Welcoming Pixium Vision’s PRIMA retinal prosthesis to Science

Max Hodak, CEO, Science Corporation. Published April 25, 2024.

Science has agreed to acquire assets from Pixium Vision SA, including three ongoing clinical trials in late-stage macular degeneration, following acceptance of its bid by the French commercial court and French Foreign Direct Investment approval.

Key content:

• PRIMA is, to Hodak’s knowledge, the first really definitive demonstration of “form vision” (the ability to recognize visual elements as parts of a larger object) in humans. Earlier devices produced phosphenes; patients could reason through piecing lines into letters but not intuitively string them into words or sentences.
• Targeting two cell types in the retina: retinal ganglion cells (RGCs — output layer; tightest information bottleneck; complex encoding; readily targetable by AAV gene therapy) vs. bipolar cells (first synapse past photoreceptors; simpler, bitmapped-like representations; not true neurons; targeted with a subretinal device).
• The Pixium device works as “a tiny solar panel with hundreds of tiny little sub-panels”: infrared light hitting a pixel excites a small electric field above the illuminated point. Glasses with a camera and small laser projector project an image onto the implant, exciting remaining bipolar cells and getting information back into the signal chain to the brain.
• Pixium had three ongoing clinical trials with the PRIMA device, including a 38-patient pivotal study in Europe (NCT04676854).
• PRIMA came out of a concept originally developed by Prof. Daniel Palanker at Stanford; Science will collaborate with him on next generations.
• Science also had an optogenetic gene therapy program and the Science Lightsheet; it is too early to know which approach (electrical or optogenetic) will work best in the retina long term. Science now has best-in-class therapies targeting both the RGCs and bipolars.