French artificial heart maker Carmat (FRA:CXT) said yesterday that it launched a pivotal trial of its bioprosthetic artificial heart, hoping to use the data to win CE Mark approval in the European Union.

The news sent CXT shares up 6.5% to $41.18 (€36.92) apiece today in late-day trading in Frankfurt. Carmat’s shares are off 9.8% so far this year, valuing the company at about $230.9 million (€207 million). Velizy Villacoublay-based Carmat posted a net loss of -$19.5 million (-€17.5 million) last year.

Yesterday the company said the 1st implantation in the 20-patient trial “has been carried out in accordance with the authorizations obtained from the ANSM (French national agency for the safety of medicines and health products) and CPP (patient protection committee).” Carmat said it would release general progress updates but not patient-specific data.

Carmat’s 1st transplant patient, a 76-year-old man, died in March 2014, 2½ months after his operation. A 2nd patient died in May 2015, 9 months after receiving the transplant. Carmat said his death was due to a technical problem with the controls of the motor. A 3rd patient was fitted with the device in April 2015.

“The 4th patient will undergo surgery once everything has been analyzed and the engineers are able to tell me, ‘Go ahead, we’ve checked everything, everything’s fixed, the new device won’t [encounter] the same issues as the previous ones,’” Dr. Alain Carpentier, who invented the device, said at the time.