (70.17–168.75)	167.41 (2.00–336.33)
C3weeks, μg/mL	28.4 (9.00)	37.6 (16.5)
AUC0-3 weeks, μg*h/mL	17486 (4850)	24840 (7827)
AUC0-6 weeks, μg*h/mL	26558 (5968)	–
AUC0-last, μg*h/mL	27198 (7031)	25193 (9003)
tlast, h	1006.75 (838.83–1009.75)	504.59 (334.83–770.88)
AUC∞, μg*h/mL	28120 (6990)	–
CL/F, L/h	0.0226 (0.0006)	–
t1/2, h	350.6 (90.8)	–
F, %c	44.28 (11.01)	–
Ctrough, μg/mL	13.8 (5.74)	37.6 (16.5)
Cavg, cycle 1, μg/mL	–	46.6 (14.8)
Cmax, dn, μg/mL/mg	0.072 (0.020)	0.075 (0.034)
C3weeks, dn, μg/mL/mg	0.047 (0.015)	0.042 (0.018)
AUC0-3 weeks, dn, μg*h/mL/mg	29.1 (8.08)	27.6 (8.70)

Pharmacokinetics following subcutaneous cetrelimab after dose 3 and following intravenous cetrelimab at steady sate (dose 9 or dose 5)
	Part 3: Low-concentration 600 mg SC Q3Wd dose 3e (Week 9–12)	Part 1: 240 mg IV Q2W dose 9f (Week 17–18)	Part 1: 480 mg IV Q4W dose 5f (Week 17–20)
Cmax, μg/mL	70.2 (28.5)	139 (18.2)	192 (33.7)
Ctrough, μg/mL	53.4 (23.9)	66.9 (10.5)	48.2 (11.3)
Cavg, μg/mL	70.2 (28.4)g	85.6 (16.9)g	75.6 (18.3)g

Data presented as mean (SD) or median (range)

^an = 9 for AUC_0-6 weeks and C_trough, and n = 5 for AUC_∞, CL/F, t_1/2, and F

^bn = 16 for C_3weeks, C_trough, and C_{3weeks, dn} and n = 15 for AUC_0-3 weeks, C_{avg cycle 1}, and AUC

^cF is obtained by dividing AUC_∞ by reference mean AUC_τ values from intravenous cetrelimab of Part 1 (480 mg old + new drug product pooled Q4W (50,808 ug*h/mL), n = 3) expressed as a percentage and compensated for the doses given

^d6-week dosing interval between dose 1 and dose 2

^eSteady state not reached for SC. n = 6 for C_max and n = 3 for C_avg and C_trough for observed pharmacokinetic parameters

^fn = 3–4

^gC_avg following intravenous cetrelimab was calculated as mean AUCτ_/τ

AUC, area under the concentration curve; AUC_∞, AUC extrapolated to infinity; AUC_0–last, AUC from time 0 to last measurable concentration; AUCτ, AUC over the dosing interval; CL/F, apparent plasma clearance; C_3weeks, concentration at 3 weeks; C_avg, average concentration; C_max, maximum drug concentration; C_trough, lowest drug concentration; dn, dose normalized to 1 mg; F, bioavailability; IV, intravenous; Q3W, every 3 weeks; SC, subcutaneous; t_1/2, half-life; t_last, time of last measurable drug concentration; t_max, time to maximum drug concentration

Fig. 1.

Mean (SD) dose-normalized serum concentration–time profiles of subcutaneous cetrelimab at low concentration (Part 3: 600 mg followed 6 weeks later by 600 mg Q3W thereafter)) andhigh concentration (Part 4: 900 mg loading dose followed 3 weeks later by 600 mg Q3W thereafter). Q3W, every 3 weeks; SC, subcutaneous; SD, standard deviation

The C_trough in Part 3 following 3 doses of 600 mg subcutaneous cetrelimab (with a 6-week interval between doses 1 and 2) was 53.4 μg/mL; the C_trough in Part 4 at the end of Cycle 7 was 69.5 µg/mL following a 900 mg subcutaneous cetrelimab loading dose and 600 mg Q3W thereafter. In comparison, the steady-state C_trough of intravenous cetrelimab RP2Ds were 66.9 μg/mL for 240 mg Q2W and 48.2 μg/mL for 480 mg Q4W (Table 1) [3].

Comparisons of mean serum concentration profiles after subcutaneous administration of either single-dose or multiple doses of low-concentration or high-concentration cetrelimab with intravenous cetrelimab dosing established in Parts 1 and 2 are shown in Supplementary Fig. 1.

Pharmacodynamics

Biomarker expression

Both dosing schedules used in Parts 3 and 4 of the study with subcutaneous cetrelimab resulted in maximum PD-1 pathway inhibition by 3–7 days after dose 1 as assessed by an ex vivo IL-2 induction assay, with stimulation ratio of 1 indicating maximum T-cell activation for both low- and high-concentration formulations throughout the dosing period (Supplementary Fig. 2). Low-concentration subcutaneous cetrelimab was associated with elevated serum levels of IP10 compared with baseline (Supplementary Fig. 3).

Receptor occupancy

PD-1 receptor occupancy saturation was reached by 72 h after the first dose of low- or high-concentration subcutaneous cetrelimab and remained near saturation at all timepoints after multiple doses (Supplementary Fig. 4).

Immunogenicity

Three of 11 (27.3%) patients were positive for anti-cetrelimab antibodies after subcutaneous administration of low-concentration cetrelimab in Part 3, and 1 of 19 (5.3%) patients was positive for anti-cetrelimab antibodies following subcutaneous administration of high-concentration cetrelimab in Part 4. All 4 patients had peak anti-drug antibody titers of 25. No patients were positive for neutralizing antibodies to cetrelimab.

Safety

One patient who received low-concentration cetrelimab experienced a DLT (grade 4 increased lipase on Day 22) that was considered possibly related to cetrelimab and was not considered an irAE. This patient had breast cancer with liver and lymph node metastases. The event resolved in 3 days and had been preceded by other enzyme elevations (grade 2 alkaline phosphatase [ALP], grade 2 aspartate aminotransferase [AST], grade 4 gamma-glutamyl transferase [GGT], grade 3 lipase, and grade 3 alanine aminotransferase [ALT]). No DLTs were observed for high-concentration cetrelimab.

Across the 2 formulations of subcutaneous cetrelimab, 27 (90.0%) patients experienced any grade TEAEs and 16 (53.3%) had grade ≥ 3 TEAEs. Incidence of TEAEs was similar between low- and high-concentration formulations. The most frequently reported TEAEs were fatigue (n = 12, 40.0%), increased ALT (n = 7, 23.3%), abdominal pain (n = 6, 20.0%), constipation (n = 6, 20%), increased AST (n = 6, 20.0%), and increased ALP (n = 6, 20.0%; Table 2). The most common grade ≥ 3 TEAEs were increased AST, increased GGT, and hyponatremia (each n = 4, 13.3%) and increased ALT (n = 3 [10.0%]). Ten (33.3%) patients had TEAEs leading to dose interruptions, which were considered treatment related in 4 patients. Three patients (10.0%) receiving high-concentration cetrelimab had TEAEs leading to treatment discontinuation, which was considered treatment- -related for one of these patients (grade 3 increased ALT and grade 3 increased AST). Serious TEAEs occurred in 8 (26.7%) patients (none were considered treatment related), and no patients experienced more than 1 serious TEAE (Table 2). Four (13.3%) patients died within 30 days of their last dose of cetrelimab: 3 patients died due to progressive disease, and 1 patient died due to abdominal sepsis considered unrelated to cetrelimab.

Table 2.

Safety with subcutaneous cetrelimab

Patients with TEAEs, n (%)	Part 3: Low-concentration (n = 11)	Part 4: High-concentration (n = 19)	Total (N = 30)
Any TEAEs	10 (90.9)	17 (89.5)	27 (90.0)
Treatment related	9 (81.8)	12 (63.2)	21 (70.0)
Any serious TEAEs	3 (27.3)	5 (26.3)	8 (26.7)
Treatment related	0	0	0
Any grade ≥ 3 TEAEs	8 (72.7)	8 (42.1)	16 (53.3)
Treatment related	4 (36.4)	3 (15.8)	7 (23.3)
TEAEs leading to drug interruption	4 (36.4)	6 (31.6)	10 (33.3)
Treatment related	1 (9.1)	3 (15.8)	4 (13.3)
TEAEs leading to treatment discontinuation	0	3 (15.8)	3 (10.0)
Treatment related	0	1 (5.3)	1 (3.3)
TEAEs leading to death	0	2 (10.5)	2 (6.7)
Treatment related	0	0	0
TEAEs in ≥ 20% of patients in either study part
Fatigue	4 (36.4)	8 (42.1)	12 (40.0)
Increased ALT	2 (18.2)	5 (26.3)	7 (23.3)
Abdominal pain	2 (18.2)	4 (21.1)	6 (20.0)
Constipation	3 (27.3)	3 (15.8)	6 (20.0)
Increased AST	2 (18.2)	4 (21.1)	6 (20.0)
Increased blood ALP	3 (27.3)	3 (15.8)	6 (20.0)
Increased GGT	3 (27.3)	2 (10.5)	5 (16.7)
Hyperbilirubinemia	1 (9.1)	4 (21.1)	5 (16.7)

A TEAE is categorized as treatment related if assessed by the investigator as possibly, probably, or very likely related to the study drug

ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate transaminase; GGT, gamma-glutamyl transferase; TEAE, treatment-emergent adverse event

Across both formulations, 21 (70.0%) patients had treatment-related AEs (Table 2). The most frequent treatment-related AEs were fatigue (n = 4, 13.3%), and increased ALT, increased AST, and increased blood ALP (each n = 3, 10.0%). Seven (23.3%) patients had grade ≥ 3 treatment-related AEs, most frequently increased ALT and GGT (each n = 2, 6.7%).

irAEs were reported in 9 (30.0%) patients, with a higher incidence in patients receiving cetrelimab on a treatment schedule with a 900 mg loading dose followed by 600 mg Q3W in Part 4 (n = 8, 42.1%) compared with patients treated with 600 mg Q3W with a 6-week interval between the first and second dose in Part 3 (n = 1, 9.1%). One patient in Part 3 experienced grade 1–2 thyroid function abnormalities (hypothyroidism and subacute thyroiditis), grade 2 abdominal pain, grade 2 dry mouth, grade 2 lymphopenia, and grade 1 pneumonitis. Among 8 patients who had irAEs in Part 4, 3 patients experienced grade 1–2 skin rash, 2 patients had grade 1–2 thyroid function abnormalities (thyroiditis, hyperthyroidism, and hypothyroidism), 2 patients had grade 2 diarrhea, and 2 patients had grade ≥ 3 hepatotoxicity events as follows. One patient with metastatic thymoma who failed 3 lines of prior therapy had grade 3 ALT and AST elevations on Day 30, leading to permanent discontinuation of cetrelimab; ALT and AST levels improved with methylprednisolone treatment. In patient with metastatic breast cancer and liver involvement who failed 8 lines of prior therapy, grade 3 AST elevation was reported as an irAE on Day 85 in the overall context of progressive disease, resulting in permanent discontinuation of cetrelimab; this patient died on Day 113 due to progressive disease. Other hepatic laboratory abnormalities observed during the study in this patient included grade 1 ALT elevation, grade 1 bilirubin elevation, grade 3 GGT elevations, and grade 2–3 ALP elevations that were not reported as irAEs and were considered not related or doubtfully related to cetrelimab. Median time to onset of irAEs in Part 4 was 28.5 (range, 10–113) days.

No systemic infusion- or injection-related reactions were observed with low- or high-concentration cetrelimab. Two (6.7%) infusion- or injection-site local reactions were observed across Parts 3 and 4: one grade 1 infusion site erythema was reported with low-concentration cetrelimab, and one grade 1 injection site bruising was reported with high-concentration cetrelimab.

Efficacy

At a median follow up of 3.7 months for Part 3 (low-concentration cetrelimab) and 4.2 months for Part 4 (high-concentration cetrelimab), the objective response rate was 6.7% (95% CI 0.8–22.1; Table 3). One patient with cholangiocarcinoma achieved PR with low-concentration cetrelimab starting on Day 71 and CR starting on Day 410 that was maintained through the last assessment for a DOR of 12.7 months. One patient with thymoma achieved PR with high-concentration cetrelimab starting on Day 65 that continued through the last assessment on Day 361 for a DOR of 9.8 months.

Table 3.

Efficacy with subcutaneous cetrelimab

	Part 3: Low-concentration (n = 11)	Part 4: High-concentration (n = 19)	Total (N = 30)
Objective response rate	1 (9.1) [0.2–41.3]	1 (5.3) [0.1–26.0]	2 (6.7) [0.8–22.1]
Clinical benefit ratea	1 (9.1) [0.2–41.3]	5 (26.3) [9.1–51.2]	6 (20.0) [7.7–38.6]
Confirmed best response
CR	1 (9.1)	0	1 (3.3)
PR	0	1 (5.3)	1 (3.3)
SD	2 (18.2)	5 (26.3)	7 (23.3)
PD	7 (63.6)	10 (52.6)	17 (56.7)
Non-CR/non-PD	0	0	0
NE	0	1 (5.3)	1 (3.3)
Unknown	1 (9.1)	2 (10.5)	3 (10.0)
Duration of response, median, months	NE	NE	NE

Data presented as n (%) or n (%) [95% CI]

^aClinical benefit rate is defined as CR + PR + SD, with SD duration required to be a minimum of 24 weeks from the start of treatment for patients with measurable disease

CR, complete response; NE, not evaluable; PD, progressive disease; PR, partial response; SD, stable disease

The clinical benefit rate across Parts 3 and 4 was 20.0% (95% CI 7.7–38.6) and was numerically higher with high-concentration versus low-concentration subcutaneous cetrelimab (26.3% vs. 9.1%; Table 3). Durable SD was observed, with 4 of 6 patients who had SD at 12 weeks maintaining SD at 24 weeks (all of whom received high-concentration cetrelimab). Tumor types for the 4 patients with durable SD were prostate cancer, peritoneal mesothelioma, urothelial carcinoma, and NSCLC.

Parts 1–2 intravenous cetrelimab update

Parts 1 and 2 evaluating intravenous cetrelimab were initiated on November 21, 2016, with a total of 204 patients analyzed for the primary analysis at the July 1, 2019 cutoff date [3]. Updated efficacy through November 17, 2023 (median follow up 12.2 [range 0.379.3] months) was generally comparable to the primary analysis results, with no new safety signals observed. The confirmed ORR was 20.1% (95% CI 14.8–26.3) and the CBR was 31.9% (95% CI 25.5–38.7) at the updated data cutoff across all tumor types. This updated analysis included 3 additional responses in MSI-H/mismatch repair deficient (dMMR) CRC: the ORR at the updated data cutoff in 48 patients with MSI-H/dMMR CRC was 22.9%.

Discussion

The safety and tolerability, clinical efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity for intravenous administration of cetrelimab and the RP2Ds with intravenous administration (240 mg Q2W or 480 mg Q4W) have been established [3]. The objective of Parts 3 and 4 of the LUC1001 study was to evaluate the safety, pharmacokinetic, and pharmacodynamic profile of two different formulations of cetrelimab that can be administered subcutaneously and to identify a subcutaneous dosing regimen that achieves systemic exposures comparable to the established intravenous RP2Ds [3].

After a single subcutaneous administration of cetrelimab 600 mg (low-concentration) in Part 3 or cetrelimab 900 mg (high-concentration) in Part 4, mean serum concentrations increased with increasing dose. However, after dose normalization, mean serum concentrations were comparable across the entire pharmacokinetic profile for the 600 mg and 900 mg doses. In addition, exposure following multiple subcutaneous administrations of cetrelimab 600 mg with or without a 900 mg loading dose was also comparable to the RP2Ds of intravenous cetrelimab (240 mg Q2W or 480 mg Q4W) identified in LUC1001 study Parts 1 and 2 [3]. In Part 3, the C_trough following multiple subcutaneous doses of low-concentration cetrelimab (53.4 µg/mL) was within the range of the intravenous RP2Ds established in Parts 1 and 2 (66.9 and 48.2 µg/mL) of the study [3]. Likewise, in Part 4, the C_trough of high-concentration subcutaneous cetrelimab at cycle 7 (67.3 µg/mL) was also near the intravenous cetrelimab RP2Ds established in Parts 1 and 2. Although steady state was not yet fully reached by subcutaneous cetrelimab in Part 3 after 3 doses, the exposure (AUC_τ) approached the values of intravenous RP2Ds. Finally, adding a 900 mg loading dose to the 600 mg Q3W dose regimen shortened the time to achieve target intravenous RP2D exposures, supporting the appropriateness of the 600 mg Q3W subcutaneous regimen as an alternative to intravenous administration.

The pharmacodynamic profile was generally comparable between the two subcutaneous cetrelimab formulations and was consistent with the pharmacodynamic profile observed following cetrelimab intravenous dosing regimens [3]. Maximum PD-1 receptor occupancy was achieved with subcutaneous cetrelimab, consistent with historical intravenous and subcutaneous PD-1 inhibitor data. In addition, subcutaneous cetrelimab induced maximum IL-2 release by 3–7 days after the initial dose across the two dosing regimens and was maintained throughout the dosing interval, indicating full T-cell activation. Finally, immunogenicity with subcutaneous cetrelimab was consistent with immunogenicity data observed with intravenous cetrelimab, with anti-cetrelimab antibodies not affecting clinical activity of subcutaneous cetrelimab [3].

The safety profile of low-concentration (30 mg/mL, 600 mg Q3W) and high-concentration (150 mg/mL, 900 mg loading dose followed by 600 mg Q3W) formulations of subcutaneous cetrelimab was consistent with that of other PD-1 inhibitors and showed no unexpected safety signals [8–10]. In addition, the incidence of treatment-related AEs (70.0%) with subcutaneous cetrelimab in Parts 3 and 4 was comparable to that of intravenous cetrelimab in Parts 1 and 2 of the study (67.2%) [3]. In Parts 3 and 4, 4 patients with treatment-related AEs with subcutaneous cetrelimab were managed by dose interruptions and 1 patient had a treatment-related AE leading to treatment discontinuation. This was consistent with the incidence of treatment-related AEs leading to dose interruptions (25.5%) and treatment discontinuations (5.9%) demonstrated in Parts 1 and 2 with intravenous cetrelimab [3]. There was a higher frequency of patients who had irAEs with high-concentration subcutaneous cetrelimab (n = 8/19, 42.1%) in Part 4 than with low-concentration subcutaneous cetrelimab (n = 1/11, 9.1%) in Part 3. The difference may be due to the intensified dosing schedule established in Part 4 comprising a 900 mg loading dose followed 3 weeks later by 600 mg Q3W. In contrast, the dosing schedule for Part 3 comprised a 600-mg initial dose followed 6 weeks later by 600 mg Q3W, which may explain why only 1 patient experienced an irAE in Part 3. The higher incidence of irAEs in Part 4 may also correspond to the higher exposure for patients who received the high-concentration formulation (67.3 µg/mL) in Part 4 compared with the lower exposure with low-concentration formulation (43.3 µg/mL) in Part 3. However, translational pharmacodynamic assessments of subcutaneous cetrelimab, such as ex vivo IL-2 induction and PD-1 receptor occupancy, were comparable across dosing regimens and consistent with Parts 1 and 2 of the study using intravenous cetrelimab. These findings suggest that differences in irAE incidence are unlikely to reflect qualitatively distinct immune activation driven by formulation or route of administration alone. Furthermore, this phase 1 study was not designed or powered to distinguish formulation-specific effects from dose- or exposure-related immune activation.

Infusion- or injection-site reactions with subcutaneous cetrelimab were reported in two (6.7%) patients, which was lower than rates of injection-site reactions seen with intravenous cetrelimab (n = 29, 14.2%) but consistent with subcutaneous pembrolizumab (2.4%) and subcutaneous nivolumab (2.9%) [3, 11, 12]. Finally, 1 DLT (grade 4 increased lipase) was observed with subcutaneous cetrelimab in a patient who received the low-concentration formulation, compared with 2 patients who experienced DLTs with intravenous cetrelimab across Parts 1 and 2 [3]. The median follow-up was notably shorter for subcutaneous cetrelimab (low-concentration, 3.7 months; high-concentration, 4.2 months) compared with the updated median follow-up for intravenous cetrelimab in Parts 1 and 2 of the LUC1001 study (12.2 months). The updated analysis of Parts 1 and 2 reported here showed that intravenous cetrelimab led to an ORR of 20.1% and a CBR of 31.9%. With subcutaneous cetrelimab in Parts 3 and 4, ORR was 6.7% and CBR was 20.0%. The difference in antitumor activity between intravenous and subcutaneous cetrelimab can be attributed to differences between the study populations. In Part 2, the study population was enriched for tumor types known to be more responsive to immune checkpoint inhibitor therapy including NSCLC, PD-L1–high NSCLC, melanoma, MSI-H/dMMR CRC, leading to higher ORR and CBR versus Parts 3 and 4, which enrolled patients with various solid malignancies without enrichment for specific tumor types [3].

Our study results should be interpreted in the context of the following limitations. Estimation of absolute bioavailability was based on comparisons with a small intravenous reference cohort and should therefore be interpreted with caution; additionally, steady-state pharmacokinetics were not fully achieved with subcutaneous cetrelimab in Part 3. Accordingly, assessment of comparable exposure relied primarily on dose-normalized pharmacokinetic parameters and trough concentrations of subcutaneous cetrelimab relative to the established intravenous cetrelimab RP2Ds. Interpretation of efficacy outcomes is limited by the shorter follow-up time in the subcutaneous cetrelimab cohorts compared with intravenous cetrelimab cohorts. Anti–PD-1 therapies are known to exhibit delayed responses, with ORR increasing with longer follow up. In our study, however, all patients in the subcutaneous cohorts had discontinued treatment or completed study participation by the time of analysis, precluding long-term outcome assessment. Furthermore, the high proportion of heavily pretreated patients (76.7% with ≥ 3 lines of prior therapy) without enrichment for specific tumor types known to respond better to immune checkpoint inhibitors likely contributed to the lower observed response rates with subcutaneous cetrelimab and may underestimate the true antitumor activity of cetrelimab.

In summary, findings from Parts 3 and 4 of the LUC1001 study characterized the safety, pharmacokinetics, pharmacodynamics, and efficacy of two formulations of subcutaneous cetrelimab in patients with advanced solid tumors and established the subcutaneous RP2D as a loading dose of 900 mg followed by 600 mg Q3W. Our results demonstrate that subcutaneous cetrelimab has a safety and pharmacokinetic profile consistent with intravenous cetrelimab and other PD-1 inhibitors, with no new safety signals identified.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 208 KB) ^{(208.1KB, docx)}

Author contributions

All authors participated in the original design of the studies, monitoring of data quality and contributed to the data interpretation, development and review of this manuscript and confirmed that they have read the journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. All authors met ICMJE criteria and all those who fulfilled those criteria are listed as authors. All authors had access to the study data, provided direction and comments on the manuscript, made the final decision about where to publish these data and approved submission to this journal.

Funding

This study was funded by Johnson & Johnson.

Data availability

The data sharing policy of Johnson & Johnson is available at https://www.jnj.com/innovativemedicine/our-innovation/clinical-trials/transparency. These data are out of scope for our data sharing policy.

Declarations

Conflict of interest

Piotr Rutkowski has received honoraria for lectures and Advisory Boards from MSD, Bristol Myers Squibb, Pierre Fabre, Genesis Pharma and Medison Pharma outside of the scope of the study. Dariusz M. Kowalski is an advisory board member and a consultant for Amgen, BeONE, Bristol Myers Squibb, Daiichi-Sankyo, Johnson & Johnson, Medison MERCK, MSD, Pierre-Fabre, Pfizer, Roche, and Takeda. Victor Moreno has received consulting fees from Abbvie, Affimed, Astra Zeneca, Bayer, Bristol Myers Squibb, Ellipses Pharma., Janssen, Merck, Miltenyi, Pan-Cancer T, Pharmamar, Roche, Syneos, and ViroFend; and is a principal Investigator (institutional funding) from Abalos Therapeutics, AbbVie, Accesion Therapeutics, Adaptimmune, Alentis Therapeutics AG, Alterome Therapeutics, Amal Therapeutics, Amgen, ArtiOS Pharma, Ascendis Pharma, Astellas Pharma, AstraZeneca, Bayer, BeiGene, Bicycle Therapeutics, BioInvent, BioNTech, Bristol Myers Squibb, Boehringer Ingelheim, Captor Therapeutics, Celgene, Corbus Pharmaceuticals, Crinetics Pharmaceuticals, Cullinan MICA, Daiichi Sankyo, Debiopharm, Egle Therapeutics, Eikon Therapeutics, Exelixis, Exscientia, F-Star Beta Limited, Genentech, Genmab, Gilead, Gilead Sciences, GlaxoSmithKline, Grey Wolf Therapeutics, Hexal AG & Sandoz, IGI Therapeutics SA, ImCheck Therapeutics, Immunocore, Immutep, Incyte, iOMX Therapeutics, Ipsen Pharma, I.R.I.S., I.R.I.S. Servier, Italfarmaco, Janssen, Kumquat BioSciences, Light Chain Bioscience, Lilly, Loxo Oncology, Marengo Therapeutics, Medicenna, Medicenna Therapeutics, MediLink Therapeutics, Merck, Merus, Miltenyi Biomedicine, MOMA Therapeutics, MonTa Biosciences, MSD, NEC Bio Therapeutics, Ningbo Newbay, Novartis, Nurix Therapeutics, One Carbon Therapeutics, Oxford Biotherapeutics, Pfizer, PharmaMar, PMV Pharma, Pyxis Oncology, Regeneron, Relay Therapeutics, Revolution Medicines, Roche, Sanofi, Schrödinger, Scorpion Therapeutics, Shattuck Labs, SystImmune, Tango Therapeutics, Tesaro, TheRas BridgeBio, Totus Medicines, Turning Point Therapeutics, and Vividion Therapeutics; and received research funding from AstraZeneca, Intheos, PMV Pharma, and Quironsalud. Aitana Calvo has received consulting fees or is an advisory board member from AstraZeneca, Bristol Myers Squibb, Daiichi, MSD, and Novartis. Fiona Thistlethwaite has received consulting fees from AstraZeneca, Grey Wolf Therapeutics, Immatics, OncoBayes, T-Knife Therapeutics, Waypoint; and is Principal Investigator (has received institutional funding) from Achilles Ltd, Adaptimmune, Amgen, Biontech, Bristol Myers Squibb, Chugai, Corbus, Crescendo Biologics, GenMab, Grey Wolf Therapeutics, Glaxo SmithKline, Immunocore, Incyte, Iovance, Janssen, Kymab Ltd/Sanofi, Leucid, Moderna, Novalgen, Nucana, Oxford Vacmedix, Roche, RS Oncology LLC, Seagen, Takeda, T-Knife, UCB, Zymeworks. Ruth Plummer has received consulting fees from, Astex Therapeutics, Benevolent AI, Bristol Myers Squibb, Cybrexa Therapeutics, Ellipses, Genmab, Immunocore, Incyte, MSD, Nerviano, Novartis, and Sanofi Aventis, and for working as an IDMC member for Alligator Biosciences, AstraZeneca GlaxoSmithKline, Onxeo, Pharmamar, and SOTIO Biotech AG (all outside scope of study). Douglas Steinbach, John Loffredo, Sydney Akapame, Daniel Jonathan, Vinod Philip, Angela Girvin, Shalaka Hampras, and Peter Hellemans are employees and stockholders of Johnson & Johnson. Iurie Bulat has no conflicts of interest.

Ethics approval

This study was conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki and that are consistent with Good Clinical Practices and applicable regulatory requirements.

Consent to participate

Patients or their legally designated representatives provided their written consent to participate in the study after having been informed about the nature and purpose of the study, Participation/termination conditions, and risks and benefits of treatment.