There have been several trials indicating survival

There have been several trials indicating survival rates in ICU’s, and otherwise, however the big question is wether this applies to us since, as several have correctly pointed out, these numbers refer mostly to critical patients and we don’t know which proportion of ours is severe and which critical.

For reference, from the metastudy posted by Daltondog:

https://investorshangout.com/post/view?id=6060263

We have that, for Europe, we have a 33.3% overall death rate (4097 patients) and in North America 39.99% (1075) patients.

However, we have more relevant data with the recent trials of NeuroRx (Revive) and Humanigen:

In the NeuroRx the overall death rate was 29.85% and 33.09% for SOC and Aviptadil respectively (yes the drug had more mortality than the placebo) over a total of 203 patients. So, for the sake of "purity", lets assume that the overall mortality is 32% (average) for the 203 patients.

The HUMANIGEN trial is very interesting. They have an adaptive trial in which they count the “events” this being survivals.

Quote:

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The data safety monitoring board (DSMB) composed of independent subject matter experts conducted an interim analysis of the unblinded data for trial sizing and powering and recommended increasing the target number of events (recoveries) from 257 to 402 to maintain the power of the study at 90 percent. The adaptive trial design only allows for the addition of patients if interim data are in the “promising zone” (i.e., achieving or surpassing an average improvement in recoveries of 29 percent (hazard ratio (HR) > 1.29) through day 28).

The company remains blinded to the data and based on the recommended number of events, the HR was calculated to be 1.37, an average of 37 percent more recoveries observed in the lenzilumab arm compared to the control arm. Any observed benefit in the lenzilumab arm would be over and above the use of remdesivir and/or steroids which are among the treatments that have been used as SOC in both the lenzilumab treatment arm and the placebo arm of the study.

At the recommendation of the DSMB, the company plans to increase enrollment to achieve 402 events (approximately 515 patients). This increase in enrollment ensures an even higher probability of success in meeting the primary endpoint and maintains the power of the study at 90 percent. The next interim analysis for efficacy is planned when the study reaches 75 percent events ( 302 events ) which will require approximately 390 patients to be enrolled in the trial.

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OK. There is lots of information hidden there. One can even calculate p-values with the data provided (as they provide the target power of the trial, I would do just that if I were a HGEN investor). But, I digress, what matters to us is: what is theirs’s SOC and expected overall death rates?

From their release we can gather the following: they expect 302 events out of 390 patients. This means an overall mortality of 22.56%.

Guess how much do we already have ??? 22.3% (assuming 87 casualties out of 390 patients); or putting it in another terms: our (already achieved) overall mortality is what HGEN is designing into their trial to show efficacy !!!

As for the SOC death-rate: we can do some basic algebra and calculate that they are expecting death rates of 27.69% SOC and 14.44% for Lenzilumab (this for 75% reading in basis of the interim data already in-hand).

This is VERY important: HGEN first readout indicates that they have incorporated an overall death rate of 27.69% into their trial to eventually achieve their efficacy an power objectives.

So, let me summarize the SOC death-rates we have as reference:

Metastudy Europe : 33.3% in 4097 patients
Metastudy North America : 39.99% in 1075 patients
NeuroRx-Relief Therapeutics : 32% in 203 patients
Humanigen Inc : 27.7% in 390 patients (based in projection from data reading from interim analysis.

These are not apples-to-apples comparisons as the definition of Severe-Critical changes, as well as the timing of the measurements, country and overall population health-status and institutional health care-sophistication. However they give a damn good indication (imo) on what to expect, mostly the last two trials which are contemporaneous and very similar to ours.