Use the following steps to remove ink stains from Acrylic Fabric, Cotton, Linen, Modacrylic, Nylon, Olefin, Polyester or Spandex:
Try a light spray of hair spray to loosen the laundry stains.
Soak in a solution of 1 quart warm water, 1/2 teaspoon dishwashing detergent, and 1 tablespoon white vinegar for 30 minutes; use care when using vinegar on cotton and linen.
Rinse with water and allow to dry.
If stain persists, apply rubbing alcohol to the stain and cover with an absorbent pad moistened with alcohol (use alcohol sparingly on acrylic and modacrylic). Let stand as long as any stain is being removed. Change pad as it picks up the stain. Keep both the stain and pad moist with alcohol. Flush with alcohol and allow to dry.
If any trace of stain remains, soak in a solution of 1 quart warm water, 1/2 teaspoon dishwashing detergent, and 1 tablespoon ammonia for 30 minutes. Rinse thoroughly with water and allow to dry.
There's stuff called Bac-Out that I have used to remove pen from carpets and couches. It's just a stain/odor remover concentrate but it worked on pen in both of those situation. I'm sure there are many better, dedicated solutions so probably not a total loss.