One problem I envisage is strict enrolment criteria and will likely require participants to have profound hearing loss for enrollment for phase 1 at least.
Yes, this is my concern too. The general idea seems to be that people who have least to lose and most to gain are the most favorable trial candidates. I think this is common practice in other trials as well for other kind of disorders or diseases.
I hope the companies widen the scope of their target market not just to cover 'profound' hearing loss but also other ear/balance related conditions + tinnitus.
I doubt it's possible to widen the scope of indications that much. They might as well just call it
TMPCAD - The Magic Pill to Cure All Diseases. I might be wrong. But
tinnitus is thought to be a secondary symptom of hearing loss. The best way to test that hypothesis is to create a treatment for hearing loss and get it out to patients who have both hearing loss and tinnitus.
I fear if the regenerative treatments cover profound hearing loss only, it will be a bitch to get any treatment that comes to market for off label use for tinnitus.
How do you normally get prescription drugs without a prescription? You can ask the same supplier. Even if you somehow get the drug you would still need a trained professional to administer it for the best outcome, not just some herbalist Joe from downtown.
But I can feel your frustration! I would hate it too if there was a treatment for "profound" hearing loss, but not for moderate or mild hearing loss. It's as if these are all different indications! Well, they are not! They are all the same indication, namely "hearing loss". It's just different levels of severity. I don't think they can compare this to formal medical classifications like Type I diabetes, and Type II diabetes. No way! It's just audiologists who found the need to "classify" people with
profound, severe, moderate and
mild hearing loss by looking at their "gold standard" audiograms.
Take
sensorineural hearing loss and
conductive hearing loss! Now that's two different medical classifications! But all levels of sensorineural hearing loss, i.e. "hearing loss", have one thing in common: damage to the sensory and/or neural cells of the cochlea.
I think the investigators might target people with severe or profound hearing loss during the trials. But once they come out of the trials and prepare for market release they will undoubtedly market the product for all levels of (sensorineural) "hearing loss".
I agree though that they should include people with moderate or mild hearing loss. For Trial 1, I would assume they will target the "profound" group in small numbers, then profound and "severe" for Trial 2 and in larger numbers, then profound, severe and "moderate" and in even larger numbers for Trial 3. Then lastly profound, severe, moderate and "mild" group in the post-trial sales phase.
They are not clear about the level of loss, but my reading is that they might not restrict the treatment/trials to severe/profound loss. (It's just marketing, but their web page on hearing loss has people with earbuds and at concerts. These don't necessarily lead to severe or profound deafness.)
These are important questions that no one seems to ask. No one except the patients with hearing loss who are waiting and hoping for a cure. You don't see the researchers and journalists discuss "hearing loss" in these terms. As I stated above, I think they might include only people with profound hearing loss in the early clinical trial. But I expect them to expand that scope as they progress to the next phases that follow.
Correct me if I'm wrong, but my understanding is that
profound, severe, moderate and
mild hearing loss is not part of the medical classification. My impression is that this 4 level "classification" is something that audiologists came up with while looking at their precious audiograms. It may also play an important role with insurance companies when you make a disability claim. Maybe you want to sue your employer for work related hearing loss. This might be an example where the level of disability might play an important role.
Under ICD-9 system, sensorineural hearing loss is classified as 389.1. This in turn can be classified in greater detail.
- 389.10 Sensorineural hearing loss, unspecified
- 389.11 Sensory hearing loss, bilateral
- 389.12 Neural hearing loss, bilateral
- 389.13 Neural hearing loss, unilateral
- 389.14 Central hearing loss
- 389.15 Sensorineural hearing loss, unilateral
- 389.16 Sensorineural hearing loss, asymmetrical
- 389.17 Sensory hearing loss, unilateral
- 389.18 Sensorineural hearing loss, bilateral
This is how sensorineural hearing loss indications are described under 389.1.
- "Due to lesions of the cochlea and the auditory division of the eighth cranial nerve; problem of cellular dysfunction rather than airborne conduction
- "Hearing loss caused by a problem in the inner ear or auditory nerve. A sensorineural loss often affects a person's ability to hear some frequencies more than others. This means that sounds may be appear distorted, even with the use of a hearing aid. Sensorineural losses can range from mild to profound"
- "Hearing loss resulting from damage to the cochlea and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the auditory nerve and its connections in the brainstem"
Source:
http://www.icd9data.com/2015/Volume1/320-389/380-389/389/389.1.htm
There is mention of "mild to profound" as a "range" of sensorineural hearing loss at the root entry of the code system. But there is no mention of this "range" in the detailed description of each of the underlying codes.
So the disease or disability is classified by type, rather than severity in the medical classification systems. However, severity might be used in disability and insurance claims systems. But we are discussing the medical part of things. So in this context at least, "profound" unilateral, sensory hearing loss is the same condition as "mild" unilateral, sensory hearing loss. Any treatment will have to match the condition or disease, not its severity.
The bigger question isn't coverage for tinnitus, it is whether insurance companies would pay to restore high frequency hearing loss with otherwise normal hearing or to restore "mild" hearing loss that doesn't require hearing aid. At least in the US, hearing aids aren't typically covered by insurance so it seems like it might be a stretch to get reimbursement for regeneration in a case where a hearing aid is not required.
You have now touched on a key issue!
If you have "mild" unilateral, sensory hearing loss, do you then qualify as 389.17? So you have sensory lesions but because your audiologist classified it as "mild" you may not be able to get reimbursement for the treatment from the insurance company.
I predict that the access to treatment in the first years will be a struggle between patients, insurance companies and audiologists. From the looks of it, audiologists might have the final and decisive word. Because people that don't have sensory lesions severe enough won't get reimbursement from their insurance company for the treatment. They will have to pay out of their own pockets. I'm sure many will do just that. But this is another reason that we need a treatment on the market as soon as possible. So that many more people may afford it in the coming years, because with time, and with availability of a successful treatment the insurance companies will have to change their policy.
It would be very useful to have much more sophisticated testing, and it is entirely possible that the need to be reimbursed might drive broader use of high frequency hearing tests or other advanced (or perhaps not net used) testing if the results of such tests resulted in insurance reimbursement.
Yeah... they have to prove you have that high frequency sensory cell lesion. How can you prove that with a standard "golden standard" hearing test that goes only up to 8000 Hz? I totally understand what you're saying, and I agree. A successful treatment for hearing loss would be completely game changing, not only for patients. It would also shake up the medical establishment! They would have to come up with a better "golden standard" for auditory assessments.
Currently OAE and ABR tests are a good complement to the standard audiogram, but they are rarely ever used. They are almost exclusively used on newborn babies, and on patients that are almost deaf and will undergo cochlear implant operation. They will have to start using OAE and ABR more extensively, until we get better diagnostic tools.