Halozyme Therapeutics said today it temporarily halted enrolling and dosing patients in its ongoing Study 202, a Phase II trial assessing its experimental drug PEGPH20 in patients with pancreatic cancer.
The halt had been recommended by the trial’s independent data monitoring committee, which is assessing study data to learn why patients treated with PEGPH20 as well as nab-paclitaxel and gemcitabine saw a higher rate of blood clots and other thromboembolic events compared with patients treated with nab-paclitaxel and gemcitabine alone.
"We will be providing additional information to the DMC as quickly as possible so they can complete their assessment and we can determine next steps,” Helen Torley, M.B. Ch. B., M.R.C.P., Halozyme’s president and CEO, said in a statement, adding: “Patient safety is our first priority.”
The statement did not say when Halozyme expects to resume enrolling and dosing patients in Study 202. The study is one of two Phase II trials for PEGPH20; the other, SWOG, also aims to assess the drug for pancreatic cancer.
PEGPH20 is an investigational PEGylated form of Halozyme’s FDA-approved recombinant human hyaluronidase rHuPH20 (marketed as Hylenex®), designed to dramatically increases the half-life of the compound in the blood and allow for intravenous administration.
Halozyme is no stranger to clinical-stage disappointment. Back in August, a Phase II trial was halted into the company’s combination immune deficiency therapy of rHuPH20 with a subcutaneous version of ViroPharma’s Cinryze, the latter already approved for angioedema. ViroPharma ended the study after talks with FDA’s Center for Biologics Evaluation and Research, as a precaution following the emergence of what Halozyme said was “an unexpected incidence and titer of non-neutralizing anti-rHuPH20 antibodies” in an unspecified number of patients with the combo.
And in 2012, FDA rejected an application for another immunodeficiency disease combo therapy that combined rHuPH20 with Baxter’s subcutaneous Immune Globulin 10%—a combination Baxter had hoped to market as HyQ. Again, FDA cited the potential effect of non-neutralizing antibodies generated against rHuPH20 on reproduction and fertility.
The PEGPH20 trial halt came just two days after Halozyme named a new vp of oncology, Sunil Joshi, who previously worked at Onyx Pharmaceuticals—where Dr. Torley was COO before taking the day-to-day reins at Halozyme four months ago.