The investigators' general impression on the injection procedure was quoted as 'difficult' in 1.1% of Ostenil and in 2.6% of Synvisc injections (p-value = 0.09).
A higher incidence of cases were discontinued for sufficient efficacy with Ostenil, and for lack of sufficient efficacy with Synvisc, without statistically significant differences between the groups (p=0.58 and p=044). The incidence of cases discontinued for adverse events was significantly higher in the Synvisc group (p=0.001).
In the main group and sub-groups of patients, the assessment of efficacy by the investigators was significantly better for Ostenil than for Synvisc (p<0.001), when the possible influence of other variables were not taken into account. With both treatment devices confounded, the effect of treatment was better in younger patients (p<0.03), was better with more injections per cycle (<0.005), tended to be better in males and in patients with lesser severity of osteoarthritis symptoms. When covariates were used in efficacy analysis, with a special correction for the number of injections (different for each treatment device), efficacy was found to be significantly better for Ostenil (p=0.04) in the sub-group "after+first cycle", while it tended to be better in the other groups (p<0.07). When Ostenil injections were limited to three, as for Synvisc standard treatment, efficacy was still better (p=0.03, without use of covariates).
The investigator's judgement of tolerability per ttt-cycle was 'good' in 98% of the cases treated with Ostenil and in 90% of the cases treated with Synvisc (p=0.001).
For the safety, 60 adverse events (AEs) were found in 50 Case Report Forms (49 patients). The corresponding symptoms amounted to 68. Out of the 60 AEs, 27 were considered as adverse device reactions (ADRs) with a causality quoted as "probably related" to the treatment. The incidences of AEs and ADRs were statistically greater in the Synvisc group than in the Ostenil group : Synvisc AE 7.7%, ADR 5.1%, Ostenil AE 2.1%, ADR 0.7 % of all injections (p<0.0001 for both AEs and ADRs). When expressed as percentage of patients, ADRs were found in 2.8% of patients treated with Ostenil and in 20.8% of patients treated with Synvisc (p<0.0001). The intensity of the ADRs was statistically more severe in the Synvisc group (p=0.03) and the incidence of cases discontinued for adverse events is lower (p=0.001) in the Ostenil group.
It is concluded that Ostenil under the conditions of this study is more efficient than Synvisc, or at least as efficient if covariates such as age, gender, number of injections and severity are taken into account. The incidence of ADRs and their intensity is significantly lower with Ostenil.