Study of PYX-106 in Solid Tumors

Inclusion Criteria:

1. Participants with histologically or cytologically confirmed solid tumors who haverelapsed, been non-responsive, or have developed disease progression throughstandard therapy.

2. Histologically or cytologically confirmed solid tumors (see details below): For the dose escalation, the following solid tumors are allowed in participants whohave relapsed, been non-responsive, or have developed disease progression throughstandard therapy and in participants for whom standard of care therapy that prolongssurvival is unavailable or unsuitable (according to the Investigator and afterinforming the Medical Monitor): non small cell lung cancer (without drivermutations/translocations), breast cancer, endometrial cancer, thyroid cancer, kidneycancer, cholangiocarcinoma, bladder cancer, colorectal cancer, and head and necksquamous cell carcinoma.

3. Clinical sites must provide archived tissue or conduct fresh tumor biopsy (formalin-fixed paraffin-embedded [FFPE]; enough to create a minimum of 14 slides).Fresh biopsy pre-treatment is preferred, archival tissue (preferably obtained within 1 year prior to the first infusion of PYX-106) is acceptable if fresh biopsy is notmedically feasible, per Investigator, at Screening. Both fresh and archival tissuesamples must be collected by core needle biopsy or surgical resection. Fine needleaspirates are not permitted.

4. Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1.

5. Participant must have at least 1 measurable lesion per Response Evaluation Criteriain Solid Tumor (RECIST) Version 1.1 criteria (by local Investigator). Participantmust have radiographic evidence of disease progression per Investigator followingthe most recent line of treatment.

6. Life expectancy of >3 months, in the opinion of the Investigator.

Exclusion Criteria:

1. History of another malignancy except for the following: adequately treated localbasal cell or squamous cell carcinoma of the skin; in situ cervical carcinoma,adequately treated; other adequately treated Stage 1 or 2 cancers currently incomplete remission; any other cancer that has been in complete remission for >2years or cancer of low risk of recurrence; or any treated or monitored indolentcancer that is unlikely to cause mortality in 5 years.

2. Known symptomatic brain metastases requiring >10 mg/day of prednisolone (or itsequivalent) at the time of signing informed consent.

3. Continuance of toxicities due to prior anti-cancer agents that do not recover toGrade 1 prior to start of PYX-106 treatment, except for alopecia or endocrinedeficiencies treated with stable hormone replacement therapy.

4. Presence of Grade ≥2 peripheral neuropathy.

5. Major surgery within 4 weeks prior to the start of PYX-106 treatment, as defined bythe Investigator.

6. Received palliative radiation therapy within 14 days prior to the start of PYX-106treatment.

7. Received a live vaccine within 28 days prior to the first dose of study treatmentand while participating in the study.