Roche Holding's estimate of the peak sales potential for a new experimental lung-cancer drug seems conservative, Citi analysts say in a research note. The Swiss drugmaker on Thursday said the drug, divarasib, met primary and key secondary goals in a late-stage trial of patients with a type of lung cancer who had been previously treated. The positive trial results represent an important first step toward approval of a medicine that has potential to be another blockbuster, according to Citi. Roche has guided for divarasib annual peak sales of 1 billion to 2 billion Swiss francs. Citi estimates the first trial alone could unlock peak sales of 1.4 billion francs, with two additional studies offering room for potential upgrades. (adria.calatayud@wsj.com)