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Atreca Stock: Biotechnology with a promise based on the first candidate ATRC-101 (NASDAQ: BCEL)

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Atreca, Inc. (NASDAQ: BCEL) is a speculative biotechnology that should be on everyone’s radar. This is because it showed some preliminary evidence that its first clinical candidate in the pipeline, ATRC-101 for the treatment of patients with solid tumors, has clinical activity. Obviously, this will have to be demonstrated with other patients, but what has been shown so far is good enough.

Not only that, there is room to specifically target patients who might benefit from it. A diagnostic target is planned to be used for the selection of patients based on the expression of their tumor. ATRC-101 is a drug under development to recognize the ribonucleoprotein complex selectively expressed in some tumor tissues. As such, moving forward is going after those who have this specific higher expression found in their tumors.

What can investors expect as catalysts? There are two catalysts that investors can expect in 2022. Further data from the ongoing Phase 1b study using ATRC-101 for solid tumors is expected to be released in the second half of 2022. This will be the use of monotherapy 30 mg / kg of ATRC-101, and then Keytruda combination therapy. Both of these datasets will be expected later this year. There is also an expansion opportunity to use ATRC-101 alongside chemotherapy. Additionally, the potential exists to use ATRC-101 to specifically target tumors that express a gene known as EphA2.

With preliminary data on the mechanism of action, catalysts and opportunities for expansion, I believe Atreca is a good speculative biotech to look at.

ATRC-101 for the treatment of patients with solid tumors

The leading clinical candidate in Atreca’s pipeline is ATRC-101, which is used to treat patients with solid tumors. The company has already reported some preliminary evidence of activity from an open-label Phase 1b study, which used ATRC-101 in patients with selected types of solid tumors. The first part of the process started with a dose escalation portion to test for safety, which I think is pretty good. This is because it was able to go from 0.3 mg / kg of ATRC-101 up to 30 mg / kg of ATRC-101 without dose-limiting toxicities. This bodes well for further improving the monotherapy part of the study and then moving on to the combined part of the study as well.

The test is divided as follows:

  • Monotherapy dosing once every 3 weeks (Q3W).
  • Once every two weeks (Q2W) monotherapy and combined dosage

Of the 47 patients enrolled and assessed for safety, 16 of them (34%) had at least one grade ≥ 3 adverse event. At first glance, this is not a good thing, but it is important to note that only two of these AESs of Grade 3 were considered potentially related to ATRC-101 treatment. To establish a first proof of concept with this drug, Atreca enrolled patients in a certain way.

What does it mean? Well, they split the monotherapy portion and the combination portion (with Keytruda) to target specific tumor expression. Since ATRC-101 targets the ribonucleoprotein complex which is selectively expressed in some tumor tissues, this is what they chose to base this study on. He separated patients like this:

  • Patient enrolled in the ATRC-101 monotherapy portion was required to have> 50% immunoreactivity to ATRC-101 in preclinical studies
  • Patients enrolled in the ATRC-101 combination portion were required to have> 30% immunoreactivity to ATRC-101

This was a good starting move. Why? This is because this theory was somewhat demonstrated with the initial data released from the open-label Phase 1b study. Consider that, of those who took ATCR-101 with H-score ≥ 50, there were 8 out of 12 patients (66%) who responded to treatment. The breakdown of this was:

  • 6 patients with stable disease
  • 1 patient with partial response
  • 1 patient with complete response

Whereas, among those with low expression for ATRC-101 (H score <50), only 2 of 12 patients (17%) achieved SD. No one got a partial answer or a full answer.

What does this mean? This means that Atreca has a population that it can chase. I think it has gone pretty well so far. The reason is that these patients have on average been treated with up to 5 prior lines of therapy. The fact that they at least responded with a stable disease is pretty impressive. These are only those patients who may respond to ATRC-101. That is, it is using diagnostics to test for tumor expression to make sure a patient has a better chance of a response. Therefore, he adjusted his recruitment based on patients having a higher expression score in the second quarter of 2022.

It won’t be long before investors know whether this data needs to be confirmed or not. This is because it is seeking to report further data on monotherapy and the combination of this phase 1b study with ATRC0-101 in solid tumor patients in the second half of 2022.

There are opportunities for expansion

The fact is that preclinical studies have shown that by combining ATRC-101 with Keytruda, good synergy was observed. Another avenue that has been observed in preclinical studies was the rationale of combining ATRC-101 with chemotherapy. Why? Mechanistic and possibly increased target expression for patients with solid tumors.

However, he will not choose to do so until he releases second-trimester weekly monotherapy data which will first arrive in the second half of 2022. Hopefully with that portion, he intends to start combining ATRC-101 with the study. chemotherapy.

Another opportunity for expansion would be the use of ATRC-101 to look for another specific gene expression. This is a gene known as EphA2 and it is possible that this drug has better activity against it.

There are several reasons why it is good that Atreca is moving towards this. One reason is that Eph proteins are the largest family of tyrosine kinase ((RTK)) receptors known in humans. Second, RTKs are already a proven class in solid tumors, which increases the chances of success.

However, there is a very important reason this is a good gene to follow. That is, only low levels of EphA2 are expressed in non-cancerous adult tissues. This means that such a lens may have a more tolerable safety profile. This, of course, must be demonstrated in humans.

Currently, Atreca is conducting IND qualification studies for the use of ATRC-101 targeting EphA2 gene expression. An IND filing for this will not be expected until the first half of 2023.


According to Deposit 10-K SECAtreca Inc. had cash and cash equivalents and investments of $ 148.1 million as of December 31, 2021. The reason for the large inflow of cash it has available was due to a loan it had completed in July 2022. It was then that it raised about $ 125 million to finance its operations. It had an underwritten public offering of 7,031,250 shares of its Class A common stock and 781,250 shares of its Class B common stock at a public offering price of $ 16 per share. The subscribers were also granted an option to purchase an additional 1,171,875 Class A ordinary shares at the same public offering price.

The company believes it has enough cash on hand to fund its operations until at least the first half of 2023. I believe Atreca may choose to raise cash sooner if its shares are trading significantly higher. If the data in the second half of 2022 from the monotherapy and combination cohort using ATRC-101 comes out very good, the stock is likely to trade much higher. It is possible that you may choose to raise money soon after.

Risks for businesses

There are risks that traders / investors should be aware of before taking a position in this biotechnology.

The first risk is that, although the preliminary data released by the phase 1b study looks good, it was done with a limited number of patients. There is no guarantee that the monotherapy and combination therapy data to be released in the second half of 2022 for ATRC-101 will be as good.

The second risk to consider would be that relating to current liquidity. Even though Atreca says it has enough funds to finance its operations until the first half of 2023, it probably won’t wait until the end to raise money. Therefore, it may at some point choose to raise money by at least the end of 2022. It may even be earlier, as I stated above, if it releases news that causes the shares to trade much higher. If that happens, he’ll want to take advantage of such a climb.


The final conclusion is that Atreca is a great speculative biotech game to examine. This is because it showed preliminary evidence that ATRC-101 helps specific solid tumor patients.

That is, those who have high reactivity to ATRC-101. Again, as this drug recognizes the ribonucleoprotein complex that is selectively expressed in some tumor tissues, it has broadened recruitment to specifically target these patients. Further results from the phase 1b study are expected in the second half of 2022. These data will include the monotherapy and combination (with Keytruda) cohorts of this study. It has the ability to expand by also combining ATRC-101 with chemotherapy. Furthermore, it is already moving towards a gene target expression of EphA2, which is a validated solid tumor target.

With initial proof of concept data for ATRC-101, the ability to expand it to other goals, and a growing pipeline, I believe Atreca, Inc. is a good speculative biotech game to look into.

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