I think that there is one thing you missed out and that is that the issue with FX-322 is not that it can't go deep enough, but rather that the current delivery method and/or formula for FX-322 won't go deep enough. Essentially we have already seen that FX-322 can provide full regrowth in the lab work.From what we know so far, three factors play a role in how effective FX-322 will be treating the individual's condition:
- Depth of damage in the cochlea that FX-322 can treat. Right now, it seems to be anything above 8 kHz on the audiogram. This may change with multiple doses, but it still probably won't reach the lowest frequencies from the Phase 2A results.
- Extent of damage in the cochlea. So far, we know that FX-322 can treat moderately severe cases, but it is unknown whether areas of severe or profound losses can be regenerated.
- Type of damage. Hair cell loss or synaptopathy. FX-322 will treat those damaged hair cells, but not those that are healthy but with broken synapses.
Expectations should be that most probably have some degree of wear/damage at all three bullets above. One or all of these conditions may be a factor contributing to their tinnitus.
In terms of outcomes, I don't think anyone should think that FX-322 will alone bring them back to complete silence in a quiet room wearing earplugs. It can't go deep enough, and treat all conditions of wear/tear to be a 'cure' back to a day-zero cochlea.
However, it's likely that FX-322 will give patients much needed relief, even if partial.
Assuming most patients have a combination of the above bullet points, let's say distributed equally between all 3. FX-322 should help restore their frequencies at the higher ranges where hair cells are missing, they should recover some level of hearing bringing them up at least 10 dB. It cannot treat synaptopathy where the hair cells are 'healthy', but likely repair adjacent hair cells that have acquired damage.
So, in this case, and for many of our cases, maybe it won't eliminate the tinnitus and fully restore hearing, but it'll be the first treatment to begin the reversal process.
As it relates to tinnitus, I would imagine many on here would be thrilled if FX-322 perhaps did even one of the following:
- Reduced 1 or more tones / static / hissing / clicking / popping / humming, but left some remaining
- Reduced the overall loudness of all the tinnitus by 25%, 30%, 50%
- Made the tinnitus less annoying on a daily basis, i.e. made it softer
- Reduced reactivity of their tinnitus
What we will see is FX-322 most probably get redosed and/or reformulated to work with wider hearing ranges. Really the issue isn't FX-322 in any way but rather the dosing.