A Further Look at SWOG Radiopharmaceuticals

I believe it may be unique in SWOG’s history in being a joint venture of two committees – in this case our radiation oncology and imaging committees (let me know if you’re aware of previous examples). That melding of these two modalities is ideal for theranostics – precision medicine that adapts radiopharmaceuticals for both diagnostics and treatment. 

It builds on the fact that the same antibodies or small molecules that carry radioisotopes used for selectively imaging lesions can also carry therapeutic radioisotopes to the same target.

One of the best known examples of theranostic therapy today involves the use of the radioconjugate Lu177-PSMA-617, which binds to prostate-specific membrane antigens (PSMA) on prostate cancer cells, delivering a dose of beta-particle radiation, and is used in conjunction with PSMA PET imaging, initially to confirm PSMA positivity and subsequently to assess treatment effectiveness.

Dr. Chul Ha, chair of our radiation oncology committee, says rapid growth in the promise of radiopharmaceuticals is part of what drove the decision to form a theranostics subcommittee. He cites a prediction several years ago from the NCI Radiopharmaceutical Development Initiative that in another decade or so more than one-half of radiotherapy clinical trials are expected to be using radiopharmaceuticals (!). 

Another indicator of interest growth is the number of new biotech companies that have formed in recent years developing new theranostic agents.

Dr. Ha notes that the field is rapidly expanding and has the potential to be applied in a wide range of cancers. He adds SWOG has an opportunity to take a leadership role in theranostics within the NCTN.

Our colleagues at NRG Oncology also seem to think the time is right for more formal attention to the field – they’ve recently formed a theranostics subcommittee of their own, under the jurisdiction of their imaging and radiation oncology committees. We launched and completed our theranostics chair search just ahead of theirs, but we can’t claim to have gotten there first – the Alliance formed a theranostics group before either SWOG or NRG.

The primary aims for SWOG’s theranostics subcommittee are as follows:

• to initiate, promote, and support the development and conduct of trials that include theranostics components
• to build a theranostics program within SWOG’s research portfolio, working with leaders of SWOG disease site committees
• to serve as a resource on theranostics for all SWOG investigators
• to work with the NCI's Imaging and Radiation Oncology Core (IROC) to set quality assurance standards for theranostics components within trials 

This subcommittee was launched at last month’s group meeting, with a radiation oncology session keynote talk on theranostics by Dr. Oliver Sartor (now vice chair of the new NRG Oncology theranostics subcommittee). A recording of Dr. Sartor’s talk is available on our website to logged-in members (recordings of most other open sessions are also available).

I want to thank Dr. Wong for taking the helm of this important subcommittee; Dr. Lawrence Schwartz, chair of imaging, for his cross-committee collaboration on the initiative; and especially Dr. Ha for taking the lead on theranostics, including co-leading the national search that brought in Dr. Wong as chair. The subcommittee should be a valuable resource for our researchers.

___________________________________________________

Trial of the Week

S2312: A Phase III Study of Cabazitaxel with or without Carboplatin in Patients with Metastatic Castrate-Resistant Prostate Cancer (MCRPC), Stratified by Aggressive Variant Signature

SWOG S2312, activated in September, is a randomized phase III study in patients with metastatic castrate-resistant prostate cancer. 

It asks if testing for aggressive variant prostate cancer molecular signature (AVPC-MS) can help guide treatment of patients with this neoplastic variant.

All S2312 participants will have their tumor tested for AVPC-MS, which is used as a stratification factor. They will then be randomized to cabazitaxel alone or cabazitaxel plus carboplatin.

The study team hypothesizes that adding carboplatin to cabazitaxel will significantly improve radiographic progression-free survival in patients whose tumors are AVPC-MS positive but not in those whose tumors are AVPC-MS negative.

S2312’s accrual goal is 500 participants, and 190 sites have already been approved to enroll to the study. If your site is not among that number, I encourage you to take a close look at the trial.

Dr. Paul Corn, of MD Anderson Cancer Center, is study chair and led an S2312 kickoff session at our group meeting last month. If you missed it, you can find a recording of the event on the SWOG website (login required).

Learn more about this trial on the SWOG S2312 page or the CTSU S2312 page.

A patient-friendly summary is also available, at swog.org/S2312, to use when presenting the trial to a potential participant.