Protalix talks up CF prospects in interim phase 2 data drop

Protalix BioTherapeutics has posted an interim look at data from a small phase 2 trial of its cystic fibrosis candidate. The Israeli biotech used the update to talk up areas in which the data compare favorably to results generated by Vertex Pharmaceuticals’ CFTR modulator on its path to approval.

Scant data from the phase 2 trial of alidornase alfa are publicly available as it stands, but the little Protalix has shared paint the drug in a favorable light.

The 13 patients evaluated to date have experienced a mean absolute increase in ppFEV1 of 4.1 points. Protalix compared this result to that generated by “a commercially available small molecule CFTR modulator” in its registration study. That commercially available drug triggered an increase in ppFEV1 of 2.5 points. Vertex’s Kalydeco and Orkambi—a combination based on Kalydeco—are the only FDA-approved CFTR modulators.

Protalix also noted the widespread use of Genentech’s Pulmozyme among participants in the trial of the commercially-available CFTR modulator. In contrast, subjects in the Protalix trial stopped taking Pulmozyme in the two weeks before starting treatment with alidornase alfa.

To Protalix, the data are evidence its DNase enzyme, which is expressed by plant cells and designed to be resistant to inhibition by actin, has the potential to take on the incumbent in cystic fibrosis and other challengers for the market.

“The preliminary efficacy results of alidornase alfa are very encouraging, even when compared to past trials of approved drugs for the treatment of CF. Although the study was performed on a small number of patients, the data is very encouraging since it shows clinically meaningful results,” Hadassah University Hospital’s Eitan Kerem said in a statement.

Other data discussed in the interim update come from analysis of sputum, the DNA content of which fell 60% compared to baseline. Protalix also reported a 90% drop in sputa viscoelasticity.

The question now is whether the apparent potential of alidornase alfa will hold up following the publication of more data from the study. Results from all 15 patients enrolled in the trial are due this quarter.