Tubulis’ next-generation antibody-drug conjugate (ADC) has been tied to an overall response rate (ORR) of 59% as the German biotech tastes its first clinical success.
The Munich-based company is testing a range of doses of the NaPi2b-targetting ADC, dubbed TUB-040, in a phase 1/2a trial in patients with platinum-resistant ovarian cancer and advanced non-small cell lung cancer.
Expectations were riding high after Tubulis secured a hefty $361 million series C funding round days earlier. But the data from 66 evaluable patients unveiled at the European Society for Medical Oncology congress in Berlin—which marks the first in-human data for the therapy—have appeared to justify investors’ interest.
Specifically, an overall response rate of 59% was observed across the 1.67 mg/kg to 3.3 mg/kg range of dose cohorts, according to Tubulis. Onset of activity was observed at low doses, the company noted, with 4.4 mg/kg identified as the maximum tolerated dose.
A confirmed disease control rate of 91% was reached across all cohorts by the time of the Sept. 1 data cut-off, Tubulis said. Patients enrolled in the study had received a median of four prior lines of therapy.
The biotech’s Tubutecan platform is designed to combine therapeutic payloads and P5 conjugation technology to reduce the toxicity of its ADCs. The idea is that by halting premature payload loss and preventing aggregation in circulation, the approach can limit target-independent toxicity without compromising the cancer-stopping power of traditional ADCs.
Tubulis CEO Dominik Schumacher, Ph.D., told Fierce he was “really excited” about the data because they demonstrate that “our platform translated very nicely from pre-clinical to clinical.”
The wide range of effective and tolerated doses means physicians would have a lot of options for treating patients with TUB-040, the CEO explained in an interview on the sidelines of the conference.
“What ADCs have done beautifully … is very good overall response rates,” he said. “But [the modality] is not there yet when it comes to the potential to potentially enlarge the durability of responses.”
“We believe that having a wide therapeutic window where you can react to individual patients still being in an active range can help to facilitate that,” Schumacher added.
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The most common treatment-related adverse events graded 3 or above in the trial data were neutropenia, which affected 22% of patients, and anemia, which impacted 9%. Schumacher pointed to the fact that only two patients had discontinued treatment due to adverse events as evidence of TUB-040’s tolerability.
“We have a very early onset of activity, low doses and a wide therapeutic window with a very, very well-tolerated drug,” Schumacher concluded.
On the back of the ESMO data, Tubulis is now gearing up to evaluate TUB-040 in earlier lines of treatment for ovarian cancer, as well as explore other undisclosed solid tumor indications.
These expanding clinical ambitions will require a lot of cash—which is where the massive series C round comes in. Schumacher explained that the secret to sustaining interest in the company has been to “continuously talk to investors.”
The CEO wouldn’t be drawn on the exact level of Big Pharma interest that Tubulis has received at ESMO, pointing instead to existing preclinical partnerships with Gilead and Bristol Myers Squibb that the biotech remains “super excited about.”
“[Those partnerships] are part of our business model,” he said. “But at the same time, we focus on our internal pipeline. It’s fully owned by us, and we want to get this to as many patients as possible as quickly as possible.”
