UPDATED: Heard the latest Kite Pharma rumor? CEO says it ain't so

Kite CEO Arie Belldegrun

Kite CEO Arie Belldegrun has a simple message for investors this morning: Relax, we're doing great and remain on track to a regulatory app by the end of 2016.

Last week Kite's shares ($KITE) took a nasty hit as rumors spread around the market that its Phase I/II study for the CAR-T drug KTE-C19 had been put under a cloud after a patient in the early-stage portion of the trial had died. This morning Kite put out the word that there was a death, early on, in the study that investigators had determined was not linked to the drug and that the FDA was comfortable with the trial continuing without any change in protocol.

In a conference call with analysts this morning, Belldegrun set out to counter what he called "misinformation" circulating about the clinical trial, adding that the results so far bode well for their lead program and that no major patent dispute is rearing its head. "We not only remain on track but are excited about the clinical reponses we have seen to date," he noted in the call.

Not only have tumors been melting away in patients, he added, Kite has also been able to demonstrate that their personalized drug can be successfully manufactured and delivered to a number of clinical sites with plans on track to file for an approval by the end of 2016.

Kite's shares immediately bounced back 6% after the company's release hit the wires.

The drug is being studied for aggressive non-Hodgkin's lymphoma among a group of very sick patients who had failed chemo. CAR-T therapies--which reengineered T cells extracted from patients with a chimeric antigen receptor, or CAR, that steers it to cancer cells--are also linked with cytokine release syndrome, a sudden reaction that can prove fatal to some patients, as Juno ($JUNO) and investigators at Memorial Sloan-Kettering found out the hard way last year.

Kite, like Juno, is building a CAR-T that targets the antigen CD19 found on the surface of B-cell lymphomas and leukemias. And the biotech has been closely allied with CAR-T pioneer Steven Rosenberg at the National Cancer Institute. Late last week, Kite filed a patent challenge to Juno's lead drug, JCAR015. But this field is teeming with patent disputes, as Juno knows all too well. Juno filed a challenge against Novartis's work with Penn, settling for a royalty stream to settle the showdown.

These companies have benefited enormously from a rah-rah marketplace in which investors have been competing to back cutting-edge drug developers. But as shares have swelled on the back of blockbuster peak sales estimates, the fetid environment on Wall Street is also a ripe breeding ground for rumors.

Belldegrun also confirmed that the biotech has seen complete responses (in which the cancer is no longer visible) and is now tracking the durability of the response.

 "In agreement with ASH, we have taken this exceptional step of providing an update on the trial in order to address recent misinformation in the market related to our clinical program," says CEO Belldegrun in a statement. "We are on track to transition to the Phase II portion of the trial and plan to present Phase I data at ASH later this year."

- here's the release