Since 2006, the March of Dimes has led the campaign for federal approval of a prenatal drug now marketed by KV Pharmaceutical Co., allowing the area drug company to use the charity's good name and logo in promotions.

During those same years, KV and its Massachusetts partner, Hologic Inc., donated nearly $1.5 million to the nonprofit, the nation's leading philanthropy focusing on the health of pregnant women and babies.

On Friday, that cozy relationship exploded at the height of tension over the $1,500 price tag KV had slapped on the drug after winning the Food and Drug Administration's blessing - a price a March of Dimes official recently called outrageous. The organization severed its corporate relationship with KV, even as the company tried in vain to appease an onslaught of critics by slashing its price by 55 percent, to $690.

KV's new price is still more than 45 times more than the $10 to $15 price that specialty pharmacies typically charge for a virtually identical compound, 17P, which doctors have prescribed without FDA approval in recent years to prevent preterm births. A full course of treatment of KV's drug would still exceed $10,000 in a typical case.