Halozyme jumps, then lands, on positive late-stage pancreatic cancer data

Halozyme saw its shares boosted by nearly 60% premarket on news that it had hit its endpoints in a midstage test of its candidate in the notoriously difficult-to-treat pancreatic cancer therapy area, but its shares rally did not last long.

In the phase 2 trial posted this morning, the San Diego biotech showed a statistically significant improvement in progression-free survival (PFS) in all evaluable patients, as well as in patients with high levels of hyaluronan, in what could also be a potential new biomarker in the disease.

The biotech also hit its endpoint of reducing thromboembolic events, although all of these data are only from a subset of patients, and the actual details were thin on the ground. 

However, the market still reacted positively given the miserable failures seen in treating this condition over the years, where any positive will be grasped and held tight. But this did not last long, as the company's gains went down to just 8% in normal hours trading this morning after its initial 60% bounce on the posting of the release

These topline results come from a combined analysis of Stages 1 and 2, as well as Stage 2 alone, of its HALO 202 study using its med PEGPH20 in combination with Celgene’s cancer drug Abraxane (nab-paclitaxel) and Lilly’s Gemzar (gemcitabine) in stage IV pancreas cancer patients.

Among its early data release, the overall study population showed a statistically significant increase in PFS in patients with high levels of hyaluronan when using the cocktail of meds when compared to HA-High patients receiving Abraxane and Gemzar alone.

The second stage of the study, which completed enrollment nearly a year ago, showed a 91% improvement in median PFS for HA-High patients in the PEGPH20 arm, 8.6 months compared to 4.5 months in the control arm, and achieved its primary endpoint by reducing the rate of thromboembolic events in the PEGPH20 arm, the company said in the release.

More data however were not given across the rest of the test, and some are concerned about what this shows about how well this cocktail works. Its ongoing phase 3 trial will likely give a better reading of its level of efficacy down the line, but some commentators were distinctly unimpressed. 

The biotech, however, was keen to chalk this up as a big win, despite the concerns from bio-Twitter and others. "These findings confirm our confidence in the development of PEGPH20 in this difficult to treat cancer," said Dr. Helen Torley, president and CEO, in the statement. "We are pleased by the overall consistency of both the efficacy and safety data which are supportive of our ongoing phase 3 clinical trial, HALO 301, currently underway at more than 160 sites worldwide."