NovoCure (NSDQ:NVCR) shares are under pressure this morning after the company reported second-quarter losses that exceeded estimates.

The British firm’s losses fell -26.7% to -$15.5 million, or -17¢ per share, on sales growth of 60.3% to $61.5 million for the three months ended June 30.

Analysts on Wall Street were looking for losses of -16¢ per share on sales of $59.5 million.

“In the second quarter of 2018, Novocure demonstrated continued commercial momentum for Optune and continued progress on key clinical development programs,” CEO Asaf Danziger said in prepared remarks. “We delivered record quarterly revenue of $61.5 million, up 60% from the second quarter 2017 and 18% from the first quarter 2018. We continued to see steady growth in prescriptions for patients with newly diagnosed GBM, representing nearly 75% of prescriptions in the second quarter, which we believe is a sign of increasing physician confidence and belief in Optune.

“I am pleased to announce Novocure submitted a local coverage determination reconsideration request to the Medicare DME MACs on June 20. Our decision to file for coverage followed a CMS announcement of new payment rules for DME products earlier in June,” added chairman William Doyle. “We believe the new CMS payment rules reflect the meaningful progress made during our multi-year dialogue with the agency and provide us with a path forward to secure Medicare coverage and payment for Optune.”

NVCR shares slid -4.1% to $35.90 apiece today in mid-morning trading.