Israeli drug developer Protalix Biotherapeutics Inc. (NYSE MKT:PLX; TASE: PLX) saw its share price plunge 15% on Wall Street yesterday, giving it a market cap of $137 million, after publishing phase II clinical trial results of alidornase alfa for the treatment of Cystic Fibrosis (CF). The treatment, it is hoped, would be more effective than its rival Roche's Pulmozyme product.
Protalix said that 16 patients were enrolled in the study, all of whom completed the study, and deemed the trial "positive."
However, writing in "TheStreet," analyst Adam Feuerstein who specializes in small and early stage drug development companies said, "Protalix BioTherapeutics is based in Israel so perhaps "positive" means something different over there than it does in the US. Maybe something got lost in translation. When final results of a tiny clinical trial come back looking worse than the interim results announced three months ago, "positive" is not the first adjective I'd reach for."
Protalix reported that the 16 cystic fibrosis patients treated for four weeks with alidornase alfa improved lung function by 3.4 points from baseline. However, Feuerstein pointed out that in January, an interim look based on the first 13 patients enrolled into the study tagged alidornase alfa with a lung function improvement of 4.1 points.
Feuerstein wrote, "So, Protalix analyzed data on three additional patients between January and today and the alidornase alfa lung function score went down. Protalix says this is a positive result, but the data got worse."
Alidornase alfa is a plant cell-expressed, chemically-modified recombinant DNase enzyme resistant to inhibition by actin, which the Company has specifically designed to enhance the enzyme’s efficacy in CF patients.
There are possible explanations for the poorer end results than intermediary results. It could be that in the first examination the Pulmozyme had not been fully flushed out of the patient's bodies and sop the results represent the combined influence of both Protalix's drug and the Pulmozyme. It could be that the first 13 patients improved more dramatically than the 3 that were subsequently added. It could be that the patients took the drug regularly earlier in the trial and became less rigorous in the later stages. Alternatively, it may be that the drug has more effect when first taken and that this diminishes with time.
Protalix will need to follow it up to discover if it should be encouraged or disappointed by these results.
Published by Globes [online], Israel business news - www.globes-online.com - on April 13, 2017
© Copyright of Globes Publisher Itonut (1983) Ltd. 2017