1. So what do we know?
The graph demonstrates antibody development in Phase 1. We know that there were 14 patients dosed as follows:
- 10μg dose - 4 patients
- 50μg dose - 5 patients (-1 withdrew)
- 100μg dose - 3 patients (-1 withdrew)
They advised that two immune-related pneumonitis events occurred, one in the 50μg/dose cohort and one in the 100μg/dose cohort and both parties were withdrawn from the study -
leaving 12 patients.
The Tumor response results state:
- 10μg dose - out of 4 patients, 1 achieved a CR (complete response) (1/4)
- 50μg dose - out of 5 patients, 2 achieved a SD (stable disease) (2/5)
- 100μg dose - out of 3 patients, 1 achieved a PR (partial response) and 2 achieved a SD (stable disease) (3/3)
- 3 patients out of 12 remain on the study.
Given the severity of the disease I think we can assume what happened to those patients not included in the information above?
2. I would assume the patient on the trial who is still with us 18months later, "whose tumour burden has been reduced to zero" would be the patient in the 10μg cohort who had a complete response. I would like to see what their antibody levels were like at such a low dose.
A Complete Response (CR) is a term used for the absence of all detectable cancer after your treatment is complete. Complete response doesn't necessarily mean that you are cured, but it is the best result that can be reported. It means the cancerous tumour is now gone and there is no evidence of disease.
So to answer your question, if there was a CR to a patient within the 10μg dose cohort then that would tell us that even at a very low dose some patients can achieve unbelievable results. Each person is different, their immune systems are all at varying stages with some further declined than others, and the amount of antibodies each patient has within their system is different.
What the 100μg dose cohort offers patients is the best possible chance at producing enough polyclonal antibodies quickly enough to produce an anticancer effect. It's a race against time really.
3. Refer to point 2. and I would also add again. Not all patients are the same, these patients are combating severe disease who have progressed on an approved PD-1 inhibitor or an approved PD-L1 inhibitor.
Imagine what could be achieved in a patient who doesn't have such a decimated immune system, and hasn't already progressed on other PD-1 or PD-L1 inhibitors?This is a clinical trial and we need to offer patients the maximum safe dosage to trigger the strongest possible chance at producing enough polyclonal antibodies.
Graph taken from the ANN titled - Imugene Presents New PD1-Vaxx Data at the 2022 World Conference on Lung CancerI hope that explains the published information a little more for you and possibly others - I think the science and the beautiful data all speaks for itself.
IMUGENE are looking for safety, tolerability and early response signals to determine the optimal dose for further development and I think that without doubt have been able to present that. DYOR GLTAH's.
Cheers,
tin-tin
