TOKYO, June 8 (Reuters) - Japan’s Nikkei stock index ended lower on Tuesday, dragged down by losses in heavyweights, including Softbank Group, while a rally in drugmakers lifted the broader Topix index. Nikkei inched down 0.2% to close at 28,963.56, while the Topix edged up 0.1% at 1,962.65. Most heavyweights fell, with global start-up investor SoftBank Group slipping 1.6%, while air-conditioner maker Daikin Industries down 3.1%. Sumitomo Metal Mining was the biggest loser dropping 4.1% decline. Eisai Co was the biggest gainer, jumping 19.4%, to its daily upper limit, after U.S. regulators on Monday approved a drug jointly developed by the drugmaker and Biogen Inc’s as the first treatment to attack a likely cause of Alzheimer’s disease. Daiichi Sankyo and Astellas Pharma also rose 4.9% and 0.8%, respectively. Leading gains among subindexes on the Topix, pharma and sea transport subindex rose 2.8% each. Air transport and land transport rose 1.6% and 0.9%, respectively. “The news on Eisai has given a boost to its peers as well as the overall market,” said Shoichi Arisawa, general manager of the investment research department at IwaiCosmo Securities. “Investors are also scooping up Japanese shares which lagged behind their global peers, as prospects of an economic recovery has brightened amid a rollout of COVID-19 vaccines.” An early gain for the Nikkei was snuffed out as investors were cautious ahead of the U.S. consumer price index (CPI) report this week and the U.S. central bank’s meeting next week, market participants said. There were 105 decliners on the Nikkei index against 110 advancers, with 10 stocks unchanged. (Reporting by Junko Fujita and Kevin Buckland; Editing by Rashmi Aich) Our Standards: The Thomson Reuters Trust Principles.