Sanofi is making a push back into oncology led by multiple myeloma drug Sarclisa, its first wholly-owned cancer medicine in a decade. But now the company’s forthcoming U.K. rollout has hit a snag thanks to cost watchdogs.

In new draft guidance, the National Institute for Health and Care Excellence (NICE) said that just how much benefit Sarclisa provides to patients versus the standard care is unknown, and that cost-effectiveness estimates for the drug are outside of recommended ranges. 

Sanofi’s Sarclisa scored a recommendation from Europe’s Committee for Medicinal Products for Human Use back in March in combo with Bristol Myers Squibb’s Pomalyst and dexamethasone (pom-dex) for patients with relapsed and refractory multiple myeloma who have received at least two prior therapies. The European Commission approved the drug last week.

For its part, Sanofi is positioning the med as a fourth-line treatment, NICE says, to be used after three prior therapies. As it stands, current fourth-line treatment includes pom-dex alone or Johnson & Johnson’s Darzalex, provided through the Cancer Drugs Fund. 

Sarclisa delays disease progression and extends patients’ lives compared with pom-dex alone, NICE says, but a trial comparing the treatments isn’t finished yet?—and that means Sarclisa’s overall benefit is unknown. Plus, cost-effectiveness estimates “are much higher than what NICE normally considers a cost-effective use of NHS resources,” the draft guidance said.

The drug’s list price isn’t yet public. NICE’s decision isn’t final and is subject to review and consultation. 

Meanwhile, Sanofi’s Sarclisa won an FDA approval in March, and it’s already chasing another. The drug recently posted positive data in combo with Amgen’s Kyprolis, setting it up to potentially challenge Darzalex.