Cells die all the time in a controlled manner that’s perfectly normal. But the way cells die matters. Sometimes cell death is violent, sparking inflammation believed to contribute to disease. Quench Bio aims to develop drugs that stop the uncontrolled forms of programmed cell death, potentially halting inflammatory disease. The Cambridge, MA-based startup has come out of stealth with $50 million in Series A financing intended to produce a drug candidate ready for tests in humans in about three years.