Fuzapladib in a randomized controlled multicenter masked study in dogs with presumptive acute onset pancreatitis

Abstract

Background

Currently, no specific treatment is available for acute onset pancreatitis (AP), and management relies on symptomatic and supportive standard of care (SOC). Fuzapladib is a novel leukocyte function‐associated antigen type‐1 (LFA‐1) activation inhibitor, blocking activation and subsequent adhesion and migration of neutrophils, potentially decreasing the risk of pancreatitis progression and systemic inflammation.

Objective

Evaluate the safety and clinical response of dogs with AP after 3 days of administration of fuzapladib.

Animals

Sixty‐one client‐owned dogs with presumptive AP.

Methods

Randomized, masked, and placebo controlled multicenter study. Sixty‐one dogs with AP were included for safety assessment, whereas 35 evaluable cases (fuzapladib, n = 16; placebo, n = 19) were included for clinical evaluation. Clinical improvement was assessed based on the change in the modified clinical activity index (MCAI) score on Day 3 compared to Day 0. Secondary variables included canine acute pancreatitis clinical severity index (CAPCSI) scores and serum concentrations of canine pancreatic lipase immunoreactivity, cytokines, and C‐reactive protein.

Results

Fuzapladib was well tolerated by all treated dogs. Mean change in MCAI scores was significantly higher in the fuzapladib‐treated (−7.75) than the placebo group (−5.68; P = .02, 95% confidence interval [CI] for the difference, −4.33, −0.35), suggesting clinical improvement in fuzapladib‐treated dogs. No significant difference was found in any of the secondary variables between groups.

Conclusions and Clinical Relevance

Administration of fuzapladib to dogs was safe, and a favorable response was detected in 2 clinical activity scores. Effects of fuzapladib on survival and duration of hospitalization were not studied.

Abbreviations

AE

adverse event

ANOVA

analysis of variance

AP

acute onset of pancreatitis

CAPCSI

canine acute pancreatitis clinical severity index

CI

confidence interval

CIBDAI

canine inflammatory bowel disease activity index

cPLI

canine pancreatic lipase immunoreactivity

CRP

c‐reactive protein

IBD

inflammatory bowel disease

IL

interleukin

ISK

Ishihara Sangyo Kaisha

ITT

intention‐to‐treat

LFA‐1

leukocyte function‐associated antigen type‐1

LSM

least squares mean

MCAI

modified clinical activity index

PP

per protocol

RMANCOVA

repeated measures analysis of covariates

SOC

standard of care

TNF‐α

tumor necrosis factor alpha

1. INTRODUCTION

Acute pancreatitis (AP) is an inflammatory disease characterized by polymorphonuclear inflammatory cell infiltration of the exocrine pancreas, edema, and necrosis associated with acute onset of a wide range of clinical signs, potential for multiple organ failure, and high mortality rate (23%‐58%) in dogs. ¹ , ² , ³ , ⁴ , ⁵ , ⁶ Although the etiology of pancreatitis remains unknown in most cases, risk factors have been identified, including dietary indiscretion, hypertriglyceridemia, hypercalcemia, drugs and toxins, endocrinopathies or other comorbidities, hereditary or breed predilections (eg, miniature schnauzers), advanced age (>7 years old), and being overweight. ⁶ , ⁷ , ⁸ , ⁹

The pathophysiology of AP includes injury and apoptosis of a critical mass of pancreatic acinar cells, resulting from trypsinogen‐dependent and independent pathways. ⁸ , ¹⁰ , ¹¹ , ¹² , ¹³ Disruption of acinar cell homeostasis leads to premature digestive enzyme activation, an inflammatory cascade, autophagy, impaired bicarbonate secretion from pancreatic ductal epithelial cells, and an inflammatory amplification loop, promoting local damage and potential multiorgan injury. ¹³ , ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷ , ¹⁸ The inflammatory cascade is initiated by activation of intra‐acinar nuclear factor‐kappa beta (NK‐κβ), triggering the release of cytokines, and recruiting resident macrophages and circulating neutrophils into the pancreas. ¹³ , ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷ , ¹⁸ , ¹⁹ Neutrophil migration into the pancreas and other tissues is facilitated by cytokine‐activation of its leukocyte function‐associated antigen type‐1 (LFA‐1) domain, binding to intercellular adhesion molecule‐1, a cell surface glycoprotein found on leukocytes, endothelial cells, epithelial cells, and fibroblasts. ¹⁸ , ¹⁹ , ²⁰ , ²¹ , ²² This interaction, in turn, stops circulating neutrophils at the site of inflammation, which then adhere to the endothelium and migrate into the surrounding tissue. ¹⁸ , ¹⁹ , ²⁰ , ²¹ , ²²

Currently, no definitive treatment addresses the pathophysiology of AP in any species. Symptomatic and supportive standard of care (SOC) consists of fluid therapy, antiemetic and antinausea agent administration, pain management, and nutritional support. ⁴ , ⁶ Thus, a critical unmet need exists for a definitive therapeutic agent for the treatment of AP in dogs. Inhibition of neutrophil migration into surrounding tissues by LFA‐1 activation inhibitors, such as fuzapladib, is a novel approach to protecting the pancreas against the inflammatory loop amplification and the patient as a whole from systemic complications. ²² , ²³

Addressing the pathophysiology of pancreatitis could improve clinical signs associated with AP, compared to SOC management alone. Fuzapladib sodium, an LFA‐1 activation inhibitor, has been shown to effectively block neutrophil extravasation in animals. ²² , ²⁴ Our aim was to assess the safety and clinical response of client‐owned dogs with presumptive pancreatitis after fuzapladib administration. Because a definitive diagnosis of AP cannot be achieved without histopathologic evaluation, and collection of a tissue biopsy specimen is rarely in the best interest of a patient with pancreatitis, we focused on dogs with acute onset of pancreatitis, assuming that most of them would have AP.

2. MATERIALS AND METHODS

2.1. Study design

This multicenter, randomized, masked, placebo‐controlled, prospective field study was conducted in the United States. The study was reviewed and approved by veterinary clinical studies and use committee of Argenta (New Brunswick, New Jersey) and all owners read and signed an informed client‐consent form before enrollment. The study was designed to evaluate the safety and clinical efficacy of fuzapladib (Panoquell‐CA1, Ishihara Sangyo Kaisha, Tokyo, Japan), a similar formulation to a drug approved in Japan (Brenda, Ishihara Sangyo Kaisha, Tokyo, Japan) for the treatment of AP in dogs. The estimated sample size required to show a significant difference between the fuzapladib‐treated and placebo groups was 19 animals per group and was based on the effect size reported in several previously conducted unpublished studies.

2.2. Inclusion and exclusion criteria

To be eligible for inclusion, dogs had to be ≥6 months of age, have good temperament allowing for blood collection and administration of treatment, ≥2 clinical signs of AP (eg, vomiting, anorexia, abdominal pain, lethargy, diarrhea, or dehydration) and have increased serum canine pancreatic lipase immunoreactivity concentration (cPLI; as measured by Spec cPL, IDEXX Laboratories, Westbrook, Maine) concentration >400 μg/L measured on Day 0. A SNAP cPL was used by the examining veterinarians on site for a presumptive diagnosis of AP on Day 0, allowing for timely recruitment of dogs into the study.

Dogs with serious concurrent clinical disease (eg, intestinal obstruction, abdominal mass, cardiopulmonary disease, liver failure, end‐stage chronic kidney disease (International Renal Interest Society [IRIS] III/IV), metabolic disease, autoimmune disease, severe anemia, systemic infection, malignancies), life‐threatening pancreatitis involving multiorgan failure (at the time of evaluation for potential enrollment), or administration of certain concomitant medications, such as corticosteroids, nonsteroidal anti‐inflammatory drugs (NSAIDs), immunosuppressants, chemotherapeutic agents, herbal or homeopathic remedies, or whole blood transfusions were excluded from the trial. Dogs intended for breeding, pregnant or lactating, those in estrus, or those having recently participated in another clinical trial also were excluded.

2.3. Randomization and masking

Dogs were randomly assigned to treatment group based on their order of enrollment into the study using randomization tables generated by a software package (SAS/STAT software, Version 9.4, Cary, North Carolina). Each site had a unique randomization schedule.

During the study period, examining veterinarians did not have knowledge of treatment group assignments. Members of the dispensing team at each study site were the only individuals not masked as to the treatment of each patient. However, as is typical at any private veterinary practice, team members multitasked when needed. Therefore, some members of the dispensing team may have been involved in other aspects of care (eg, animal restraint, replacing IV fluids) of the patients. Regardless, such individuals were not involved in the assessment of any of the patients. No unmasking occurred during the study.

2.4. Treatment phase

Dogs assigned to the fuzapladib group received 0.4 mg/kg of fuzapladib IV once daily for 3 consecutive days (Days 0 to 2). Dogs assigned to the placebo group received an aqueous solution of lyophilized excipients (placebo) IV once daily for 3 days. The fuzapladib and placebo (excipients only) were packaged in 3 mL glass vials containing the lyophilized powder. Each vial was uniquely identified with a 4‐digit vial number affixed to the bottom of the vial. Before use at the veterinary hospital, the lyophilized powder was solubilized in 1 mL of sterile water for injection. The resulting fuzapladib and placebo solutions were both clear solutions and indistinguishable from each other. Both treatments were administered at a volume of 0.1 mL/kg and administered over 15 seconds to 1 minute. The duration of the study was 4 days (Days 0 to 3).

Depending on the condition of the patient, dogs were either hospitalized, treated as outpatients, or a combination of both. All dogs received SOC management for AP, which if deemed necessary by the attending veterinarian included nutritional support according to the calculated resting energy requirement ±15%, SC or IV fluid and electrolyte therapy, analgesic medication (except NSAIDs), antiemetic or antinausea agents, and treatment for ongoing preexisting stable medical conditions if indicated. Some dogs also received additional medications not considered to be SOC for AP but administered at the discretion of the primary care veterinarian (eg, antibiotics).

2.5. Assessment of safety of fuzapladib

Safety assessment was performed through complete physical examinations once daily before treatment on Day 0 and to the end of the study. Samples for hematology, serum biochemistry profile, and urinalysis were collected on Day 0 and again on Day 3 and analyzed by a central laboratory (IDEXX Laboratories, Westbrook, Maine). All adverse events (AEs) and serious AEs (ie, those causing death, life‐threatening condition, or permanent disability) were recorded. Although clinical signs directly associated with AP (as listed in the inclusion criteria) were not considered AEs, they still were recorded.

2.6. Assessment of clinical efficacy of fuzapladib

Assessment of the clinical efficacy of fuzapladib was evaluated by an examining veterinarian once daily for 4 consecutive days (ie, before administration of fuzapladib or placebo on Day 0, after administration on Days 1 and 2, and 24 hours after the last treatment on Day 3). A modified canine activity index (MCAI) originally was developed using the canine inflammatory bowel disease activity index (CIBDAI) for assessing inflammatory bowel disease in dogs as the basis and the canine acute pancreatitis clinical severity index (CAPCSI) scores for monitoring disease progression were assigned, as previously described. ⁴ , ⁶ To prevent confusion about what the MCAI describes, we used the term modified clinical activity index for our study, while continuing to use the same acronym, MCAI. The MCAI scoring system was the primary endpoint and included assessment of the patient's activity, appetite, vomiting, cranial abdominal pain, dehydration status, and fecal consistency, with the addition of absence or presence of blood in the feces for the purpose of the study, with a possible maximum MCAI score of 19 (Table 1). The CAPCSI scoring system was used as a secondary endpoint, combining the presence of systemic involvement of the cardiovascular or respiratory systems, intestinal integrity, and vascular factors (ie, blood pressure), with a possible maximum score of 10. ⁶ Additional secondary endpoints included serum cPLI concentrations (as measured by Spec cPL; first measured to confirm that the positive SNAP cPL test was truly positive) and serum concentrations of C‐reactive protein (CRP), cytokines (interleukins [IL]‐2, IL‐6, IL‐8, IL‐10, and tumor necrosis factor‐alpha [TNF‐α]) in samples collected daily (Days 0‐3) that were sent to the Gastrointestinal Laboratory at Texas A&M University (TAMU) for analyses. Analytical validation for the immunoturbidimetric assay for the measurement of CRP has been described previously. ²⁵ The multiplex cytokine assay used for the study has been analytically validated for use in dogs, but results have not yet been published (personal communication 2022).

TABLE 1.

Modified clinical activity index (MCAI) scoring system used as the primary endpoint for evaluating the clinical response to a daily IV administration of fuzapladib or placebo for 3 consecutive days to dogs with acute pancreatitis (AP).

Variable	Score	Description
Activity	0	Normal (as usual)
	1	Slightly decreased (stands less than usual)
	2	Moderately decreased (is reluctant to stand)
	3	Severely decreased (cannot stand up)
Appetite a	0	Normal (ate more than ¾ of food offered)
	1	Slightly decreased (ate about ½ of food offered)
	2	Moderately decreased (ate about ¼ of food offered)
	3	Severely decreased (did not eat or not much of the food offered)
Vomiting	0	None
	1	1‐2 times/day
	2	3‐4 times/day
	3	≥ 5 times/day
Cranial abdominal pain	0	None (no signs of pain)
	1	Mild (abdominal wall resistance or other signs of pain are elicited upon palpation of abdomen; moves slowly or is less responsive)
	2	Moderate (resists palpation; is reluctant to move when encouraged; does not lie on its side)
	3	Severe (persistent vocalization, howling and/or insomnia)
Dehydration	0	None (<5%, no signs of dehydration)
	1	Mild (5%, slight loss of skin elasticity)
	2	Moderate (6%‐8%, increased skin turgor, slightly delayed capillary refill time, dry mucous membranes, sunken eyes)
	3	Severe (≥10%, severely decreased skin turgor, delayed capillary refill time, deeply sunken eyes, severely dry mucous membranes)
Fecal consistency	0	Normal (well formed)
	1	Soft (slightly watery and poorly formed)
	2	Moderate (no form or runny)
	3	Watery (watery with no solids and pale)
Blood in feces	0	Absent
	1	Present

Abbreviations: AP, acute pancreatitis; MCAI, modified clinical activity index.

^a Voluntary food intake.

The intent‐to‐treat (ITT) safety population consisted of all enrolled dogs that received at least 1 dose of fuzapladib or placebo. The per protocol (PP) efficacy population included all dogs that completed the study with no major protocol deviations.

2.7. Statistical analyses

The primary clinical response variable was the change in MCAI scores between Day 0 and Day 3. Individual and total scores for MCAI and CAPCSI, and serum concentrations of cPLI, CRP, and cytokines were summarized at each timepoint for each group and descriptive statistical analyses were performed. The P‐value for Day 0 was derived from analysis of variance (ANOVA) modeling with group as a fixed effect and random effects of site and group‐by‐site interaction. P‐values for the change (Day 3 minus Day 0) were derived by repeated measures analysis of covariance (RMANCOVA), including group, day, and group‐by‐day as fixed effects, site and group‐by‐site interaction as random effects, and Day 0 as a covariate using compound symmetry (CS) as a covariance structure. The least squares mean (LSM) difference between groups and the 95% confidence interval (CI) were calculated using this model. Assumptions of normality of residuals were investigated for each model using the Shapiro‐Wilk test. If it was determined that the distribution could not be approximated by a normal distribution curve (P ≤ .01), then a rank transformation was applied before the analysis. Clinical improvement rate was calculated as a percentage change (Day 3 minus Day 0 divided by Day 0 times 100) in MCAI and CAPCSI scores, and in serum concentrations of cPLI and CRP for each group and compared. All comparisons were tested at the .05 level of significance.

Adverse events were tabulated and summarized. All hematology, serum biochemistry, urinalysis, physical examination, and AE data were summarized, but no statistical tests were performed.

3. RESULTS

3.1. Study population

Of the 77 dogs screened, 61 client‐owned dogs diagnosed with presumptive AP were enrolled at 11 US sites and included in the safety assessment. The mean age of dogs was 10.1 years (range, 1.8‐15.9 years) and the mean body weight was 10.8 kg (range, 3.1‐44.9 kg). Most dogs were purebred (71%) and most were spayed females (55%), followed by neutered males (37%), and intact males (8%).

Data from the PP population were used for the clinical response assessment and consisted of 35 patients (n = 16 in the fuzapladib group; n = 19 in the placebo group; Figure 1).

FIGURE 1.

Study selection flowchart for the multicenter, randomized, masked, controlled pilot field trial in client‐owned dogs with acute pancreatitis (AP). ^aSite error.

3.2. Assessment of safety for the ITT population

No differences were evident between groups for any of the clinical pathology or other clinical data at baseline. A total of 142 AEs were recorded during the study in 41/61 dogs (67%; each dog could have multiple reported AEs). The total percentage of fuzapladib‐treated dogs with AEs was 74.2% (23/31) whereas it was 63.3% (19/30) in the placebo dogs. The most common AEs were tabulated in descending order according to the number of occurrences reported in both the fuzapladib‐treated and placebo groups (Table 2).

TABLE 2.

Number and percentage (%) of the most frequently reported adverse events (AEs) from the ITT population (n = 61) in dogs with AP after 3 days of IV administration of 0.4 mg/kg of fuzapladib or placebo.

Adverse event	Fuzapladib‐treated group (n = 31)	Placebo‐treated group (n = 30)
Anorexia	5 (16.1%)	2 (6.7%)
Digestive tract disorders a	5 (16.1%)	3 (10.0%)
Respiratory tract disorders b	4 (12.9%)	3 (10.0%)
Hepatopathy, jaundice	4 (12.9%)	2 (6.7%)
Abnormal urine c	3 (9.7%)	2 (6.7%)
Diarrhea	3 (9.7%)	1 (3.3%)
Arrhythmia	2 (6.5%)	1 (3.3%)
Cardiac arrest	2 (6.5%)	0
Hyperthermia	2 (6.5%)	0
Pruritus, urticaria	2 (6.5%)	0
Hypersalivation	2 (6.5%)	0
Heart murmur	1 (3.2%)	2 (6.7%)
Limb edema	1 (3.2%)	2 (6.7%)
SC swelling, bruising at the injection site	1 (3.2%)	1 (3.3%)
Tremor/shivering/shaking	1 (3.2%)	1 (3.3%)
Abrasion	1 (3.2%)	1 (3.3%)
Cerebral edema	1 (3.2%)	0
Anaphylaxis	1 (3.2%)	0
Hypertension	1 (3.2%)	0

Abbreviation: ITT, intent‐to‐treat.

^a Digestive tract disorders included regurgitation (1 fuzapladib, 2 placebo), vomiting (1 fuzapladib, 1 placebo), flatulence (1 fuzapladib), nausea (1 fuzapladib), and diarrhea (1 fuzapladib).

^b Respiratory tract disorders included pneumonia (2 fuzapladib, 1 placebo), inspiratory crackles (1 fuzapladib, 2 placebo), tachypnea (2 fuzapladib), and dyspnea (1 fuzapladib).

^c Abnormal urine included proteinuria (2 fuzapladib, 2 placebo), hematuria (2 placebo), and malodorous urine (1 fuzapladib).

Twenty‐seven serious AEs occurred in 5 patients that died or were euthanized during the study.

In the fuzapladib‐treated group, 2 dogs died spontaneously and 2 were euthanized during the study on Days 0‐2. Owners allowed necropsy of 3/4 dogs, which identified chronic active pancreatitis with peripancreatic fat necrosis, fibrinous peritonitis, and valvular endocardiosis with cardiac dilatation (n = 1), multifocal chronic interstitial pancreatitis with peripancreatic fat necrosis and steatitis (n = 1), and intestinal lymphoma (n = 1). The dog that did not undergo necropsy was euthanized with a clinical diagnosis of aspiration pneumonia. In the placebo group, 3 dogs were euthanized because of poor prognosis, 1 on Day 2 and 2 after removal from the study on Day 3 or immediately after completion of the study on Day 4, respectively. Necropsy in 2/3 dogs disclosed severe necrotizing pancreatitis, multiorgan thromboses and left adrenal cortical adenocarcinoma (dog euthanized on Day 2), and focal mild interstitial pancreatitis with peripancreatic fat necrosis and steatitis, diffuse liver cirrhosis, and pheochromocytoma (dog euthanized on Day 4).

3.3. Assessment of clinical efficacy of fuzapladib for the PP population

At baseline (Day 0), mean MCAI scores were slightly higher in dogs treated with fuzapladib (8.6 ± 3.0; out of a maximum score of 19) than in placebo‐treated dogs (7.7 ± 2.6; Figure 2). However, this difference was not significant (P = .36). In contrast, on Day 3, the mean decrease in MCAI scores was significantly different between the fuzapladib (−7.8 ± 2.5) and placebo (−5.7 ± 3.8; P = .02) groups. The mean change in MCAI scores between Days 0 and 3 also was significantly different between groups with a larger improvement recorded in the fuzapladib group (LSM, −2.34; P = .02; 95% CI, −4.33, −0.35; Figure 3). When removing “fecal consistency” and “blood in feces” as less relevant clinical signs of the MCAI in the investigated population, the resulting MCAI5 showed an increase in the significance of the clinical score change between the fuzapladib‐treated and placebo groups of P = .01 (from P = .02; using RMANCOVA).

FIGURE 2.

Mean total MCAI scores (±SD) over time from the PP population of 35 client‐owned dogs with AP after a 3‐day IV treatment with 0.4 mg/kg fuzapladib (n = 16) or a placebo (n = 19). Maximum total MCAI score possible was 19.

FIGURE 3.

Box plot of mean change (differences between Day 3 [post treatment] and Day 0 [before the first treatment administration]) of total MCAI scores from the PP population of 35 client‐owned dogs with AP after 3 days of IV treatment with 0.4 mg/kg fuzapladib (n = 16) or a placebo (n = 19). Blue dots = mean. *Significant difference at P < .05 between groups.

The distribution of the residuals for secondary endpoints did not support the normality assumption; therefore, medians and ranges are reported (Table 3). The CAPCSI scores at baseline were low, ranging from 0 to 3 (median, 1.5) and 0‐4 (median, 0) for the fuzapladib and the placebo groups, respectively (out of a maximum score of 10), whereas serum cPLI concentrations were increased for both the fuzapladib (median, 1000 μg/L; range, 401‐6456 μg/L) and placebo (median, 1276 μg/L; range, 397‐12 808 μg/L) groups with no significant difference between groups for either pretreatment. However, baseline CRP concentrations were significantly lower in the fuzapladib group (median, 18.6 mg/L; range, 2.5‐129.2 mg/L) than in the placebo group (median, 58.8 mg/L; range, 2.5‐227.6 mg/L; P = .04) pretreatment. Lastly, no significant differences were found in any of the serum cytokine concentrations between groups at baseline (Table 3).

TABLE 3.

Changes in CAPCSI scores, and serum concentrations of cPLI, CRP, and cytokines on Day 3 (after the third treatment administration) when compared to Day 0 (before treatment administration) from the PP population of 35 client‐owned dogs with AP after 3 days of IV administration of 0.4 mg/kg fuzapladib or placebo.

	Fuzapladib‐treated group (n = 16)		Placebo‐treated group (n = 19)
Secondary endpoint	Median	Min, Max	Median	Min, Max	P‐values a , b
CAPCSI score	−1.5	−3.0, 0.0	0	−4.0, 2.0	.06
cPLI (μg/L)	−338	−5703, 2102	−758	−8080, 5388	.29
CRP (mg/L)	−2	−87, 43	−19	−191, 40	.75
IL‐2 (pg/mL)	−4.9	−102.5, 15.0	1.5	−27.7, 43.2	.31
IL‐6 (pg/mL)	−5.0	−286.1, 74.2	−3.4	−210.2, 81.7	.97
IL‐8 (pg/mL)	38.1	−5720, 2596	185.7	−2191, 6183	.87
IL‐10 (pg/mL)	0	−3.6, 96.6	0	0.0, 0.4	.52
TNF‐α (pg/mL)	−0.4	−24.6, 4.9	0.2	−5.5, 7.0	.68

Abbreviations: CAPCSI, canine acute pancreatitis clinical severity index; cPLI, canine pancreatic lipase immunoreactivity; CRP, C‐reactive protein; IL, interleukin; TNF‐α, tumor necrosis factor‐alpha.

^a P‐value for Day 0 derived from ANOVA including group as fixed effect and random effects of site and group‐by‐site interaction. LSM difference (95% CI) and P‐value for the change (Day 3 minus Day 0) derived by repeated measures ANCOVA, including group, day, and group‐by‐day as fixed effects, site and group‐by‐site as random effects, and Day 0 as a covariate using CS as covariance structure.

^b Indicates values were ranked before ANOVA/ANCOVA, if the p‐value of the Shapiro‐Wilk test of the residuals was ≤.01.

Posttreatment, median CAPCSI scores decreased to 0 for both the fuzapladib (no range) and placebo (range, 0‐2) groups. Median cPLI serum concentrations on Day 3 decreased to 429.5 μg/L (range, 30‐2928 μg/L) for the fuzapladib group and to 1142 μg/L (range, 36‐11 880 μg/L) for the placebo group and, whereas median CRP remained high for both groups (fuzapladib median, 21.7 mg/L; range, 2.5‐65.4 mg/L; placebo median, 28.7 mg/L; range, 4.4‐197.2 mg/L), these differences were not significantly different. No significant differences between groups were found in CAPCSI scores, or in serum cPLI, CRP, or cytokine concentrations for the change from Day 0 to Day 3 (Table 3).

A significant difference in improvement rates of MCAI scores between the fuzapladib‐treated dogs (−91.6%) and the placebo‐treated dogs (−67.8%) was observed (P = .03). Similarly, a significant difference in improvement rates of CAPCSI scores was found between fuzapladib‐treated dogs (−75.0%) and placebo‐treated dogs (−31.6%; P = .001). No significant differences in improvement rates were observed for serum concentrations of CRP or cPLI between the 2 groups (P > .05).

4. DISCUSSION

Our prospective clinical trial investigated the safety and efficacy of 0.4 mg/kg of fuzapladib, a novel LFA‐1 activation inhibitor, given IV for 3 days to client‐owned dogs with a presumptive diagnosis of AP. The presumption of AP was based on the presence of at least 2 clinical signs compatible with pancreatitis and serum cPLI concentrations ≥400 μg/L at the time of presentation. However, the lack of abdominal ultrasound examination or histopathological evaluation of a tissue sample means that the diagnosis of AP was presumptive.

None of the AEs observed were unexpected in this study population, and none were considered to be treatment‐related because they occurred in both groups of dogs with similar frequency. None of the abnormalities identified during necropsy were considered to be treatment‐related, but rather consequences of exacerbation of pancreatic disease or of 1 of the comorbidities. Thus, fuzapladib was considered to be safe. As is the case for any new pharmaceutical agent, additional data in larger numbers of patients will be needed to more comprehensively assess the safety of fuzapladib. Results indicated the potential of fuzapladib to improve clinical signs associated with AP when compared to SOC management alone, based on a MCAI score adapted to the disease pathophysiology. Significant improvements of secondary endpoints (ie, cPLI, CRP, cytokines) after fuzapladib treatment were not found in this cohort.

The most common clinical signs reported in dogs with AP are anorexia, vomiting, lethargy, abdominal pain, and diarrhea. ⁴ , ⁶ , ⁹ , ²⁶ The use of the MCAI scoring system, which includes these clinical signs, proved valuable in our study to allow for objective assessment of the clinical response of dogs with AP to treatment with fuzapladib. A new score, the MCAI5, was constructed by including the most relevant combination of clinical signs in dogs with AP (ie, activity, appetite, abdominal pain, vomiting, and dehydration), thereby increasing the clinical relevance. Based on these results, it seems likely that the MCAI5 may be of better use as a primary endpoint for future studies in dogs with AP than the MCAI (using 7 variables).

The CAPCSI scoring system was based on 4 clinical variables representative of systemic inflammation. ⁶ However, the usefulness of the CAPCSI scoring system was limited in our study because of the low scores recorded throughout the study in both groups, suggesting that most study patients did not present with severe forms of pancreatitis.

Serum concentration of pancreatic lipase immunoreactivity (cPLI) is a valuable biomarker for the diagnosis of pancreatitis in dogs when measured using an analytically valid assay and combined with clinical signs and diagnostic imaging findings. ² , ²⁷ , ²⁸ , ²⁹ , ³⁰ Good sensitivity and specificity of the in‐laboratory Spec cPL assay with a good to excellent agreement with the in‐house SNAP cPL assay have been demonstrated previously. ³⁰ In our study, the SNAP cPL was performed on Day 0 for timely recruitment of dogs, with confirmation by measurement of serum cPLI concentration. Eighteen of 61 enrolled dogs (9 per treatment group) were withdrawn from the study because of a serum cPLI concentration < 400 μg/L. This outcome was to be expected because the SNAP cPL was designed to be abnormal when serum cPLI concentrations are ≥200 μg/L, which is considered a result that is either “equivocal for a diagnosis of pancreatitis” (200 μg/L < cPLI < 400 μg/L) or “diagnostic for pancreatitis” (cPLI ≥ 400 μg/L). In contrast, the inclusion criterion for our study was a serum cPLI concentration that is considered to be diagnostic for pancreatitis (ie, ≥ 400 μg/L). No evidence of a significant difference in the cPLI improvement rates was found between the fuzapladib (66%) and the placebo (25%) groups. We hypothesize that a larger sample size might have identified a significant difference.

The relevance of the difference in mean CRP results between groups before treatment is unknown. One interpretation would be that dogs in the fuzapladib‐treated group had more severe systemic complications than did dogs in the placebo‐treated group. However, this explanation does not seem reasonable, given that neither the clinical scores nor any of the other variables assessing systemic inflammation (eg, serum cytokine concentrations) showed any significant differences. It would appear more likely that the large degree of interindividual variability contributed to these findings. Although mean CRP concentrations from dogs treated with fuzapladib were lower throughout the study, concentration ranges within groups were wide and not significantly different at any point beyond Day 0. As an acute phase reactant, CRP indiscriminately increases in response to various diseases and serum CRP concentrations may have been influenced by the presence of comorbidities, possibly confounding results. Furthermore, the short duration of the study may not have allowed for normalization of this variable, reported to take 3 to 14 days to decrease in the absence of other inflammatory foci. ³¹ Similar results were reported in another study in dogs, demonstrating a lack of correlation between MCAI scores and CRP concentrations. ⁶

All dogs received fluid therapy (SC or IV) and maropitant. Many dogs also received famotidine (54%) although it is not routinely recommended for the management of AP. Antibiotic and analgesic agents also were among the most commonly administered concomitant medications. Antibiotics are not routinely recommended as part of the SOC management for AP in dogs, but they often are administered by primary care veterinarians. ⁶ , ⁸ , ⁹ Treatment for comorbidities (eg, diabetes mellitus, cardiovascular disease, parasitic infestation, gastrointestinal disturbances, or ocular disease) was administered as deemed appropriate by the primary care veterinarian. Considering the complexity and severity of AP and the use of nonstandardized treatments to manage clinical signs related to this disease as well as comorbidities in this target population, the observed changes in the clinical activity scores associated with fuzapladib treatment in this multi‐institutional study, although promising, must be interpreted with caution. Additional studies are needed to confirm these findings.

Our study had some limitations, including relatively small sample size, short study duration, multiple study sites, and absence of ultrasonographic evidence to confirm a diagnosis of AP and assess severity in the dogs enrolled. Another limitation was the fact that concurrent gastrointestinal disease, which would be expected to be associated with similar clinical signs as pancreatitis, was not definitively excluded in any of the dogs. However, concurrent gastrointestinal disease is not frequently described in dogs with AP. Finally, the nonstandardized treatment protocol for all dogs enrolled in the study was a major limitation. However, given the complexity of AP and the involvement of a large number of primary care veterinarians involved in this study, perfect standardization was not achieved.

The use of previously described scoring systems for assessing the clinical efficacy of fuzapladib in our study, although not validated for AP, was justified. The resulting MCAI scoring system, including the most clinically relevant signs of AP in dogs, assesses the pathophysiology of this life‐threatening disease.

Fuzapladib, a novel LFA‐1 activation inhibitor, administered IV at 0.4 mg/kg daily for 3 days to dogs with AP decreased MCAI scores compared to dogs that only received SOC management and placebo. Future studies evaluating the clinical response (including outcome and duration of hospitalization) of a larger number of dogs with AP to fuzapladib, using the more refined clinical scoring system (MCAI5) may confirm the efficacy of fuzapladib in improving clinical signs, and address a serious unmet clinical need.

CONFLICT OF INTEREST DECLARATION

Drs Y. Noshiro, Y. Domen and H. Shikama are employed by Ishihara Sangyo Kaisha Limited. Ishihara Sangyo Kaisha Limited owns the intellectual property and patents associated with fuzapladib sodium. Drs H. Sedlacek and S. Bienhoff are employed by the Contract Research Organization (CRO) that received compensation for conducting the study. Dr. Chantal Lainesse is employed by IntegRxal Consulting Strategies, Inc. and received payments for writing and editorial services. Drs K. Doucette and D. Bledsoe received payments as independent consultants and service providers to Ishihara Sangyo Kaisha Limited. Dr. Steiner also serves as a paid consultant for IDEXX Laboratories, the manufacturer of the Spec cPL and SNAP cPL assays and for Ishihara Sangyo Kaisha, Ltd (ISK) as well as ISK Animal Health LLC, the manufacturer of fuzapladib.

OFF‐LABEL ANTIMICROBIAL DECLARATION

Authors declare no off‐label use of antimicrobials.

INSTITUTIONAL ANIMAL CARE AND USE COMMITTEE (IACUC) OR OTHER APPROVAL DECLARATION

The study was reviewed and approved by the animal care and use committee of Argenta and all owners signed an informed client‐consent form before enrollment.

HUMAN ETHICS APPROVAL DECLARATION

Authors declare human ethics approval was not needed for this study.

Steiner JM, Lainesse C, Noshiro Y, et al. Fuzapladib in a randomized controlled multicenter masked study in dogs with presumptive acute onset pancreatitis. J Vet Intern Med. 2023;37(6):2084‐2092. doi: 10.1111/jvim.16897