robenacoxib: what the FDA reviewed for dog products
4 Freedom of Information summaries from the FDA Center for Veterinary Medicine for products containing robenacoxib, as typed records: every value below is followed by the verbatim passage it was taken from. Species as stated by each summary: Cats; Dogs; Dogs and cats.
Products
- Robenacoxib Injection (NADA/ANADA 200-804)
- onsior® injection (NADA/ANADA 141-443)
- onsior™ (NADA/ANADA 141-463)
onsior® injection NADA 141-443, Original approval, August 05, 2015; sponsor Elanco US Inc.; species: Cats; foi_id 934; FDA PDF
Indication
Control of postoperative pain and inflammation associated with orthopedic surgery, ovariohysterectomy and castration in cats at least 4 months of age, for up to a maximum of 3 days.
Dose regimen
0.91 mg/lb (2 mg/kg), subcutaneous injection, once daily, Maximum of 3 days; first dose approximately 30 minutes prior to surgery with the pre-anesthetic agents; subsequent doses may be interchanged with the oral tablet (maximum 3 total doses over 3 days).
For cats > 4 months: The dose of ONSIOR (robenacoxib) injection is 0.91 mg/lb (2 mg/kg) subcutaneously once daily, for a maximum of 3 days.
Pharmacokinetics
| Parameter | Value | Conditions | Quote |
|---|---|---|---|
| other | dose-normalized oral AUC 0-4 approximately twice that of the injectable | 37-day interchangeable use study in 4-month-old cats; 2.4 mg/kg oral tablet vs 2 mg/kg SC injection (1X); samples at 0.75 and 4 h post-dose | The dose normalized oral robenacoxib exposure (AUC 0-4) was approximately twice that observed with the injectable formulation. |
| other | 2X injectable dose gave 1.4X exposure; 3X dose gave 2.3X exposure (slightly less than dose-proportional); no significant accumulation once daily | 37-day interchangeable use study, SC 2/4/6 mg/kg | Furthermore, a slightly less than dose proportional increase in exposure was observed with an increase in injectable dose (a 2X dose resulted in a 1.4X increase in drug exposure; a 3X increase in dose resulted in a 2.3X increase in drug exposure). There was no significant accumulation following once daily administration. |
Target-animal safety
dose multiples 1X, 2X, 3X; duration 37 days (alternating 7 days oral tablet / 3 days subcutaneous injection); animals 17 male and 17 female cats.
Seventeen healthy intact male and 17 intact female domestic short hair cats. At the time of the first dose, cats were 120 to 124 days old, weighing 1.7 – 3.0 kg.
| Finding | Quote |
|---|---|
| Dose-dependent QT interval increase at all three dose levels. | There was a dose-dependent increase in the QT interval at all 3 dose levels that was statistically significantly different from control group values following treatment. |
| Injection-site edema in controls and treated; significantly more occurrences in 2X (8 h) and 3X (24-48 h). | However, a significant increase in the number of edema occurrences was observed in the 2X group when compared to the control group in the 8-hour post-dose observation. |
| Soft stools more frequent in higher dose groups; one 2X cat vomited. | Soft stools were noted sporadically in all groups, including the controls, during the treatment period. However, soft stools were seen more frequently in the higher dose groups. |
| Minimal erosion/ulcer on the tongue in one 1X cat. | One 1X cat had a histologic observation of a minimal erosion/ulcer on the tongue. |
| Conclusion: supports interchangeable use at 2 mg/kg/day injection with 1 mg/kg/day tablets for up to 3 days; findings were injection-site changes, vomiting/soft feces, QT prolongation and oral ulceration. | Treatment-related findings include: injection site changes (transient edema with minimal or mild, subacute/chronic inflammation histologically); vomiting/soft feces, prolongation of the QT interval on ECG evaluation, and oral ulceration. |
| 5X (10 mg/kg) for 3 days: GI signs, elevated creatine kinase, injection-site necrosis/inflammation. | Subcutaneous administration of ONSIOR (robenacoxib) injection at a dose of 10 mg/kg once daily for three days was associated with gastrointestinal (vomiting, soft feces) effects, elevated creatine kinase levels, and local effects at injection sites. |
Effectiveness
Masked, randomized (1:1), multi-center (13 clinics) placebo (saline)-controlled field study (Study 11-001) in cats undergoing ovariohysterectomy or castration plus forelimb onychectomy; 2 mg/kg SC approximately 30 minutes before surgery and once daily for two more days; all cats also received butorphanol and a ring block.; n = 348 cats evaluated for effectiveness (173 ONSIOR, 175 control); 349 for safety; primary endpoint: Treatment success (no rescue pain medication or removal for adverse events) through 52 hours post-surgery.; result: Least-squares mean success 83.5% ONSIOR vs 61.9% saline (139/173 vs 102/175), p = 0.0370; individual pain, behavior and posture scores favored ONSIOR at 1-8 hours.
Effectiveness was evaluated in 348 cats and field safety was evaluated in 349 cats. In the ONSIOR (robenacoxib) injection group, 139 of 173 cats were treatment successes. In the control group, 102 of 175 cats were treatment successes. Based on the statistical analysis, the estimate least squares mean success rates are 83.5% and 61.9% for the ONSIOR (robenacoxib) injection and saline group, respectively.
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| Incision site infection, dehiscence | 9/174 | 0/175 | Adverse Reaction* ONSIOR (robenacoxib) injection N = 174** Placebo Control (saline) N = 175 Incision site infection, dehiscence 9 0 Increased incision site bleeding 6 4 Vomiting 5 0 Decreased appetite 4 3 Lethargy (after day of surgery) 4 2 |
| Increased incision site bleeding | 6/174 | 4/175 | Adverse Reaction* ONSIOR (robenacoxib) injection N = 174** Placebo Control (saline) N = 175 Incision site infection, dehiscence 9 0 Increased incision site bleeding 6 4 Vomiting 5 0 Decreased appetite 4 3 Lethargy (after day of surgery) 4 2 |
| Vomiting | 5/174 | 0/175 | Adverse Reaction* ONSIOR (robenacoxib) injection N = 174** Placebo Control (saline) N = 175 Incision site infection, dehiscence 9 0 Increased incision site bleeding 6 4 Vomiting 5 0 Decreased appetite 4 3 Lethargy (after day of surgery) 4 2 |
| Decreased appetite | 4/174 | 3/175 | Adverse Reaction* ONSIOR (robenacoxib) injection N = 174** Placebo Control (saline) N = 175 Incision site infection, dehiscence 9 0 Increased incision site bleeding 6 4 Vomiting 5 0 Decreased appetite 4 3 Lethargy (after day of surgery) 4 2 |
| Lethargy (after day of surgery) | 4/174 | 2/175 | Adverse Reaction* ONSIOR (robenacoxib) injection N = 174** Placebo Control (saline) N = 175 Incision site infection, dehiscence 9 0 Increased incision site bleeding 6 4 Vomiting 5 0 Decreased appetite 4 3 Lethargy (after day of surgery) 4 2 |
Extraction notes: SPECIES CAVEAT: FOI 934 (NADA 141-443, ONSIOR injection) is approved for CATS, not dogs, although it is listed in the dog catalogue; the n_dogs field therefore holds cat counts. The summary reports no classical PK parameters (half-life, Cmax, etc.) for the injection; only relative-exposure statements from the 37-day interchangeable-use TAS study are captured as 'other'. Target animal safety uses the 37-day 0/1X/2X/3X interchangeable use study; a 5X 3-day injection-site tolerance study (n=24), a 2X comparative injection-site study, a single IV study and a 0/1X/5X pilot interchangeable study (renal tubular changes at 5X) are also summarized. Adverse reactions are from the pivotal field study Table 3 (N=174 ONSIOR incl. one anesthetic-related death, N=175 saline); a second field study (06-0024, n=187) provides additional safety data. The '>' in the indication/dose quotes is the source rendering of the 'at least 4 months' symbol.
Robenacoxib Injection NADA 200-804, Original approval, March 09, 2026; sponsor Cronus Pharma Specialities India Private Ltd.; species: Dogs and cats; foi_id 18230; FDA PDF
Indication
Dogs: control of postoperative pain and inflammation associated with soft tissue surgery in dogs 4 months of age and older, up to a maximum of 3 days (cats: orthopedic surgery, ovariohysterectomy and castration).
Dose regimen
0.91 mg/lb (2 mg/kg), subcutaneous injection, once daily, for a maximum of 3 days, dogs: first dose approximately 45 minutes before surgery; subsequent doses SC or interchanged with oral tablet, maximum 3 total doses over 3 days
The dose of Robenacoxib Injection is 0.91 mg/lb (2 mg/kg) subcutaneously once daily, for a maximum of 3 days.
Effectiveness
Biowaiver: injectable solution with the same active ingredient, concentration and dosage form as RLNAD onsior injection (NADA 141-443); no in vivo bioequivalence study; result: Biowaiver granted
Based on the formulation characteristics of the generic product, Cronus Pharma Specialities India Private Ltd. was granted a biowaiver for the generic product Robenacoxib Injection (robenacoxib).
Extraction notes: Generic ANADA (2026) for dogs and cats; no studies. Effectiveness entry records the biowaiver only. Same 2 mg/kg SC dose labeled for cats.
onsior™ NADA 141-463, Original approval, May 17, 2016; sponsor Elanco US Inc.; species: Dogs; foi_id 948; FDA PDF
Indication
Control of postoperative pain and inflammation associated with soft tissue surgery in dogs (>= 5.5 lbs / 2.5 kg and >= 4 months of age), for up to a maximum of 3 days.
Dose regimen
0.91 mg/lb (2 mg/kg), oral (tablet), once daily, for a maximum of three days; in the field study the first dose was given approximately 45 minutes before surgery
The dose of ONSIOR (robenacoxib) tablets is 0.91 mg/lb (2mg/kg) orally once daily, for a maximum of three days.
Pharmacokinetics
| Parameter | Value | Conditions | Quote |
|---|---|---|---|
| tmax | 1.3 hour (mean) | single oral lactose tablet, 0.5-8 mg/kg, fasted adult Beagles (n=12), dose-titration synovitis study | At all doses, robenacoxib was rapidly absorbed (mean Tmax = 1.3 hour) and rapidly eliminated (harmonic mean terminal half-lives = 0.60 to 0.91 h) when administered as tablets to fasted dogs. |
| half-life | 0.60 to 0.91 h (harmonic mean terminal half-lives) | single oral lactose tablet, 0.5-8 mg/kg, fasted Beagles (n=12) | At all doses, robenacoxib was rapidly absorbed (mean Tmax = 1.3 hour) and rapidly eliminated (harmonic mean terminal half-lives = 0.60 to 0.91 h) when administered as tablets to fasted dogs. |
| tmax | 0.25-0.5 h (median) | single PO or SC dose of approximately 1 mg/kg, four-phase crossover, 12 Beagles | Results showed that robenacoxib was rapidly absorbed after PO and SC administration (median Tmax =0.25-0.5 h). |
| half-life | 0.66 hours (IV), 0.82 hours (SC), 0.86 hours (PO fasted), 1.15 hours (PO fed) | single dose ~1 mg/kg, four-phase crossover, 12 Beagles | Elimination was also shown to be rapid, with mean terminal elimination half-lives (t1/2) of 0.66 hours (IV), 0.82 hours (SC), 0.86 hours (PO, fasted) hours, and 1.15 (PO, fed) hours. |
| bioavailability | 0.84 (PO fasted), 0.62 (PO fed), 0.88 (SC) | absolute bioavailability vs IV, single dose ~1 mg/kg, 12 Beagles | Bioavailability was high at 0.84 (PO, fasted), 0.62 (PO, fed) and 0.88 (SC). |
| other | food effect: Cmax decreased ~14% and AUC decreased ~30% | fed vs fasted oral tablet, ~1 mg/kg, 12 Beagles | Food decreased the mean Cmax and AUC 0-inf by approximately 14% and 30% respectively. |
| auc | 2003 ng*hr/mL (AUC0-inf, average months 0-6) | 2 mg/kg/day oral tablets, 6-month margin-of-safety study, whole blood | On average (months 0 – 6), a 2 mg/kg/day dose resulted in AUC 0-inf values of 2003 ng*hr/mL and Cmax values of 996 ng/mL. |
| cmax | 996 ng/mL (average months 0-6) | 2 mg/kg/day oral tablets, 6-month margin-of-safety study, whole blood | On average (months 0 – 6), a 2 mg/kg/day dose resulted in AUC 0-inf values of 2003 ng*hr/mL and Cmax values of 996 ng/mL. |
Target-animal safety
dose multiples 0.5X (2 mg/kg), 1.5X (6 mg/kg), 2.5X (10 mg/kg); duration 6 months, once daily orally, Days 1-181; animals 4 males/4 females per group; 4 groups (treated and sham control).
Three treatment groups of four male and four female dogs received the test article at 0.5, 1.5, and 2.5 times the maximum target exposure based on the inherent dose bands of the tablet sizes. One additional group of 4 males and 4 females served as the negative control (sham dosing).
| Finding | Quote |
|---|---|
| Soft/mucoid/watery feces more frequent in treated groups than control | Similarly, soft/mucoid/watery feces was noted in all groups, but observed more frequently in the treated groups as compared to the control group. |
| Increased buccal mucosal bleeding time in one 1.5X female and one 2.5X male on Day 178 | Increased BMBTs were observed in one 1.5X female and one 2.5X male on Day 178. |
| Unilateral retinal dysplasia (single retinal fold) in one 2.5X female on Day 177 | One 2.5X female had a normal ophthalmoscopic exam prior to dosing and unilateral retinal dysplasia noted on Day 177. |
| Abnormal neurological examinations on Day 178 in two 0.5X and two 2.5X dogs | On Day 178, abnormal neurological examinations were noted in two 0.5X dogs and two 2.5X dogs. |
| Mean ovarian weights significantly decreased in 1.5X and 2.5X females (no gross/histologic ovarian change) | Mean ovarian weights (all parameters) were statistically significantly decreased in 1.5X and 2.5X group females as compared to the controls. |
| Overall treatment-related findings per FDA conclusion | Treatment-related findings included: abnormal feces, effects on coagulation, retinal changes, neurological abnormalities, ECG changes, gross pathology changes, and organ weight changes. |
| Hepatic toxicity in 3 dogs in a month-long pilot study (1 or 2 mg/kg daily); two euthanized | In a month-long pilot study, 3 dogs that received ONSIOR developed hepatic toxicity. |
Effectiveness
Masked, randomized, vehicle-controlled, multi-center field study at 11 US clinics (GCP); ONSIOR tablets 2 mg/kg orally once daily for 3 days (first dose ~45 min before soft tissue surgery) vs vehicle tablets, 1:1; 239 dogs enrolled; n = 231 evaluated for effectiveness (116 ONSIOR, 115 control); 239 for safety; primary endpoint: Treatment success vs failure (failure = CMPS-SF total pain score > 6, rescue analgesia, or removal for adverse event) over Days 0-2; result: Treatment success 76.72% (89/116) ONSIOR vs 64.35% (74/115) vehicle control, p = 0.0188
Results: Effectiveness was evaluated in 231 dogs and field safety was evaluated in 239 dogs. A statistically significant difference (p-value = 0.0188) in the proportion of treatment successes in the ONSIOR tablets group (76.72%) compared to the control group (64.35%) was observed (Table 1). Table 1. Results by Treatment Group Treatment Group Number of Treatment Successes Number of Treatment Failures Total Number of Evaluable Cases ONSIOR (robenacoxib) tablets 89 (76.72%) 27 (23.28%) 116 Vehicle control 74 (64.35%) 41 (35.65%) 115
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| Diarrhea | 6/119 | 3/120 | N = 119 Control (vehicle tablets minus robenacoxib) N = 120 Diarrhea 6 3 Vomiting 6 4 Decreased appetite 3 0 Weight loss 1 0 Hypotension 1 0 |
| Vomiting | 6/119 | 4/120 | N = 119 Control (vehicle tablets minus robenacoxib) N = 120 Diarrhea 6 3 Vomiting 6 4 Decreased appetite 3 0 Weight loss 1 0 Hypotension 1 0 |
| Decreased appetite | 3/119 | 0/120 | N = 119 Control (vehicle tablets minus robenacoxib) N = 120 Diarrhea 6 3 Vomiting 6 4 Decreased appetite 3 0 Weight loss 1 0 Hypotension 1 0 |
| Weight loss | 1/119 | 0/120 | N = 119 Control (vehicle tablets minus robenacoxib) N = 120 Diarrhea 6 3 Vomiting 6 4 Decreased appetite 3 0 Weight loss 1 0 Hypotension 1 0 |
| Hypotension | 1/119 | 0/120 | N = 119 Control (vehicle tablets minus robenacoxib) N = 120 Diarrhea 6 3 Vomiting 6 4 Decreased appetite 3 0 Weight loss 1 0 Hypotension 1 0 |
Extraction notes: Indication quote truncated before the weight/age limits because the PDF text renders the >= symbols inconsistently. Adverse reaction counts come from Table 2 (soft tissue surgery field study; ONSIOR N=119, control N=120), whose rows survived PDF extraction. TAS n_animals: total 32 dogs (4 groups x 8) is implied but the number 32 is not stated in the text. Dose multiples are relative to 2 mg/kg (0.5X=2, 1.5X=6, 2.5X=10 mg/kg) as given in Table 3.
onsior® injection NADA 141-443, Supplemental approval, November 16, 2016; sponsor Elanco US Inc.; species: Dogs; foi_id 935; FDA PDF
Indication
Control of postoperative pain and inflammation associated with soft tissue surgery in dogs over 4 months of age, for up to a maximum of 3 days (supplement adds injection and interchangeable injection/tablet use).
Dose regimen
0.91 mg/lb (2 mg/kg), subcutaneous injection, once daily, for a maximum of 3 days, first dose approximately 45 minutes before surgery with pre-anesthetic agents; subsequent doses SC or interchanged with oral tablet (dogs at least 5.5 lbs and 4 months), maximum 3 total doses over 3 days
For dogs ≥ 4 months: The dose of onsior™ (robenacoxib) injection is 0.91 mg/lb (2 mg/kg) subcutaneously once daily, for a maximum of 3 days.
Pharmacokinetics
| Parameter | Value | Conditions | Quote |
|---|---|---|---|
| cmax | log-transformed dose-normalized peak concentrations approximately 2.5 to 3.0 ng/mL | toxicokinetics in the interchangeable-use safety study; whole blood sampled 1 and 5 h post-dose; oral 0.5X-3X and SC 2X-6X doses; regardless of dose, route or dosing day | The results show that regardless of the administered dose, route of administration, or dosing day, log transformed values of the peak concentrations were approximately 2.5 to 3.0 ng/mL. |
| other | no accumulation; sequential oral/SC dosing did not alter rate or extent of exposure | interchangeable-use safety study toxicokinetics | However, there were no trends observed that would indicate that the sequential uses of doses/routes altered the rate and extent of robenacoxib exposure. |
| auc | AUC(0-inf) used as pivotal equivalence parameter (values not reported) | two relative bioavailability studies bridging 1% (10 mg/mL) to final 2% (20 mg/mL) formulation | In both studies, the equivalence of the formulations was based on the pivotal parameter AUC(0-inf) (area under the time concentration curve extrapolated to infinity). |
Target-animal safety
dose multiples 0X (control), oral 0.5X/1X/1.5X (7-day) and 1X/2X/3X (3-day) alternating with SC injection 2X (4 mg/kg), SC 4X (8 mg/kg), SC 6X (12 mg/kg); duration 88 days: three 20-day oral/SC dosing cycles (7 d oral low dose, 3 d oral POP dose, 3 d SC injection, 7 d oral low dose) separated by 14-day washouts; animals Thirty-two (4/sex/group).
Study Animals: Thirty-two healthy, 4-month old mongrel dogs, ranging in weight from 11.9 to 19.3 kg at the start of the study were included in the 4 treatment groups (4/sex/group).
| Finding | Quote |
|---|---|
| More injection-site edema and erythema at 4X and 6X than 2X and control | There was a greater number of injection sites with edema at 8 hours post-injection and with erythema at 24, 48, and 72 hours post-injection in 4X and 6X dogs compared to the 2X injection group and control dogs. |
| Injection-site ulcers or fluid-filled cysts: 1 control, 2 (2X), 4 (4X), 4 (6X) dogs | Ulcers or fluid-filled cysts occurred in one control dog, 2 dogs in the 2X injection group, 4 dogs in the 4X injection group, and in 4 dogs in the 6X injection group. |
| Subcutaneous necrosis/degeneration/fibrosis at injection sites at 2X and above | Microscopic findings at dorsoscapular injection sites included minimal to severe subcutaneous necrosis, degeneration, and/or fibrosis with occasional involvement of the underlying panniculus muscle in dogs given ≥ 2X doses. |
| Increased kidney-to-body weight ratios in robenacoxib groups | There was a significant increase in kidney-to-body weight ratios in the groups administered robenacoxib compared to the controls. |
| Vomiting in 2, 3 and 2 dogs of Groups 2, 3 and 4 | Clinical observations included vomiting in 2 dogs in Group 2 (0.5X and 1X oral; 2X injectable), in 3 dogs in Group 3 (1X and 2X oral; 4X injectable), and in 2 dogs in Group 4 (1.5X and 3X oral; 6X injectable). |
| Conclusion: injection site reactions and mild gross/histopathology changes | Significant findings included injection site reactions and mild gross pathology and histopathology changes. |
Effectiveness
Masked, randomized (1:1), multi-center (12 US clinics), placebo (saline)-controlled pivotal field study; 2 mg/kg SC ~45 min before soft tissue surgery then once daily for 2 more days; 317 dogs enrolled; n = 303 evaluated for effectiveness (317 for safety); primary endpoint: treatment success (no rescue analgesia, CMPS-SF total pain score not > 6, not withdrawn for adverse events); result: Treatment success 73.7% (108/151) onsior vs 58.1% (85/152) placebo, p = 0.0055; response-to-touch (p=0.0013) and posture/activity (p=0.0466) scores improved; total pain score not significant
Results: Effectiveness was evaluated in 303 dogs and field safety was evaluated in 317 dogs. A statistically significant difference (p = 0.0055) was observed in the proportion of treatment successes in the onsior™ injection group (73.7%) compared to the placebo group (58.1%) (Table 1).
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| Pain on injection | 18 | 8 | Pain on injection** 18 8 |
| Diarrhea | 15 | 8 | Diarrhea 15 8 |
| Vomiting | 10 | 6 | Vomiting 10 6 |
| Bradycardia | 6 | 1 | Bradycardia 6 1 |
| Decreased appetite | 5 | 2 | Decreased appetite 5 2 |
| Hypotension | 2 | 0 | Hypotension 2 0 |
Extraction notes: Supplemental NADA adding the injectable for dogs (tablets previously approved). Adverse-reaction rows quoted as extracted from Table 2 (column order: term, n onsior injection N=159, n placebo N=158; counts, not percentages). Target animal safety is the 88-day interchangeable-use study (oral tablet and SC injection multiples in 4-month-old mongrels); dose multiples are as expressed by the summary. Additional 3-day injection-site tolerance study at 1X and 5X (2 and 10 mg/kg, Beagles, 4/sex/group) showed transient swelling and minimal myonecrosis; telemetry study showed no cardiovascular effects at 2 and 4 mg/kg IV. PK values are toxicokinetic/bridging statements, not a dedicated PK study.
Reproduce: foi_structured_search(query="robenacoxib") and foi_summary_get(foi_id=...) in dog-geroscience-mcp; dataset foi-summaries-dog (config structured).