EnGene reveals initial key data for NMIBC therapy

A small US and Canadian biotech company specializing in gene therapy has unveiled promising data from its experimental bladder cancer treatment, seeking to enter a competitive market that includes industry heavyweights such as CG Oncology, ImmunityBio, Johnson & Johnson (J&J), and UroGen.

EnGene announced on Thursday that its non-viral gene therapy achieved a complete response in 71% of the 21 patients evaluated so far in the key cohort of its Phase 2 LEGEND trial. This therapy is one of several being tested for patients with Bacillus Calmette-Guérin (BCG)-unresponsive, non-muscle invasive bladder cancer (NMIBC).

The treatment, known as detalimogene voraplasmid or EG-70, is administered to the bladder using a catheter four times over a 12-week cycle, up to four cycles. EnGene reported that the treatment was "generally well-tolerated," with no patients discontinuing the study due to drug-related safety issues. Most adverse effects were mild to moderate, with only two cases—peripheral edema and urosepsis—reaching severe levels.

EnGene anticipates collecting data on approximately 80 more patients from the pivotal cohort of the open-label study before seeking regulatory approval. The company aims to submit a biologics license application by mid-2026, a timeline adjustment from its initial projection when it went public through a SPAC merger last November. CEO Ron Cooper, who took the helm this summer, explained that the initial timeline was an estimate and that the company now feels more confident about the new schedule given the current enrollment rates.

BCG, manufactured by Merck, remains the standard treatment for certain types of bladder cancer. However, BCG is in short supply and not effective for all patients. Merck has indicated that a new production facility in Durham, NC, will be completed by late 2026 to address these supply issues.

ImmunityBio received FDA approval for its IL-15 agonist, Anktiva, in combination with BCG for certain bladder cancer patients in April, following an initial rejection. However, this approval does not solve the ongoing BCG supply problems. J&J is developing a "pretzel" drug-device combination, while UroGen is advancing a gel-based delivery of a decades-old chemotherapy for specific NMIBC types. UroGen recently sought FDA approval for this treatment.

In May, CG Oncology reported interim data from its Phase 3 trial, showing a 75.2% complete response rate at any time in 79 out of 105 patients treated with cretostimogene grenadenorepvec. In enGene's Phase 2 pivotal cohort, the complete response rate was 71% at any time, decreasing to 67% at three months and 47% at six months. For comparison, CG's Phase 3 trial showed a 63.6% complete response rate at six months, while their Phase 2 study had a 44% rate.

As enGene progresses with its pivotal trial, it is making protocol amendments to align with clinical practice, according to chief medical officer Raj Pruthi, a urological oncologist who joined the company in April after working on bladder cancer at J&J. One recent amendment involves re-resection of T1 tumors, and another allows for resection and reinduction of therapy at three months for patients with recurrence. Pruthi noted that reinduction of therapy is a familiar practice among urologists, especially with BCG.

CG Oncology expects to release more data by the end of this year and plans to package these results for an FDA approval request. Their immunotherapy uses a virus to target and destroy tumor cells and had a significant IPO earlier this year, raising $380 million in January.