Zila’s OraTest Oral Cancer Screen Lags At CDER; ZTC Clears Premarket Hurdle

Zila Medical bypasses lengthy CDER regulatory path, gains 510(k) clearance for ZTC tolonium chloride compound at CDRH. Oral cancer test’s identical compound, OraTest, remains under CDER review.

Zila Medical's strategy of seeking an adjunctive claim for its ZTC tolonium chloride compound enabled a relatively quick device review, CEO Douglas Burkett said in a Feb. 7 conference call.

Announced Feb. 2, ZTC gained clearance as an adjunct to the previously 510(k)-cleared ViziLite . ZTC, which is used to evaluate oral lesions, is the same chemical compound - made with the identical ingredients and manufacturing processes - as the firm's OraTest , which has been under review at FDA's Center for Drug Evaluation & Research for a number of years.

The tolonium chloride compound marks problematic lesions by changing color upon contact. ZTC is intended for use following an initial exam using the ViziLite low-energy light system, which makes abnormal tissues appear white.

Although FDA had classified OraTest as a drug based on its chemical make-up, ZTC was assigned to the Center for Devices & Radiological Health because its predicate, ViziLite, is a device.

"There are many advantages to moving to approval through the device branch as opposed to the drug branch at FDA," Burkett said.

OraTest went before the Oncology Drugs Advisory Committee in 1999, receiving a unanimous vote against approval for the new drug application. Subsequently, a clinical trial on recurring oral cancer patients was conducted, Zila says.

Additionally, CDER is evaluating a trial protocol to support an NDA for the compound's use on high-risk patients with precancerous, cancerous and severe dysplasic lesions. OraTest now is being reviewed by CDER's Dermatological & Dental Drugs Group.

Burkett acknowledged the CDRH path has imposed certain limits on ZTC's commercialization. "We've had to be careful what we've been able to even try to get here in terms of marketing claims on the device side in order to facilitate device approval."

He explained: "The more aggressive the claims...the more likely you are to cross out of devices and back over to the drug side."

In clinical trials, ZTC marked 100% of lesions later found to be cancer or dysplasia, Burkett reported.

Although the current indication is for oral cancer, Burkett suggested that ZTC may be effective "in marking lesions on other parts of the body, such as the cervix, in the case of cervical cancer."

"This might allow us to expand the market for ZTC," and the oral cancer "approval provides us with a new plat­form for which we can conduct other clinical studies," the exec added.

Zila likely will consider CDRH when pursuing future indications. "There may be opportunities both in drugs and devices for...other applications and the device opportun­ities are presumably going to be the shorter route," Burkett noted.

The firm is planning a fall launch for ZTC based on "research and experience [that] tell us it is difficult to launch a new product in the late spring and summer months." The launch may coincide with the meeting of the American Dental Association.

Because of the late entry, Burkett said that he does not expect a meaningful impact on earnings for the remainder of fiscal 2005, other than minor "precommercial­ization efforts." The firm's fiscal 2006 begins Aug. 1.

Although Zila partnered with Trylon Corp. to bring ZTC to market, it plans to market the diagnostic itself, as it currently does for its other products, including dietary supplements Ester-E and Ester-C .

Future applications also will be brought to market using a partner, Burkett said. "This approval through the device branch opens up a less expensive route. [However,] it would still remain our goal to partner for those applications where it is outside the oral cavity."

According to Burkett, roughly 75 mil. people visit a dentist annually in the U.S. ViziLite and ZTC, however, currently have marketing clearance for anyone "who is over 40 years old or anyone who smokes or drinks alcohol," he said.

ViziLite sells for roughly $20, the exec said, but ZTC "will be more expensive than that." The two systems will not be bundled, enabling dentists with ViziLite in inventory to purchase ZTC as a stand-alone.

[Editors' note: This story originally appeared in the Feb. 14, 2005 issue of "The Gray Sheet."]

- Kathleen Connors Michael