Shares of Juno Therapeutics Inc. (JUNO) and Kite Pharma Inc. (KITE) tumbled on Tuesday after the rivals presented the results of their respective CAR T-cell therapies to treat non-Hodgkins lymphoma. (For more, see Kite Pharma Initiates Trial for DLBCL.)

Kite achieved a 76% objective response rate (ORR) and a 47% complete response (CR), while Juno fared achieved an overall response rate of 80% and a complete response rate of 60%. (See also: Novartis, Kite In CAR-T Cancer Drug Race.)

ORR is the proportion of patients with tumor size reduction of a predefined amount and for a minimum time period, while a complete response indicates a potential cure, meaning all detectable tumor has disappeared.

The CAR-T therapy involves extracting immune system cells out of the patient’s body, which are fabricated through a genetic process to identify cancer, and later infused back in the patient’s body to fight the cancer. (For more, see Will These Cancer Therapies Pay Off?)

However, reports of severe side effects have dominated discussions about CAR-T technology.

Cautious Market Reaction

Despite optimistic trial results, there is skepticism about the timelines by which these drugs could hit the market.

Juno expects its JCAR-017 drug to be available "as early as 2018," while analysts stretch it to 2019 or beyond.

Kite’s KTE-C19 remains ahead of Juno, whose interim results in September were positive. (For more, see Positive Data Boosts Kite Pharma Shares.)

However, Juno has placed a hold on its lead drug candidate JCAR015 for acute lymphoblastic leukemia trials following the deaths of two patients last month. (For more, see Juno Tanks 33% After 2 Study Patients Die.) It led to more uncertainty around its other two CAR-T therapies, JCAR-014 and JCAR-017.

Kite Pharma closed at $51.10 per share, down 4.7% on December 6, while Juno stock lost 4%, to close at $19.60. (See also: New CAR-T Cell Therapy May Cure Tumors.)

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