A new drug that blocks cancer from repairing its DNA has stopped tumors from growing in more than half of the patients in a clinical trial.
The 21 people treated had a number of advanced cancers, including breast, colon and prostate tumors, and had been treated with other drugs.
The drug, currently known under the code BAY1895344, stopped tumor growth in eight patients and shrank tumors in another four, according to a journal published Cancer discovery on Tuesday.
The researchers said the early-stage study, led by the Institute for Cancer Research (ICR) and the Royal Marsden NHS Foundation Trust, highlights the potential of a new class of drugs known as ATR inhibitors that block a key molecule which they are involved in repairing DNA.
Professor Paul Workman, Executive Director of the ICR, said: “It is exciting to see a new class of precision medicine show such prospects in early studies.
“At the ICR, we pioneered the treatment of cancer by exploiting the weaknesses that tumors often have in repairing their DNA. I hope that later studies will show that this new class of ATR inhibitors can be used against cancer Having defective systems can prove effective for DNA repair.
“And we’re very keen to see if they can prevent tumors from developing resistance to another important class of drugs, the PARP inhibitors, which work in a similar way.”
Further studies are ongoing with the hope that the drug could be developed into a new targeted treatment for patients with cancer who have certain defects in DNA repair.
Study leader Professor Johann de Bono, Professor of Experimental Cancer Medicine at the ICR and Consultant Medical Oncologist with the Royal Marsden Trust, said: “Our new study shows that this promising new treatment is safe and can benefit some patients even in very advanced cancers.
“The new drug, currently only known under the code BAY1895344, blocks a molecule called ATR, which is involved in repairing DNA.
“It appears to be particularly effective in patients whose tumors have defects in a gene called ATM, which means their ability to repair DNA is already weakened – suggesting that this could become a new form of targeted treatment.
“There is great promise that patients will respond in such an early study and we look forward to further clinical trials to test the drug’s effectiveness.”