** Shares of drugmaker MannKind MNKD.O rise 8.4% to $3.10 premarket
** Co says tie-up with United Therapeutics UTHR.O to develop inhaled version of ralinepag, aimed at pulmonary arterial hypertension, a rare condition that raises blood pressure in lungs
** Co says United Therapeutics pays $5 mln upfront; MannKind eligible for up to $35 mln in milestones and 10% of net sales
** Says United Therapeutics to lead manufacturing and regulatory filings
** Says inhaled drug to be tested first in healthy volunteers, then in PAH patients
** Adds drug, not yet approved, could expand to other lung diseases like pulmonary fibrosis
** As of last close, stock down ~50% YTD
(Reporting by Sahil Pandey in Bengaluru)
((Sahil.Pandey@thomsonreuters.com))