Gene therapy offers a functional cure, which does not directly eliminate the virus, but it primes a patient’s body to be able to control and kill the infection without the use of ART. Companies taking this approach include: Sangamo Bioscience with 3 HIV studies in phase I/II and 2 in phase I, Calimmune with a study in phase I/II, and Takara Bio with a study in phase I.13
Sangamo’s gene therapy known as zinc finger SB-728 in clinical trials has shown that after a single injection, this therapy is capable of killing off the virus, restoring immune function, and eliminating the need for ART. 9 out of 9 participants, 36 months after stopping ART, maintained a decrease in HIV reservoirs. At 16 weeks, 3 out of 7 participants had a 1 log drop in HIV; 1 was undetectable and 1 remained undetectable a year after stopping Sangamo’s therapy is a new way to cure HIV, which can be fast-tracked for FDA approval in a time frame of 6 months or less.16The majority of Sangamo’s trials are towards the end of phase II. Phase III could span the course of 2015 and possibly into 2016. The remaining time in 2016 would be used for FDA approval. 2017 would be the year of the mass migration from daily tablets to an infusion of modified CD4 cells. We predict that in 2018, ART dependency would drop significantly. The only hope for Gilead would be if Sangamo’s cost to patients is out of reach. However, Sangamo has a long standing relationship with Shire Pharmaceuticals. Shire would be the most likely partner to help Sangamo mass produce and bring their cure to market at reasonable prices (see appendix Projected Market Share
Questions asked during CAN GENE THERAPY CURE HIV?, our community forum with Nobel laureate David Baltimore and stem cell expert Paula Cannon. Hosted by Paris Mullen for the defeatHIV Community Advisory Board on August 12, 2015 at Fred Hutch.
The world's first gene-editing trials took place in California, involving a different technique, ZFNs. Around 80 patients with HIV had immune cells in their blood removed.
Scientists then deleted a gene called CCR5 which HIV uses to gain entry to cells. The treatment is based on a rare, gene mutation which gives some people a natural immunity to the disease. One of the volunteers was Matt Chappell, 52, who has lived with HIV most of his adult life and witnessed the devastating impact that HIV/Aids has had on the gay community in San Francisco. Matt has been off all antiretroviral medication for two years since having his immune cells gene edited. These were small trials so caution is needed before reading too much into the results, but they are nonetheless extremely promising.
The HIV treatment was created by Sangamo Biosciences of Richmond, California, which has the exclusive licence for ZFN technology.
The company is about to begin patient trials in the serious blood-clotting disorder haemophilia and is also working on a treatment for beta thalassemia.
