Date Posted – 7 June 2021
Small cap immunotherapy biotech Immutep is a step closer to commercialising its leading drug candidate, “efti”, after releasing promising data showing the effectiveness of the drug in treating various types of lung, head and neck, and solid tumour cancers.
The positive clinical trial data will be a boon for the business, which is already trading up 58.3 per cent for the year-to-date at 66¢, thanks to the growing interest from the global biotech community in the LAG-3 checkpoint, which Immutep is targeting. This interest has been driven by the progress that Bristol Myers Squibb has made with its own LAG-3 immunotherapy.
Immune checkpoints are the regulators of the immune system, controlling the activation, proliferation and function of the body’s T cells. There are different types of checkpoints and the first immunotherapy to be approved in 2011 by the US Food and Drug Administration (FDA) was pilimumab (sold under the brand name Yervoy and now owned by Bristol Myers Squibb), targeting the CTLA-4 checkpoint.
After market on Friday, Immutep released data from its phase two trial that combines efti with Merck drug Keytruda, revealing a 41.7 per cent response rate in non-small cell lung cancer and a 29.7 per cent response rate in second-line head and neck cancer. Second-line therapies are those given after the patient has already failed to respond to a different therapy.
Immutep CEO Marc Voigt said the trial took on patients regardless of if they were likely to react to Keytruda or not, with up to a third of patients in its non-small cell lung cancer group unlikely to benefit from Keytruda because their cells do not express enough of a certain biomarker called PD-L1, which is necessary to trigger a response from Keytruda.
“These results are very encouraging,” Mr Voigt said.
“In non-small cell lung cancer we’re seeing a response rate much higher than what you’d expect with Keytruda alone.
”In second-line head and neck cancer, with the best available standard of care, the median overall survival rate is only six to nine months. It’s a terrible, extremely aggressive disease and with Keytruda alone you expect a response rate (where the tumour shrinks) of around 15 per cent, but we’re seeing a rate of about 30 per cent.”
While the overall response rates were positive, especially given the tough-to-treat nature of the cancers, Firetrail Investments equity analyst Eleanor Swanson was most bullish about the fact that five patients in the head and neck cancer trial had a complete response, meaning the efti plus Keytruda combination destroyed the cancer.
“To have five patients with tumours go to zero, that’s pretty unusual,” she said. “It goes to show the drug is working in conjunction with Keytruda.”
This was the most exciting outcome of Immutep’s results, said Michael Murray, Australian Ethical head of domestic equities.
He said with the culmination of data coming out from Immutep, the company may increasingly be on the radar of the biotech giants as a possible acquisition target.
“You have this little Australian company in the big league,” he said.
“It’s already got collaborations going on with companies like Merck, Novartis and GlaxoSmithKline. That to some extent validates that the interest is there.
“What we want to see is the [patient] numbers getting bigger. There’s always this thing where if the numbers are small, it’s harder to be confident in them. You want to see the positive benefit you’ve seen at smaller numbers retained,” Mr Murray said.
Ms Swanson was also keen for Immutep to bring on more patients to its trials, saying this would further validate Immutep’s work and lead to a higher acquisition price if the company ends up being bought by one of the biotech giants.
Immutep is currently recruiting for more patients for its non-small cell lung cancer study, as well as beginning a phase 2B study for head and neck cancer, which it expects will be enough for possible registration with the FDA.
Immutep, which is dual-listed on the NASDAQ, is the result of the locally listed Prima BioMed acquiring French biopharmaceutical company Immutep SA in 2014 and subsequently rebranding.
Immutep’s Frédéric Triebel, who joined the business via the acquisition, is considered a leader in the field of immunotherapy and was responsible for developing the company’s drug candidate.
After market on Friday Immutep also released results of a less-progressed phase one safety study into the use of efti and Merck’s drug, avelumab, for the treatment of a range of solid tumours, including gastroesophageal and cervical cancer that typically do not respond to immune checkpoint therapies.
This found that the combination was well tolerated by patients, with no dose-limiting toxicities discovered.
Mr Voigt said the company was not making a decision yet as to whether or not it would move to a phase two study in solid tumours.
“[The results] are encouraging, but it was only 12 patients,” he said.
“We have a broad fundament of different data in different combinations in different indications… so we’ll decide at the right time if we’ll move forward in that setting.“
Article by Yolanda Redrup