Committed to significantly enhancing immunotherapy response

Combination therapies are being actively pursued as the next generation of immunotherapies. Sonnet’s versatile platform has been demonstrated to improve delivery of immunotherapy to the tumor and also overcomes past challenges with interleukins, which are viewed as a powerful tool in improving immunotherapy response rates.

Checkpoint inhibitors are the cornerstone of current cancer immunotherapy. These monoclonal antibodies can be very effective when the patient’s immune response to a tumor has been activated. However, adequate activation does not occur in the majority of patients. To reach their potential, checkpoint inhibitors will need other agents to help activate the immune response. Interleukins are a proven method for activating this response. By addressing past challenges with interleukins, Sonnet promises to unleash the true potential of checkpoint inhibition treatments.


The National Cancer Institute ranks certain interleukins (IL12, IL15, IL2) as top cancer targets, but:

  • Short pK:  Due to there small size, interleukins have a short half life, passing quickly out of the body. This means that a high dose is required to generate a response.  However, when high doses are administered, severe toxicity issues arise.
  • Non-Selective:  Interleukins disperse around the body and do not specifically seek tumor tissue. This presents challenges in delivering sufficient quantities of interleukins to the tumor environment.


Sonnet has developed a proprietary Albumin Binding Domain (ABD) with the following key features:

  • Extended pK:  The Sonnet ABD features a half-life of 2-4 weeks.
  • Targeted delivery:  The Sonnet ABD vehicle attaches to albmumin, which seeks a protein overexpressed by tumors. This leads to selective accumulation at tumor sites.
  • Versatile Use:  Sonnet’s ABD platform can provide a vehicle for a variety of interleukins and other priority immunotherapy molecules.
  • Single or Dual Weaponry:  The Sonnet ABD platform can accommodate a single or dual biological mechanism of action

Sonnet proof-of-concept data demonstrates the following improvements for interleukin therapies:

  • Longer half-life means interleukins can be administered in lower, safer doses.
  • Tumor specificity ensures that interleukins accumulate at the tumor, resulting in improved immune response at the tumor, and reducing the likelihood for toxicity elsewhere.