AACR22: After FerGene blowup, a startup touts even better bladder cancer gene therapy results in tiny study
A private California biotech is raising some eyebrows on the final day of AACR22 as it reported interim data for its experimental drug in combination with Keytruda.
Looking at 18 patients with non-muscle-invasive bladder cancer who are unresponsive to bacillus Calmette-Guérin (an FDA-approved agent for bladder carcinomas), CG Oncology found that 16 of the 18 achieved a complete response after just three months. On top of this, 13 maintained their response through six months, nine through nine months and eight after a year — the study’s primary endpoint.
That initial three-month mark is good for an 89% CR rate. The two other patients did not respond to the therapy at all, dropping out at three months and six months, respectively, according to a presentation from Moffitt Cancer Center’s Roger Li.
Happy to share very promising results from CORE-1 trial combining CG0070 and pembro for #BCGunresponsivedisease, presented by Dr. Uchio @ #AACR22! 14/16 CR, all 6 with durable response who reached 12mo! @garysteinbergmd @UroDocAsh @tbivala1 @pcvblack @KuanArthur @cgoncology https://t.co/B2zPucUhYH
— Roger Li (@UrogerliMD) April 12, 2022
CG Oncology’s Phase II study, like many early- and mid-stage trials in the oncology space, is small and open-label, and no firm conclusions can be drawn just yet. The biotech is planning on enrolling 35 total patients for the study, and it’s possible the response rate — and complete response rate — diminish over time.
But the 89% figure represents a head-turning number nonetheless, particularly as Keytruda monotherapy achieved only a 41% complete response rate in the study Merck used to support FDA approval. The green light came back in January 2020 for the same NIMBC patients who are BCG resistant and who are ineligible for, or chose not to undergo, cystectomy.
CG Oncology also found no Grade 3 or higher side effects in the study so far, noting most of the adverse events included frequent or painful urination, blood in the urine, bladder spasms, fatigue and chills.
The experimental drug in question is known as CG0070, an oncolytic immunotherapy using a modified adenovirus designed to destroy bladder tumor cells through the defective retinoblastoma pathway, the biotech says. CG0070 contains a “GM-CSF transgene” that prompts an immune response after the tumor cells rupture, releasing antigens and GM-CSF to be targeted.
It’s a similar approach to the one taken by FerGene — both companies used adenovirus vectors, but different transgenes to garner the immune responses. CG Oncology will likely want to avoid FerGene’s pitfalls, however: FerGene received a CRL on its drug due to several manufacturing and CMC issues, prompting waves of layoffs and C-suite departures.
CG Oncology has remained private since being founded in 2010, and its most recent fundraise came in December 2020. The biotech put together a $47 million Series D to fund a Phase III NIMBC monotherapy study, as well as the Keytruda combo trial.
In addition to Merck, CG Oncology has also partnered with Bristol Myers Squibb to pair CG0070 with Opdivo for muscle-invasive bladder cancer and with Roche to attack solid tumors in combination with Tecentriq.