The American Society of Hematology (ASH) annual meeting this past weekend was chock-full of excitement, including an unexpected snowstorm in Atlanta and a slew of game-changing non-Hodgkin lymphoma (NHL) and multiple myeloma trial results for chimeric antigen receptor T-cell therapies (CAR-T). These CAR-T trial results suggest we're fast approaching a major shift in how we battle blood cancer, so let's look at the latest data.

A bit of background

Cancer cells often express proteins on their surface that healthy cells usually don't, and CAR-T therapy that targets those proteins is proving to be an effective way to battle back against blood cancer.

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So far, the FDA has already approved two CAR-T therapies for use in heavily pretreated patients. In August, the FDA approved Novartis' (NYSE:NVS) Kymriah for use in relapsing or refractory acute lymphoblastic leukemia patients. and in October, it OK'd Gilead Sciences' (NASDAQ:GILD) Yescarta for use in tough-to-treat cases of NHL, including diffuse large B-cell lymphoma (DLBCL).

In both cases, these therapies uncloak cancer cells by using an inactivated virus to insert a gene in a patient's T-cells that allows them to bind to CD19, a protein commonly expressed in B-cell cancers.

Competition's heating up

Novartis filed for FDA approval of Kymriah in DLBCL in October, paving the way for a potential showdown with Yescarta sometime in 2018. At the ASH conference, Novartis unveiled six-month results for Kymriah showing a 37% overall response rate and 30% complete response rate in NHL that matches up similarly to Yescarta.

Gilead Sciences countered with its own long-term follow-up data for Yescarta, showing that 82% of patients responded to it, including 58% of patients who achieved a complete response. At a median of 15.4 months post-infusion, 42% of patients were still achieving a response, including 40% of patients who were in complete remission.

Yescarta's durability is impressive, but Juno Therapeutics' (NASDAQ:JUNO) JCAR017 could outmaneuver both Yescarta and Kymirah. JCAR017's results presented at the conference show that it may be as effective as Yescarta and Kymriah, but with far fewer safety risks. A whopping 50% of patients on high-dose JCAR017 were in complete response at the six-month mark, and importantly, far fewer patients suffered from severe-grade cytokine release syndrome and neurotoxicity on JCAR017 than was observed in Yescarta and Kymriah's separate trials.

CAR-T's efficacy isn't limited to NHL, either. At the conference, Celgene (NASDAQ:CELG) and bluebird bio (NASDAQ:BLUE) released updated data from their phase 1 study of bb2121 in heavily pretreated multiple myeloma patients. In that study, 94% of patients responded to bb2121 therapy. The therapy, which targets BCMA, a protein expressed on multiple myeloma cells, delivered a complete response in 56% of patients -- a remarkable proportion because patients participating in the trial had previously failed a median seven prior treatments.

Patients are already enrolling in Celgene and bluebird bio's pivotal study, but it may not have the BCMA market all to itself for long. Juno Therapeutics recently licensed technology from Eli Lilly & Co. and the Fred Hutchinson Cancer Research Center that increases BCMA expression so that its multiple myeloma CAR-T can work better.

Where we go from here

CAR-T therapy is a major advancement in cancer treatment that could save thousands of lives, so investors ought to be paying close attention to the progress these companies are making. Treatment options available to late-stage cancer patients are limited, and real-world use in late-stage patients could clear the way toward CAR-T's use earlier in patient treatment. If so, then these gene therapy companies could end up generating significant sales, because blood cancers such as NHL and multiple myeloma are multibillion-dollar markets.

Todd Campbell owns shares of Celgene and Gilead Sciences. The Motley Fool owns shares of and recommends Bluebird Bio, Celgene, and Gilead Sciences. The Motley Fool recommends Juno Therapeutics. The Motley Fool has a disclosure policy.