While our motivation is simple, the science that goes into creating a lung surfactant that resembles the real thing is a little more complicated.
Highest level of SP-B to phospholipid ratio makes Infasurf® (calfactant) less affected by inhibitory proteins.
Plasma proteins can leak into alveolar space and inhibit surfactant function. Infasurf® (calfactant) was the most resistant to the three surfactant-inhibiting proteins studied.1
Comparison of SP-B in Exogenous Surfactants* SP-B Content as a % of Phospholipids
|Native Lung Surfactant (calf)||Infasurf® (calfactant)||Curosurf® (poractant alfa)||Survanta® (beractant)|
- Infasurf® (calfactant) contains the highest levels of SP-B as a percentage of total phospholipids, same as native calf lung surfactant (0.74%)1,2,5
- Lab bench testing has shown surfactant films high in SP-B may be less susceptible to inhibitory proteins1
Protein Inhibition Profile for Surfactants1 Adsorption and Surface Tension Lowering
|Infasurf® (calfactant)||Unaffected||Unaffected||Moderately Affected|
|Curosurf® (poractant alfa)||Severely Affected||Severely Affected||Severely Affected|
|Survanta® (beractant)||Severely Affected||Severely Affected||Severely Affected|
- Even when exposed to high levels of inhibitory proteins, Infasurf® (calfactant) still rapidly adsorbs and lowers surface tension to near zero
- Adsorption and surface tension lowering properties of the other surfactants are inhibited by plasma proteins at low concentrations
* Chart does not imply clinical superiority of Infasurf® (calfactant).
While clinical studies have demonstrated that SP-B is an essential element, they have not determined the minimum SP-B to phospholipid ratio required for optimal surfactant efficacy.
There are no prospective, randomized clinical trials comparing Infasurf® and Curosurf® with respect to safety or efficacy.