A different anti-BCMA CAR-T tested by the National Cancer Institute demonstrated a single complete response among 12 patients that lasted for 17 weeks before relapase but also caused significant toxicity. Looking ahead, Bluebird intends to enroll additional multiple myeloma patients into the phase I study and explore higher doses of BB2121. (Two patients have already been treated with an 800 million-cell dose but haven't been followed long enough to determine response.) Barring any problems and assuming an optimal dose is found, Bluebird believes it can advance BB2121 directly into a pivotal clinical trial, which if successful, could lead to marketing approval. The regulatory path of BB2121 is basically the same used by Kite Pharma ( KITE ) for its CAR-T to treat lymphoma patients. Bluebird is in charge of completing the ongoing phase I study. Under their collaboration agreement, Celgene would take over development of BB2121 to conduct the pivotal study. Adam Feuerstein writes regularly for TheStreet.