Light-activated guided missile

A spin out from Imperial College London is developing new light-activated therapies for a range of cancers and microbial infections.

PhotoBiotics, a spin out from Imperial College London, is developing photodynamic therapy (PDT), a method of killing diseased cells using light and photosensitising drugs.

At the moment, PDT is a niche treatment for superficial cancers and Age-related Macular Degeneration, the most common form of blindness among over 50’s in the Western World.

Existing PDT treatment begins with the injection of a photosensitising drug into a patient that spreads throughout the body and accumulates slightly in tumours. A non-heating laser light is then shone onto the tumour. This light activates the drug, rapidly producing a potent and toxic form of oxygen, which kills the target. The cytotoxic form of oxygen produced can be likened to ‘photochemical bleach’. There is little scarring, few side effects and no drug resistance.

However, this approach has several severe drawbacks, including lack of specificity, low penetration of light into the tissues, low potency, acute and painful skin photosensitivity, and extended treatment periods.

PhotoBiotics has come up with the idea of targeted PDT, using specially designed carriers and new photosensitising drugs that are tuned to respond to tissue penetrating red light.

‘We’ve combined targeting and new photosensitising drugs to make a kind of light-activated guided missile,’ says Dr Mahendra Deonarain, PhotoBiotics’ technical director of biochemistry.

‘An antibody carries the sensitisers to the target, for example a cancer cell or microbe, where they are subsequently activated by the laser. Targeted PDT has much higher specificity for target tissues, higher light penetration, high potency, very little photosensitivity and it requires fewer treatments overall. In other words, it’s a technology with all the advantages of existing PDT but none of the disadvantages,’ says Dr. Deonarain.

Imperial Innovations, the technology transfer office of Imperial College, was instrumental in recognising the commercial potential of Photobiotics’ technology. Imperial Innovations initiated the intellectual property protection, worked with the inventors to prepare the case for initial seed funding, identified a consultant to help prepare the business plan, led the company formation process and continues to provide active support to the company as it grows and develops.

‘We obtained a seed funding round of £500K over a year ago from the (Imperial College) University Challenge Fund and business angels Helms-Brown. We have made some really excellent progress and demonstrated proof of principle. Now it’s time to begin the search for more funding so we can reach other significant milestones and get our first drug to Phase I/II trials,’ he added.

‘However it is a tough funding environment out there at the moment. The financial markets are on the floor and a small biotech company like ours needs all the help it can get to survive and keep going,’ he concluded.