Sanofi is stepping up the development of a fixed combination of diabetes treatments Lantus and Lyxumia to sidestep an earlier setback with a similar pen device and take advantage of the delayed U.S. launch of competitor Novo Nordisk's new insulin.

The French drugmaker, which on Thursday reported first-quarter results, said it would provide a fresh timeline for the fixed-combination pen device, currently in mid-stage trials, next month.

Having a product that effectively combines two of its key diabetes treatments would bolster Sanofi's portfolio in a market that is becoming increasingly crowded despite the delayed arrival of a new insulin product by Novo Nordisk.

The Danish drugmaker could see the U.S. launch of Tresiba, its biggest drug hope, delayed until 2018 while it conducts more tests to satisfy regulators, it said on Wednesday.

The development of a variable combination of insulin Lantus and Lyxumia faced a setback earlier this year when Sanofi said the product would not start late-stage trials in 2013 because of problems with the injecting device.

The so-called Fix-Flex device was meant to offer a fixed dose of Lyxumia but would let patients adjust their dose of Lantus, which could help them control blood sugar levels better than each therapy used alone.

Lyxumia is part of a new class of diabetes treatments called GLP-1 analogues which prompt the body to release insulin when a diabetic's blood sugar level climbs too high.