Table 2.
Studies using an ONA:ABO conversion factor ≤1:3.
| Authors | Study | Authors‘ Conclusions |
|---|---|---|
| Marion et al., 1995 [16] | Open study of 74 pts, 37 with idiopathic blepharospasm and 37 with hemifacial spasm switched from ONA to ABO 1:3 ratio | Correct ONA:ABO conversion ratio is 1:3 |
| Whurr et al., 1995 [17] | Open study 16 pts with spasmodic dysphonia | Correct conversion ratio ONA:ABO is 1:3 |
| Sampaio et al., 1997 [24] | RCT 91 pts with blepharospasm and hemifacial conversion ratio ONA:ABO 1:4 | ABO groups, in the conditions applied in the included trials, tend to have a higher efficacy, longer duration of action, and higher frequency of adverse reactions; A 1:4 ONA:ABO ratio is too high |
| Odergren et al., 1998 [19] | RCT of 73 patients with CD ABO (n = 38) vs. ONA (n = 35) Conversion ratio 3:1 | Efficacy and tolerability equivalent with an ABO:ONA ratio of 3:1 |
| Tidswell and King, 2001 [26] | Open study 35 pts with CD switched from ONA to ABO conversion ratio 1:5 | 1:5 is too high; proposed 1:3. The authors report with insufficient efficacy and duration of action with ONA, suggesting that an ONA:ABO conversion ratio of 1:3 is more appropriate |
| Ranoux et al., 2002 [27] | RCT, cross-over 54 pts with CD Conversion ratio ABO:ONA 3:1 or 4:1 | Both with a ratio 3:1 and 4:1, they observed a higher and longer clinical efficacy of ABO vs. ONA with a higher risk of side effects; This suggests that the 3:1 conversion ratio is more appropriate |
| Poewe, 2002 [29] | RCT 54 pts with CD Conversion ratio ABO:ONA 3:1 or 4:1 | The author comment on Ranoux′s paper confirming its conclusions: the ABO:ONA conversion ratio should not be >3:1 |
| Sampaio et al., 2004 [30] | Systematic review Blepharospasm CD/hemifacial spasm | The ABO:ONA 4:1 ratio is clearly too high, and even with a ratio of 3:1, ABO continues to have a longer duration of action |
| Wohlfarth et al., 2008 [21] | 79 healthy volunteers | ABO:ONA ratio 3:1 too high Equivalence ratio of 1.57:1 (95% CI: 0.77–3.2) To investigate the 2:1 ratio |
| Van den Berg et al., 1998 [31] | Open study 10 pts with DC 10 pts with blepharospasm switched to ABO from ONA Conversion ratio 2.36:1 | Dose equivalence ABO:ONA = 2.36:1 |
| Rosales et al., 2006 [32] | Review of preclinical and clinical studies | Appropriate conversion ratio ABO:ONA equal to 2.5–3:1 or lower |
| Wohlfarth et al., 2009 [33] | Review of clinical studies | Dose equivalence ABO:ONA 2–2.5:1. Conversion ratios ≥4:1 should be considered overdosed for ABO |
| Shin et al., 2009 [20] | Open study of 48 pts with blepharospasm switched to ABO from ONA; conversion ratio 2.5:1 | Clinical and safety equivalence |
| Mohammadi et al., (2009) [22] | Retrospective study 137 patients with spasticity, conversion ratio ABO:ONA 2 to 3:1 | Clinical and safety equivalence |
| Kollewe et al., 2010 [18] | 97 pts with hemifacial spasm treated with ABO or ONA | Clinical and safety equivalence at conversion ratio of 2.56:1 |
| Karen-Capelovitch et al., 2010 [34] | 16 pts with cerebral spastic palsy treated with ONA 12 U/kg or ABO 30 U/kg (ratio 1:2.5) | Clinical equivalence |
| Rystedt et al., 2012 [23] | Retrospective study of 75 pts with CD | 1.7:1 is the more appropriate ABO:ONA conversion ratio |
| Brockmann et al., 2012 [35] | Retrospective study of 51 pts with Cervical CD | Dose equivalence ABO:ONA 3:1; Conversion ratios ≥ of 4:1 or superior should be considered overdosed for ABO |
| Kollewe et al., 2014 [36] | Retrospective study of 288 patients with blepharospasm Conversion ratio ONA:ABO 1:2.3 | No significant differences with regard to safety or efficacy |
| Rystedt et al., 2015 [37] | RCT compares ONA and ABO in two different dose conversion ratios (1:3 and 1:1.7) when diluted to the same concentration (100 U/mL) for 46 patients with CD | No significant differences were seen between ONA and ABO (1:1.7); At week 12, a statistically significant difference in efficacy between ONA and ABO (1:3) was observed, suggesting a shorter duration of effect for ONA when this ratio (low dose) was used |
| Yun, 2015 [38] | 103 patients with CD in a two-period crossover RCT | With regard to safety and efficacy, ABO was not inferior to ONA in patients with CD at a conversion factor of 2.5:1 |
ABO = abobotulinumtoxinA, CD = cervical dystonia; CI = confidence interval; ONA = onabotulinumtoxin A; RCT = randomized controlled trial.