The global gene therapy market is forecast to grow at an astounding compound annual growth rate of 33.3% over the next six straight years, according to a report by Allied Market Research. This incredible growth spurt is being driven by a number of technological breakthroughs that have opened up novel ways to address diseases with few available treatment options at present. 

Bellicum Pharmaceuticals (NASDAQ:BLCM) and bluebird bio. (NASDAQ:BLUE), for instance, are two clinical-stage biotechs angling to become top players in this red-hot emerging market. Armed with this insight, let's consider which company is better equipped to take advantage of this enormous opportunity going forward. 

A cartoon illustration showing a DNA molecule.

Image source: Getty Images.

The case for Bellicum

Houston-based Bellicum is developing cell-based cancer therapies that incorporate a unique molecular switching mechanism. This proprietary molecular switch is designed to trigger the infused therapeutic cells to either increase in number in order to boost a response, or undergo programmed cell death if a severe adverse reaction occurs. No FDA-approved adoptive cell therapy currently offers such finite control after infusion, and dangerous side effects generally have to be treated with powerful immunosuppressants. 

While this novel approach should produce a safer and more potent form of adoptive cell therapy in theory, the company was recently stung by a clinical hold by the Food and Drug Administration (FDA) for its lead product candidate, BPX-501. BPX-501 is being developed initially as a possible treatment for graft-versus-host-disease in patients undergoing hematopoietic stem cell transplants. 

The hold reportedly stems from three patients in an ongoing trial experiencing an abnormal form of brain function known as encephalopathy. Bellicum, in response, requested a change in study protocols last month in an attempt to get BPX-501 back on track in the United States. Now, the good news is that this clinical hold did not impact the drug's ongoing pivotal trials in Europe, which are expected to pave the way for a regulatory filing in the back half of 2019. 

Apart from BPX-501, the company is also developing a next-generation chimeric antigen receptor T cell (CAR-T) therapy for patients with pancreatic cancer. This product candidate dubbed "BPX-601 GoCAR-T" is currently in an early stage trial, where it's reportedly showing some early signs of efficacy in this particularly hard-to-treat malignancy. As pancreatic cancer remains a largely untapped market, BPX-601 could prove to be a key value driver for the company moving forward.  

The main drawback with this cutting-edge biotech is that the company has yet to forge any major partnerships to shore up its balance sheet. As a result, Bellicum may be forced to tap the public markets for funds before the year is up. 

The case for bluebird

Bluebird bio has been one of Wall Street's favorite gene therapy stocks over the last two years, thanks to the company's impressive progress across its broad late-stage clinical pipeline. Last January, for instance, the biotech rolled out a road map for how it plans on filing regulatory applications for three high-value product candidates by 2020

Turning to the specifics, bluebird's gene therapy, LentiGlobin, is on track to become a potential functional cure for the rare blood disorder known as transfusion-dependent beta thalassemia major. The company is therefore hoping to have the therapy under regulatory review in Europe in the second half of 2018.

Next up, bluebird has also been making steady progress with its other lead gene therapy, Lenti-D, as a treatment for a rare X-linked metabolic disorder known as cerebral adrenoleukodystrophy. Bluebird expects to release Lenti-D's top-line data this year. If positive, the company plans on filing for regulatory approval next year. 

Lastly, bluebird and its development partner Celgene Corp. (NASDAQ:CELG) could end up filing for approval for their breakthrough multiple myeloma CAR-T therapy, bb2121, within the next year as well. This game-changing cell therapy, after all, reportedly produced a stunning 94% response rate in heavily pretreated multiple myeloma patients in an early stage study. 

As an added bonus, bluebird has an exceptionally strong cash position due to its partnerships with biotech heavyweights like Celgene. Bluebird exited the most recent quarter with an astonishing $1.6 billion in cash, cash equivalents, and marketable securities. So the risk of dilution is minimal at this point. 

Which gene therapy company is the better buy?

In this head to head match up, bluebird is the obvious winner, and it's not even all that close. Bluebird's pipeline is much closer to producing multiple regulatory filings within the next two years, and the company shouldn't need to dilute shareholders via a secondary offering to do so. Bellicum, on the other hand, will need to raise additional cash to advance BPX-501's pivotal trials in Europe, and keep the rest of its pipeline on track.  

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.