Genitope says phase 3 data for MyVax similar to phase 2 findings; Kaplan-Meier curve not as expected

By Jennifer Lanning Drey

Eugene, Ore., Aug. 17 - Genitope Corp. said patients who relapsed in the phase 3 clinical trial of MyVax did so quickly and received little benefit from the drug, while a significant body of patients continued in the trial without relapse.

"As we look at the data, the thing we focus on is that, as well as we can tell, we seem to be replicating the phenomenon that we experienced not only in our phase 2 trial but that has been observed in other trials at Stanford and the National Cancer Institute with this drug," said Dan W. Denney Jr., chief executive officer of Genitope, during a company conference call held Thursday.

MyVax is a potential personalized immunotherapy being tested in patients with previously untreated follicular lymphoma. The clinical trial involved 287 randomized patients, which included patients who received MyVax and patients who received a controlled substance.

On Aug. 1, Genitope filed an 8-K report with the Securities and Exchange Commission showing a curve of the Kaplan-Meier estimate of the probability of progression free survival, generated using the blinded data for all 287 randomized patients. The selected data was cut at 18 months from randomization.

The data used to generate the curve showed that 158 patients had documented progression dates and 129 patients had no documentation of progression as of each patient's last documented clinical follow-up, according to a filing made with the SEC on Wednesday.

Of the 158 patients with documented progression dates, 28 had progression dates at least 18 months after the randomization dates, according to the filing.

When put into the Kaplan-Meier chart, the data show the two curves separating later than expected, Denney said.

Denney said Thursday that it is possible that one of the two groups in the trial has not reached the median.

He also said, "It is within realm of possibility that if the drug is what we think it is, it could be quite some time before the treated group reaches the median, if that's the reason for the numbers as they exist."

When asked by an analyst about what needs to happen in order for the trial to meet its statistical endpoint, Denney said that if the drug is driving the result, it will only require time.

"If we're replicating what we've seen in phase 2 in the past, we're going to drive a very, very vigorous result. It just takes time to get to that result," he said.

Denney also said that the Kaplan-Meier curve for the phase 2 clinical trial of MyVax changed between 2003 and 2005 to become more compelling.

"That's just the way these trials work. The more patients you get out in time on essentially a flat line Kaplan-Meier, the more impressive it looks. The more separation you get from the non-progressing patients to the progressing patients, the clearer the result is. It's that flat line result that has a lot of people excited and optimistic about this drug," Denney said.

On July 27, Genitope announced that its independent Data Safety Monitoring Board had reviewed the second planned interim analysis of data for the efficacy in the trial and recommended that the trial continue as planned.

The company said it expects to present immune response data from the trial in the spring of 2007. The phase 3 clinical trial is expected to conclude late in 2007, Denney said.

Genitope is a Redwood City, Calif., biotechnology company focused on treating cancer.

© 2015 Prospect News.
All content on this website is protected by copyright law in the U.S. and elsewhere. For the use of the person downloading only.
Redistribution and copying are prohibited by law without written permission in advance from Prospect News.
Redistribution or copying includes e-mailing, printing multiple copies or any other form of reproduction.