Cancer cell–selective in vivo Treating cancer with light activated, antibody-dye conjugates by Amol Kapoor and Teddy Leithead Makoto Mitsunaga, Mikako Ogawa, Nobuyuki Kosaka, Lauren Rosenblum, Peter L Choyke & Hisataka Kobayashi near infrared photoimmunotherapy targeting specific membrane molecules

Overview Cancer treatments focus on minimal side effects with maximal cancer cell death Photoimmunotherapy (PIT) IR700 + Trastuzumab and Panitumumab. IR700 toxic only when bound Specific antibodies could allow for the treatment of many cancers

Background Photo Dynamic Therapy (PDT) Excited photosensitizers -> Singlet oxygen Singlet oxygen -> cell death Immunotherapy  Uses the body's defense mechanism  Antibodies

Introduction PIT = PDT + Immunotherapy PDT -> Toxicity Immunotherapy -> Specificity PIT makes a strong therapy because of low healthy cell death

Review PDT PIT Immunotherapy

Results-In Vitro 73%78% 3T3-HER2 cells and A431 HER1 cells Significant cell death from both conjugates Irradiation -> Cell death

Results-In Vitro (Cont.) Tra-IR toxic only when bound Cellular uptake is unnecessary

Results-In Vivo

Results-In Vivo (Cont.) Tumor size Life span Rats w/ treatment Repeated treatment of drug led to tumor free survival at over four months

Discussion IR700 is hydrophilic and has high extinction coefficient More effective than other photosensitizers. mAb-1700 is highly selective Conjugate is non-toxic when unbound from Kobayashi: Mechanism of action and FDA trials

Conclusion/Summary A target specific PIT was developed NIR light irradiation + the conjugate leads to large cancer cell death Highly effective in vitro and in vivo

Future Research For clinical trials, mAb-IR700’s toxicity mechanism must be understood Researchers must confirm a minimal threat to non- cancerous cells Unique mAbs -> PIT applied to multiple cancers for diagnosis and treatment

Why It Matters Completely Revolutionizes Field Potentially makes other drugs obsolete The likelihood of one of us getting cancer is high. Perfected, this offers a way to stop all cancers.