P
PhotoThera
Medical device company developing laser energy therapies for the neurology market
About PhotoThera
PhotoThera, Inc. was a medical device company established in 1997 by Jackson Streeter, M.D., and headquartered in Carlsbad, California. The firm concentrated on developing laser energy therapies for the neurology market, with a primary focus on treating acute ischemic stroke. Dr. Streeter, a former U.S. Navy flight surgeon, founded the company after becoming intrigued by the therapeutic potential of infrared energy, aiming to create a viable treatment for stroke, a leading cause of death and disability. His background in medicine and experience as a Top Gun staff instructor provided a unique foundation for tackling complex medical challenges.
The company's core technology was Transcranial Laser Therapy (TLT), a non-invasive treatment designed to be administered within 24 hours of stroke onset. The product, known as the NeuroThera System, consisted of a console, a fiber optic cable, and a handheld probe used to deliver near-infrared (NIR) laser energy at a wavelength of 808 nm to predetermined sites on the scalp. The proposed mechanism involved stimulating mitochondria in brain cells exposed to hypoxic conditions, potentially preserving tissue in the ischemic penumbra. The entire procedure was designed to take approximately two to three hours.
PhotoThera's business model was centered on research, clinical development, and eventual commercialization of its TLT technology, contingent on regulatory approval. The company successfully raised significant capital to fund its extensive clinical trials, securing a total of $80.5 million over several funding rounds. This included a $30.5 million Series C round in 2006 and a substantial $50 million Series D round in 2009, led by investors such as Warburg Pincus, Delphi Ventures, and De Novo Ventures. These funds were crucial for financing a series of large-scale, double-blind, sham-controlled clinical trials, including NEST-1, NEST-2, and the planned NEST-3, to establish the safety and effectiveness of the NeuroThera System. Early trials showed encouraging safety data and suggested potential benefits for certain stroke patient cohorts. However, a definitive Phase III trial (NEST-3) was terminated after a futility analysis of over 500 patients found no measurable neuroprotective effect compared to a sham procedure. Following these results, financial support was withdrawn, and PhotoThera, Inc. was dissolved.
Source: Dealroom company dataAt a glance
- Status
- Operational
- Founded
- 1997
- Headquarters
- Carlsbad, United States
- Open positions
- None listed
- Dealroom signal
- 21.0/100
- Industry
- Health
- Sub-industry
- BioTechnology, Medical Devices
- Sector
- Biotech & Life Sciences, Biotechnology, Neurology, Biotech and Pharma, Hard Tech, DT and LS, science-based
- Client focus
- b2b
Knowledge graph
More headlines
Funding history
Company financing events and reported valuations.
| Deal type | Date | Amount | Valuation | Investors | Source |
|---|---|---|---|---|---|
| SERIES DOther financing | May 2009 | $50M | $200M | DeNovo Ventures · The Vertical Group · Delphi Ventures · Warburg Pincus | — |
| SERIES COther financing | Apr 2006 | $31M | $122M | The Vertical Group · Hamilton BioVentures · Warburg Pincus · DeNovo Ventures | — |
Growth signals
Latest recorded traffic for PhotoThera is 230 monthly website visits, up 130% over the last three months.
Similar companies
Company identity and context are open; selected comparison metrics preview what is available on the platform.
Investments and acquisitions
Recent portfolio relationships for companies that also act as investors or acquirers.
Investors
From Dealroom's funding and investor records, grouped by the round each investor first entered.
Series A7 investors entered at this stage
- HVHamilton Technology Ventures
California Technology Ventures- DVDeNovo Ventures
- SCSolstice Capital
The Vertical Group- HBHamilton BioVentures
Delphi Ventures
Series B and later1 investor entered at this stage
Source: Dealroom Talent Intelligence.
Global footprint
Market sentiment
An AI-synthesised read of the highest-engagement posts about PhotoThera on X, ranked by likes and reposts, corporate channels excluded.
Reading the room on X — pulling top posts and synthesizing themes…
Source: X recent search ranked by engagement (likes + retweets) · Synthesis by Claude · Cached for 1 hour
See PhotoThera’s full profile on Dealroom
Request a free trial to see the complete deal history, financials, people graph and growth signals.
Takes under a minute. Already use Dealroom? Log in.








