April 6 (Reuters) - Bristol Myers Squibb (BMY.N), opens new tab said on Saturday data from late-stage studies of its experimental schizophrenia drug showed it helped reduce symptoms of the disorder without the common side effect of weight gain tied to other antipsychotics.The drugmaker gained access to the treatment, called KarXT, through its $14 billion deal to buy Karuna Therapeutics last year. Long-term data of the drug reinforced the findings that were seen in previous short-term studies, the company sa ...