Novartis, Roche and GlaxoSmithKline all returned for the series B round, having already supported a $22m series A round for the Harvard spinout in 2015.

Macrolide Pharmaceuticals, a US-based antibiotics developer spun out from Harvard University, has closed a $20m series B round co-led by pharmaceutical firms Novartis, Roche and GlaxoSmithKline.

The three corporates invested through their respective corporate venturing vehicles Novartis Venture Fund, Roche Ventures and SR One. They co-led the round with Advent Life Sciences and Gurnet Point Capital.

Founded in 2015, Macrolide is developing antibiotics to address serious infections caused by resistant Gram-negative pathogens – bacteria that have become resistant to existing…