It has been announced that the primary endpoint was met in the predefined Step-1 analysis of its Phase 3 clinical trial of investigational vaccine OSE-2101, called Atalante 1, in HLA-A2 positive non-small cell lung cancer (NSCLC) patients after failure from immune checkpoint inhibitors (PD-1/PD-L1).

In the Phase 3 Step-1 analysis, the statistically positive preliminary results show at least 12-month survival for 29 patients out of 63 patients in the OSE-2101 arm, corresponding to a 12-month survival rate of 46% with the lower limit (33%) of the 95% confidence interval* [33% - 59%], above the pre-specified futility boundary of 25%.

Considering the population of the treated patients in both trial arms randomised at least 12 months before the time of the Step-1 analysis (N=99), the primary objective of Step-1 of the Atalante 1 trial planned in the protocol was met.

The observed rate of 46% is also above the assumption of a survival rate of 40% specified for the alternative efficacy hypothesis in the protocol.

In the chemotherapy control arm the results show at least 12-month survival for 13 patients out of 36 patients, corresponding to a 12-month survival rate of 36%.

Alexis Peyroles, CEO of OSE Immunotherapeutics, said: “We are very pleased with these positive results for [OSE-2101] in Step-1 and with a 10% absolute difference in 12-month survival rate versus chemotherapy in NSCLC patients after failure of checkpoint inhibitor treated in Atalante 1 Step-1 trial. This outcome confirms the therapeutic value of our neoepitope product in a patient population for whom there are no registered product today and who needs new therapeutic options.

"Based on these positive results, we are now eager to engage in discussions with regulatory authorities to evaluate OSE-2101’s current clinical results and agree upon the best options for further development to maximise on the product’s positive data in terms of benefit/risk ratio. In parallel, given the significant value added by positive Step-1 results, we continue exploring potential partnership opportunities for [OSE-2101]".

OSE Immunotherapeutics together with the Independent Data Monitoring Committee (IDMC) and the Steering Committee of the trial have reviewed the potential impact of the COVID-19 outbreak on the Atalante 1 trial.

There is ongoing concern that trial data may be markedly impacted given the current worldwide COVID-19 pandemic and the increased risk for patients with NSCLC as COVID-19 can cause serious pulmonary complications in this immunocompromised patient population.

In addition, recommendations from several medical societies include voluntary holds on recruitment of new patients in oncology trials for the time being, due to patient safety concerns.

Consequently, following the recommendation from both IDMC and Steering Committee of Atalante 1, OSE Immunotherapeutics voluntarily decided to terminate patient screening and accrual in the initially planned and now cancelled Step-2.

Further analysis of the positive Step-1 data will commence while engaging with regulatory agencies on the best development path forward for the vaccine given the significant unmet medical need in the NSCLC patient population post-checkpoint inhibitor therapy failure.

Source: OSE Immunotherapeautics