Immutep's Landmark Pharma Deal Undone by a Shock Trial Failure
A US$370 million partnership with Dr Reddy's validated Immutep's lead cancer drug, before an unexpected Phase 3 lung cancer trial failure wiped out most of the stock's value.
31 Mar 2026 · 3 min read
In short
Immutep signed a US$370 million partnership with Dr Reddy's for its lead cancer drug Eftilagimod, including US$20 million upfront and US$349 million in milestone payments, rallying the stock 36-38%.
An unexpected Phase 3 lung cancer trial failure at an interim futility analysis wiped out 85-88% of the share price in a single month, described by Perennial Partners as disappointing given the drug's strong prior trial performance.
Most fund managers, including Pengana Capital Group, Renaissance Asset Management and Quest Asset Partners, exited their positions following the trial failure, even as Immutep continues developing Eftilagimod in other cancer types.
Immutep signed a major US$370 million licensing partnership with Indian pharmaceutical giant Dr Reddy's for its lead cancer immunotherapy drug Eftilagimod, validating its commercial value and rallying the stock 36 to 38 percent, before an unexpected Phase 3 lung cancer trial failure at an interim futility analysis wiped out 85 to 88 percent of the share price in a single devastating month.
A validating global partnership
Perennial Partners said Immutep was the best performing stock in the portfolio, having long argued that while high risk, there is very significant upside potential in the stock should its clinical trials continue to generate positive results, with some of that upside realised when the company announced an agreement with a global pharmaceutical partner. Pengana Capital Group said Immutep rose 38 percent after signing a regional licensing deal for its lead cancer immunotherapy drug Eftilagimod with Indian pharmaceutical company Dr Reddy's, covering all countries outside the US, Europe, Japan and Greater China, with the deal including US$20 million of upfront cash and US$349 million of milestone payments, so-called biobucks, plus double-digit royalties. Quest Asset Partners said Immutep performed well with a significant de-risking from signing a major US$370 million partnership with Dr Reddy's, providing an immediate A$30 million cash injection and confirming the commercial value of its lead drug, efti, with its main lung cancer trial reaching a key milestone in patient enrolment and on schedule for a critical futility analysis.
Australian biotech Immutep rose 38% after signing a regional licensing deal for its lead cancer immunotherapy drug Eftilagimod with Indian pharmaceutical company Dr Reddy's, covering all countries outside the US, Europe, Japan, and Greater China. The deal includes USD 20 million of upfront cash and USD 349 million of milestone payments, plus double-digit royalties.
— Pengana Capital Group, Monthly Report, December 2025
An unexpected trial failure wipes out most of the value
Cyan Investment Management said Immutep fell massively after discontinuing its cancer drug trial. Pengana Capital Group said Immutep failed a futility analysis in its Phase 3 lung cancer trial, an unexpected outcome that led to an 85 percent fall in the share price, reducing fund performance by 3.6 percent for the month, though the company continues developing Eftilagimod in other cancer types and has an early-stage autoimmune program, IMP-761, prompting the fund to exit its position. Renaissance Asset Management said the pivotal Phase 3 clinical trial failed during the quarter, with most of the company's value attributed to this prospective drug, and the share price collapsed following the announcement, leading the fund to ultimately sell the stock.
Immutep announced that the company's Phase III trial for evaluating the company's 'efti' product in patients in 1st line lung cancer has recommended the discontinuation of the trial following an interim futility analysis. This was an unexpected and disappointing outcome given the product's performance in previous trials and the relatively low bar to satisfy the requirements of the interim analysis.
— Perennial Partners, Monthly Report, March 2026
Quest Asset Partners said fund performance was very disappointing, driven partly by the shock Phase III clinical trial failure, with Immutep's 88 percent fall accounting for nearly half the portfolio's underperformance, prompting the fund to fund increases elsewhere by reducing or exiting several positions, including Immutep.
What fund managers say they are watching next is continued development of Eftilagimod in other cancer types beyond the failed lung cancer indication, progress of the early-stage autoimmune program IMP-761, whether the Dr Reddy's partnership's commercial value survives the trial setback, and whether any remaining shareholders see a path to recovery given most funds have now exited.
Questions
What was Immutep's partnership with Dr Reddy's?
Immutep signed a regional licensing deal for its lead cancer immunotherapy drug Eftilagimod with Indian pharmaceutical company Dr Reddy's, covering countries outside the US, Europe, Japan and Greater China, including US$20 million upfront cash and US$349 million in milestone payments.
Why did Immutep's share price collapse 85-88%?
Immutep's Phase 3 lung cancer trial evaluating its 'efti' product recommended discontinuation following an interim futility analysis, an unexpected outcome given the drug's strong performance in previous trials.
Is Immutep still developing its lead drug after the trial failure?
Yes. Pengana Capital Group notes Immutep continues developing Eftilagimod in other cancer types and has an early-stage autoimmune program, IMP-761, even though most fund managers have exited their positions following the trial failure.
5 managers, 14 comments, with each manager's latest recorded position.
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