Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety data reflect exposure to ustekinumab in 3117 adult subjects with plaque psoriasis, including 2414 exposed for at least 6 months, 1855 exposed for at least one year, 1653 exposed for at least two years, 1569 exposed for at least three years, 1482 exposed for at least four years and 838 exposed for at least five years.

Table 5 summarizes the adverse reactions that occurred at a rate of at least 1% with higher rates in the ustekinumab groups during the placebo-controlled period of Ps STUDY 1 and Ps STUDY 2

Adverse reactions that occurred at rates less than 1% in the controlled period of Ps STUDIES 1 and 2 through week 12 included: cellulitis, herpes zoster, diverticulitis and certain injection site reactions (pain, swelling, pruritus, induration, hemorrhage, bruising, and irritation).

One case of PRES occurred during adult plaque psoriasis clinical trials

In the placebo-controlled period of clinical trials of subjects with plaque psoriasis (average follow-up of 12.6 weeks for placebo-treated subjects and 13.4 weeks for ustekinumab-treated subjects), 27% of ustekinumab-treated subjects reported infections (1.39 per patient-years of follow-up) compared with 24% of placebo-treated subjects (1.21 per patient-years of follow-up). Serious infections occurred in 0.3% of ustekinumab-treated subjects (0.01 per patient-years of follow-up) and in 0.4% of placebo-treated subjects (0.02 per patient-years of follow-up)

In the controlled and non-controlled portions of plaque psoriasis clinical trials (median follow-up of 3.2 years), representing 8998 patient-years of exposure, 72.3% of ustekinumab-treated subjects reported infections (0.87 per patient-years of follow-up). Serious infections were reported in 2.8% of subjects (0.01 per patient-years of follow-up).

In the controlled and non-controlled portions of plaque psoriasis clinical trials (median follow-up of 3.2 years, representing 8998 patient-years of exposure), 1.7% of ustekinumab-treated subjects reported malignancies excluding non-melanoma skin cancers (0.60 per hundred patient-years of follow-up). Non-melanoma skin cancer was reported in 1.5% of ustekinumab-treated subjects (0.52 per hundred patient-years of follow-up)

The safety of ustekinumab was assessed in two trials of pediatric subjects with moderate to severe plaque psoriasis. Ps STUDY 3 evaluated safety for up to 60 weeks in 110 pediatric subjects 12 to 17 years old. Ps STUDY 4 evaluated safety for up to 56 weeks in 44 pediatric subjects 6 to 11 years old. The safety profile in pediatric subjects was similar to the safety profile from trials in adults with plaque psoriasis.

The safety of ustekinumab was assessed in 927 subjects in two randomized, double-blind, placebo-controlled trials in adults with active psoriatic arthritis (PsA). The overall safety profile of ustekinumab in subjects with PsA was consistent with the safety profile seen in adult psoriasis clinical trials. A higher incidence of arthralgia, nausea, and dental infections was observed in ustekinumab-treated subjects when compared with placebo- treated subjects (3% vs. 1% for arthralgia and 3% vs. 1% for nausea; 1% vs. 0.6% for dental infections) in the placebo-controlled portions of the PsA clinical trials.

The safety of ustekinumab was assessed in 1407 subjects with moderately to severely active Crohn's disease (Crohn's Disease Activity Index [CDAI] greater than or equal to 220 and less than or equal to 450) in three randomized, double-blind, placebo-controlled, parallel-group, multicenter trials. These 1407 subjects included 40 subjects who received a prior investigational intravenous ustekinumab formulation but were not included in the efficacy analyses. In trials CD-1 and CD-2 there were 470 subjects who received ustekinumab 6 mg/kg as a weight-based single intravenous induction dose and 466 who received placebo

The overall safety profile of ustekinumab was consistent with the safety profile seen in the adult psoriasis and psoriatic arthritis clinical trials. Common adverse reactions in trials CD-1 and CD-2 and in trial CD-3 are listed in Table 6 and Table 7, respectively.

Other less common adverse reactions reported in subjects in trials CD-1 and CD-2 included asthenia (1% vs 0.4%), acne (1% vs 0.4%), and pruritus (2% vs 0.4%).

In subjects with Crohn's disease, serious or other clinically significant infections included anal abscess, gastroenteritis, and pneumonia. In addition, listeria meningitis and ophthalmic herpes zoster were reported in one patient each

With up to one year of treatment in the Crohn's disease clinical trials, 0.2% of ustekinumab-treated subjects (0.36 events per hundred patient-years) and 0.2% of placebo-treated subjects (0.58 events per hundred patient-years) developed non- melanoma skin cancer. Malignancies other than non-melanoma skin cancers occurred in 0.2% of ustekinumab-treated subjects (0.27 events per hundred patient-years) and in none of the placebo-treated subjects.

In CD trials, two subjects reported hypersensitivity reactions following ustekinumab administration. One patient experienced signs and symptoms consistent with anaphylaxis (tightness of the throat, shortness of breath, and flushing) after a single subcutaneous administration (0.1% of subjects receiving subcutaneous ustekinumab). In addition, one subject experienced signs and symptoms consistent with or related to a hypersensitivity reaction (chest discomfort, flushing, urticaria, and increased body temperature) after the initial intravenous ustekinumab dose (0.08% of subjects receiving intravenous ustekinumab). These subjects were treated with oral antihistamines or corticosteroids and in both cases symptoms resolved within an hour.

The safety of ustekinumab was evaluated in two randomized, double-blind, placebo- controlled clinical trials (UC-1 [IV induction] and UC-2 [SC maintenance]) in 960 adult subjects with moderately to severely active ulcerative colitis

In subjects with ulcerative colitis, serious or other clinically significant infections included gastroenteritis and pneumonia. In addition, listeriosis and ophthalmic herpes zoster were reported in one subject each

With up to one year of treatment in the ulcerative colitis clinical trials, 0.4% of ustekinumab-treated subjects (0.48 events per hundred patient-years) and 0.0% of placebo-treated subjects (0.00 events per hundred patient-years) developed non- melanoma skin cancer. Malignancies other than non-melanoma skin cancers occurred in 0.5% of ustekinumab-treated subjects (0.64 events per hundred patient-years) and 0.2% of placebo-treated subjects (0.40 events per hundred patient-years).

The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of ustekinumab or of other ustekinumab products.

Approximately 6 to 12.4% of subjects treated with ustekinumab in plaque psoriasis and psoriatic arthritis clinical trials developed antibodies to ustekinumab, which were generally low-titer. In plaque psoriasis clinical trials, antibodies to ustekinumab were associated with reduced or undetectable serum ustekinumab concentrations and reduced efficacy. In plaque psoriasis trials, the majority of subjects who were positive for antibodies to ustekinumab had neutralizing antibodies.

In Crohn's disease and ulcerative colitis clinical trials, 2.9% and 4.6% of subjects, respectively, developed antibodies to ustekinumab when treated with ustekinumab for approximately one year. No apparent association between the development of antibodies to ustekinumab and the development of injection site reactions was seen.

The following adverse reactions have been reported during post-approval use of ustekinumab products. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to ustekinumab product exposure.