An FDA advisory panel narrowly recommended approval last week for the Kamra Inlay for presbyopia made by Medtronic (NYSE:MDT)-backed AcuFocus, voting that the device is effective but splitting over its safety.
The FDA’s 8-member Ophthalmic Devices panel voted 7-1 that Kamra is effective, but was evenly split on the question of safety, with chairman Dr. Neil Bressler breaking the tie to make the vote 5-4 against (the chairman only votes to break ties). The panel was also divided on the question of whether the Kamra Inlay’s benefits outweigh the risks, with 4 panelists voting yes, 3 no and 1 abstaining.
In the U.S., reading glasses are currently the most common choice for treating presbyopia. But many patients are troubled by having to use reading glasses for close vision. The Kamra device would provide an alternative for them, a company spokesman said.
Although the panel ultimately recommended that the FDA grant pre-market approval for the Kamra device, some members questioned the validity of the clinical data submitted by AcuFocus.
"We’re asking does it seem valid, and I think we’re hearing some people are very bothered by it and others say, well, there’s some validity to it, but then there’s some limitations because of it," Bressler said.
Kamra failed to meet a targeted adverse event rate of less than or equal to 5% at 12 months and also failed to meet a goal of less than or equal to 1% per single adverse event type, the FDA noted. The inlay needed to be surgically removed in 3% of patients in the pivotal trial and from 6% in the confirmatory trial.
"I’m used to hypothesis testing and clinical trials where you decide ahead of time what your criteria are and did you meet them or not," said panelist Dr. William Swanson. "I’d say they gave us the criteria and they failed to meet them, so by the criteria they gave us, their data show it’s not safe in the way they define safety."
AcuFocus acknowledged safety risks associated with the implant, including persistent best corrected distance visual acuity loss of 0.6% at 12 months, though the majority of this is transient in nature, the company said. There was also a low rate of steroid-related intraocular pressure increases, decrease in monocular contrast sensitivity function within normal ranges, no change in binocular CS function from baseline, minimal increases in postoperative symptoms reported on patient reported outcomes, and early surgical endothelial cell density loss with minimal estimated long-term loss.
Despite Kamra’s failure to meet safety criteria in the trial, nearly half of the panel voted Kamra safe because they felt the safety incidents during the trial were minor.
Why Kamra, not reading glasses?
The Kamra implant is placed under a corneal flap, where it reduces the aperture of the eye and increases the depth of focus to improve near vision. According to AcuFocus, Kamra poses little or no risk to distance visual acuity and, unlike current surgical options, the lens is removable and sustains its effect over time.
There are no devices approved in the U.S. for implantation in the cornea to treat presbyopia via a mechanism other than refractive correction, the FDA noted in background materials released ahead of the advisory panel meeting.
Kamra has been on the market outside the U.S. since 2009, with approval in 50 countries; AcuFocus estimates that nearly 20,000 of the devices have been implanted. The company said it’s received 815 complaints, or 4.1%, from that group, including 362 removals (1.8%; 44.4% of complaints), 28 other secondary surgical interventions (0.1%) and 425 packaging complaints (2.1%), the FDA noted.
People who have presbyopia but good distance vision are a challenge, because they have no history of spectacle use and are resistant to using contact lenses or glasses. They’re also reluctant to compromise their distance vision for a gain in near vision.
"A good surgical correction of presbyopia remains a significant unmet need," AcuFocus said during the June 6 panel meeting. Data show that the Kamra inlay consistently improves near vision by increasing depth of focus while maintaining distance vision, sustained through 3 years, the company said.
And data from the total study population "strongly support a favorable risk benefit profile," according to AcuFocus.
"As long as people understand the benefits that they get out of this product and the potential downsides, I think its been demonstrated that it’s an effective product for a good percentage of the people that it’s intended for," industry representative Michael Pfleger said.
The company did a "good job" explaining what the safety risks are, he added. "So what they give up versus what they’re getting, I think, is a benefit that people should be able to make their own decision on."
AcuFocus raised $65 million in November 2011 in a round led by Cowen Healthcare Royalty Partners. Prior backers Medtronic (NYSE:MDT), Bausch & Lomb, Accuitive Medical Ventures, Versant Ventures, Carlyle Group and SV Life Sciences also participated.
"[AcuFocus has] great science. It hits an age group that’s post-Lasik, pre-cataract, so there really isn’t a treatment other than glasses," Versant operating partner James Mazzo told MassDevice.com last year. "We’re approved and selling in Japan, we’re approved in many countries across the globe. We just got approval in Canada and Mexico, so we have a very strong global footprint, but obviously the U.S. is a critical phase for this company and takes it obviously to the next level."