Adar Poonawalla, billionaire CEO of Serum Institute of India (SII), has acquired a 50% stake in Karan Johar's Dharma Productions, one of the country's leading film production houses. The deal, valued at Rs 1000 crore, will see Poonawalla's Serene Production acquire a 50 percent stake in the production house, with Johar retaining the remaining 50 percent.